JP2006158738A - Centrifugal method of leukoreduction system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a centrifugal method of a leukoreduction system including an elastic leukocyte filter preventing an leukoreduction material from closely sticking to an outlet side container due to a pressure generated in filtering caused by a stress by a centrifugal operation, having no risk of inhibiting a blood flow, namely having uniform blood flow and having a high blood processing speed. <P>SOLUTION: The leukoreduction system is constituted of a blood collecting bag 1; a flat-plate leukocyte filter 5 filling the leukoreduction material inside the flexible container having a blood inlet nozzle 5-b and a blood outlet nozzle 5-a and provided with a spacer 15 between the leukoreduction material and the outlet side inner face; one or more satellite bags 2, 3 and 4; and a connecting tube liquid-tightly connecting them to one another. The centrifugal separation is executed by superimposing the blood collecting bag, the satellite bags, and the leukocyte filter, setting the superposed matters in a centrifugal cup with their erected, and setting a bag with the blood outlet nozzle positioned in the centrifugal cup in the inverse direction to the centrifugal force. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a centrifugation method of a leukocyte removal system including a leukocyte removal filter for removing microaggregates, leukocytes and / or platelets in blood. In particular, the present invention relates to a method for centrifuging a leukocyte removal system including a leukocyte removal filter used for the purpose of removing microaggregates and leukocytes that cause transfusion side effects from whole blood preparations for blood transfusion, erythrocyte preparations, platelet preparations, plasma preparations, etc. The present invention also relates to a method for centrifuging a leukocyte removal system including a leukocyte removal filter used for extracorporeal circulation leukocyte removal therapy.

  Whole blood collected from blood donors is separated and collected into medically useful components such as erythrocytes, platelets, and plasma by means of centrifugation, etc., and stored, and so-called component transfusions are widely used in recent years. It is. In addition, since microaggregates and leukocytes contained in each of these blood component preparations (hereinafter referred to as blood preparations) cause various side effects of blood transfusion, these undesirable components are removed before blood transfusion before blood transfusion. The method is becoming popular. In recent years, in particular, the necessity of leukocyte removal has been widely recognized, and in Europe, there are some countries that have legalized the use of all blood products for blood transfusion after undergoing leukocyte removal treatment.

  The most common method for removing leukocytes from a blood product is to treat the blood product with a leukocyte removal filter. Conventionally, the treatment of blood products by this leukocyte removal filter has often been performed at the bedside during blood transfusion operations. However, in recent years, in order to control the quality of leukocyte-removed preparations and improve the stability of leukocyte-removing treatments, it is becoming common for blood centers to carry out treatment before storing blood (“leukocytes before storage”). Called "removal").

  To collect blood from a donor, separate into multiple blood components, and store each blood component, typically two to four flexible bags and conduits connecting them, anticoagulant, red blood cell preservation solution A blood collection / separation set including a blood collection needle has been used for some time. As a system that can be suitably used for the above-mentioned “leukocyte removal before storage”, a system in which a leukocyte removal filter is incorporated into these blood collection and separation sets is widely used, such as “closed system” or “integrated system”. It is called by name (Patent Document 1 and Patent Document 2).

  Conventionally, as leukocyte removal filters, leukocyte removal materials made of non-woven fabric or porous material filled in a hard container such as polycarbonate have been widely used. However, since the container has low vapor permeability, sterilization of blood collection and separation set There was a problem that it was difficult to apply high-pressure steam sterilization widely used as a process. In addition, the “closed system” includes a method in which leukocytes are first removed from a whole blood product after blood collection, a leukocyte removal filter is cut off, and a centrifugation operation for separating components is performed. Some leukocytes are removed after being separated into blood components. In the latter case, the leukocyte removal filter is also centrifuged together with the blood collection / separation set. At this time, the hard container damages the bag and the conduit, or the hard container itself breaks without being able to withstand the stress during centrifugation. There was danger.

As a method for solving these problems, there is a flexible leukocyte removal filter that uses a flexible and vapor-permeable material that is the same as or similar to that used in the bag of the blood collection separation set. Has been developed.
A flexible leukocyte removal filter is obtained by welding a leukocyte removal material to a sheet-like flexible frame, and then welding the flexible frame to a flexible container (Patent Document 3 and Patent Document 4). The leukocyte removal material can be broadly classified into those directly welded to a flexible container (Patent Documents 5 and 6) (hereinafter, the former may be referred to as a frame welding type and the latter as a container welding type). These flexible leukocyte removal filters have a blood inlet and outlet at a part of the container, and the inner space of the container is partitioned into an inlet side space and an outlet side space by a leukocyte removing material.

  Normally, when processing blood with these leukocyte removal filters, the bag containing the blood product to be processed, connected via a conduit to the blood inlet side of the filter, is positioned 20 to 100 cm higher than the filter. Install in. Then, the blood product is passed through the filter by the action of gravity, and the filtered blood product is stored in a collection bag connected to the blood outlet side of the filter via a conduit. At this time, pressure loss occurs in the flow path due to the resistance of the leukocyte removal material, and the space on the filter inlet side becomes positive pressure. Therefore, if the container is flexible, the gap between the inner surface on the container inlet side and the leukocyte removal material At the same time, the positive pressure causes the white blood cell removing material to be pressed against the inner surface of the outlet side of the container. On the other hand, the gap between the inner surface of the outlet side of the container and the leukocyte removal material is that the blood in the conduit connected to the outlet drops due to gravity, and is usually placed at a position 50 to 100 cm lower than the leukocyte removal material after filtration. In order to move to the bag for storing blood, the space on the filter outlet side becomes negative pressure, and the inner surface of the outlet side of the container and the leukocyte removal material tend to adhere to each other. That is, the leukocyte-removing material is brought into close contact with the inner surface of the container on the outlet side by the double force of the positive pressure on the inlet side and the negative pressure on the outlet side, thereby inhibiting blood flow.

As a method for solving this problem, a spacer is arranged between the leukocyte removal material and the blood outlet side of the flexible container to provide an appropriate space to prevent the adhesion between the leukocyte removal material and the inner surface of the container outlet side. Various prior arts have been disclosed. As an example, a method of inserting a soft PVC tube called a connecting rod between the leukocyte-removing material and the outlet side inner surface of the container to prevent adhesion (Patent Document 3), a method of inserting a screen made of knit fiber, etc. Document 6), a method of arranging a mesh or a protrusion (Patent Document 7), a method of providing unevenness with a height difference of 0.2 to 2 mm on the inner surface on the outlet side of the soft container (Patent Document 4), or Between the filter element for removing leukocytes and the outlet side container, the air permeability when converted to a thickness of 1 cm is 3 to 40 cc / cm ² / sec, the third thickness is 0.04 to 0.25 cm There has been proposed a method (Patent Document 8) for providing a flexible blood treatment filter in which a blood flow is not hindered even when a filter element is arranged and an outlet side container is in close contact with the filter element. These are all empty during filtration. It was effective in terms of formation.

However, if a blood collection set that incorporates a leukocyte removal filter, that is, a leukocyte removal system is centrifuged to separate the whole blood in the blood collection bag into a plurality of blood components and leukocyte removal is performed, leukocyte removal with a spacer as described above is performed. Even if a filter is used, the expected leukocyte removal performance may not be obtained. This is because the space previously formed between the leukocyte removal material and the outlet side inner surface of the container using a spacer is crushed during the centrifugation process, and the spacer does not function effectively when the leukocyte removal process is actually performed. This is thought to be the cause. As described above, when the leukocyte removal system including the leukocyte removal filter provided with the spacer is subjected to the centrifugal treatment, problems such as a decrease in leukocyte removal performance and an increase in processing time have not yet been sufficiently solved.
JP-A-1-320064 International Publication No. 92/20428 Pamphlet European Patent Application No. 0526678 Japanese Patent Laid-Open No. 11-216179 JP 7-267871 A WO95 / 17236 pamphlet Japanese Patent Laid-Open No. 2003-180822 International Publication No. 01/05964 Pamphlet

  An object of the present invention is a method for centrifuging a leukocyte removal system including a leukocyte removal filter, wherein the space formed on the outlet side inside the filter by the spacer is not easily damaged by the centrifugal operation, and as a result stable and high leukocyte removal performance Is to provide a centrifugation method.

As a result of intensive studies to solve the above problems, the present inventors have determined that the height of the space formed between the leukocyte removal material and the outlet side inner surface of the container by the spacer is the centrifugal cup used for the centrifugal treatment. It has been found that it varies depending on how the leukocyte removal system is placed inside. And if it centrifuges according to a specific arrangement | positioning method, it will find that the original function of a spacer is not impaired, and when performing subsequent filtration, it will discover that a high leukocyte removal performance is obtained stably, and completes this invention by these. It came to.
That is, the present invention provides a leukocyte removal material filled in a flexible container having at least a blood collection bag filled with collected blood, a blood inlet nozzle and a blood outlet nozzle, and the leukocyte removal material and the outlet of the container. A leukocyte removal system comprising a plate-shaped leukocyte removal filter provided with a spacer between the side inner surface, one or more satellite bags, and a connecting tube for fluidly connecting them; In the method of laminating the satellite bag and the leukocyte removal filter and setting the laminate on a centrifuge cup in a standing state to centrifuge the blood, the centrifuge cup so that the blood outlet nozzle is positioned in the opposite direction of the centrifugal force It is a centrifugation method of the leukocyte removal system, characterized in that it is set to centrifuge and centrifuged.

  According to the centrifugation method of the leukocyte removal system of the present invention, since the function of the spacer provided in the leukocyte removal filter is not impaired, the blood product for removing leukocytes after separating whole blood into a plurality of blood components by centrifugation In the preparation process, a stable leukocyte removal process can be performed without slowing the blood flow even after centrifugation. In addition, a stable and high leukocyte removal performance can be obtained by stabilizing the blood flow.

The present invention will be described in detail below with reference to the drawings.
The leukocyte removal system referred to in the present invention includes at least a blood collection bag filled with collected blood, a leukocyte removal filter in which a flexible container is filled with a leukocyte removal material, a satellite bag, and a connection for connecting them in a liquid-tight manner. Although it is comprised from a pipe | tube, the following structures can be mention | raise | lifted as a more concrete example.

  As a first example, a leukocyte removal system as shown in FIG. 1 can be mentioned. This system consists of a blood collection bag (1) filled with collected blood, a satellite bag (2) filled with red blood cell preservation solution, a satellite bag (3) that does not contain liquid, and a satellite bag (3) that does not contain liquid ( 4) and a leukocyte removal filter (5) for concentrated erythrocyte preparation, the blood collection bag (1) and the satellite bag (2) are connected by the connecting pipe (6), and the blood collection bag (1) and the satellite bag (3) Are connected by a connecting tube (7), the blood collection bag (1) and the blood inlet of the leukocyte removal filter (5) are connected by a connecting tube (8), and the blood outlet of the leukocyte removal filter (5) and the satellite bag (4) Is a leukocyte removal system configured by being connected by a connecting pipe (9). In this example, a satellite bag (4) or a Y-shaped connecting pipe (10) having a sealing means between the connecting pipe (9) and the connecting pipe (8) can be used as one of variations.

  As a second example, a leukocyte removal system as shown in FIG. 2 can be mentioned. This system consists of a blood collection bag (1) filled with collected blood, a first satellite bag (2) filled with red blood cell preservation solution, a satellite bag (3) without liquid, and no liquid It is composed of a satellite bag (4) and a leukocyte removal filter (5) for concentrated red blood cell preparation, and the blood collection bag (1) and the satellite bag (3) are connected by a connecting tube (6), and the blood collection bag (1) and the satellite bag (4) is connected by the connecting pipe (7), the blood inlet of the satellite bag (4) and the leukocyte removal filter (5) is connected by the connecting pipe (8), and the blood outlet of the leukocyte removal filter (5) and the satellite bag. (2) is a leukocyte removal system configured by being connected by a connecting pipe (9).

In both the first example and the second example, before use, that is, before blood collection, blood collection means such as a blood collection needle is connected to the blood collection bag (1) by a connecting tube. In addition, it is preferable from the viewpoint of safety that the connecting scissors are appropriately excised after sealing before blood collection and before centrifugation.
The above first and second specific examples only show the configuration of a general leukocyte removal system used for obtaining a leukocyte-removed concentrated erythrocyte product and a plasma product, and the system used in the present invention is not limited to these. It is not limited to.

[Leukocyte removal filter]
Any leukocyte removal filter of the present invention can be used as long as it is a filter intended for leukocyte removal. For example, the leukocyte removal system is for concentrated red blood cell preparations, but in addition to this, in the case of a leukocyte removal system to obtain leukocyte removal concentrated platelet preparations, platelet-passing leukocytes for concentrated platelet preparations or platelet-rich plasmas There are removal filters.

  The configuration of the leukocyte removal filter of the present invention will be described. In the leukocyte removal filter, a flexible container is filled with a leukocyte removal material, and a blood inlet nozzle and an outlet nozzle are formed on the upper surface and the lower surface of the flexible container. The internal space of the flexible container is separated into a blood inlet side space and an outlet side space by a leukocyte removing material, and a spacer is provided in the blood outlet side space. In such a leukocyte removal filter, blood to be processed flows into the inlet side space from the blood inlet nozzle, and undesired components such as leukocytes are removed when passing through the leukocyte removal material and move to the outlet side space. Then, it flows out from the outlet nozzle to the outside of the flexible container. At this time, the spacer plays a role of preventing the flexible container and the leukocyte removing material from coming into close contact with each other in the outlet side space, and ensuring a uniform and stable blood flow.

  The shape of the leukocyte removal filter is not particularly limited, but the overall shape is that the flexible container and the leukocyte removal material filled therein can be stacked on each other, and the thickness is several mm to several cm. A substantially flat filter is effective. Moreover, as long as it is a substantially flat plate shape that can be stacked, the outline thereof may be any of a polygon, a circle, etc. in addition to a rectangle, a square, and a rhombus.

  It is preferable that the flexible container and the leukocyte removing material are integrally welded at the periphery of the blood filtration part, and further, the flexible container, the leukocyte removing material and the spacer are integrally welded for mass production. More preferred. Examples of a method for integrally welding the flexible container, the leukocyte-removing material, and the spacer include high frequency welding and ultrasonic welding.

The flexible container constituting the leukocyte removal filter of the present invention is preferably formed from a flexible synthetic resin sheet, and the synthetic resin is preferably a thermoplastic resin.
The material of the flexible container should be similar to the leukocyte removal material in terms of thermal and electrical properties, such as soft polyvinyl chloride, polyurethane, ethylene vinyl acetate copolymer, polyolefin such as polyethylene and polypropylene, styrene / Butadiene / styrene copolymer hydrogenated products, thermoplastic elastomers such as styrene / isoprene / styrene copolymers or their hydrogenated products, and mixtures of thermoplastic elastomers and polyolefins, softeners such as ethylene / ethyl acrylate Etc. are mentioned as suitable materials. Preferred are soft polyvinyl chloride, polyurethane, ethylene / vinyl acetate copolymer, polyolefin, and thermoplastic elastomers based on these, and more preferred are soft polyvinyl chloride and polyolefin.

  The flexible container has a blood inlet nozzle on the blood inlet side and a blood outlet nozzle on the blood outlet side. These blood inlet and outlet nozzles may have any shape as long as they can be connected in an airtight manner to the inside of the flexible container and each connecting pipe, but the container inner volume is minimized and more airtight. In order to obtain a high connection part, it is preferable to install on a flexible container outer surface. In order to install the inlet and outlet nozzles on the outer surface of the flexible container, for example, the inlet and outlet nozzles as shown in FIG. 3 are prepared in advance by injection molding or the like, and the flexible container is mounted using a high-frequency welding apparatus or the like. There exists a method of welding on the sheet-like material to form.

  As the leukocyte removing material, a known filtration medium such as a fibrous porous body such as a nonwoven fabric or a woven fabric, or a porous body having three-dimensional network continuous pores such as a sponge-like structure can be used. Examples of these materials include polypropylene, polyethylene, styrene / isobutylene / styrene copolymer, polyurethane, polyester, and the like. Polyester nonwoven fabrics are particularly preferred from the viewpoint of productivity and availability.

  The filtration medium constituting the leukocyte removal material is preferably surface-modified as appropriate according to the use conditions and purpose. For example, improving the wettability of the filtration medium by hydrophilizing the surface of the material is effective for allowing blood to flow uniformly in the leukocyte removal material, and is preferably selected. It is also preferable to improve blood cell capture performance by introducing a charged functional group. Copolymers of monomers such as hydroxyethyl (meth) acrylate having a hydrophilic functional group and dimethylaminomethyl (meth) acrylate or dimethylaminoethyl (meth) acrylate having a basic functional group have both properties and are suitable. It is. Suitable surface modification methods include polymer coating and graft polymerization.

  As described above, the leukocyte removal filter referred to in the present invention has a spacer between the leukocyte removal material and the inner surface on the outlet side of the flexible container. The spacer here refers to the leukocyte removal material and the container. This refers to a structure for providing a space between the inner surface of the outlet side and, for example, a sheet in which uneven heights are formed by a projecting structure, a knit fiber screen, mesh, embossing, etc. And a sheet-like porous body itself having a high porosity. These are formed in the space on the outlet side of the flexible container between the leukocyte removing material and the inner surface of the flexible container, when formed on the inner surface of the container, or formed on the leukocyte removing material. There are cases.

  According to the centrifugation method of the leukocyte removal system of the present invention, for example, when the spacer is a protrusion-like structure formed on the inner surface of the container, the protrusion installed in the direction of the leukocyte removal material from the inner surface of the container is In addition, the load applied to the flexible container can be prevented from sinking into the leukocyte removing material, and the space formed between the leukocyte removing material and the flexible container can be held without being crushed. In addition, when the spacer is a screen or mesh made of knitted fiber, it is possible to prevent the fiber from being embedded in the leukocyte removal material due to the load received during centrifugation, and the space between the fibers can be maintained without being crushed. Furthermore, when the spacer is a sheet-like porous body formed with uneven height difference, the protrusion is prevented from being crushed by the load applied to the filter during centrifugation, and the height is sufficient to form a space. Can hold the difference without breaking it. Furthermore, when the spacer is a sheet-like porous body having a high porosity, it is possible to prevent the voids formed inside the sheet-like porous body from being crushed by a load received during centrifugation and maintain a sufficient space. Moreover, in any case, there is an effect that the function of the spacer can be maintained without being impaired.

  Among these, the method of the present invention functions most effectively when a sheet-like porous body is used as the spacer and when a protruding structure formed on the inner surface of the container is used. In the case of the former, especially in the case of a sheet-like porous body with a high open area ratio, the strength as a spacer is not sufficient for the load received during centrifugation. This is probably because when the load is concentrated, the nozzle portion is easily damaged. In the latter case, it is considered that when the leukocyte removal system is centrifuged, the load tends to concentrate on the top of the protruding structure, and the size of the space formed by the spacer is easily reduced.

  When the spacer is a sheet-like porous body, a non-woven fabric is preferably used because it is easily available and easy to process. The material of the sheet-like porous body is preferably similar in thermal and electrical properties to the leukocyte removal material, and more preferably the same as the leukocyte removal material, from the viewpoint of ease of integral welding. Polyester nonwoven is preferably used because it is easily available and is a material generally used as a leukocyte removal material.

  In the case where the spacer is a sheet-like porous body having an uneven height difference, the uneven height difference is preferably 0.2 mm or more and 3.5 mm or less. This is because the blood that has passed through the leukocyte-removing material is discharged to the outlet even if the inlet-side space of the leukocyte-removing filter is positive and the filter outlet-side space is in a negative pressure due to the unevenness of the height in this range. This is because the blood can flow through the space held by the irregularities when traveling, and the time required for filtration and recovery can be shortened. The height difference of the unevenness is more preferably 0.3 mm or more and 3.0 mm or less, further preferably 0.4 mm or more and 3.0 mm or less, and particularly preferably 0.5 mm or more and 2.5 mm or less.

  It is preferable that the space | interval of the several unevenness | corrugation which the sheet-like porous body in which the uneven | corrugated height difference was formed has is 1-20 mm. If the interval is narrower than 1 mm, the space on the outlet side of the leukocyte removal filter is reduced, which is not preferable because the effect of shortening the filtration and recovery time is reduced. Also, if the distance is larger than 20 mm, the flexible container may enter the space on the outlet side of the leukocyte removal filter after centrifuging the leukocyte removal system, and there is a possibility that the space through which blood flows is lost.

  The shape of the plurality of projections and depressions in the sheet-like porous body in which the projections and depressions are formed may be point-like or linear. When the unevenness is point-like, it may be any one of a cone, a cylinder, a polygonal pyramid, a polygonal column, a hemisphere, a semi-doughnut shape, and when the unevenness is linear, it is a straight line, curved line, zigzag, lattice The height of the unevenness can be reduced by the positive pressure on the filter inlet side generated during blood filtration or the pressure on the flexible container outlet side of the leukocyte removal material generated by the negative pressure on the filter outlet side. A shape that can be maintained is preferred. Moreover, it is preferable that unevenness exists in the whole spacer, and it is more preferable that it is arrange | positioned uniformly in the whole filter.

  When the spacer is composed of a plurality of projecting structures provided on the inner surface of the container, the height difference of the projecting structures is preferably 0.2 mm or more and 3.5 mm or less. This is because blood that has passed through the leukocyte removal material, even if the inlet side space of the leukocyte removal filter is at a positive pressure and the filter outlet side space is at a negative pressure due to the plurality of protruding structures having a height within this range. This is because when blood goes to the outlet, blood can flow through the space held by the projecting structure, so that the time required for filtration and recovery can be shortened.

  The interval between the plurality of protruding structures is preferably 1 to 20 mm. If the interval is narrower than 1 mm, the space on the outlet side of the leukocyte removal filter is reduced, which is not preferable because the effect of shortening the filtration and recovery time is reduced. If the interval is larger than 20 mm, the leukocyte removal material may enter the space formed between the protruding structures when the leukocyte removal system is centrifuged, and there is a possibility that the space in which blood flows is lost.

  The shape of the protruding structure may be a dot or a line. When the protruding structure is a dot, it may be any one of a cone, a cylinder, a polygonal pyramid, a polygonal column, a hemisphere, a semi-doughnut type, and when the protruding structure is a line, a straight line or a curve Any of the shape, zigzag type, lattice type, etc., but against the pressure on the flexible container outlet side of the leukocyte removal material generated by the positive pressure on the filter inlet side generated during blood filtration or the negative pressure on the filter outlet side A shape that can maintain the height difference of the protruding structure is preferable. Moreover, it is preferable that the protruding structure exists on the entire inner surface of the outlet-side flexible container, and it is more preferable that the protruding structure is disposed evenly on the entire surface.

The leukocyte removal system of the present invention has the above-described configuration. When such an entire system is centrifuged, how to set each part constituting the system in the centrifuge cup in the centrifuge. Is important.
In the present invention, it is necessary to set the centrifuge cup so that the blood outlet nozzle of the filter is located in the opposite direction of the centrifugal force. By doing so, the space previously formed between the leukocyte removal material and the outlet side inner surface of the container by the spacer is maintained without being crushed, especially the outlet portion from the blood filter, and subsequently filtered. This is because a stable leukocyte removal process can be performed without slowing the blood flow. In addition, it is possible to obtain a stable and high leukocyte removal performance by stabilizing the blood flow. On the other hand, if the blood outlet nozzle of the filter is set in the centrifugal cup so as to be positioned in the direction of the centrifugal force, the space, particularly the space of the outlet portion from the blood filter, is crushed, and the function of the spacer is not exhibited, A stable leukocyte removal process cannot be performed.
At that time, it is preferable that the blood circuit connection portion provided in the blood collection bag is laminated so as to be positioned in the same direction as the blood outlet nozzle, and is set in a centrifugal cup and centrifuged.

Further, in the present invention, among the blood collection bag and the satellite bag, a plurality of bags constituting the leukocyte removal system are stacked such that at least a bag containing liquid is positioned on the inlet side surface of the leukocyte removal filter. (Hereinafter, it may be simply referred to as a blood bag.) Collect at least the blood that contains blood such as whole blood and the liquid medicine such as red blood cell preservation solution, and place it on the surface of the blood inlet side of the leukocyte removal filter. On the other hand, it is preferable that the bags containing no liquid are stacked together so as to be located on the surface on the blood outlet side, and set in a centrifuge cup in a state where the stacked product is erected, and then centrifuged. This is because, as described above, the load containing the liquid that swells in the direction of the wall of the centrifuge cup is applied to the filter during centrifugation, while leukocyte removal is performed between the spacer and the blood bag containing liquid. This is because the load applied directly to the spacer can be reduced by arranging the material. By doing so, the space on the blood outlet side of the flexible container, in particular the blood outlet nozzle, is compressed and depressed toward the leukocyte removal material during centrifugation, reducing the space on the blood outlet side. Can be further reduced.
A blood collection bag, a leukocyte removal filter, and a satellite bag are laminated in such a preferable state, and an example of a state in which the laminate is inserted and set in a centrifuge cup in an upright state is shown in FIG. An example is shown in FIG.

  When centrifuging, a load is applied from the top to the bottom of the centrifuge cup, so a flexible bag containing a liquid such as a blood bag swells greatly toward the bottom of the centrifuge cup and occupies most of the volume in the centrifuge cup. Transforms into That is, the flexible leukocyte removal filter set while standing in the centrifugal cup is pushed toward the wall surface of the cup by the movement of the liquid in the bag and simultaneously receives a load toward the cup bottom. A plurality of centrifuge cups are usually set in a centrifuge in a ring shape, and rotated by a rotating means for centrifugal separation. At this time, the cup is brought into a state in which the bottom is directed from the rotation axis toward the outside, that is, in the lateral direction by centrifugation. Therefore, the centrifugal force is applied to the bottom of the cup, and the liquid sealed in each bag tends to move in the lateral direction (arrow direction in FIG. 8) in the centrifugal cup.

The centrifuge cup referred to in the present invention is a container for a centrifuge and may be any one that can set the leukocyte removal system of the present invention. There are shapes that have a curved bottom, flat surfaces, etc., and any of them can be used.
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to those examples.

[Create leukocyte removal filter]
Two vinyl chloride resin sheets having a thickness of 0.4 mm, which were cut into a rectangle having a length of 105 mm and a width of 84 mm, were prepared as a cut resin sheet. For each of these cut resin sheets, on the straight line connecting the centers of both short sides and at a position 31 mm from the center of either short side, the liquid passing nozzle is welded and installed, A flexible container raw material sheet was obtained. As shown in FIG. 3, the liquid passing nozzle (14) has a height of 7.3 mm, a length of 16.5 mm, a width of 6.6 mm, and a bent passage (13) is formed therein, and the outer diameter is 4 mm. The blood circuit can be inserted and fixed.
Four polyester nonwoven fabrics (A) having an average fiber diameter of 12 μm, a basis weight of 30 g / m ² , and a thickness of 0.21 mm, and a polyester nonwoven fabric having an average fiber diameter of 1.7 μm, a basis weight of 66 g / m ² and a thickness of 0.4 mm. One sheet of (B), 22 sheets of polyester nonwoven fabric (C) having an average fiber diameter of 1.2 μm, a weight per unit area of 40 g / m ² and a thickness of 0.22 mm, and one sheet of polyester nonwoven fabric (B) thereon From the laminated nonwoven fabric laminated body, it cut out into the rectangle of length 91mm and width 74mm, and was set as the leukocyte removal material. An average fiber diameter of 12 μm, with an unevenness processing of 1.36 mm in height difference by embossing press on the side where the nonwoven fabric (B) of leukocyte removing material is the outermost layer, weight per unit area 70 g / m ² , thickness 0.35 mm, length A sheet-like polyester nonwoven fabric having a width of 91 mm and a width of 74 mm was stacked as a blood outlet side spacer (15). From both sides, the flexible container raw material sheet is covered with the leukocyte-removing material at the center, and the liquid-passing nozzle is positioned point-symmetrically across the leukocyte-removing material. The flexible container raw material (16), the leukocyte removal filter material, the spacer and the second flexible container raw material (16) are 81 mm in outer circumference, 64 mm in width, 74 mm in inner circumference, 57 mm in width, inner circumference. A high frequency welding machine was used to form an integrated weld portion (17) having a shape with a peripheral distance of 3.5 mm. Further, using a high frequency welding machine, the peripheral portions of the first flexible container raw material and the second flexible container raw material are integrally welded to a width of 3.5 mm, and leukocyte removal having the cross-sectional structure shown in FIG. Created a filter.

[Creation of leukocyte removal system]
A leukocyte removal system incorporating the above leukocyte removal filter is shown in FIG. This system was created as follows.
The connection length of the blood outlet nozzle installed on the outlet side of the leukocyte removal filter container, that is, the side where the spacer is inserted, and an empty vinyl chloride resin satellite bag (4) with a capacity of 600 mL is 461 mm. Connected by a blood circuit with an outer diameter of 4 mm so that the blood inlet nozzle installed on the inlet side surface of the leukocyte removal filter container, that is, the side where the spacer is not inserted, and the Y-shaped connecting pipe (11) are connected. Was connected with a blood circuit having an outer diameter of 4 mm so that the distance was 223 mm. Further, the Y-shaped connecting tube (11) and the satellite bag (4) were connected by a blood circuit having an outer diameter of 4 mm including one breakable connector so that the connection length was 1380 mm.
A blood collection needle (20) and a 600 ml vinyl chloride resin blood collection bag (1) filled with 70 mL of anticoagulant CPD were connected by a blood circuit with an outer diameter of 4 mm so that the connection length was 1710 mm. One breakable connector integrally connected to the bag (1) and the Y-shaped connecting pipe (10) were connected by a blood circuit having an outer diameter of 4 mm so that the connection length was 112 mm. A Y-shaped connecting tube (10) and a Y-shaped connecting tube (11) are further connected to the Y-shaped connecting tube (10) by connecting a Y-shaped connecting tube (12) with a blood circuit having an outer diameter of 4 mm to a connection length of 242 mm. Were connected by a blood circuit having an outer diameter of 4 mm including one breakable connector so that the connection length was 155 mm. The remaining two connection ports of the Y-shaped connecting tube (12) are each a 300 mL vinyl chloride resin satellite bag (2) containing 110 mL of red blood cell preservative ADSOL, and a 300 mL chloride containing no drug. A vinyl resin satellite bag (3) was connected by a blood circuit having an outer diameter of 4 mm so as to have a connection length of 310 mm. The integrated multi-blood bag system with leukocyte removal filter prepared as described above was sterilized with high-pressure steam to prepare a leukocyte removal system.

[Blood collection and centrifugation]
The blood of a healthy blood donor was collected into a blood collection bag (1) through the blood collection needle of the leukocyte removal system while thoroughly mixing with the anticoagulant CPD encapsulated in advance, and this was used as whole blood. The whole blood in the obtained blood collection bag (1) was 500 mL. The blood circuit connecting the blood collection needle and the blood collection bag (1) was melted and cut near the junction with the blood collection bag (1). The leukocyte removal system containing whole blood was stored at 4 ° C. for 20 hours.
The leukocyte removal system stored at 4 ° C. for 20 hours was removed at room temperature of 22 ° C. Lay the blood collection bag (1) on its side, put the satellite bag (2) filled with liquid on it, and place the leukocyte removal filter (5) on the blood outlet nozzle (5-a) above the satellite bag. So that the blood circuit connection port of the blood outlet nozzle (5-a) faces in the same direction as the blood circuit connection part (1-a) of the blood collection bag (1), and an empty satellite bag is placed thereon. (3) was overlaid, and an empty satellite bag (4) was overlaid thereon and laminated as shown in FIG.
The laminate (leukocyte removal system) is placed so that the blood circuit connection port side of the blood outlet nozzle (5-a) of the leukocyte removal filter (5) faces upward, that is, the blood circuit connection portion (1) of the blood collection bag (1). -A) is inserted in a cylindrical centrifuge cup having an inner diameter of 100 mm and a depth of 150 mm in a state where the laminate is erected so as to be above the centrifuge cup, and this centrifuge cup is set in a high-speed centrifuge (Hitachi, himac CR7B3), Centrifugation was performed at 4140 rpm for 15 minutes.

[Collecting blood components and removing leukocytes]
After the centrifugation, the laminate (leukocyte removal system) is carefully taken out from the centrifuge cup, and then the blood circuit connecting the Y-shaped connecting tube (12) and the satellite bag (2) is closed with forceps to collect blood. The breakable connector integrally connected to the bag (1) is folded, the blood collection bag (1) and the blood bag (3) are communicated, and the supernatant of the whole blood separated in the blood bag (1), that is, platelet-rich The plasma layer was transferred to the blood bag (3) while slowly pressing the blood collection bag (1).
Thereafter, the blood circuit connecting the Y-shaped connecting tube (12) and the satellite bag (3) is closed with forceps, and then the forceps that have been closed between the Y-shaped connecting tube (12) and the satellite bag (2) are removed. After removing and connecting the satellite bag (2) and the blood collection bag (1), the total amount of ADSOL enclosed in the satellite bag (2) remains in the blood collection bag (1) after centrifugation. That is, when added to the erythrocyte concentrate, the ADSOL-added erythrocyte concentrate (hereinafter referred to as erythrocyte preparation) in the blood collection bag (1) was 341 mL. The blood circuit connecting the Y-shaped connecting pipe (12) and the Y-shaped connecting pipe (10) was melted and cut, and the satellite bags (2) and (3) were removed. When the leukocyte concentration in the erythrocyte preparation was measured using an automatic blood cell counter (Sysmex Corporation, K-4500), it was 11,600 co / μL.
Leukocyte removal system portion comprising the remaining blood collection bag (1), Y-shaped connection tube (10), Y-shaped connection tube (11), leukocyte removal filter (5), satellite bag (4), and blood circuit connecting each of them Was suspended with the blood collection bag (1) at the top so that the drop between the blood collection bag and the satellite bag was 150 cm. The surface temperature of the blood collection bag (1) containing the erythrocyte preparation was measured using an infrared surface thermometer (Cos, CT-30) and found to be 8 ° C. The breakable connector installed in the blood circuit connecting the Y-shaped connecting tube (10) and the Y-shaped connecting tube (11) is folded and communicated, and the red blood cell preparation in the blood collection bag (1) is introduced into the leukocyte removal filter, Filtration with a filter was started. The time from when the breakable connector is folded (hereinafter referred to as the filtration start time) to the time when the red blood cell preparation in the blood collection bag (1) substantially disappears (hereinafter referred to as the filtration completion time) is defined as the filtration time. The collection time was defined as the time until the red blood cell preparation substantially disappeared on the inlet side of the filter, and the total time of the filtration time and the collection time was defined as the treatment time. In this example, the filtration time was 41 minutes, the recovery time was 31 minutes, and the treatment time was 72 minutes.
The erythrocyte product from which leukocytes were finally recovered collected in the satellite bag (4) was weighed as a white erythrocyte preparation to be 300 mL. Further, the concentration of leukocytes contained in the white blood erythrocyte preparation was measured using a flow cytometer (BECTON DICKINSON, FACSCalibur), and found to be 0.2 co / μL.
When the leukocyte removal performance was calculated using the following formula (1), the leukocyte removal performance in this example was 4.82 (see Table 1).
Leukocyte removal performance = −log {(white blood cell preparation amount (mL)) × (white blood cell concentration in white blood cell preparation (mL ⁻¹ )) / (red blood cell preparation amount (mL) × white blood cell concentration in red blood cell preparation (mL ⁻¹⁾ ))}. . . (Formula 1)

When laminating each blood bag and leukocyte removal filter of the leukocyte removal system, it was carried out except that the leukocyte removal filter was stacked on the satellite bag (2) so that the blood outlet nozzle (5-a) was on the lower side. The blood was processed in the same manner as in Example 1.
In this example, the filtration time was 43 minutes, the recovery time was 36 minutes, and the treatment time was 79 minutes. The white blood cell concentration contained in the white blood cell preparation was measured using the automatic blood cell counter and found to be 0.3 co / μL. The leukocyte removal performance in this example was 4.64 (Table 1).

Comparative Example 1

When laminating each blood bag and leukocyte removal filter of the leukocyte removal system, the blood circuit connection port of the blood inlet nozzle (5-b) faces the same direction as the blood circuit connection portion (1-a) of the blood collection bag (1). The blood treatment was performed in the same manner as in Example 1 except that they were overlaid.
In this example, the filtration time was 54 minutes, the recovery time was 51 minutes, and the treatment time was 105 minutes. Further, the concentration of leukocytes contained in the white blood erythrocyte preparation was measured using the automatic blood cell counter, and found to be 0.6 co / μL. The leukocyte removal performance in this example was 4.34 (Table 1).

Comparative Example 2

When laminating each blood bag and leukocyte removal filter of the leukocyte removal system, a comparison was made except that the leukocyte removal filter was stacked on the satellite bag (2) so that the blood outlet nozzle (5-a) was on the lower side. The blood was processed in the same manner as in Example 1.
In this example, the filtration time was 62 minutes, the recovery time was 68 minutes, and the treatment time was 130 minutes. In addition, the concentration of leukocytes contained in the white blood cell preparation was measured using the automatic blood cell counter, and found to be 2.4 co / μL. The leukocyte removal performance in this example was 3.74 (Table 1).

[Create leukocyte removal filter]
The flexible container raw material sheet and the leukocyte removal material were prepared in the same manner as in Example 1. A high-frequency welder is used on the surface of the flexible container raw material sheet on which the liquid passing nozzle is not installed, and a hemispherical protruding structure having a height of 1 mm and a bottom diameter of 2.2 mm is evenly provided on the bottom surface. Spacers were formed so as to have an interval of 2.2 mm and used as spacers.
From the both sides of the leukocyte-removing material, the flexible container raw material sheet, the sheet on which the spacer is formed become the outermost layer of leukocyte-removing material polyester non-woven fabric (B), and the leukocyte-removing material is arranged in the center respectively. In addition, it was welded using a high frequency welding machine after covering the leukocyte removal material so that the liquid passing nozzle was positioned point-symmetrically. For welding, the first flexible container raw material, the leukocyte removal material, and the second flexible container raw material are 81 mm in outer circumference, 64 mm in width, 74 mm in inner circumference, 57 mm in width, and distance between inner circumference and outer circumference. Was welded so as to form an integrally welded portion having a shape of 3.5 mm. Furthermore, the peripheral portions of the first flexible container raw material and the second flexible container raw material are integrally welded to a width of 3.5 mm using a high frequency welder, and a leukocyte removal filter as shown in FIG. Created.

[Creation of leukocyte removal system]
A leukocyte removal system incorporating the above leukocyte removal filter (FIG. 5) was prepared in the same manner as in Example 1.

[Blood collection, centrifugation, blood component collection and leukocyte removal operation]
In the same manner as in Example 1, the time for blood collection, centrifugation, preparation of erythrocyte preparation and filtration with a leukocyte removal filter, and time for treatment, leukocyte concentration measurement, and leukocyte removal performance were calculated.
In this example, the filtration time was 39 minutes, the recovery time was 35 minutes, and the treatment time was 74 minutes. The white blood cell concentration contained in the white blood cell preparation was measured using the automatic blood cell counter and found to be 0.3 co / μL. The leukocyte removal performance in this example was 4.64 (Table 1).

Comparative Example 3

When laminating each blood bag and leukocyte removal filter of the leukocyte removal system, the blood circuit connection port of the blood outlet nozzle (5-a) of the leukocyte removal filter is connected to the blood circuit connection part (1-a) of the blood collection bag (1). The blood was processed in the same manner as in Example 3 except that they were stacked so as to face in the opposite direction.
In this example, the filtration time was 50 minutes, the recovery time was 48 minutes, and the treatment time was 98 minutes. Further, the concentration of leukocytes contained in the white blood erythrocyte preparation was measured using the automatic blood cell counter, and found to be 0.6 co / μL. The leukocyte removal performance in this example was 4.34 (Table 1).

[Create leukocyte removal filter]
As the blood outlet side spacer (15), the same configuration as in Example 1 except that a nonwoven fabric layer in which four polyester nonwoven fabrics (A) having an average fiber diameter of 12 μm, a basis weight of 30 g / m ² and a thickness of 0.21 mm are used is used. And a leukocyte removal filter was prepared by the method.

Using the leukocyte removal system (FIG. 5) incorporating the leukocyte removal filter, blood was treated in the same manner as in Example 1.
In this example, the filtration time was 46 minutes, the recovery time was 50 minutes, and the treatment time was 96 minutes. Further, the concentration of leukocytes contained in the white blood erythrocyte preparation was measured using the automatic blood cell counter, and found to be 0.12 co / μL. The leukocyte removal performance in this example was 4.52 (Table 1).

Comparative Example 4

When laminating each blood bag and leukocyte removal filter of the leukocyte removal system, the blood circuit connection port of the blood outlet nozzle (5-a) of the leukocyte removal filter is connected to the blood circuit connection part (1-a) of the blood collection bag (1). The blood treatment was performed in the same manner as in Example 4 except that they were stacked so as to face in the opposite direction.
In this example, the filtration time was 58 minutes, the recovery time was 70 minutes, and the treatment time was 128 minutes. The white blood cell concentration contained in the white blood cell preparation was measured using the automatic blood cell counter, and found to be 2.8 co / μL. The leukocyte removal performance in this example was 3.67 (Table 1).

  Since the centrifugal method of the leukocyte removal system of the present invention has the effect of being able to stably filter without reducing the filtration rate of blood and maintaining high leukocyte removal ability, among the closed systems used for leukocyte removal before storage, In particular, it can be suitably used for a closed system of a type in which leukocyte removal operation is performed after blood is centrifuged.

It is a schematic diagram which shows an example of a structure of a leukocyte removal system. It is a schematic diagram which shows the other example of a structure of a leukocyte removal system. It is a cross-sectional schematic diagram which shows the example of the structure of a blood inlet or outlet nozzle. It is a cross-sectional schematic diagram which shows the internal structure of a leukocyte removal filter. It is a schematic diagram which shows the structure of the leukocyte removal system used by the Example and the comparative example. It is a schematic diagram which shows the example of the state which laminated | stacked each blood bag of the leukocyte removal system, and the leukocyte removal filter. It is a schematic diagram which shows the example of the state in which the leukocyte removal system was set to the centrifuge cup, and the state in the cup during centrifugation. It is a schematic diagram which shows the example of the state in the cup of the leukocyte removal system during centrifugation.

Explanation of sign

DESCRIPTION OF SYMBOLS 1 Blood collection bag 1-a Blood circuit connection part 2-4 Satellite bag 5 Leukocyte removal filter 5-a Blood outlet nozzle 5-b Blood inlet nozzle 6-9 Connection pipe 10-12 Y-shaped connection pipe 13 Passage 14 Nozzle for liquid passage 15 Spacer 16 Flexible container raw material 17 Welded portion 20 Blood collection needle

Claims (5)

A blood collection bag filled with at least blood collected and having a blood circuit connection portion;
A flat plate leukocyte removal filter in which a leukocyte removal material is filled in a flexible container having a blood inlet nozzle and a blood outlet nozzle, and a spacer is provided between the leukocyte removal material and the inner surface on the outlet side of the container. When,
One or more satellite bags,
A connecting pipe for liquid-tightly connecting them,
A leukocyte removal system consisting of
In the method of laminating the blood collection bag, the satellite bag, and the leukocyte removal filter, and centrifuge the blood by setting the laminate in a centrifuge cup in a standing state,
A method for centrifuging a leukocyte removal system, characterized in that the blood outlet nozzle is set in a centrifuge cup so as to be positioned in a direction opposite to the centrifugal force and then centrifuged.   The method for centrifuging a leukocyte removal system according to claim 1, wherein the blood circuit connection portion provided in the blood collection bag is set in a centrifuge cup so as to be positioned in the same direction as the blood outlet nozzle and centrifuged.   The blood collection bag and the satellite bag are laminated so that at least a bag containing liquid is positioned on the inlet side surface of the leukocyte removal filter, and the laminate is set in a centrifuge cup and centrifuged. The method for centrifuging a leukocyte removal system according to 1 or 2.   The method for centrifuging a leukocyte removal system according to claim 1, wherein the spacer is a sheet-like porous material. The method for centrifuging a leukocyte removal system according to claim 1, wherein the spacer is a plurality of protruding structures provided on the inner surface of the container on the outlet side.