CA1206831A

CA1206831A - Blood bag system with integral filtering means

Info

Publication number: CA1206831A
Application number: CA000429598A
Authority: CA
Inventors: Leonard A. Wisdom
Original assignee: Miles Laboratories Inc
Current assignee: Bayer Corp
Priority date: 1982-06-04
Filing date: 1983-06-03
Publication date: 1986-07-02
Also published as: US4596657A

Abstract

Inventor: LEONARD A. WISDOM

Invention: BLOOD BAG SYSTEM WITH
INTEGRAL FILTERING MEANS

Abstract of the Disclosure A multiple blood bag system is disclosed having at least two blood bags and conduit means providing sealed flow communication between the bags and a filtering means integrally disposed between two of the bags for removing platelets and white cells from a red cell concentrate in the blood bag system. In the method of the invention a red cell concentrate is provided in one of the blood bags of the above system and an additive solution is mixed therewith. The mixture of the red cell concentrate and additive solution is passed through the filtering means from one of the bags to another.

Description

83~

Background of the Invention Field of the Invention: this invention relates to and has _ among its objects novel apparatus and methods for providing packed red blood cells (erythrocyte~) which are substantially free of platelets and contain low levels of white cells and have a storage life of up to about 35 days. Further objects of the invention will be evident from the following description wherein parts and percentages are by weight unless otherwise specified.

Description of the Prior Art: It is desirable, for patients who require frequent blood transfusions, to remove white cells and platelets from donor blood prior to transfusion. Febrile reactions, which are usually attributable to transfused HULA antigens on white cells and platelets present in the blood may occur in 3.6~ of patients infused. Such side effects are usually more frequent and severe in patients who receive multiple transfusions.

The removal of HULA antigen may be accomplished in a number of ways. Perhaps the most effective means, but unfortunately the most costly, involves the reconstitution of frozen blood.

A less expensive approach is to wash blood with saline in a number of washes. However, this saline wash approach is time consuming not only in the processing of batches but also in continuous operation. Furthermore, significant loss of red cells occurs and less predictable removal of white cells and platelets is obtained.

CLUE

.

` no Kilcugawa et at in Vow Sang., Vol. 3g, 281 - 290 ~1975) describe commercial cotton wool filters for filtering blood to remove the above HULA antigen. Issue filters axe, however, expensive and cumbersome to use.
S
Diepenhorst et at in Vow Sang., Vol. 23, 308 - 320 (1972) and Vol. 29, 15 - 22 (1975) disclose cotton wool filtration of blood under pressure. This method, while efficient, requires a special apparatus that is expensive.
All of the above techniques require that the treated blood be infused within 24 hours of treatment in order to avoid the potential risk of infection. Prolonged shelf life of blood so treated is not possible.
Summary of the Invention The invention described herein provides for apparatus and methods for preparing red blood cells which are sub Stan-tidally free of platelets and contain low levels of white cells (thus preventing formation of micro aggregates) and have a storage life of at least about 21 days, preferably up to about 35 days, depending on the nature of the anticoagulant and red cell storage solution employed.
The apparatus of the invention comprises a multiple closed blood bag system having at least two blood bags and conduit means providing sealed flow communication between the bags. A filtering means is integrally disposed between two of the blood basso In the method of the invention a red cell concentrate is provided in a blood bag of a multiple blood bag system ; comprising at least two blood bags and conduit means CLUE

~Z(~3:1 providing sealed flow communication between said bay and a filtering means integrally disposed between two of the bags. The red cell concentrate is mixed with an additive solution and the mixture is passed through the filtering means from one of the bags to the other. The filtering means is designed to remove platelets and White cells, and thus prevent formation of rnicroaggregates in the red cell concentrate.

The primary advantage of the present invention is its simplicity and its effectiveness. The apparatus of the invention is easy and inexpensive to use. A further advantage of the invention is that the red cells prepared as above have an extended storage life of at least about 21 days or more. Above all, the filtered red blood cells are essentially free of platelets and have very low levels of white cells and mlcroaggregates, thus reducing the incidence of febrile reactions or HULA sensitization in the infusion of the treated red cells.
the blood bag system having an integral filter assures that sterility will not be breached during the filtering operation. Prolonged shelf life is assured, and there is no added risk of infection.
Brief Description of the Drawing Figure 1 is a three-dimensional depiction of an apparatus in accordance with the present invention.
Figure 2 is a three-dimensional depiction of a filtering means in accordance with the invention.

CLUE

: `

: ::

~;~Q~83~

Description of the Preferred Embodiments In a preferred embodiment the multiple blood bay system of the invention comprises at least three bays, a primary bag and at least two satellite bags, connected by conduit means providing sealed flow communication between the bags and a filtering means integrally disposed between two of the bays. Red blood cells in the multiple blood bag system may be passed from one of the bags to another through the filtering means comprising a housing containing a filtering medium which removes platelets and white cells and provides extended storage life of the red cells when the red cell concentrate is mixed with an additive solution, e.g., a red cell storage solution prior to filtration by introducing the additive solution into the red cell concentrate.

In the method of the invention whole blood is introduced, e.g., by collection from a donor, into the primary bag of the above system. After centrifugation, plasma is ` expressed into one of the satellite bags which does not have a filtering means disposed between it and the primary bawd Next, the additive solution in the satellite bag that is separated from the primary bag by the filtering means is passed through the filtering means into the donor bag wherein it is mixed with the red cells. The mixture of red cells and solution is then passed back therewith filtering means into the satellite bag in which they may be stored for extended periods. The so-treated red cells are substantially free of platelets (i.e., containing less than lo of the original platelets) and of white cells (i.e., containing less than 10% of the original white cells); also micro aggregate formation is virtually eliminated.
CLUE

,- -- --I 33~

The apparatus and method of the invention will next he described in detail with reference to Figures 1 and 2, Blood bay system 10 includes primary or donor bag 12 connected to satellite bags 14 and 16 by means of flexible tubing or conduit means 18, which provides sealed flow communication between 12 and 14 and 16. Bag 12 is adapted for receiving blood from a donor and includes blood collection tube 20 and donor needle 22. Satellite bag 24 is connected to bag 14 by means of flexible tubing 18.

Fluid flow through tubing 18 is controlled by conventional valving means such as snap-off plugs, removable plugs, or slide clamps. Conventional access ports 28, 30, 32, and 15~ 34 are found on bags 12, 14, 16, and 24, respectively, which may also contain other design features known in the art.

The blood bags of system 10 may be of conventional construction being made of a plastic material that is blood compatible, flexible, translucent, and sterilizable.
The plastic may be a polyvinyl chloride, polyester, .
polyolefin, polyurethane, and so forth and may include blends of the above materials. Flexible tubing 20 and 18 may be made of a plastic material that is the same as or different from the plastic material of the blood bags.

Filtering means 26 is integrally disposed between bags 12 and 16 and is attached at its ends to tubing 18.
Filtering means 26 includes a housing 36 made of rigid polyvinyl chloride or the like and tubing figments 38.
Filtering means 26 is filled with a filtration medium 40 such as cotton wool or cellulose acetate or other synthetic fibers such as polyester, polyamides, and the CLUE

'' ~Z~331 like. Preferred filtration medium for purposes of this invention is either cotton wool as prepared by the method of Diepenhorst et at referred to above or cellulose acetate. The amount of filtration medium depends upon the amount of red cells to be filtered. Usually about 20-50 grams of filtration medium are employed per 200-250 ml of red cell concentrate.
Bag 16 contains an additive solution for mixing with the red cells to be filtered to prolong the storage life of the red cells. This additive solution may be, for example, a conventional red cell storage solution such as that described in Ginsburg et at, Bible ~aemotol., 1971, No. 3, Pt. 2, 217-220; Wood et at, Blood, Vow 42, No. 1, 1973, 17-25; Butler, "The Red Cell in Vitro", Gum and Stratton, New York, NOW., 1974, p. 201; Lovric et at, Medical Journal of Australia, Vol. 2, 183-18~, 1977; US. Patent No. 4,267,269; in an amount of about 50-100 ml per 200-250 ml of red cell concentrate.
In use blood is collected into bag 12 through donor tube 20 under conventional conditions. Donor bag 12 may con-lain an anticoagulant such as Adenine-Citrate-Dextrose (AND), Citrate-Phosphate-Dextrose (CUD), Citrate Pros-I; photo millimoles Dextrose (CP2D), CUD plus adenine, or other conventional anticoagulant, with which the collected blood mixes. The collected blood Jay then be processed directly or stored usually at about 4-6C. At processing, bag system 10 is centrifuged as is customary in the art causing the red cells in the blood in bag 12 to settle at the bottom of the bag. Blood plasma is expressed by conventional techniques from 12 into 14 ; from which fresh plasma and a platelet concentrate, for : : :

, .
' Jo 1;~1D6~31 _ 7 _ example, may be obtained in bags I and 24, respectively.
Bag system 10 ma optionally be equipped with other satellite bags into which other blood components may be expressed or processed as necessary or desired.
The additive solution from bag 16 is drained through filter 26 into donor bag 12 now containing the red blood cell concentrate. The red cells are back-filtered, preferably by gravity, through filter 26 into bag 16.
lo This may be accomplished, conveniently in the refrigerator or cool room, at a temperature of about - 6 C, e.g., overnight or for the period of time necessary to filter all of the red blood concentrate, usually about 2 - 4 hours or more.
A blood bag system with only two blood bags in sealed flow communication and an integral filtering means disposed between the bags is within the purview of the invention.
However, in use such a system would require connection of a third receptacle to receive plasma separated from the red cell concentrate. Such connection may be made, for example, at one of the ports of the donor bag by means, for example, of a sterile connector having a third bag attached thereto for receiving plasma.

The invention is demonstrated further by the following illustrative example.
For experimental purposes 59 units of donor blood (425 -450 ml) were collected into blood bags containing 63 ml of citrate phosphate and 277 my dextrose anticoagulant, specially designed for the purpose by Tutu Laboratories, CLUE

.....

,.~

Sue 6~3~

Lane Cove, Sydney, Australia. (For purposes of carrying out these experiments the donor bag was part of a blood bag system of the type exhibited in Figure 1 but containing an additional satellite bag integrally attached by means of flexible tubing to the donor bag.) Following centriEugation at 4,000 g for 10 minutes, the plasma was removed. The residual packed red cells were split into two halves. One half was suspended in a satellite bag containing 50 ml of an aqueous additive solution of disodium hydrogen phosphate (25 my), adenine ~0.5 my sodium chloride (123 my), dextrose (40 my), trisodium citrate (15 my), and citric acid (9.75 my). Control data were obtained from this portion of the packed red cells.

The test data were obtained from the other half of the packed red blood cells; the same additive solution was also contained in a satellite bag separated from the donor bag by a filter integral with the tubing connecting the donor and satellite bag This 50-ml volume additive solution was passed through the filter into the donor bag containing the remaining half of the residual packed red cells. The filter medium comprised cotton wool (20 g) prepared by the method of Diepenhorst et at mentioned above. Next, the red cell concentrate in the donor bag was filtered overnight by gravity at 4 - 6 C through the filter and into the satellite bag integrally connected therewith.

Autologous erythrocyte survival studies douche et at, "Practical Hematology", Thea Ed., Churchill Livingston, Edinburgh,~1975) were assessed in 10 volunteers following unformed consent, and were determined either at 28 or 35 days of storage. Oxygen dissociation curves were drawn with the Hem-O-Scan~instrument (Amino, Silver Springs, , :
CLUE 1 /, , ,.,, ,. ,,,.. I.

~Z(~6~33~

My.). The P50 values were determined by first removing the supernakant after centrifugation. The packed red cells were then adjusted to a hematocrit of 40% and pi 7.4 with a reagent mixture containing A plasma and Tricycle buffer (pi 9.0l and then tested immediately. Adenosine triphosphate (AT), 2,3-dipho~oglycerate (2,3-DPG) super-Nat ant hemoglobin, phi potassium and ethylene blue uptakes were tested as describe in Lovric et at, Vow Sang., Vol. 33, 346 - 352, 1977. Erythrocyte deformability was measured with the 5- m polycarbonate filtration method tried et at, J. Olin. Path., Vol. 29, 853 855, 1~76) using a negative pressure of 130 mm Hug.
I:
Micro aggregate counts were done on allocates kept between 4 and 6 C until just prior to counting using a OF Courter Counter with a 200-~m orifice coupled to the Courter Channelyzer kilter Electronics, Hoyle, Fly.). The packed red cells were first resuspended by gentle mixing, and a 1/100 dilution made in isotonic saline (Isoton, Courter Electronics). Bubble formation could be avoided by first aspirating the sample into the Courter diluter, and subsequent release near the bottom of the vessel already containing the delineate. Next, erythrocytes were lucid by adding 50 I of 10% saponin (Fisher Scientific, Fair lawn, NAY.) and a stop watch started. It is essential that the saponin be added slowly, the container inverted slowly twice only and without shaking, lest bubble formation preclude reproducible counts. Exactly 65 sec.
after the addition of saponin the count is commenced and the mean of duplicates recorded for each of the channels.
The background count values were subtracted from blanks not containing blood, but handled identically. The coefficient of variation with this procedure is less than 5%.
CLUE

~Z~6~3~

The results of all tests are tabularized below:

Table 1 Storage P50 (mm Hug) (weeks) Filtered Control 1 25.5 24

2 23 20

3 22 lo I: 4 21 19 :: 5 : 20 --; Table 2 :: : : : :
Storage AT molt Hb*3 (weeks) Filtered Control

4-4 4.4 :20 3.8 3.8 2 ; 3.4 3.0 3 I 2.3 :: : 4 : 2.5 1.8 2.2~ 1.7 I: ; 25~
* Hemoglobin : 30 ;

: CLUE : : :

.. :;., :

: : :

' -` Liz 5131 Table 3 Storage Supernatant Potassium (meekly) (weeks) Filtered Control ____

5 0 5 6 : :
Table 4 : Storage Microa~gregate_Counts [(10-15 em) x 10 /1]
Icky) Filtered Corltrol : 10 125 ; 2 :10 375 3 :10 400 : 4 I: 10 375 25:~

`

30~
:: : I: :: :;
: :

::: : ::
CLUE
:: :: :
":~

, ~Z~6~3~

Table 5 Storage Microa~yre~ates ~(15-30 em) x_109/1]
(weeks) Filtered Control lo 35 Table 6 Erythrocyte (5 em) Storage filtration rate, ml/min (weeks Filtered Control ; 0 1.50 .10 1 1.20 .15 2 1.10 .20 3 1.00 .10 I: :

0.95 --:
:
2,3-DPG levels fell to 20% of initial values at 3-weeks storage with a further decline at dyes to about 12%.
; There was no difference in the pi values when comparing filtered to unfiltered allocates and similarly, ethylene blue uptakes were 14i2% of original levels after 35 days ; storage. The~supernatant hemoglobin did not exceed 0.5 gull after 35 days storage. Mean Or autologous I: ::::
erythrocyte~survivals in the lo units of filtered blood were 85% no range 83 - 87%) after 28 days and 79% no CLUE
::

. . ..: . ., .: .,,:

Al 683~

range 67 - 91%) after 35 days storage. The loss of erythrocytes on the filter averaged 10% (range 8 - 15%), while trapping over 90% of white cells (range 85 go and all platelets. The final hematocrit ox the filtered blood was in the range of 53 - 58%.

, CLUE

:

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a multiple blood bag system comprising at least two blood bags and conduit means providing sealed flow communication between said bags, the improvement which comprises a filtering means com-prising a housing containing a filtering medium capable of removing platelets and white cells from red cells.

2. The multiple blood bag system of claim 1, wherein the filtering medium is cotton wool.

3. The multiple blood bag system of claim 1, wherein the filtering medium is cellulose acetate.

4. The multiple blood bag system of claim 1, wherein the filtering medium is a synthetic fiber.

5. A method for removing platelets and white cells from a red cell concentrate which comprises -(a) providing a red cell concentrate in a first blood bag of a multiple blood bag system comprising at least two blood bags and conduit means providing sealed flow communication between the bags and a filtering means comprising a housing containing a filtering medium capable of removing platelets and white cells from red cells, integrally disposed between two of said bags;

(b) introducing an additive solution into the red cell concentrate;
(c) passing the mixture of red cell concentrate and additive solution through the filtering means from said first bag to a second bag of said at least two bags.

6. The method of claim 5, wherein the additive solution is contained in said second blood bag and is mixed with the red cell concentrate by passing the solution through the filtering means into the first blood bag containing the red cell concentrate.

7. The method of claim 5 or 6, wherein the additive solution is a red cell storage solution.

8. In a multiple blood bag system comprising a primary bag and at least two satellite bags connected by conduit means providing sealed flow communication between the bags, the improvement which comprises a filtering means integrally disposed between two of said bags such that red cells in the multiple blood bag system may be passed from one of said bags to another through said filtering means, said filtering means comprising a housing containing a filtering medium capable of removing platelets and white cells from red cells.

9. The multiple blood bag system of claim 8, wherein the primary bag is integrally fitted with a needle and tubing for collecting blood from a donor.

10. The multiple blood bag system of claim 8 or 9, wherein one of said satellite bags contains an additive solution for mixing with a red cell con-centrate.

11. The multiple blood bag system of claim 8, wherein the filtering means is integrally disposed between said primary bag and one of said satellite bags.

12. The multiple blood bag system of claim 8, 9 or 11, wherein the filtering medium is selected from the group consisting of cotton wool, cellulose acetate and synthetic fibers.

13. The multiple blood bag system of claim 8, 9 or 10, wherein the filtering means removes plate-lets and white cells thus prevent formation of micro-aggregates in red cell concentrates.

14. The multiple blood bag system of claim 8, wherein one of said satellite bags contains an additive solution for mixing with red cell con-centrate.

15. The multiple blood bag system of claim 14, wherein the additive solution is a red cell storage solution.

16. In a multiple blood bag system comprising a primary bag and at least two satellite bags each connected by conduit means to the primary bag and providing sealed flow communication between the bags, the improvements which comprise one of the satellite bags containing an additive solution for mixing with a red cell concentrate, and a filtering means integrally disposed between the primary bag and the satellite bag containing the additive solution such that the additive solution of the satellite bag may be passed through the filter to the primary bag and red cells in the primary blood bag may be passed through said filtering means to the satellite bag, said filtering means comprising a housing containing a filtering medium.

17. The multiple blood bag system of claim 16, wherein the primary bag is integrally fitted with a needle and tubing for collecting blood from a donor.

18. The multiple blood bag system of claim 16 or 17, wherein the filtering medium is selected from the group consisting of cotton wool, cellulose acetate and synthetic fibers.

19. The multiple blood bag system of claim 16 or 17, wherein the filtering means is effective to remove platelets and white cells thus preventing formation of microaggregates in red cell concentrates.

20. The multiple blood bag system of claim 16 or 17, wherein the additive solution is a red cell storage solution.

21. A method for removing platelets and white cells from a red cell concentrate, which comprises -(a) providing a multiple blood bag system containing blood, said system comprising a primary bag and at least two satellite bags connected by conduit means providing sealed flow communication between the bags, and which comprises a filtering means integrally disposed between two of said bags such that red cells in the multiple blood bag system may be passed from one of said bags to another through said filtering means comprising a housing containing a filtering medium capable of removing platelets and white cells from red cells, (b) treating the collected blood to separate a red blood cell concentrate therefrom;
(c) mixing the additive solution from the satellite bag with the red cell con-centrate; and (d) passing the mixture of red cell concentrate and additive solution through the filtering means from one bag to another bag.

22. A red cell concentrate prepared by the method of claim 5 or 21, characterized by being sub-stantially free of platelets and white cells, thus preventing formation of microaggregates therein and having a storage life of at least 21 days.