B L O O D D O N O R S A N D C O L L E C T I O N

Plateletpheresis in 90- to 110-pound donors using the CS-3000 blood cell separator

D.H. Buchholz, 1.E. Squires, J.H. Herman, A.T. Ng, 1.K Anderson, and S.L. Hedberg

BACKGROUND: Increases in the use of single-donor apheresis components have increased the need for platelet donors. In the United States, persons must weigh 110 pounds or more to qualify as blood donors, and the same weight limitation has been placed on apheresis donors. Because automated plateletpheresis with some instruments differs considerably from whole- blood donation with respect to the volume of blood re- moved from the donor, the feasibility of using persons weighing between 90 and 110 pounds as platelet donors was evaluated by the use of the CS-3000 blood cell separator. STUDY DESIGN AND METHODS: The study was per- formed using female subjects who met all usual donor requirements except for minimum weight. The standard platelet collection procedure of the instrument was used, except that the blood processing rate was manually se- lected so as to optimize the blood withdrawal and return rate in individuals. Vital signs were recorded before and after donation as were signs or symptoms of any type of donor reaction. RESULTS: Twenty-six of 28 women completed the do- nation procedure; in two instances, collection was termi- nated prematurely because of an inability to maintain adequate venous access. An average of 4.5 x 10” platelets were collected during a mean donation time of 110 minutes. All donors tolerated the procedure well, and no serious adverse reactions were seen. Because of the administration of priming solution and anticoagu- lant during apheresis, there was a net positive fluid bal- ance following the procedure, in spite of the removal of approximately 220 mL of platelet concentrate. CONCLUSION: These preliminary studies suggest that 90- to 1 10-pound persons may serve as plateletpheresis donors. Additional studies are needed to more fully document the safety and efficacy of this approach. The use of lower-weight donors may significantly increase the number of persons available to provide single-donor

~ platelet components.

ecent increases in the use of single-donor plate- lets have resulted in a need for greater numbers of apheresis donors. Currently, the minimum weight for persons accepted for routine blood do-

nation in the United States is 110 pounds (50 kg).’ A large number of persons who weigh between 90 and 110 pounds are deferred despite their willingness to be volunteer blood donors. If platelet collection could be performed with some of these persons as donors, the ability to provide single-do- nor apheresis platelet components might be significantly enhanced.

Limitation on the use of smaller donors has been based upon considerations of donor blood volume (typically, 70- 75 mLlkg) and of the volume removed during whole-blood donation. Under current worst-case conditions (525 mL of blood removed from a 110-lb donor), approximately 15 per- cent of the blood volume is removed during the collection process. Because this loss is well tolerated by most donors, we elected to evaluate the removal of 200- to 250-mL vol- umes of platelet concentrate from the blood of 90- to 110- pound donors. Under these conditions, the volume of the platelet component removed did not exceed approximately 8 percent of the donor’s estimated blood volume.

MATERIALS AND METHODS All donors who participated in the study were in good health and met current Food and Drug Administration and Ameri- can Association of Blood Banks guidelines for blood dona- tion, with the exception of the 110-pound minimum weight. Informed consent was obtained prior to study participation. All 28 donors were female, as are most whole-blood donors deferred for weight. Weight was recorded on the basis of

From the Fenwal Division, Bnxter Biotech, Deerfield, Illinois; Ameri- c a ~ ~ Red Cross Blood Services, Carolinas Region, Charlotte, North Carolina; American Red Cross Blood Services, Penn Jersey Region, Philadelphia, Pennsylvania; and American Red Cross Blood Services, Central Ohio Region, Columlws, Ohio.

December 21,1996, and accepted January3,1997. Received for publication December 21, 1995; revision received

TRANSFUSION 1997;37:715-718.

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BUCHHOU ET AL.

information provided by the donor, and platelet counts were not required as a prerequisite to study participation.

Collection procedures were performed using one of two blood cell separators (CS-3000 with the platelet separation chamber, or CS-3000 Plus with the TNX-6 separation cham- ber; both: Fenwal Division, Baxter Biotech, Deerfield, IL). Closed-system apheresis kits (Code 4R2230) were used for all collections. The blood cell separators were used accord- ing to the manufacturer's recommendations (Procedure 1 [platelet collectionl) with the exception that the procedure's default whole blood withdrawal rate, 50 mL per minute, was not used; instead, we selected as the blood-processing rate the greatest rate at which blood could be successfully drawn from the donor's vein. As is customary, the blood cell sepa- rator was primed with approximately 360 mL of 0.9-percent sodium chloride solution before the start of each procedure; this priming solution was administered to the donor at the start of the donation. In addition, each donor received ap- proximately 150 mL of saline at the completion of the pro- cedure during automated return of red cells. Hematocrit and hemoglobin and white cell and platelet counts were deter- mined before and after donation.Vita1 signs were also moni- tored as part of each apheresis procedure, and the donor's subjective assessment of symptoms of citrate toxicity or other untoward effects was recorded. A paired t test was used to assess predonation and postdonation changes in vital signs.

RESULTS Twenty-six plateletpheresis procedures were completed, and two were discontinued because of inadequate venous ac- cess. Donor weight distribution was as follows: 3 donors weighed between 90 and 95 pounds, 8 weighed 96 to 100 pounds, 5 weighed 101 to 105 pounds, and the remaining 10 weighed 106 to 109 pounds. The weights of the donors in- volved in incomplete procedures were 101 and 105 pounds. From 3.2 to 5.2 L of blood were processed during a mean time of 110 minutes (average blood flow rate, 43 mllmin). Platelet yield ranged from 2.3 to 7.2 x 10" and averaged 4.5 x 10" per collection. Ninety-two percent of collections re- sulted in platelet yields of greater than 3.0 x 10"; further information is provided in Table 1.

TABLE 1. Plateletpheresis in 90- to 11 0-lb donors using the CS-3000

Mean SD Ranoe Procedure time (min) 110 18 70-1 57 Blood flow rate (mumin) 43 4 32-55 Blood:ACD ratio 11:l NA' 10:1-15:1 Volume processed (mL) 4194 424 3200-5002 Component volume (mL) 221 18 21 4-309 Platelet yield (x 10") 4.5 1.1 2.3-7.2

* Not applicable.

TABLE 2. Changes in vital signs associated with DlateletDheresis in 90- to 110-lb donors

Mean

Systolic blood pressure (torr) Before donation 1 02

After donation 96

Before donation 65

After donation 62

Before donation 80

After donation 78

Diastolic blood pressure (torr)

Pulse

pvalue' SD Range

11 86-122 0.007

9 84-120

9 50-86 0.079

6 50-80

10 60-100 0.38

13 54-104

p value recorded for the change in each vital sign before and after donation.

No medically significant changes in donor blood pres- sure, pulse, or temperature were associated with the dona- tion procedure. Donor blood pressure recorded before and after donation averaged 102/65 and 96/62 torr, respectively. This change was significant for systolic (p = 0.007) but not diastolic (p = 0.079) pressure. Donor pulse remained in the normal range, with a mean f SD value of 80 ? 10 before the procedure and 78 f 13 after donation (p = 0.38). Changes in donor vital signs are summarized in Table 2.

No serious untoward effects were associated with apheresis in these low-weight donors. Six persons (21%) experienced transient symptoms consistent with hypocal- cemia (5, perioral tingling; 1, leg muscle cramps). These ci- trate reactions were mild and were easily controlled by tem- porary slowing of the rate of blood processing and/or by providing oral calcium carbonate. One 98-pound donor experienced slight dizziness 10 to 15 minutes after donation; this symptom rapidly resolved without treatment.

As expected, platelet counts were lower after donation (mean f SD, 158 k 34 x 103/pL) than before donation (270 f 73 x 103/pL). Donor hematocrit also declined from 40 to 36 percent immediately after donation, because of hemodilu- tion induced by fluids administered during the collection procedure. Changes in donor hematologic measures are shown in Table 3.

DISCUSSION The weight limitation of 110 pounds imposed on blood do- nors in the United States has been applied to plateletphere- sis collections without apparent regard for fundamental dif- ferences between the collection of whole blood and the procurement of single-donor apheresis platelets. When whole blood is collected, the donor experiences a sudden, fKed (usually450-470 mL) loss ofblood volume that is slowly corrected only by normal physiologic mechanisms. In con- trast, during plateletpheresis using the CS-3000, the donor

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LOW-WEIGHT DONORS FOR PLATELETPHERESIS

TABLE 3. Comparison of hematologic changes in 90- to 110-lb and >110-lb unselected

olateletoheresis donors Mean SD Ranoe

90- to 11 0-lb donors (n = 26) Hematocrit (“A)

Before donation 40 After donation 36

Before donation 6.6 After donation 6.1

Before donation 270 After donation 158

White cell count (x 103/pL)

Platelet count (x 103/pL)

>110-lb unselected donors Hematocrit (%) (n = 107)

Before donation 43 After donation 41

White cell count (x 103/pL) (n = 74) Before donation 6.2 After donation 6.4

Platelet count (x 103/pL) (n = 106) Before donation 255 After donation 207

3 3

1.8 1.7

73 34

4 4

1.2 1.4

54 54

37-46 33-43

3.1-9.5 2.8-8.4

132-403 96-228

remains in positive fluid balance throughout the course of the donation, because of the administration of priming so- lution, the use of anticoagulant, and the use of fluid to re- turn donor cells at the completion of the procedure (Table 4). Because of these factors, persons donating platelets via this instrument typically gain volume, rather than lose it, as a result of apheresis.

Contributing to the possibility of using of low-weight donors is the fact that the platelet component volume in the CS-3000 is determined by the size of the collection cham- ber (approx. 200 mL) and is thus fmed; the component vol- ume remains the same irrespective of the number of plate- lets collected. This limited plasma volume loss and the positive net fluid balance help to make plateletpheresis fea- sible in 90- to 110-pound donors. That hypovolemia was not a significant problem in this study was confirmed by the ab- sence of symptoms usually associated with significant fluid loss during donation. Only one first-time donor was noted to experience any symptom (dizziness) that might be related to intravascular volume depletion.This 98-pound donor was

noted to have a predonation pulse of 76 and blood pressure of 100160 torr and postdonation values of 70 and 90160 torr, respectively.

These donation procedures were well-tolerated, al- though some symptoms associated with the administration of citrate-containing anticoagulant were seen. These reac- tions were mild, but it must be kept in mind that blood-pro- cessing rates were somewhat slower (mean, 43 mL1min) than those routinely used in larger donors. Although, in some instances, the flow rate was limited by donor intoler- ance for citrate, in most donations, it was venous access rather than citrate toxicity that determined the blood-pro- cessing rate selected. While no moderate or severe manifes- tations of donor hypocalcemia were noted during the study, it should be kept in mind that anticoagulant toxicity may occur more frequently in 90- to 110-pound donors if usual blood processing rates (50-70 rnllmin) are used, because body size is directly related to the rate at which administered citrate is metabolized.

In spite of reduced blood-processing rates, it is clear that a therapeutic dose of platelets can be routinely collected from 90- to 1 10-pound donors in a reasonable (albeit longer) donation time. During this study, an average of 4.5 x 10” platelets was harvested in 110 f 18 minutes. That 92 percent of donations exceeded yields of 3.0 x 10” serves to indicate the potential of low-weight donors to be a useful source of platelets. Selection of low-weight donors based upon predonation platelet count may further enhance platelet yield. Average postdonation platelet counts in this study (158,0001pL) were lower than those seen in donors weigh- ing more than 110 pounds (207,0001pL) in an earlier studyZ using the same instrument (Table 3). This is not especially surprising, as the total number of platelets present in the body is likely to be less in smaller donors, and as above, post- donation platelet count decreases can be minimized by se- lecting donors with higher predonation platelet counts. Because of the greater percentage of loss, we would not rec- ommend routine use of low-weight donors in such proce- dures as double-dose platelet collection.

These studies have demonstrated the potential feasibil- ity of using 90- to 110-pound donors as a source of single- donor platelets. Although only women were studied, there

is no inherent reason that these results should not be equally applicable to

TABLE 4. Donor volume considerations during plateletpheresis with the CS-3000

Time Blood volume Volume Cumulative net

removed returned fluid balance

Start of donation 360 mL 360 mL 0 mL (whole blood) (saline prime solution)

During donation Volume of blood Equal to that removed +275 to +400 mL processed (plus 275-400 mL (anticoagulant)

of anticoagulant) After donation 220 mL 150 mL (saline, plus +205 to +330 mL

(platelet concentrate) residual red cells)

men in the same weight range. Use of low-weight donors clearly requires further evaluation for more complete documentation of the safety and suit- ability of the procedure; however, these preliminary studies suggest that the use of 90- to 110-pound persons may be a way to increase the availabil- ity of donors as the demand for single- donor apheresis platelet components increases.

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REFERENCES 1. Klein HG, ed. Standards for blood banks and transfusion ser-

vices. 17th ed. Bethesda: American Association ofBlood Banks, 1996. Buchholz DH, Porten JH, Menitove JE, et al. Description and use of the CS-3000 blood cell separator for single-donor plate- let collection. Transfusion 198323: 190-6.

2.

AUTHORS

D.H. Buchholz, MD, Vice President, Medical and Scientific Affairs, Fenwal Division, Baxter Biotech, Route 120 and Wilson Road, Round Lake, IL60073. [Reprint requests]

Jerry E. Squires, MD, Principal Officer, American Red Cross Blood Services, Carolinas Region, Charlotte, NC.

Jay H. Herman, MD, Associate Professor of Pathology and Lah- oratory Medicine, Temple University School of Medicine; Medical Director, American Red Cross Blood Services, Penn-Jersey Region; and Director, Transfusion Medicine Hematology Laboratories, Christophine Hospital for Children, Philadelphia, PA.

AmbroseT. Ng, MD, MB, BS, Principal Officer, American Red Cross Blood Services, Central Ohio Region, Columbus, OH.

Joy K. Anderson, PhD, Director, Global Marketing, Fenwal Di- vision, Baxter Biotech, Round Lake, IL.

Sandra L. Hedberg, BS, Senior Clinical Research Associate, Fenwal Division, Baxter Biotech; current address: Manager, Regula- tory Affairs, Information Data Management, Rosemont, IL.

pany that makes the CS-3000. Disclosure: One of the authors (SLH) owns stock in the com-

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