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Modern blood separators rapidly process many liters of donor blood and efficiently collect vast quantities of blood components from donors, who may be stimulated with potent recombinant hematopoietic growth factors or cytokines. Accordingly, the potential risks of modern multiple product/unit apheresis donations and recombinant growth factors is analyzed in this report. As is true for all medical procedures, risks are associated with apheresis donations. Risks of a "standard" apheresis donation, in which one unit of PLTs or plasma is collected, are comparable to the risks of whole blood donation. Risks of multiple unit apheresis donations, in which either vast quantities of a single blood component or multiple units of various components are collected, are incompletely understood, particularly, when donors are stimulated with recombinant hematopoietic growth factors to increase component yields. To minimize donor risks and to increase knowledge of multiple component apheresis donations, both short-term problems (e.g., donor reactions accompanying apheresis procedures and pre- vs. post-procedure changes in results of donor laboratory studies) and long-term problems (e.g., medical diagnoses/problems and abnormalities of donor blood counts and laboratory test results) should be monitored, ideally, by a repeat donor registry. When recombinant hematopoietic growth factors are prescribed, donors should give informed consent, and blood center professionals must be aware of 1) the effects of these drugs given at pharmacologic, rather than physiologic, doses; 2) the differences between the molecular structure of recombinant vs. natural/endogenous growth factors; 3) the fact that recombinant growth factors have both narrow/focused and broad biological activities; and 4) the probability that results of studies in sick/immunosuppressed patients may not be applicable to healthy/immunocompetent donors., (Copyright 2003 Wiley-Liss, Inc.)

A survey was completed by 25 medical directors at different institutions performing plateletpheresis. The practices of these 25 physicians were analyzed regarding the acceptance/rejection of plateletpheresis donors with a history of cardiac disease/surgery, seizures/epilepsy, cancer, or autoimmune diseases. Although available medical literature documents little risk of these disorders either to donors (i.e., donation reactions) or to transfusion recipients (i.e., disease transmission), up to 24% of medical directors outright reject some of these potential donors while others accept patients/donors with these illnesses, providing they meet certain medical/health criteria. Acceptance/rejection of individuals with medical disorders has relevance for the availability of the blood supply and blood product shortages because several million Americans, diagnosed with these illnesses, represent a sizable pool of potential blood and platelet donors., (Copyright 2002 Wiley-Liss, Inc.)

Background: A relatively young man (43 years old) was found to have a cataract after receiving prednisone before each of 35 neutrophil (PMN) donations over several years. Because corticosteroids are known to induce posterior subcapsular cataracts (PSCs), additional repeat PMN donors were examined ophthalmologically., Study Design and Methods: A controlled, blinded study was performed in 11 PMN donors who received prednisone with or without G-CSF before 17 to 46 leukapheresis donations over an average of 8.5 years. Control subjects were nine plateletpheresis donors of comparable age and donation experience, but they had never donated PMNs. A complete eye examination was performed by an ophthalmologist who was unaware of the donor's status (PMN vs. platelet)., Results: Mild PSCs were found in 36 percent (4/11) of PMN donors versus 0 of 9 platelet donors (p = 0.068). Five of the 22 PMN donor eyes involved versus 0 of the 18 platelet donor eyes involved exhibited PSCs (p = 0.040). Cortical and nuclear cataracts were found similarly in both groups of donors (82% PMN vs. 56% platelet donors; p = 0.217); this indicated that lifestyle factors, independent of corticosteroids, that might predispose to cataract formation probably were comparable., Conclusion: Corticosteroids given before PMN donations by leukapheresis might increase the risk of PSCs. Because of widespread renewed interest in PMN transfusions, this potential risk factor--if confirmed by studies of additional PMN donors--is of great international importance. Other centers are urged to perform ophthalmologic examinations on repeat PMN donors to clarify this issue.

Background: Preterm infants are among the most heavily transfused of patient groups, yet multiply transfused infants only rarely produce alloantibodies against RBC or WBC antigens. It is not known whether rates of alloimmunization might be increased by repeated exposure to RBCs and WBCs from the same donor, as in limited-donor-exposure programs, or whether infants might benefit from WBC-reduced RBC components as a means of diminishing the risk of possible alloimmunization., Study Design and Methods: Preterm infants (birth weight 0.6-1.3 kg) received prestorage WBC-reduced RBCs from dedicated donors, collected in AS-3 as a means of limiting donor exposures. Blood samples were collected serially from infants shortly after birth until either discharge or age 6 months and were studied for RBC and WBC antibodies-the latter with reactivity against either HLA class I or neutrophil-specific antigens., Results: Thirty preterm infants received 139 transfusions (mean, 4.6; median, 4 transfusions per infant), with 81 percent of transfusions obtained from one donor per infant. Eighty-four blood samples (mean, 2.7/infant) were studied, and no infant produced RBC antibodies. Twenty-seven percent of infants exhibited WBC antibodies, but only 13 percent actually produced WBC antibodies (passive maternal antibody excluded). Of the WBC antibodies produced by infants, three were against HLA class I and one was against neutrophil-specific antigens; none were linked to adverse effects., Conclusions: Because infants only rarely produce RBC antibodies, no changes in blood banking practices are necessary for limited-donor-exposure programs. Although the production of WBC antibodies by infants occurs, it seems to be uncommon; thus, the possible benefits, if any, of WBC reduction are uncertain, and further study is required before changes in practice can be justified.

Background: Most very low birth weight (<1.0 kg) infants receive RBC transfusions. Several reports have demonstrated that RBCs stored up to 42 days can be transfused safely in small volumes to preterm infants to decrease donor exposure without consequent hyperkalemia, acidosis, or other adverse effects. Although biologic parents are likely candidates as donors of blood for their neonates, it has been suggested that their blood may be serologically incompatible with that of their infants., Study Design and Methods: A two-arm randomized study was conducted to compare the feasibility and immediate safety of two single-donor programs for providing small-volume RBC transfusions to preterm infants: in one arm, infants received RBCs collected from unrelated donors and stored up to 42 days, and in the other arm, RBCs were collected from one of the biologic parents and stored identically. All infants received compatible RBCs that were WBC reduced before storage, stored in AS-3, and gamma-radiated. All transfusions were given uniformly as 15 mL per kg of RBCs transfused over 5 hours, during which time the infants were closely observed for clinical reactions. In addition, laboratory studies were performed shortly before and after each transfusion., Results: A total of 40 preterm infants received 120 RBC transfusions. Biologic parents experienced several donor eligibility problems. However, once enrolled as donors, they were able to supply all RBCs needed by their infants. Significant differences in rates of clinical transfusion reactions and laboratory abnormalities were rare and had no apparent clinical importance, regardless of whether RBCs were donated by biologic parents or unrelated donors., Conclusion: A single-donor system, in which AS-3 RBCs were collected either from unrelated blood donors or from biologic parents and then stored up to 42 days, was able to supply small-volume RBC transfusions needed by individual preterm infants without immediate, adverse effects. Because the risk of infectious disease transmission is likely reduced by limiting donor exposure, it is logical to conclude that single-donor programs should increase transfusion safety and that biologic parents should be considered as blood donors for their infants.

Background: Very-low-birthweight infants have typically been given fresh red cells (RBCs), a practice in which aliquots of RBCs for several infants were issued each day from a single unit. Recently, to limit donor exposures, large volumes of RBCs are reserved for the long-term transfusion support of individual infants., Study Design and Methods: Medical records were examined retrospectively to assess the costs of a limited-donor program for providing RBC transfusions to very-low-birthweight infants. Costs of multiple- and limited-donor programs were compared by using two samples of 30 consecutive infants treated at The University of Iowa Hospitals and Clinics in 1993 and 1997. Effectiveness was evaluated with respect to the number of donor exposures per infant., Results: The cost, in 1997 dollars, of preparing each small-volume transfusion in the multiple-donor program was $27.86 per transfusion, while that in the limited-donor program was $34.83. This difference was largely attributable to use of white cell reduction in association with the limited-donor program in 1997. Eliminating the costs associated with white cell reduction rendered the costs of the limited- and multiple-donor transfusions comparable. The limited-donor program had donor exposures of 2.0 per infant, while the multiple-donor program had 3.6 exposures per infant (p<0.002)., Conclusion: The limited-donor blood program reduces donor exposure without adversely affecting costs.

Although widely used, the reliability of fingerstick platelet counts for determining donor eligibility and for use with plateletpheresis predict yield programs has not been established. We compared platelet counts obtained from fingerstick vs. venous samples in several aspects of apheresis platelet collection. Analysis of 25 paired fingerstick and venous predonation samples demonstrated a poor correlation between platelet counts (r2 = .43), with fingerstick counts having a 20% lower mean value (P < .05). The effect of using fingerstick vs. venous predonation platelet counts with apheresis instrument predict yield calculations to obtain target yields was determined. Mean yields collected using fingerstick/predict yield were 12% (Fenwal CS3000 PLUS) and 15% (Haemonetics MCS+) higher than venous/predict yield units (P < .05). The coefficients of variation (CV) of fingerstick/predict yield and venous/predict yield collections were comparable (15% vs. 14% [CS3000] and 23% vs. 21% [MCS+], respectively), indicating that possible differences in accuracy between fingerstick and venous platelet counts had little effect on the variability of predict yield collections. A retrospective analysis of the CV of 100 fingerstick/predict yield units vs. 100 units collected by processing standard volumes showed no difference: 22% vs. 20% (F = 0.99, CS3000), and 22% vs. 24% (F = 0.89, MCS+), respectively. We conclude that fingerstick platelet counts are systematically lower and correlate poorly with venous counts, though their use seldom results in false disqualification of donors. We also conclude that fingerstick count/predict yield collections do not produce more consistent yields of platelets than standard volume collections.

Background: Despite recent optimism about the use of erythropoietin therapy to treat the anemia of prematurity, very-low-birth-weight infants who are severely ill receive multiple red cell (RBC) transfusions. Many physicians transfuse relatively fresh RBCs to newborn infants, exposing them to multiple donors and possibly increasing their risk of acquiring transfusion-transmitted infections., Study Design and Methods: A randomized, single-blind clinical trial was conducted to determine, as the primary endpoint, whether RBCs collected from one dedicated donor and stored for < or = 42 days in AS-1 storage media could safely supply all small-volume RBC transfusions (15 mL/kg/dose) needed by very-low-birth-weight infants (0.6-1.3 kg) during the first 84 days of life. Secondary endpoints were the assessment of the possible adverse clinical and biochemical effects of transfusing AS-1 RBCs stored for < or = 42 days. Control infants received identical nursery care, except they received fresh RBCs stored < or = 7 days in CPDA-1., Results: Infants transfused with AS-1 RBCs were exposed to a mean of 1.6 donors,-compared with an exposure to 3.7 donors for infants given CPDA-1 RBCs (p < 0.05). Neither clinical transfusion reactions nor the results of multiple laboratory tests were significantly different in infants who received slow transfusions (15 mL/kg) of AS-1 RBCs stored for < or = 42 days and in infants who received the same volume of CPDA-1 RBCs stored < or = 7 days., Conclusion: AS-1 RBCs, usually from only one dedicated donor, can safely supply all RBCs needed by most very-low-birth-weight infants-a practice that decreases donor exposure and likely increases transfusion safety.

For over 20 years blood components have been collected from normal donors by automated hemapheresis. Cell separators have become increasingly sophisticated, and relatively pure component "concentrates" can be obtained quite safely. Cytapheresis donors are monitored carefully, and serious reactions are very rare. In contrast, therapeutic apheresis procedures may be technically demanding and frequently are performed on very sick patients. Large volumes of blood are rapidly removed from the patient, anticoagulated, and separated into components by the automated cell separator. The blood component containing the pathogenetic factor (e.g., plasma containing an antibody) is retained outside of the body, and the remaining components (e.g., red cells, white cells, and platelets) plus the replacement fluid are reinfused. Complications can occur in normal cytapheresis donors because of the technical challenges of the procedure (e.g., extracorporeal circuit to be filled, use of citrate anticoagulant, need for large bore intravascular access, and rapid blood flow rates). All of these factors apply also to therapeutic patients plus the additional requirement for replacement fluids, and the clinical features of the underlying illness for which each patient is being treated. Fortunately, even with therapeutic patients, most complications are of modest severity and are easily managed with only temporary slowing or interruption of the hemapheresis procedure.

Our practice is to defer donors with blood platelet (PLT) counts of < 180 x 10(9)/L because PLT yields are low, when compared to PLT units collected from donors with higher counts. In an attempt to minimize deferral, we determined whether 33 donors, who repeatedly demonstrated low-normal PLT counts (150-180 x 10(9)/L) on multiple occasions during the prestudy period. might safely donate satisfactory apheresis PLT units simply by extending the apheresis collection time by 20 min (men) and 40 min (women). Repeat plateletpheresis procedures were scheduled at > or = 28-day intervals. The mean PLT yield (N = 92) was 5.8 x 10(11) with 97% of units containing > or = 4.0 x 10(11) PLTs. Although donors entered the study only after they had repeatedly exhibited predonation PLT counts of < 180 x 10(9)/L, PLT counts were not always below this level at the time of study collections. However, analyzing only donations with true predonation PLT counts of < 180 x 10(9)/L (N = 35), the mean PLT yield was excellent-5.4 x 10(11) with 97% of units containing > or = 4.0 x 10(11) PLTs. The average fall in donor blood PLT counts (pre-vs. postdonation) was 36%, with only ten of 99 postdonation counts being < 100 x 10(9)/L; the lowest was 69 x 10(9)/L. Thus, extending the apheresis collection time permitted donors who in the past were routinely deferred because of low PLT counts to safely donate satisfactory PLT units.

To determine whether the physician or patient had initiated the discussion regarding preoperative autologous blood donation (PABD) and to assess the relative importance of the physician's recommendation in patients' decision to donate, responses were obtained from 254 of 409 patients (62%) who had donated preoperatively during the 3 study months. Nearly all (96%) strongly agreed they would donate again for themselves and nearly all (94%) strongly agreed they would recommend PABD to others. Patients initiated the discussion about PABD 23% of the time, while 71% indicated strong surgeon input. The remaining respondents said their surgeon had "mentioned it, but said it was up to me." The importance of avoiding transfusion reactions was rated significantly greater among those whose surgeons had initiated the discussion, as was the relative weight of the surgeon's recommendation. The desire to alleviate the blood shortage was rated much less important among patients who had initiated the discussion themselves.

Background: Historically, paid blood donors were found to transmit hepatitis at higher rates than volunteers. In those older studies, paid donors frequently were recruited from prisons or slum areas--a finding consistent with the belief that monetary payment in itself did not necessarily lead to the high-risk status of commercial blood. Instead, it was the population base from which the donors were recruited that was important., Study Design and Methods: Today, cytapheresis donors are in great demand. Because payment is one incentive that might entice donors to undertake the increased commitment of repeated cytapheresis donation, the results were studied of infectious disease history and laboratory testing performed concurrently in 917 volunteer whole-blood donors and 1240 paid cytapheresis donors, who were enrolled in distinct programs at the DeGowin Blood Center from October 7, 1987, through November 30, 1990., Results: When first, repeat, and overall donations made by these donors were evaluated separately, paid cytapheresis donors were found to exhibit no increase in infectious disease history or test results beyond those of volunteer whole-blood donors., Conclusion: Thus, paid cytapheresis donors, when managed within a formal program, should not necessarily be presumed to be more dangerous than volunteers, from an infectious disease aspect. However, definitive proof of safety (comparison of transfusion-transmitted infection rates in two groups of patients receiving blood components exclusively from either paid cytapheresis or volunteer donors) was not pursued by long-term follow-up studies.

Background: To avoid the need, in serial apheresis donors, either to delay plateletpheresis until a predonation platelet count is completed or to obtain a postdonation count after each procedure, a statistical model has been developed to predict the postdonation platelet count from the donor predonation platelet count, weight, and hematocrit., Study Design and Methods: Predonation and postdonation platelet counts were measured in two groups of approximately 100 consecutive donors (Group A to test the model and Group B to validate it), and the postdonation counts were calculated with the model. Using stepwise multiple linear regression from donor data, estimated postdonation platelet counts were found to be comparable to the postdonation platelet counts actually measured., Results: Estimated postdonation platelet counts x 10(9) per L (mean +/- SD) for each group, respectively, were Group A, 195 +/- 35, versus actual platelet counts of 195 +/- 39 (p = 0.43), and Group B, 183 +/- 36, versus actual platelet counts of 189 +/- 34 (p = 0.14). Sensitivity and specificity, respectively, were Group A, 57 and 99 percent and Group B, 62 and 99 percent., Conclusion: For most serial apheresis donors, application of this predictor model should preclude the need to obtain an extra postdonation platelet count.

All blood components collected by automated cytapheresis contain donor leukocytes. The possibility that repeated cytapheresis donation might lead to clinically important leukocyte losses and immunodeficiency has been a long-standing concern. Although convincing data do not exist to substantiate this concern, it is common practice to limit the number of annual cytapheresis donations per donor and to monitor donors for developing lymphocytopenia. Clinically significant immunodeficiency is unlikely to occur unless donors lose > 1 x 10(11) lymphocytes within a few weeks period of time or unless donor lymphocyte counts fall persistently to < 0.5 x 10(9)/L. Each plateletpheresis procedure, when performed using modern cell separators that are designed to produce a relatively "pure" platelet concentrate, leads to the loss of 1.0 x 10(6) to 5.0 x 10(7) leukocytes. Thus, automated plateletpheresis as performed in 1994 is extremely unlikely to cause clinically significant lymphocyte depletion and consequent immunodeficiency.

To determine the amount of blood lost, the number of transfusions, and the effectiveness of preoperative autologous blood donation in radical prostatectomy, 163 patients' records from 1987 to 1991 were reviewed at four university hospitals and three community hospitals. Calculated red cell volume lost was 1003 +/- 535 mL (mean +/- SD), which corresponds to 44 +/- 18 percent (mean +/- SD) of total red cell volume. Preoperative donation of blood for autologous use reduced the rate of transfusion of allogeneic blood from 66 to 20 percent (p < 0.001). Of the patients who donated 1 to 2 units, 32 percent received allogeneic blood; 14 percent of those who donated 3 units received allogeneic blood. Donation of 4 units reduced the allogeneic transfusion rate to 11 percent. However, as the number of units donated increased (1-3 units), the units not transfused also increased (0-21%). Ninety-one (56%) of 163 patients donated fewer than 3 units. Autologous blood donation is effective in minimizing the transfusion of allogeneic blood to radical prostatectomy patients, but many patients do not donate enough blood (< 3 units). The donation of 3 units of blood for autologous use is recommended for patients who undergo radical prostatectomy.

Preoperative autologous blood donation for elective surgery patients at university hospitals was underused in the past. More recently, national educational efforts have been made. To test the impact of local surgeon interviews and education, in 1988 the same local educational program was instituted at three university hospitals; three community hospitals were used as controls. Donation by appropriate patients of interviewed surgeons (elective surgery, crossmatch recommended, no contraindications to donation) increased from 24 percent (44/180) to 40 percent (88/222) (p = 0.002) and 15 percent (21/143) to 32 percent (41/127) (p = 0.001) at two university hospitals where the investigator-educators were on site, but not at the three community hospitals. Between 1987 and 1989, donation rates at all six hospitals remained low among patients for whom autologous donation was (probably) less appropriate. Donation rates for type and screen procedures were 3.0 percent (131/4587) in 1987 and 3.0 percent (199/6606) in 1989 (p = 0.67). Donation rates for "no blood order" procedures were 0.2 percent (15/9429) in 1987 and 0.1 percent (9/11,239) in 1989 (p = 0.14). It can be concluded that appropriate autologous blood donations increased at university hospitals where surgeons were individually interviewed and educated by an investigator on site. However, despite this increase, apparently eligible elective surgery patients in 1989 still failed to donate. This situation deserves additional investigation.

Donor exposure can be strikingly reduced for patients with classical hemophilia A and von Willebrand's disease when large volumes of potent cryoprecipitated AHF are prepared from donors following DDAVP (1-deamino-8-D-arginine vasopressin) stimulation and automated plasmapheresis--a procedure called "plasma exchange donation." Although this procedure has been reported to be relatively safe for donors, data are limited. Accordingly, we studied 20 donors during 48 procedures using DDAVP (0.3 micrograms/kg IV) followed by 2-3 L plasma collection. Replacement fluid for each initial plasma exchange donation was plasma protein fraction; autologous cryoprecipitate-poor plasma was used for subsequent procedures. Mild reactions, particularly facial flushing, were noted in all 48 procedures. No procedure was discontinued, but four were modified due to either an increased pulse rate (> or = 20/min from baseline) or a fall in systolic or diastolic blood pressure (> or = 20 mm Hg from baseline). No donor was deferred or withdrew from the program. Based on our modest experience, DDAVP stimulated plasma exchange donation appears to be a safe and effective method for collecting large quantities of plasma from which potent cryoprecipitated AHF can be prepared.

Premature neonates require blood transfusions, and biological parents may wish to be directed donors. Biological mothers pose a potential danger because their plasma may contain antibodies that will react with blood cell antigens inherited by the infant from the father. We studied 25 healthy, pregnant women at the time of delivery for the presence of antibodies against red blood cell, leukocyte and platelet antigens. Mothers known to have red cell antibodies earlier in pregnancy were excluded, and no new red cell antibodies appeared at delivery. Antileukocyte and antiplatelet antibodies were found in 16 and 12% of mothers, respectively. Because these antibodies have the potential to cause adverse reactions when transfused passively, we suggest that either biological mothers not provide blood components containing plasma for their neonates or that maternal red cells and platelets be given as washed products.

A blood sampling pack is available on closed system apheresis kits for the Fenwal CS3000 blood cell separator to facilitate same day donor testing while maintaining the closed system. Conceivably, the accuracy of complete blood counts (CBC) performed using pack samples might be compromised by clotting in the pack, by adherence of blood cells to the inner surface of the pack, or by dilution of the sample with priming fluid--should it inadvertently contaminate the pack. We studied paired blood samples collected simultaneously via the pack and a separate venipuncture in 17 donors. When collected properly, CBC values from pack and vein were nearly identical. Even when purposely contaminated with saline, pack values were lowered only slightly. Thus, the inline pack permits accurate sampling of donor blood for CBC while maintaining a closed system.

Studies of risk factors associated with reactions among autologous blood donors have been limited. Therefore, 2091 autologous and 4737 homologous donations were examined. Donors at greatest risk for reaction were autologous donors who had reactions at first donation; among 45 who made repeat donations for the same surgery, 17 (38%) had repeat reactions. The group least likely to experience reactions were the autologous donors greater than or equal to 66 years old; they experienced a 1.9 greater than or equal to percent (6/310) incidence of reactions. More reactions were seen in both autologous and homologous donors in the categories of first-time donor, female gender, decreasing age, and lower weight. Multiple logistic regression analysis showed that all of these variables were independent predictors of donor reaction, with first-time donation (odds ratio, 2.4) and female gender (odds ratio, 1.9) being the strongest predictors of reaction. Donor room personnel should be alerted that autologous donors who react at first donation are very likely to react at subsequent donations. Contrary to common concern, elderly autologous donors are least likely to have reactions.

Modern techniques of mechanical hemapheresis have made it possible to selectively remove vast quantities of lymphocytes and plasma immunoglobulins, and the concentration of these substances in donor blood can fall below the normal range. It is feared that this may lead to immunosuppression; a condition associated in some clinical settings with infections, malignancy and autoimmune diseases. Using primary immunodeficiency diseases and induced immunodeficiency states (for example, therapeutic lymphocytapheresis, chronic thoracic duct drainage and intestinal lymphangiectasia) as models to judge competency of the immune system, it can be predicted that body defense mechanisms can become defective when serum IgG levels are less than 200 mg/dl or the blood lymphocyte count is less than 1000/microliter. However, impaired immunologic function can occur in the presence of normal quantities of these substances in the blood stream; conditions that may be related either to imbalances of immune regulatory factors or to qualitative (rather than quantitative) abnormalities of the immune system. A number of investigators have documented the losses of lymphocytes and plasma immunoglobulins incurred by donors experiencing mechanical hemapheresis. In addition, both the immediate and long-term decreases in the concentration of these substances in donor blood have been reported. In summary, the immediate decreases in blood lymphocyte counts and serum immunoglobulin concentrations are of slight to moderate degree and are without known adverse effects. Less information is available regarding long-term alterations of the immune system, and little data have been collected from prospective studies in which large numbers of donors have been thoroughly evaluated by modern techniques. In general, results of many laboratory studies have been altered. However, these abnormalities have been transient for the most part, and it has been difficult to document clinically significant adverse effects. Thus, the quantities of blood lymphocytes and plasma immunoglobulins that can be removed from healthy donors without causing significant immediate or long-term harm is unknown. Bearing these limitations in mind, the following recommendations are suggested regarding the frequency of repeated mechanical plasma-and-cytapheresis. 1) The usual requirements for whole blood donation must be met if the frequency of mechanical hemapheresis does not exceed once every eight weeks.(ABSTRACT TRUNCATED AT 400 WORDS)

Thirteen HLA-identical bone marrow donors served as the sole source of daily granulocyte transfusions for respective marrow recipients during the period of severe neutropenia between transplantation and engraftment. They experienced 12 to 29 (median, 17) daily, continuous flow centrifugation leukapheresis procedures using hydroxyethyl starch, but no corticosteroids, with little serious difficulty. No immediate clinical reactions occurred in 90 percent of 228 procedures. Mild citrate reactions were noted in 9 percent, and only two procedures (0.8%) were discontinued due to severe reactions. Ten donors (77%) answered a questionnaire mailed weeks later, and six reported transient, late clinical adverse effects. Five had moderate dermatologic problems; one had minimal hypertension requiring no therapy. Donors were monitored daily for laboratory abnormalities while donating granulocytes. Hemoglobin concentration and platelet counts remained stable (autologous red cell transfusions had been given). Blood leukocyte counts gradually fell (p less than 0.05), particularly after 10 or more daily granulocyte donations, and this fall was associated with a decrease of about 33 percent in leukocyte yields. No attempts were made to improve yields by giving higher doses of hydroxyethyl starch or by corticosteroid stimulation. With primary emphasis on donor safety, it seems feasible for a few compatible donors to provide prolonged granulocyte transfusion support for designated patients. However, diminishing leukocyte yields may result from intensive, repeated leukapheresis.