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Certain infectious organisms, including cytomegalovirus, are associated 'exclusively' with blood leukocytes (WBC), and their transmission by transfusion is strikingly diminished by marked WBC-reduction of cellular blood components. Based on several reports of WBC-reduction, it is clear that the risk of CMV is nearly eliminated by consistently removing WBC to a level < 1-5 x 10(6) WBCs/unit (< or = 1 x 10(6) preferred in Europe; < or = 5 x 10(6) in the United States). Alternatively, the rate of CMV infections is reduced by transfusing blood components collected from donors negative for CMV antibody. However, neither technique is perfect, with a failure rate of 1-4%. Although WBC-reduction is favored by many experts, practitioners must choose the method that they believe to be most efficacious--being mindful that data do not exist to establish additive protection by combining WBC-reduction and transfusion of blood components collected from antibody negative donors.

Hematopoietic stem cells, collected by leukapheresis from peripheral blood, can be used as an alternative to autologous bone marrow transplantation following high-dose chemotherapy as treatment of several malignancies. We compared the ability of the Cobe Spectra and the Fenwal CS3000 to collect peripheral blood mononuclear cells (MNC) for autologous peripheral blood stem cell transplantation. Ten patients experienced repeated leukapheresis (10 L blood processed per procedure) using both instruments. Procedures were alternated between the two until a total of 7 x 10(8) MNC/kg was collected. Data from 61 Spectra and 50 CS3000 collections were analyzed. The yield (mean per procedure) of nucleated cells (NC) and MNC was higher (P less than .005) with the Spectra (0.77 x 10(10) NC and 0.54 x 10(10) MNC) than with the CS3000 (0.59 x 10(10) NC and 0.40 x 10(10) MNC). However, colony forming units (CFU-GM) were not different (P greater than .05) for Spectra (0.92 x 10(4)) and Fenwal (0.65 x 10(4) collections. Platelet contamination was lower (P less than .001) with the Spectra (2.2 x 10(11)) than the CS3000 (5.0 x 10(11)). This correlated with a higher patient blood platelet count immediately following Spectra collections (117 x 10(9)/L) versus the CS3000 (86 x 10(9)/L). Using the methods described, the Spectra product contained greater yields of NC and MNC with less platelet contamination than did the CS3000.

Techniques for collecting granulocytes for transfusion either to neutropenic patients or to neonates are described. Currently, the best granulocyte concentrates are prepared using continuous-flow centrifugation leukapheresis of steroid-stimulated donors in the presence of pentastarch. Donor reactions are mild and are similar to those expected with automated plateletpheresis.

Effects of intermittent-flow centrifugation leukapheresis (IFCL) on leukocyte counts in donor blood have not been reported. Accordingly, total and differential white blood cell counts were preformed serially during IFCL. A significant decrease (p less than 0.05) in all types of leukocytes occurred in donor blood early in pheresis and was probably the consequence of hemodilution. Concentrations of most leukocyte types remained decreased throughout the procedure, and a rebound leukocytosis was not detected. Thus, leukocyte kinetics in donor blood during IFCL differ from those reported for filtration leukapheresis in which the pattern of selective neutropenia followed by rebound neutrophilia has been ascribed to complement activation.

The properties of neutrophils, collected by discontinuous-flow centrifugation leukapheresis in the presence of hydroxyethyl starch and citrate were studied in an attempt to insure that cells harvested in this fashion are suitable for transfusion. Neutrophils obtained from leukocyte units prepared for transfusion by leukapheresis were found to perform similarly to those isolated from the venous blood of corresponding donors prior to the pheresis procedures when assessed by morphology, viability, hexose monophosphate shunt activity, superoxide anion generation, nitroblue tetrazolium dye reduction, chemiluminescence, adherence to nylon fibers, random mobility, chemotaxis and staphylococcal killing. The results compared favorably with values previously established for healthy control subjects. Neutrophils prepared in this manner should serve as a satisfactory blood component.

Immunologic studies were performed immediately before and after leukapheresis in five subjects undergoing four granulocyte donations (separated by 3- to 4-week intervals) using continuous-flow centrifugation leukapheresis with a rapidly excreted investigational analog of hydroxyethyl starch. Postleukapheresis donor blood lymphocyte counts and serum immunoglobulin levels decreased transiently, but significantly, during each procedure when compared with preleukapheresis values due simply to plasma volume expansion (acute effects of dilution). Possible long-term effects of repeated procedures were investigated by comparing preleukapheresis values before the first and fourth procedures. Total lymphocyte, total T-lymphocyte, and T4-lymphocyte counts, as well as serum immunoglobulin values and anti-A and B titers measured before the fourth procedure remained unchanged when compared with values obtained before beginning the series of procedures. In contrast, the B-lymphocyte count was decreased, the T8-lymphocyte count was increased, and the T4:T8 ratio was decreased due to the increase in the T8-lymphocyte count. Although statistically significant (p less than 0.05), all changes were slight, and clinically significant effects on donor humoral immunity could not be detected. The mechanisms involved, however, may be of biologic and therapeutic interest.

Currently, the frequency of granulocyte donation is limited by the prolonged circulation of hydroxyethyl starch (HES). We conducted a Phase I, uncontrolled, multicenter trial to evaluate both the efficacy and safety of a rapidly excreted low-molecular-weight analog of HES (LMW-HES). Seventy-five donors underwent 179 centrifugation leukapheresis procedures using LMW-HES as the red-cell-sedimenting agent. The efficacy of LMW-HES was established by harvesting adequate numbers of leukocytes. Most granulocyte concentrates contained at least 20 X 10(9) neutrophils when 8 l of blood was processed from donors optimally stimulated with steroids. The safety of LMW-HES was documented by the detection of almost no clinically significant adverse effects. In only 1.7 percent of procedures did donors require special attention, and only 1 of 179 procedures (0.6%) was permanently discontinued. Results of laboratory studies were usually normal or their values decreased transiently (approximately 15-25%) as a consequence of plasma volume expansion (dilution). Based on previous experience with HES, LMW-HES and HES perform comparably during leukapheresis. When commercially available, use of this new, rapidly excreted analog should permit more frequent leukapheresis donation.

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)

Platelet dysfunction and prolonged bleeding have been seen in man when glucose polymer solutions, such as dextran, are used to volume replacement. Hydroxyethyl starch (HES) is a glucose polymer slightly different from dextran, which is used as a sedimenting agent in leukapheresis procedures. This controlled study was performed to evaluate the effect of HES on platelet function in centrifugation leukapheresis donors. Plateletpheresis using the same machines and techniques but without HES was the control. Platelet function was assessed by bleeding time, platelet count, adhesiveness to glass beads and aggregation to collagen, epinephrine and several concentrations of ADP, before and after the pheresis procedures. Except for a decrease in platelet count after both procedures, no other major changes in platelet function were seen. After one exposure in previously unpheresed donors, HES does not induce platelet dysfunction.

Analysis of blood coagulation was done on samples of blood collected from ten donors undergoing combined platelet and leukapheresis using the Haemonetics Model 30 Blood Processor. Blood samples were obtained from the donors prior to, during, and following pheresis. Blood was also obtained from the blood-return line after the first collection of leukocytes and platelets, but before it was returned to the donor. Although the citrate anticoagulant was returned to the donor and there were some decreases in the concentrations of fibrinogen, platelets, and factors V and VIII, there were no changes of sufficient degree to suggest that development of a potential bleeding disorder. In addition there was no evidence to suggest that any activation of blood coagulation occurred during the pheresis or that thrombogenic substances were returned to the donors. Combined platelet and leukapheresis using the Haemonetics Model 30 Blood Processor, therefore, do not appear to subject the donor to risks for either bleeding or thrombotic complications.

The effectiveness of neutrophils prepared for transfusion by intermittent flow centrifugation leukapheresis (IFCL) as treatment for serious bacterial infections in neutropenic patients has not been documented in the literature. Their value, in fact, has been questioned. We report that IFCL neutrophils are similar to cells prepared by other techniques in the ability to support neutropenic patients with culture-proven, gram-negative sepsis unresponsive to antibiotics.

With the advent of sophisticated automated blood processors, the collection of large numbers of granulocytes for transfusion has been made more practical in the past ten years. Harvesting granulocytes by filtration leukapheresis has been abandoned in most centers because of adverse reactions in both donors and recipients. Currently, both continuous and discontinuous flow centrifugation leukapheresis techniques are available. However, both corticosteroids and hydroxyethyl starch are required for optimal granulocyte collection. In this paper, we critically compare the three major cell separators used for the collection of granulocytes by centrifugation leukapheresis. All three instruments separate blood cells by centrifugation; the IBM-2997 and the Fenwal CS-3000 function by continuous-flow centrifugation, and the Haemonetics Model 30 by discontinuous-flow centrifugation. Factors such as the donor preapheresis white blood cell count, the blood flow rate through the machine and the centrifuge speed effect granulocyte collection. Comparisons will be made of the cost of the software for each machine, the time required for granulocyte collection, the convenience of set-up and tear-down, the amount of skill and experience demanded of the operator. Donor factors will be discussed. Since the blood processor may be used for other procedures including plateletpheresis, therapeutic plasma exchange, lymphocytapheresis and erthrocytapheresis, the pros and cons of each machine as used for some of these procedures will be included in the discussion. In our experience, total leukocytes and granulocytes (neutrophils) collected with the three different instruments varied only slightly when unstimulated donors were studied.(ABSTRACT TRUNCATED AT 250 WORDS)

One donor can provide separate platelet and granulocyte-platelet units that have the potential to fulfill the needs of two recipients. Combined platelet and leukapheresis were performed in the presence of hyddroxyethyl starch and citrate employing the Haemonetics Model 30 Blood Separator. Platelets and granulocytes were separated subsequently by centrifugation and two individual units were prepared for transfusion. The platelet units contained a mean of 4.4 x 10(11) platelets/unit and were nearly devoid of leukocytes. The combined granulocyte-platelet units contained a mean of 7.38 x 10(9) neutrophils/unit and 3.06 x 10(11) platelets/unit. Thus two separate units containing sufficient numbers of cells for transfusion can be obtained from pheresis of one donor.

The effects on platelet function of intermittent-flow centrifugation pheresis were measured employing platelets collected from ten donors by combined platelet-leukapheresis with hydroxyethyl starch (LP) and from ten by plateletpheresis (PP) by similar techniques except without starch. Greater numbers of platelets were produced by LP than by PP. Aggregation of platelets collected by both LP and PP was normal (did not differ from prepheresis baseline) to collagen and to 10(-5)M adenosine diphosphate (ADP). Slight impairment to aggregation with 2 X 10(-6)M ADP and 5.5 X 10(-5)M epinephrine occurred with both techniques. These abnormalities, however, were significantly less severe in platelets collected by LP. Platelet morphology by electron microscopy was nearly normal, although glycogen granules were absent in LP platelets. Thus, hydroxyethyl starch, at doses currently used during a single LP, does not enhance abnormalities of platelet aggregation over those expected to result from PP alone. Actually, LP platelets function better in vitro than those collected by PP. Large numbers of platelets can be harvested by LP, and their use as a component that is comparable to PP platelets may mean improved efficiency and reduced costs for pheresis centers.