Mechanisms of adverse effects during hemapheresis

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. © 1996 Wiley-Liss, Inc.     

Detection of plasmapheresis-induced platelet activation using monoclonal antibodies

Twelve volunteer plasma donors were studied so as to determine the extent and duration of in vivo platelet activation caused by automated plasmapheresis. Samples obtained immediately before and after donation were mixed with murine monoclonal antibodies PAC-1 and S12, which bind specifically to activated platelets. Antibody binding on platelets was quantitated by flow cytometry. The change in the mean fluorescence intensity (MFI) (MFI after donation minus MFI before donation) was 61 +/- 23 (confidence interval [CI], 48-75) for PAC-1 and 56 +/- 64 (CI, 19-92) for S12 in plasmapheresis donors, as compared to 0.3 +/- 0.8 (PAC-1; CI, -0.2-0.8) and 0.3 +/- 0.9 (S12: CI, -0.3-0.9) in whole blood donors (p less than 0.05). Additional studies showed circulating activated platelets up to 48 hours after plasmapheresis. In contrast to other data, significant platelet activation was demonstrated following plasmapheresis on an automated machine. None of the donors had clinical complications. Nevertheless, it may be appropriate to delay subsequent plasmapheresis and platelet procurement from such donors until evidence of platelet activation has disappeared.     

Filtration plasmapheresis in vivo

A continuous-flow filtration plasmapheresis system has been developed as an alternative to conventional techniques for conducting plasmapheresis from blood donors. The system was tested in two stages, nonreinfusion and continuous reinfusion. Donor safety, separation efficiency, and plasma quality were examined. These studies indicate that membrane plasmapheresis is feasible, safe to the donor, and yields sufficient plasma for either therapeutic or component therapy use.     

Peripheral blood mononuclear cell collection from patients undergoing adoptive immunotherapy or peripheral blood-derived stem cell transplantation and from healthy donors.

The demand for collection of mononuclear cells from the peripheral blood of patients for therapeutic purposes is rapidly increasing. Automated blood cell separators are usually designed for collection of blood components from healthy donors. We reviewed safety and efficiency of collection data of a new procedure for the Fenwal CS 3000 blood cell separator in 125 collections from normal donors and 101 collections from patients after IL-2 pretreatment or chemotherapy. The new procedure set red blood cell spillovers to occur at 3.5 minute intervals, using procedure 1 with the interface detector set at 1,000 and the standard granulocyte and collection chambers. Despite significant anemia and thrombocytopenia in a large number of patients no serious procedure-related side effects occurred. The lymphocyte yield was 4.74 +/- 1.6 x 10(9) per 5 liters of blood processed in normal donors and 24.2 +/- 12.0 x 10(9) per 10 liters of blood processed after IL-2 treatment. After chemotherapy the lymphocyte yield was 4.5 +/- 3.1 x 10(9) per 10 liters of blood processed; the collection efficiency was found to be significantly lower in this group. The main problem was the platelet loss of 35.6 +/- 12% of the initial count in normal donors, 40.3 +/- 14.1% after IL-2 treatment, and 42.1 +/- 18.0% after chemotherapy. The platelet loss is, however, closely related to the preapheresis platelet count; patients with thrombocytopenia lose fewer platelets than normal donors. Therefore the procedure was found to be safe for patients with a platelet count as low as 20/nl. This report provides a basis for safe, effective mononuclear cell collection from patients with very abnormal peripheral blood counts.     

Effectiveness of Platelet Transfusion in Leukemia and Aplastic Anemia

Hemorrhage resulting from thrombocytopenia in patients with acute leukemia and aplastic anemia can be controlled by platelet transfusions. Severe gross hemorrhage was rarely observed when platelet counts were higher than 20,000 per cu. mm. Transfusion of 1 × 10¹¹ platelets produced an average increment of 12–14,000 platelets per cu. mm./square meter (m²) of body surface in acute leukemia. One unit of platelet rich plasma (PRP) contains an average of 1 × 10¹¹ platelets and 4 PRP/m² twice weekly will maintain the platelets above 20,000 per cu. mm. most of the time. When very large doses of platelets are required in a small volume then platelet concentrates (PC), prepared by centrifuging PRP and removing most of the plasma, are used. PC are 80 to 90 per cent as effective as PRP in elevating the platelet count if prepared from plasma with a p H of 6.8 or less, achieved by the addition of citric acid.
The major hazard of platelet transfusion is posttransfusion hepatitis. This can be minimized by the use of plasmapheresis thus using the same donors repeatedly. In the presence of anemia platelets can be given effectively in fresh whole blood transfusions until the patient's hematocrit is raised.     

Clinical evaluation of a flat-plate membrane plasma exchange system

A new flat-plate membrane plasma separation system specifically designed for therapeutic plasma exchange (TPE) was clinically evaluated in both research and routine clinical settings. The study included a comparison to a currently available centrifugal cell separation system employed for TPE. A total of 267 membrane procedures were performed on 39 patients over a 14-month period. Both qualitative and quantitative studies showed that membrane plasma exchange procedures were equivalent to centrifugal procedures in the removal of plasma constituents from patients. A notable difference between the two types of procedure was the effect on the peripheral blood platelet count: the plasma filtrate from the membrane system was essentially cell-free and platelet counts fell only 11% during the procedure, compared to a 53% decrease during the centrifugation runs. Patient responses to both types of procedure were similar and the frequency of side-effects was low. A sampling of patient opinion revealed a preference for the membrane system for a variety of reasons. Procedure times were shorter with the membrane system because of higher achievable blood flow rates, and thus higher plasma exchange rates, while the overall nursing time requirement was lower. The results show that this flat-plate membrane TPE system enables rapid and effective plasma exchange therapy, and offered a number of monitoring and control functions that provided a safer, more efficient therapeutic procedure in the majority of patient treatments performed in this study.     

Plateletpheresis concentrates produced in 30 minutes along with plasma and packed red cells: Preliminary results

Centrifugal devices for donor plasmapheresis that collect platelets as a by-product have recently been introduced. The platelet yield ranges from 1.2 to 2 × 10¹¹ per collection, and the collection time exceeds 50 minutes. An attempt to increase yields and to reduce the procedure time was carried out at our center, taking advantage of the Dideco Eccentriplate (Dideco spa. Mirandola, Italy). Within 30 minutes, 510 ml of plasma were collected along with 3.3 × 10¹¹ platelets. The shift of donors from whole blood to plasma and platelet donation generated a progressive decrease in red-cell availability. In order to maintain plasma and platelet production without affecting the erythrocyte production, a technique was developed that allows the collection of 3.68 × 10¹¹ platelets, 250 ml of plasma, and 225 ml of packed red blood cells with a hematocrit of 66.5%. The mean procedure time was 31.6 minutes; 2,671 ml of blood were processed at flow rates of 85–100 ml/minute. The cellular cross contamination of the platelet concentrates was 1.76 × 10⁸(leukocytes) and 2.23 × 10⁸ (erythrocytes). Although me procedure was carried out in a selected group of donors, the technical experience has strongly modified our procedure for platelet and plasma collection.     

Plasma collection using an automated membrane device

A plasmapheresis device with both membrane filtration and centrifugation features was tested. The device permits the collection of 500 ml of plasma within 30 minutes; when run at a 1:12.5 ratio with acid-citrate-dextrose (ACD-A) the resultant plasma factor VIII levels were 1.05 units per ml and the albumin was 41 g per l. Free hemoglobin was not detected, and there was no evidence of fibrinopeptide A, prekallikrein, or activation of complement. The plasma had a zero hematocrit value and contained few platelets and white cells. Before and after the procedure, donors and aliquots from the return line did not show any significant effect on cell count or function. This device functioned well to collect plasma for infusion or fractionation and was accepted well by donors. A major advantage is the relatively low cost for the software package ($15.00, US, 1985), which should make plasmapheresis with this device economically feasible.     

A new technique for the collection of plasma: machine plasmapheresis

The Haemonetics Model 50 permits the collection of 500 ml of plasma within an average of 30 minutes, and the donor is never disconnected from his cells. In a detailed assessment of 28 donors, we found no detrimental effect of the procedure. There was no evidence of fibrin split products or complement activation. The plasma showed good recovery of protein with slightly elevated factor VIII levels; citrate levels are only two-thirds of manual plasmapheresis values. While there was a relatively large number of platelets collected into this plasma, the platelets were small, with a mean diameter of 1.8 mu and poor response to aggregation. Therefore it would appear that this plasma should not be used to make a platelet preparation. Nonetheless, evaluation of this machine indicated that the performance parameters are acceptable and that donor acceptance is exceptional, with widespread enthusiasm for this "new" method of blood donation.     

Volunteer donor apheresis.

Volunteer donor apheresis has evolved from early plasmapheresis procedures that collected single components into technically advanced multicomponent procedures that can produce combinations of red blood cells, platelets, and plasma units. Blood collection and utilization is increasing annually in the United States. The number of apheresis procedures is also increasing such that single donor platelet transfusions now exceed platelet concentrates from random donors. Donor qualifications for apheresis vary from those of whole blood. Depending on the procedure, the donor weight, donation interval, and platelet count must be taken into consideration. Adverse effects of apheresis are well known and fortunately occur in only a very small percentage of donors. The recruitment of volunteer donors is one of the most challenging aspects of a successful apheresis program. As multicomponent apheresis becomes more commonplace, it is important for collection centers to analyze the best methods to recruit and collect donors.     

Plasma separation using a hollow fiber membrane device

A disposable hollow fiber device was evaluated by collecting approximately 550 ml of normal donor plasma (n = 43) and by performing sham (n = 10) and therapeutic (n = 12) plasma exchanges. Blood was processed at 70 ml per min, and plasma flux averaged 23 (collection) and 25 (exchange) ml per min (mean separation efficiencies of 52 and 60%, respectively). The procedures were tolerated well by all donors and patients. The plasma hemoglobin concentration in separated plasma averaged 1 mg per dl, and cell contamination was negligible (mean of 1, 3, and 6 RBCs, platelets and WBCs/microliter, respectively). There was no evidence of in vivo classical or alternative pathway complement activation as assessed by total hemolytic complement generation (CH50), alternative pathway hemolytic activity (AP50), C3 conversion, or C5 activation, nor were unexpected changes seen in the results of laboratory tests performed after the procedure. Sieving coefficients during sham plasma exchange averaged as follows: albumin, 1.03; IgM, 1.0, IgG, 1.0; IgA, 0.98; factor V, 1.07; factor VII, 0.89; factor VIII, 1.05; and factor IX, 1.19. The device appears to be useful for separation of cell-free plasma from blood during therapeutic plasma exchange procedures.     

Improved red cell quality after erythroplasmapheresis with MCS-3P

The cell separator MCS-3P is an apheresis system offering the flexibility to collect standardized red blood cells, plasma, and/or platelets from one donor. Two different programs were used for the red cell apheresis'RBCP (collection of one unit of red cells and two units of plasma) and RBCPS (one unit of red cells and one unit of plasma). The quality of the red cell concentrates (RCC resuspended in SAG-Mannitol) during the storage time of 42 days was measured by biochemical (ATP, 2,3-DPG, pH, free Hb, free potassium, glucose, lactose, p⁵⁰, hemoglobin derivatives) and Theological (morphological index, filtration/rigidity index) parameters. The donation time with 53 donors was 20 min for 355 ml RCC-SAGM and 440 ml plasma and 7 min for 335 ml RCC-SAGM and 239 ml plasma. The donor tolerance was analogous to plateletpheresis or plasmapheresis. Twenty units of the RCC-SAGM were in-line filtered within 6 or 24 hours after donation. The results obtained for red blood cell storage are at least as good as with standard collection (free hemoglobin, free potassium, glucose, lactose, hemolysis) or better (ATP, 2,3-DPG, p⁵⁰, hemoglobin derivatives, filtration/rigidity index) owing to prevention of collection lesion. All blood preparations were sterile after storage (red cells 42 days, plasma after freezing). The erythroplasmapheresis with MCS-3P can be especially recommended for application in an autologous blood program because the application of autologous blood donation in hospitals is often limited by the preconditions of component separation. The erythroplasmapheresis data with MCS-3P are encouraging for the development of a new blood collection methodology.     

Automated platelet production during plasmapheresis

Manual plasmapheresis is widely used to permit collection of fresh- frozen plasma with return of the red cells to the donor. However, this method is time-consuming and carries the inherent risk of returning the wrong cells to any individual donor. Automated plasmapheresis, using a specially designed discontinuous cell separator, permits the collection of 500 ml of plasma within 30 minutes without disconnecting the donor from the bag containing the donor's red cells. However, this plasma contains a small number of platelets which are not suitable for transfusion. We now report the modification of this machine to permit simultaneous collection of 3 units of platelet concentrate as well as 500 ml of plasma in less than 50 minutes. Reduction of the g force of the separator from 1200 to 650 g permits the simultaneous collection of plasma and a platelet concentrate with an average yield of 2.21 × 10(11) platelets. Platelet size distribution, in-vitro function. 51Cr survival, posttransfusion increment, and bleeding time correction are all normal. This modification has increased the flexibility of the separator and provides an instrument which can be used with a random volunteer blood donor population to generate both plasma and cells in less than 50 minutes and with increased cost-effectiveness over plasmapheresis alone.     

Effects of serial plasmapheresis on serum IgA levels in IgA-deficient blood donors with IgA-suppressor T cells

Seventeen IgA-deficient blood donors, without antibodies to IgA, underwent plasmapheresis four to eight consecutive times at intervals of 8 weeks or less to provide fresh-frozen plasma for patients with anti-IgA. Blood samples, drawn for analysis no more than 1 hour before plasmapheresis and again at the conclusion of each procedure, were analyzed for lymphocyte subpopulations and serum IgA levels. Five lymphocyte subpopulations, including natural killer cells, the suppressor-inducer CD4 subset, the suppressor-precursor CD8 subset, non-major histocompatibility complex (MHC)-restricted cytotoxic T cells, and CD5+ B cells, were all decreased significantly after plasmapheresis (p less than 0.05). In a subgroup of IgA-deficient donors with excessive IgA-suppressor T-cell activity, serum IgA increased to levels exceeding 0.05 g per L following the fourth consecutive plasmapheresis procedure. Serum IgA levels did not similarly increase in IgA-deficient donors without excessive IgA-suppressor T-cell activity or in controls without IgA deficiency. Our study shows the potential, in a subpopulation of IgA-deficient donors who undergo frequent plasmapheresis, for a transient increase in serum IgA to a level no longer considered IgA deficient.     

Use of plasmapheresis and partial plasma exchange in the management of patients with cryoglobulinemia

The management of patients with cryoglobulins often meets with limited success. Reported here is the use of plasmapheresis and/or partial plasma exchange in the management of five patients with cryoglobulinemia. The procedure was carried out at room temperature with reinfusion through a blood warmer. Circulating levels of mixed cryoglobulins and monoclonal IgM cryoglobulins were more easily reduced than were IgG cryoproteins. Improvement in symptoms was associated with removal of the cryoprotein. Pheresis can be used as primary therapy for reduction of cryoglobulin levels in cases of symptomatic essential cryoglobulinemia. Where an etiology for cryoglobulinemia is known and specific treatment exists, pheresis can be used as effective adjunct therapy.     

Current topics on centrifugal plasmapheresis technologies.

In the field of plasmapheresis centrifugal technology has recently focused on the collection of peripheral blood stem cells (PBSCs) for both autologous and allogeneic transplantation in patients with malignancies or hematological diseases and on donor plasmapheresis. PBSC transplantation is rapidly replacing bone marrow transplantation in such patients. Various kinds of apheresis equipment were applied and described for PBSC collection. Comparison among machines is described. Allogeneic PBSCs were collected from healthy normal donors. Specific attention to the dose and administration duration of granulocyte colony-stimulating factor and a careful apheresis procedure should be made for donor safety. In platelet transfusion practice, a platelet concentrate product derived plateletpheresis from a single donor is preferable to minimize and to prevent adverse transfusion reactions. The status of platelet collection and its efficacy by various kinds of plateletpheresis equipment are discussed. The Amicus and CCS might be preferable plateletpheresis machines because of their collection efficiencies and wider indication for donors. With the limited number of donors, it is essential that plateletpheresis should be more effectively performed and managed by each regional blood center. The status of plasma and red cell collection by apheresis technologies is described also briefly.     

Leukocyte and Platelet Collection from Normal Donors with the Continuous Flow Blood Cell Separator

Continuous-flow centrifugation of blood from normal donors with the NCI-IBM Continuous Flow Blood Cell Separator can be used safely and effectively to collect large quantities of normal granulocytes, lymphocytes, and platelets. Comparison with single-unit leukapheresis demonstrated a threefold greater collection of granulocytes and a fivefold greater collection of lymphocytes per hour of leukapheresis with continuous flow centrifugation. Granulocyte collections can be enhanced by giving the donors etiocholanolone or cortisone prior to leukapheresis. Plateletpheresis can be combined efficiently with granulocyte collction during continuous-flow centrifugation, but it offers no particular advantage over platelet collection by standard plasmapheresis technics.     

Description and use of the CS-3000 blood cell separator for single- donor platelet collection

A new computer-controlled seal less continuous flow blood cell separator has been developed to harvest platelets, plasma, or leukocytes and perform plasma exchange. One hundred seven platelet collection procedures were performed using an instrument prototype during developmental evaluation of a number of differently configured platelet collection chambers. An average of 3.6 (range 2.6-5.5) × 10¹¹ platelets was collected during a 90-minute period (blood withdrawl rate, 32 ml/minute) with the best chamber. Only a small number of other cells, from 0.1 to 0.2 times 10⁹ white blood cells and 0.7 to 1.0 times 10⁹ red cells was collected with the platelets. Total procedure time averaged 115 to 120 minutes and included 5 minutes to install the blood processing pathway, 10 minutes to prime the system under computer control, 5 minutes to return donor erythrocytes at the completion of the procedure, and 5 minutes to remove the processing set and resuspend the platelets. The average donor platelet count declined 48 times10³per μ (19%) by the completion of the procedure, and, with the exception of a decline in inorganic phosphorus from 3.4 to 2.5 mg per dl, no unexpected changes in serum chemistry levels were seen. Use of either of two larger separation chambers in a production version of the instrument permitted more rapid blood processing rates (?45 ml/minute); an average of 4.2 (range 2.1–7.8) × 10¹¹ platelets was collected in 90 minutes using a larger chamber designed for platelet separation (n = 164). Platelets could also be collected using the chamber designed for white blood cell collection by omitting the use of hydroxyethyl starch and by selecting the platelet collection computer program rather than the white cell collection program. Using that chamber, an average of 4.3 ± 1.8 times 10¹¹ platelets was collected in 90 minutes (56% collection efficiency; n = 31). Leukocyte contamination of platelets was greater using the larger chambers. Infusion of autologous platelets labeled with ⁵¹Cr demonstrated a 70 percent average recovery and a mean survival of 9.1 days (n = 10). Seven nonalloimmunized thrombocytopenic patients were transfused with platelets collected using the prototype cell separator and an average of 86 percent of the expected number of platelets was present in the circulation 2 hours after transfusion with 63 percent of the cells remaining in the circulation at 24 hours. Template bleeding times were corrected in six of seven recipients following transfusion, and hemostasis was achieved in three bleeding recipients. Therapeutically useful numbers of functionally effective platelets can be collected using this blood processing instrument.     

血浆置换治疗在儿科危重患者抢救中的经验

目的探讨血浆置换治疗在儿科危重症患者的应用价值和治疗方案。方法应用GAMBR0-PRISMA床旁血滤机和TPE2000膜式血浆分离器对15例危重症患儿（1岁10月～15岁，平均6．8岁）进行39次血浆置换治疗；以新鲜冰冻血浆作置换液，置换量为40-70ml／（kg·次），血泵速度为50～120ml／min，治疗时间2～3h／次：结果39次血浆置换治疗均顺利成功实施，无明显并发症出现；14例在治疗后临床症状及生化指标好转，5例痊愈。结论血浆置换可以应用于多种危重症儿科疾病，治疗方案需根据病情制定。