Complement changes during leukapheresis

On the biocompatibility of IBM 2997 continuous flow plateletapheresis

During the procedure of centrifugation cytapheresis donors occasionally experience adverse clinical reactions. We evaluated the possibility of whether activation of granulocytes and their subsequent release reactions, which may have been triggered by this extracorporeal circuit, were responsible for these adverse effects. Six blood samples were obtained during various set intervals during plateletapheresis. Of these, four samples were taken directly from each donor. The remaining two were drawn from the efferent lines, i.e. those which return blood from the cytapheresis machine back to the donor. Reactive oxygen species produced by granulocytes were monitored by chemiluminescence using microamounts of whole blood or isolated granulocytes. Furthermore, secreted granulocyte products such as neutral proteinase elastase, present in plasma in a complex with alpha 1-proteinase inhibitor (complexed elastase), and lysosomal beta-glucuronidase were examined. A complete blood cell count, as well as values of haemoglobin, haematocrit, lactate dehydrogenase, protein, albumin and proteinase inhibitors such as alpha 2-macroglobulin and alpha 1-proteinase inhibitor were also determined. Complexed elastase increased from a preapheresis value of about 140 micrograms/l to about 180 micrograms/l at the end of the cytapheresis. All other clinical chemical and cytological values were 8 to 12 percent lower than preapheresis values, which can be attributed to inherent plasma volume expansion. Reduced chemiluminescence was observed upon stimulation of phagocytes in the whole blood assay (about 700 counts/min x 10(3) x 50,000 cells vs. about 600 counts/min x 10(3) x 50,000 cells). This decrease was also seen with stimulated granulocytes (about 5800 counts/min x 10(3) x 50,000 cells vs. about 4500 counts/min x 10(3) x 50,000 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Therapeutic plasmapheresis and plasma exchange

Plasma exchange is a process in which large volumes of plasma, usually equivalent to one plasma volume, are exchanged with donor plasma or a plasma substitute. This permits the removal of antibody, immune complexes, inflammatory mediators, paraproteins, drugs, toxins, and other plasma constituents. Plasma exchange may also have an effect on the immune system by enhancing the function of the reticuloendothelial system, removing blocking antibody, increasing clearance of tumor cells, and making lymphocytes more vulnerable to immunosuppressive drugs. Over 100 diseases have been treated with plasma exchange with variable success. Results of controlled studies are less dramatic than those of earlier uncontrolled case reports. Reports of complications and even death have tempered initial enthusiasm. Now, over a decade since the initial promising reports began to appear in the literature, the role of plasma exchange remains undefined.

Peripheral blood lymphocyte numbers, lymphocyte proliferative responses in vitro, and serum immunoglobulins in regular hemapheresis donors

Selected tests of lymphoid function were used to screen a population of volunteer hemapheresis donors. Testing included: 1) absolute lymphocyte numbers, and percentage of T-cell, B-cell, and mononuclear phagocytes, 2) serum immunoglobulins, and, 3) in vitro proliferative responses to lectin mitogens (phytohemagglutinin, concanavalin A, and pokeweed mitogen), soluble antigens (staphylococcal filtrate, candida, and streptococcal varidase), and cell-bound alloantigens (mixed lymphocyte culture). A control population of first-time plateletpheresis donors was examined similarly. Regular donors manifested a small but statistically significant decrease in absolute lymphocyte counts (p less than 0.02), and IgM (p less than 0.02) compared to controls. Leukapheresis donors also manifested significant decreases in percentage of T cells (p less than 0.02). These findings are qualitatively similar to changes reported following intensive lymphocytapheresis and indicate the need for conservative policies regarding donation frequency in hemapheresis programs.

Plasma separation in patients with bronchial asthma, atopic dermatitis and hyperimmunoglobulinaemia E

The effect of intensive plasma separation performed eight times within 5 weeks in four patients with atopic dermatitis, bronchial asthma and hyperimmunoglobulinaemia E was followed as regards clinical symptoms and changes in the concentrations of serum (S) IgE, S IgG, S IgA, S IgM, plasma complement C3 split products, S transferrin, blood eosinophils, chemotaxis of neutrophil cells and histamine metabolites in urine in samples obtained consecutively during the period of observation. The occurrence of circulating immune complexes (IC) was analysed by a polyclonal rheumatoid factor (pRF) agglutination inhibition assay and an IgE IC specific technique. IgE IC were demonstrated in three of the patients prior to plasma separation, complexed IgE was 2-3% of the total concentration of S IgE. In one patient complexes were detected by the pRF agglutination inhibition assay, also. In the three patients with IgE IC, the complexes disappeared during treatment, but recurred in two of the patients shortly after the last plasma separation. Shortly after eight separations the S IgE was reduced in all patients to a mean level of 46% of the pre-exchange concentrations. During the following 3 weeks the relative increase of S IgE in three of the patients was similar to the values obtained for S IgG. Serum IgG was subnormal in all patients during the period of treatment. Increasing numbers of eosinophils were observed in three of the patients after the fifth separation procedure. The histamine metabolite 1,4-methylimidazoleacetic (1,4- MIAA ) in urine was increased in all patients, but no significant changes were observed during the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Complement metabolism during membrane plasma separation

Because it has been found that some plasma separator membranes can activate complement in serum, this study focuses on the behavior of complement during actual membrane plasmapheresis. Complement metabolism in subjects undergoing membrane plasma separation with three different prototypic devices was studied. Complement activation was judged by crossed immunoelectrophoretic analysis of C3 in plasma. A cellulose acetate separator employed with heparin as the anticoagulant caused extensive C3 conversion (up to 50%) in separated plasma. A polysulfone separator used with citrate, and a polyvinylchloride derivative separator employed with heparin plus citrate, caused only small amounts of C3 conversion (0-10%) in separated plasma. C3 conversion in the cellulose acetate separator was reduced when citrate was included in the anticoagulant regimen, whereas C3 conversion in the polyvinylchloride derivative separator was increased when citrate was omitted. Activation of complement by the membrane material may occur during membrane plasma separation. Selection of membranes judged weakly activating by in vitro screening and the use of citrate anticoagulation would appear to minimize complement activation in membrane plasma separators.

Adverse reactions to whole blood donation and plasmapheresis

Whole blood donation is recognized to be extremely safe, yet there have been reports of serious problems stemming from whole blood donation, and so-called "donor reactions" are regularly seen. While the physiologic causes of the common donor reactions are not completely understood, some effects of whole blood donation (such as transient iron deficiency) are understood but probably not significant. In order to avoid accepting any volunteer donor who might be at risk of a serious reaction, we may have been overly cautious in exclusion of potential donors. The pheresis donor is subjected to potential depletion of the protein or cellular elements being removed, problems caused by the device used for automated pheresis, or problems related to the infusion of potentially toxic substances. Documented benefit to the patient must balance these additional risks.