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

Effect of long-term platelet donation on lymphocyte subsets and plasma protein concentrations

Previous studies of changes in immune function in platelet donors have investigated subjects who were undergoing plateletpheresis using older equipment that is no longer in general use. Therefore, the purpose of this study was to determine the effect of long-term platelet donation on lymphocyte numbers and subsets and plasma protein concentrations in platelet donors using newer cell separators. Three groups included in the study were nondonor controls (n = 27), long-term whole blood donors (n = 29), and long-term platelet donors (n = 20). Using a cross-sectional analysis, lymphocyte numbers and subsets were determined and compared among the three groups. Plasma concentrations of total protein, globulin, albumin, and IgG were also compared. Among the three groups there were no significant differences in total white blood cell counts, percentage or absolute number of lymphocytes, or percentage or absolute number of lymphocyte subsets. Serum total protein, globulin, albumin, and IgG concentrations of platelet donors were within normal ranges. These data support the current Food and Drug Administration (FDA) and American Association of Blood Banks' standards for the frequency of platelet donation allowed and monitoring required for plateletpheresis donors. Furthermore, these data indicate that the FDA could eliminate the requirement for the warning in informed consents about lymphocyte depletion in platelet donors.

In vitro study of immunologic changes in long-term cytapheresis donors

Several in vitro measurements of immune function were examined retrospectively in a population of active long-term cytapheresis donors (group I; n = 50) and the results were compared to age- and sex-matched controls (group II; n = 50) who had donated only whole blood. In group I, significantly different mean absolute lymphocyte counts (P = .0025), total T-cells (P = .0026) and T-helper cells (P less than .0001), and helper-to-suppressor ratios (P = .0279) were present. No differences were noted between the two groups for peripheral blood mean B-cell count, T-suppressor numbers, lymphocyte responsiveness to mitogens or alloantigen, and serum immunoglobulin level. The reduced mean absolute lymphocyte count in group I was due to the reduction in T-helper cell numbers and accounted for the imbalance in the helper-to-suppressor ratio. These disturbances are currently unexplained and, while no clinical consequences have so far become evident, there is a need to continuously monitor the immunologic status of cytapheresis donors. It is also important to determine whether reversal of the defects occurs and, if so, over what time interval.

Effects of plasmapheresis on peripheral blood mononuclear cell populations from patients with macroglobulinemia

Effects of plasmapheresis on peripheral blood T-cell, B-cell, monocyte, and natural-killer-cell populations were studied in ten macroglobulinemia patients with hyperviscosity syndrome. Following plasmapheresis, there was a transient decrease in the number of T4+ helper cells and a longer-lasting decrease in the number of Leu-7+ natural killer cells and Mo2+ monocytes. In addition, there was a greater than 50% decrease in the in vitro ingestion capacity of monocytes. Although no significant changes in the numbers of IgM+, B1+, B4+, or PCA+ B cells (P greater than .05) were detected, there was a highly significant (P less than .01) increase in I2 antigen density on the surface of IgM+ B cells and in the bromodeoxyuridine uptake by these cells 7-9 days after plasmapheresis. These findings suggest that following plasmapheresis, IgM+ B cells are activated. Using flow cytometry to determine when maximum IgM+ B cell activation occurs by measuring I2 antigen density on the cell surface may be useful in determining the postplasmapheresis timing of chemotherapy in macroglobulinemia patients with hyperviscosity syndrome who require more aggressive treatment.