ABSTRACT
NK cell activity of peripheral blood lymphocytes was determined in voluntary blood bank donors in a standard 4-hr 51Cr-release cytotoxicity assay. When blood donors were divided into groups according to the total amount of blood they had donated in the past, decreased NK activity was found in "moderate" donors who had donated between 3 and 9 l of blood, but not in those who had donated < or = 3 or more than 9 l of blood before testing. This observation was the rationale for a study on the effects of regular blood donations on NK activity in randomly selected voluntary blood bank donors re-tested over a period of time. The study demonstrated decreased NK activity in the second measurement in donors who had donated up to 6 l of blood before the study, and an increase in NK activity between the first and the second testing in those who had donated more than 6 l of blood. This result, together with data obtained at the population level, suggests that some compensatory mechanism(s) regulate NK activity in the course of regular blood donation.
Subject(s)
Blood Donors , Killer Cells, Natural/immunology , Adult , Cytotoxicity, Immunologic , Humans , Male , Middle Aged , Time FactorsABSTRACT
In the H-2-compatible donor-recipient combination (BALB/c----DBA/2), pretransplant donor-specific blood transfusion (DST) significantly prolonged graft survival. Concomitant use of immunosuppression by cyclophosphamide (CY) brought about potentiation of DST effect, resulting in long-term graft survival. In contrast, in the 'strong' H-2-incompatible combination (BALB/c----CBA/H) pretreatment of the recipients with donor-specific blood resulted in hyperacute graft rejection or in impairment of drug-induced immunosuppression when DST was used with a single dose of CY. In this model however, combination of DST with both pre- and posttransplant CY immunosuppression interacted beneficially to produce significant donor-specific prolongation of graft survival.
