Evaluation of antibody synthesis in broadly sensitized patients

This study was conducted to evaluate the rate of lymphocyte antibody synthesis in broadly sensitized patients. Antibody synthesis was estimated utilizing two approaches. In one, the time required by the antibodies to reach half their original values was determined by quantitating their levels by flow cytometry over periods of several months. In the other approach we measured the rate at which antibodies rose after inducing an artificial reduction by means of plasma exchanges. Patients not previously transplanted and not transfused during the study period showed low antibody synthesis and decreasing panel reactivity. In most previously transplanted patients panel reactivity did not change during the observation period. However, some patients displayed low antibody synthesis activity whereas others produced antibodies at a high rate. Extensive studies in one patient demonstrated active antibody synthesis even though he had not been transfused for more than two years. The results suggest that while frequent plasma exchanges can reduce antibody concentrations, concomitant use of immunosuppression may be needed only in patients shown to be actively producing antibodies.