Immunologic abnormalities in patients receiving multiple blood transfusions.

Concern for the potential risk of the acquired immunodeficiency syndrome among blood cell recipients led us to measure immunologic functions in patients who had received multiple transfusions. Abnormalities of two immunologic tests, natural killer cell function and helper/suppressor (T4/T8) lymphocyte subpopulation ratio, have characterized patients with the acquired immunodeficiency syndrome and are prevalent in populations at risk for this syndrome. Natural killer cell function was severely depressed in multiply transfused patients. However, T4/T8 ratios were normal in this population. The role of chronic antigenic stimulation was studied by measurement of HLA-DR expression on T cells. The expression of HLA-DR antigen is markedly elevated in multiply transfused patients. These results show that chronic exposure to foreign antigens may be associated with abnormalities of immunologic function, but that chronically transfused patients do not have the same immunologic profile as reported in some homosexuals and hemophiliacs.