The use of monoclonal anti-T cell antibodies to study T cell imbalances in human diseases.

Monoclonal antibodies are now available to evaluate human T cell subsets by direct counting using indirect immunofluorescence analysis. The critical use of these antibodies has already permitted the delineation of the T cell imbalances present in a number of immunologically mediated diseases such as autoimmune haemolytic anaemia, chronic active hepatitis, myasthenia gravis, glomerulonephritides, multiple sclerosis, leprosy, or immunodeficiency syndromes. The potential diagnostic and therapeutic application of this new methodology are emphasized.

Lymphocytotoxins in leprosy and in asymptomatic hepatitis B virus infection.

Serum lymphocytotoxic antibodies (LCAs) were detected in 67% of Papua New Guinean lepromatous leprosy patients who were persistent carriers of hepatitis B surface antigen (HBsAg). Lymphocytotoxins were not associated with asymptomatic HBsAg in either healthy controls or tuberculoid leprosy patients. It was apparent that, although HBsAg itself is a poor indicator of in vitro lymphocytotoxicity, when the antigen occurred in a host with impaired immune response, lymphocytotoxicity, when the antigen occurred in a host with impaired immune response, lymphocytotoxicity was enhanced. In contrast to this finding, lepromatous leprosy patients without HBsAg had significantly depressed LCA production in comparison with tuberculoid patients and controls. The interaction between leprosy and hepatitis B virus was highly significant (P = 0.001) in an analysis of variance of cytotoxicity scores. It is proposed that the previously reported equivocal results regarding autoantibodies in leprosy patients may be explained by this unusual interaction between lepromatous leprosy and hepatitis B virus infection.