Hereditary abnormalities of the OKT4 human lymphocyte epitope in two families.

The lymphocytes of two unrelated black individuals exhibited no immunofluorescent staining by a monoclonal antibody, OKT4, that reacts with T helper/inducer cells, but the lymphocytes reacted normally with four other monoclonal antibodies that identify T helper cells. Four first-degree relatives of these individuals were available for study. They had a normal proportion of OKT4+ lymphocytes but these cells had approximately half the normal number of OKT4 sites. This abnormality appears to be inherited as an autosomal recessive state.