OKT4 epitope deficiency in patients infected with the human immunodeficiency virus: a cause of underestimation of the CD4 lymphocyte count.

Two black patients who were infected with the human immunodeficiency virus (HIV) and who had hereditary deficiency of OKT4 epitope were investigated. The patients' lymphocytes lacked the OKT4 surface antigen but reacted with other monoclonal antibodies recognizing the CD4+ helper-inducer T lymphocytes. The CD4 lymphocyte count is a surrogate marker for clinical progression of HIV disease, but it could be unreliable in regard to patients with partial or complete OKT4 epitope deficiency.