OKT4+ T cell deficiency and an association of immunoglobulin deficiency in systemic lupus erythematosus.

A patient with systemic lupus erythematosus and selective serum IgA and IgM deficiency also had a deficiency of OKT4+, OKT4A+, OKT4B+, and OKT4E+ T cells in circulating blood. This deficiency of helper/inducer T cell subsets in blood was associated with impaired T cell responses to phytohaemagglutinin in vitro, and an impaired ability to produce IgA and IgM by the patient's B cells. The patient's OKT4+ (CD4+) T cell deficient population suppressed IgM synthesis by normal B and T cells.