Defective expression of OKT4 antigen on the cell surface of helper T lymphocytes in a patient with systemic lupus erythematosus.

OKT-monoclonal antibodies directed to total T-cells (OKT3), inducer/helper (OKT4) or suppressor/cytotoxic (OKT8) T-cells recognize developmental antigens on human T-cells. We report here an 18 year old male patient with systemic lupus erythematosus who had a prominent decrease in the proportion of OKT4-reactive T-cells in his peripheral blood, although the proportion of OKT3- and OKT8-reactive T-cells were essentially normal. His peripheral blood lymphocytes (PBL) responded well to stimulation by phytohemagglutinin-P (PHA) or concanavalin-A (Con A), which are stimulators for OKT4-reactive T-cells or for both subsets. Furthermore, helper T-cell function for B-cell proliferation was demonstrable in the patient's T-cells which lacked both OKT4 and OKT8 antigens. Trypsinization of PBL from healthy individuals abrogated detection of the OKT4 antigen, and a complete recovery of the antigen was observed after 6 days of culture of the treated PBL. The OKT4 antigen, however, could not be expressed on the patient's PBL after this treatment and incubation. In addition, the patient's serum could not block the recovery of OKT4 antigen on trypsinized T-cells from healthy individuals. The decrease in the percentage of OKT4-reactive T-cells was relatively stable in the patient, while his clinical disease activity and medications were variable. Taken together, these results suggest a defective expression of OKT4 antigen on the helper T-cell subset in this patient.