Lymphocyte and neuronal antigens in neuropsychiatric lupus: presence of an elutable, immunoprecipitable lymphocyte/neuronal 52 kd reactivity.

OBJECTIVE: To examine specific lymphocyte or neuronal antigens immuno-precipitated by systemic lupus erythematosus (SLE) sera. METHOD: SLE sera were screened for the presence of antibodies binding to surface antigens of CD4(+) HUT-78 or SK-N-SH and IMR-6 neuroblastoma cells using Western blotting or radioimmunoprecipitation. RESULTS: IgG eluates from both lymphocytes and neuroblastoma cells recognised a 52 kd band in HUT 78 cell lysates. Eight sera studied further using radioimmunoprecipitation also demonstrated binding to a 52 kd antigen (4/8 on HUT-78, 8/8 on SK-N-SH cells), partially depleted by absorption with viable HUT-78. CONCLUSION: A 52 kd antigen recognised by SLE sera on lymphocytes and neuronal cells may play a role in the pathogenesis of neuropsychiatric-SLE.