Spontaneous production of Epstein-Barr virus by B lymphoblastoid cell lines obtained from patients with Sjögren's syndrome. Possible involvement of a novel strain of Epstein-Barr virus in disease pathogenesis.

OBJECTIVE: To investigate the involvement of Epstein-Barr virus (EBV) in the pathogenesis of Sjögren's syndrome (SS) and to examine whether the spontaneous production of EBV is unique to SS B cell lines.
METHODS: B cell lines were established from peripheral blood mononuclear cells (PBMC) of patients with systemic lupus erythematosus, rheumatoid arthritis, and SS. The cord blood immortalization assay, flow cytometric analysis, and polymerase chain reaction (PCR) were used to detect EBV production by B cell lines.
RESULTS: SS B cell lines produced EBV at a higher frequency, and in significantly larger amounts, than did other B cell lines. However, no correlation with the amount of EBV DNA in the genome of B cell lines was found. PCR analysis revealed that EBV with a B95-8--like U2 region was dominant in SS B cell lines.
CONCLUSION: Spontaneous, massive production of EBV by B cell lines is unique to SS, and may contribute to the polyclonal B cell activation seen in this disease.