Treatment of Experimental Autoimmune Dacryoadenitis with Cyclosporin A

Abstract

Experimental autoimmune dacryoadenitis (EAD) was induced in SJL/J mice by a single injection of purified lacrimal gland antigen (LG-Ag) in complete Freund's adjuvant. The disease is characterized by lymphocytic infiltration of the lacrimal gland and production of lacrimal gland-specific antibodies. We examined the effects of cyclosporin A (CsA) on the development and progression of this inflammatory disease. CsA (100 mg/kg/day), given from the time of immunization for 14 days, completely blocked the development of EAD in all treated mice. Both cellular and humoral immune responses to LG-Ag were markedly reduced by the administration of CsA as evidenced by the near absence of lymphocyte proliferative response and the reduced production of circulating anti-LG-Ag antibodies. Delayed CsA treatment beginning on Day 7 after immunization totally abrogated the development of lacrimal histological lesions and lymphocyte proliferative response to LG-Ag. However, serum anti-LG-Ag titers were only marginally decreased in CsA-treated animals. Treatment with CsA was found effective even when daily injections were started 14 days after immunization with LG-Ag. CsA prevented the inflammatory cell response in 5 of 10 mice when the disease was established. The lymphocyte proliferative response to LG-Ag was moderately depressed in CsA-treated animals, but antibody titers were the same as those in the oil-treated control. These studies demonstrate that CsA has a therapeutic effect in this murine model of dacryoadenitis and suggest a critical role for T lymphocytes in the pathogenesis of EAD.