Purpose: MRL/Mp-lpr/lpr (MRL/lpr) mice spontaneously develop an autoimmune disease characterized by lymphoproliferation, vasculitis, glomerulonephritis, autoantibody production, and ocular and lacrimal gland inflammation. Lacrimal gland lesions in MRL/lpr mice are a model for the human disorder Sjögren's syndrome. The target organ lesions in MRL/lpr mice, including those in the eye and lacrimal gland, are composed largely of CD4+ T cells, with lesser numbers of CD8+ T cells and B cells. Cyclosporine therapy was evaluated for its effect on the autoimmune disease, particularly in the eye and lacrimal gland.
Methods: MRL/lpr mice were administered cyclosporine intraperitoneally at a dosage of 2 mg daily from age 1 to 5 months. Animals were killed at 5 months and evaluated for the presence of autoimmune disease. Control groups consisted of animals given daily injections with either saline or the cyclosporine diluent.
Results: Cyclosporine therapy was effective in reducing the ocular and lacrimal gland disease. Intraocular inflammation was present in 73% of control animals but in only 15% of cyclosporine-treated animals (P < 0.003). Multifocal lacrimal gland inflammatory infiltrates were present in 100% of controls but in only 23% of cyclosporine-treated animals (P < 0.0001). Mean percent area involved by lacrimal gland inflammation was reduced from 19.7% to 4.7% by cyclosporine therapy (P = 0.0003). Systemic autoimmune disease manifestations, including lymphoproliferation, vasculitis, glomerulonephritis, and serologic abnormalities, also were improved.
Conclusions: Chronic cyclosporine therapy, started at an early age, is effective in controlling the autoimmune disease in MRL/lpr mice, including the ocular and lacrimal gland lesions.