Effects of cyclosporine and cortisone on the pathogenesis of primary infection with cytomegalovirus in the guinea pig.

Effects of the immunosuppressive agents cyclosporine (CsA) and cortisone on the pathogenesis of primary infections with cytomegalovirus (CMV) were investigated in the guinea pig model. All animals received 10(4) 50% tissue culture infectious doses of virulent salivary gland-passaged guinea pig CMV (GPCMV) subcutaneously on day 0. Oral CsA (20 mg/kg per day) and/or subcutaneous cortisone (10 mg/kg per day) were administered until the animals were killed on day 14. Untreated controls developed lymphocytosis, and GPCMV was isolated from 19.4% of cocultivated tissues. Animals treated with CsA alone developed lymphopenia, and GPCMV was isolated from 53% of their tissues, including 16 of 16 lungs. Histopathology showed widespread viral inclusions and minimal inflammatory response to GPCMV in CsA-treated animals. Guinea pigs treated with either cortisone or CsA/cortisone did not develop lymphopenia, and their rates of isolation of GPCMV were significantly lower than those of CsA-treated animals.