Effects of oral aspirin and oxaprozin on the development of lupus-like disease in MRL/1 mice.

We examined the effects of two prostaglandin synthetase inhibitors, aspirin and oxaprozin, on the development of lupus-like disease in MRL/1 mice. Daily oral administration of 100 mg/kg of these compounds over a period of 3 months significantly reduced thymic lymphoid hyperplasia. In addition, aspirin but not oxaprozin significantly lowered total lymphocyte counts in the peripheral blood. Other drug-related changes, including reduced hyperplasia in the spleen and lymph nodes and an improvement in kidney vasculitis by aspirin, did not reach statistical significance. Neither aspirin nor oxaprozin influenced the circulating levels of anti-ds DNA antibodies or the severity of kidney glomerulonephritis. While the overall effects of these cyclooxygenase inhibitors were not dramatic, the results do indicate that further studies are warranted to determine the precise therapeutic role, if any, for PG-synthetase inhibitors in lupus-like disease.