Inhibition by cyclosporin A of streptococcal cell wall-induced hepatic granulomas in LEW/N rats.

A single intraperitoneal injection of an aqueous suspension of group A streptococcal cell wall fragments into susceptible LEW/N female rats results in the development of noncaseating hepatic granulomas as a consequence of deposition and persistence of the cell walls in the liver. We have studied the effect of daily intramuscular injections of CS-A, an inhibitor of T lymphocyte activation, on granuloma formation. CS-A-treatment resulted in the pronounced inhibition of granuloma formation, although no appreciable differences in quantity of streptococcal cell wall antigens, which were deposited in the liver, could be demonstrated. These data suggest that activated T lymphocytes play a key role in the pathogenesis of this granulomatous process.