The inhibition of granuloma formation around Schistosoma mansoni eggs.

The effect of protein, calorie, and vitamin deficiency states on the granulomatous response of mice to eggs of S mansoni injected into the microvasculature of the lungs was studied. Moderate to severe protein and calorie deficiencies, as well as thiamine and vitamin C deficiencies, inhibited the host's granulomatous response to S mansoni eggs, which is a form of delayed-type hypersensitivity. The antivitamins neopyrithiamine hydrochloride and desoxypyridoxine hydrochloride were both highly effective in suppressing granuloma formation, but the former proved highly toxic at the doses utilized. Desoxypyridoxine hydrochloride given at a dose of .05 mg/mouse/day produced almost complete inhibition of granuloma formation; marked suppression was also present at fivefold dilution. This antivitamin appearts to be one of the most powerful immunosuppressive measures so far examined.