Splenomimetic effect of Corynebacterium parvum in fulminant pneumococcemia

The efficacy of Corynebacterium parvum to stimulate splenic growth and to boost host survival was examined by using adult Sprague-Dawley rats in a highly spleen-sensitive model of fulminant pneumococcemia. Rats were either treated (10 days or 1 hr before or 1 hr after) or not treated with C. parvum; were depleted of complement; underwent partial, total, or sham splenic resection; and then were challenged with either a low (2 X 10(2)) or a high (2 X 10(5)) dose of pneumococci. In the absence of C. parvum, survival (percent and duration) was lowest after total splenectomy and was proportional to remnant spleen weight after partial splenectomy. Although C. parvum treatment sharply increased splenic weight, nucleated cell numbers, and survival, the lowered mortality and improved survival time were independent of spleen weight. The rapidly acting, extrasplenic, splenomimetic protective effect of C. parvum suggests that this class of immunomodulators may be a useful adjunct in managing sepsis associated with defective or absent splenic function.