Experimental pyelonephritis. The effect of T-cell deficiency on the course of hematogenous enterococcal pyelonephritis in the mouse.

The course of experimental hematogenous pyelonephritis due to Streptococcus faecalis was compared in athymic (nu/nu) mice and euthymic (nu/+) littermates. Up to 7 weeks following infection, there were no significant differences in renal microbial populations. At 63 and 107-131 days there was significant escalation of infection in nu/nu mice, while the nu/+ mice were decreasing their infections. There was no increase in gross abscess formation in nu/nu mice, but in late stages significantly more gross scarring occurred in nu/nu as compared with nu/+ mice. Microscopically there was also greater scarring in nu/nu mice late in the disease, except for calyceal lesions. The data suggest that immunologic factors (T cells) are involved in the pathogenesis of chronic pyelonephritis.