Retrograde Proteus pyelonephritis in rats. Localization of antigen and antibody in treated sterile pyelonephritic kidneys.

Rats with retrograde proteus pyelonephritis were treated with antibiotics until their kidneys became sterile. Using fluorescent antibody techniques, specific P. mirabilis antigen was found in some sterile pyelonephritic kidneys 20 weeks after cessation of treatment and presumed renal sterilization. Persistent antigen was associated with interstitial chronic inflammation but not with acute inflammation or progressive scarring. Rat gamma globulin and proteus antibody were localized in plasma cells of the renal inflammatory infiltrates. It is suggested that persistent antigen in chronic pyelonephritis may lead to the continued local appearance of antibody-producing cells.