Role of autoantibodies against tubular brush border antigens in tubulointerstital nephritis associated with Heymann nephritis

Previous studies have shown that al rat experimental model of membranous ne phropathy (Heymann nephritis) is often associated with tubulointerstitial c hanges. Although antibody-dependent tubular injuries have been proposed in this model, precise mechanisms have been ill-defined. In the present report , we established a model of acute tubulointerstitial nephritis (TIN) by inj ecting puromycin aminonucleoside (PAN) to Wistar rats which had been immuni zed with tubular antigens (Tub-Ag). In this model, TIN developed 4 weeks af ter Tub-Ag immunization when rats had a high titer of circulating anti-Tub- Ag antibodies and began to excrete massive proteinuria. Deposits of immunog lobulins along tubular brush borders were also demonstrated. Rats receiving either Tub-Ag or PAN alone failed to develop TIN during this relatively ac ute phase. These results suggest that anti-Tub-Ag antibodies excreted into the urine play a role in developing TIN in this model.