[Studies on the immunopathogenesis of experimental tubulointerstitial nephritis in Wistar rats].

Tubulointerstitial nephritis (TIN) model was successfully induced in female Wistar rats by immunization with rabbit tubular basement membrane (TBM) etc. By using immunohistochemistry and computer assisted image processing, characterization of mononuclear cells in the TIN models were determined, and the relationship between Ia antigen expression of renal tissue and TIN studied. The results showed: TIN was characterized by deposition of IgG in a linear pattern along TBM and mononuclear cells infiltrates, which suggests the production of anti-TBM antibodies. Among the mononuclear cells, most are T cells. Granuloma formation was observed in parts of TIN. B cells gradually decreased while monocytes gradually increased. The renal tissue lesions show tubular atrophy and peritubular fibrosis. This model strongly suggests that cellular immune responses play an important role in the development of TIN. Ia antigen expression is higher in cells of the tubular epithelium and Bowman's capsule of lesion site than in control group (P < 0.01). This is strong evidence that the abnormal expression of Ia antigen may be affected by the production and development of TIN.