Characterization of the interstitial cellular infiltrate in experimental chronic cyclosporine nephropathy

In a recently described rodent model of chronic cyclosporine nephropathy (CCN) (consisting of irregularly distributed areas of interstitial inflammation, interstitial fibrosis, and tubular atrophy) we have characterized the interstitial inflammatory cells. Using a modified avidin-biotin peroxidase technique, kidney tissue was examined with monoclonal antibodies directed against leukocyte-common antigen (LCA), T lymphocytes, T helper and T nonhelper lymphocytes, I(a) (B cell marker), and macrophages. Injured cortex from cyclosporine-treated animals demonstrated increased numbers of T helper and B lymphocytes, macrophages, and cells bearing LCA. Cytotoxic (T nonhelper) cells were scant. Non-injured areas of cortex from CsA-treated animals demonstrated only a modest increase in macrophages when compared with vehicle controls and normal rats. We conclude that CCN in rodents is characterized by an interstitial inflammatory infiltrate of T helper cells, B cells, and macrophages. The role of these cells in the pathogenesis of CCN, however, remains speculative.