Autoimmune tubulointerstitial nephritis: insight from experimental models

Many forms of tubulointerstitial nephritis (TIN) may have an autoimmune origin. To understand the pathogenesis of autoimmune TIN it is important to examine suitable animal models where the initiation and development of tubulointerstitial diseases can be assessed with precision. Experimental models of autoimmune anti-tubular basement membrane (anti-TBM) disease for example have allowed to define the nephritogenic role of antibodies which target tubulointerstitial moieties. Several tubulointerstitial antigens which are recognized by specific anti-TBM antibodies have been characterized at a molecular level in these models. The CBA/CaH-kdkd mouse strain represents another model of TIN where complex T-cell networks are uniquely altered, resulting in cell-mediated interstitial nephritis. Characteristic tubular alterations (up-regulation of adhesion molecules and CD44, cytokine and chemokine secretion) are prominent in several models of experimental TIN, promoting T-cell and monocyte infiltration. The complex interplay between tubular epithelial cells and immune cells is probably a prerequisite for a coordinated immune response in many forms of TIN, resulting in autoimmune renal tubulointerstitial injury and ultimately in renal failure.