RENAL EXPRESSION OF INTERLEUKIN-2 RECEPTOR MESSENGER-RNA IN PATIENTS WITH CRESCENTIC GLOMERULONEPHRITIS

We studied paraffin sections of renal biopsies from 7 patients with cr escentic glomerulonephritis (CGN) by in situ hybridisation, to detect sites of interleukin-2 receptor (IL-2R) mRNA expression. Frozen sectio ns from a further patient with CGN were studied by immunohistochemistr y with a monoclonal antibody to CD25, to detect IL-2R protein. Positiv e control sections were taken from biopsies of acute cellular renal tr ansplant rejection and negative controls from biopsies of membranous g lomerulonephritis. No autoradiographic signal was detected in negative controls. IL-2R mRNA expression was seen in rejected transplants and in sections from 4 of 7 patients with CGN. Expression was seen in cort ical interstitial cells, renal tubular epithelial cells, cells within glomerular crescents and in one glomerulus at the margin of Bowman's c apsule. Tubular cell expression of IL-2R protein was confirmed by immu nohistochemistry. We have confirmed that IL-2R mRNA expression occurs locally within the kidney in CGN and have identified expression in tub ular epithelial cells. The results suggest that local activation of im munocompetent cells occurs in the kidney and may be of significance in the pathogenesis of CGN.