INTRARENAL LOCALIZATION OF INTERLEUKIN-1-BETA MESSENGER-RNA IN CRESCENTIC GLOMERULONEPHRITIS

Il-1 beta is a potent proinflammatory peptide, and induces expression of other cytokines which are involved in the immune response. Kidney b iopsies from nine patients with crescentic GN were studied by in-situ hybridization to determine the site of expression of Il-1 beta mRNA. B iopsies from nine patients with non-proliferative renal disease were s tudied as negative controls, and tonsillar tissue was studied as a pos itive control. An Il-1 beta cDNA probe was P-32-labelled by random pri mers and hybridized to paraffin-embedded tissue sections after de-waxi ng. Il-1 beta mRNA was expressed in tonsil, but not in negative contro ls. Positive mRNA expression was seen in four of the nine crescentic b iopsies. This was observed in interstitial cells with morphological ch aracteristics of macrophages adjacent to tubular cells, in cells withi n the glomerular tuft, and in tubular epithelial cells. Il-1 beta mRNA is expressed in renal tissue in crescentic GN. Tubular and interstiti al expression of Il-1 beta mRNA appears of equal prominence to glomeru lar expression. Intrarenal cytokine synthesis may be involved in the p athogenesis of crescentic glomerulonephritis.