Intragraft expression of transforming growth factor beta 1 gene in isolated glomeruli from human renal transplants

Background: Experimental evidence suggests that transforming growth factor (TGF) beta 1 is a fibrogenic cytokine. The histopathological changes of chr onic renal allograft nephropathy are dominated by fibrotic changes and TGF- beta may have an important aetiological role. This study investigated the r elationship between intragraft TGF-beta gene expression and extracellular m atrix protein deposition in human renal allografts. Methods: Sixteen cadaveric renal transplant recipients immunosuppressed wit h cyclosporin and steroids were studied. Individual glomeruli were isolated from protocol needle-core biopsies and, following messenger RNA extraction , intragraft gene expression was studied by reverse transcriptase-polymeras e chain reaction. Collagen III deposition in these renal transplant biopsie s was examined by immunohistochemistry and quantified by computerized histo morphometry. Results: There was a positive correlation between renal cortical collagen I II immunostaining and the levels of glomerular complementary DNA for TGF-be ta 1. Conclusion: TGF-beta 1 is a profibrotic influence in human renal transplant s. The methods described should prove of benefit in investigating the mecha nisms of chronic renal allograft damage.