Significance of kidney tissue expression of TGF-beta in pathogenesis and progression of focal segmental glomerulosclerosis

Pathogenesis of focal segmental glomerulosclerosis(FSGS)is not resolved.It is assumed that TGF-beta might be involved in the formation of extracellular matrix resulting in interstitial fibrosis and glomerular lesions of FSGS.The aim of our study was to analyze TGF-beta expression considering pathohistological findings and clinical course.TGF-beta expression was determined using mouse monoclonal antibodies and estimated semiquantitively in 51 patients with biopsy proven FSGS.The degree of tissue damage was determined morphometrically as degree of glomerular sclerosis and interstitial fibrosis.Significantly positive correlation was found between TGF-beta expression and irreversible histological changes of glomeruli(R=0.414 ; p=0.024).Also the patients with severe degree of interstitial fibrosis showed significantly greater TGF-beta expression than those with mild or moderate fibrotic changes(R=0.531 ; p=0.0061).Greater TGF-beta expression was found in patients with severe proteinuria(>3.5 g/day)which is one of the indicators of unfavorable prognosis(p>0.05). On the basis of our results it could be concluded that TGF-beta is a cytokine that might influence natural course of FSGS.It is speculative whether increased expression of TGF-beta might be of prognostic value in individual cases.The greater expression of TGF-beta was found in the patients with clinical and histological signs of advanced disease.