Brazilian Journal of Medical and Biological Research
On-line version ISSN 1414-431X
GELEILETE, T.J.M.; COSTA, R.S.; DANTAS, M. and COIMBRA, T.M.. a-Smooth muscle actin and proliferating cell nuclear antigen expression in focal segmental glomerulosclerosis: functional and structural parameters of renal disease progression. Braz J Med Biol Res [online]. 2001, vol.34, n.8, pp. 985-991. ISSN 1414-431X. http://dx.doi.org/10.1590/S0100-879X2001000800003.
The aim of the present study was to investigate the expression of a-smooth muscle actin (a-SM-actin) and proliferating cell nuclear antigen (PCNA) in renal cortex from patients with focal segmental glomerulosclerosis (FSGS) and their correlations with parameters of renal disease progression. We analyzed renal biopsies from 41 patients with idiopathic FSGS and from 14 control individuals. The a-SM-actin immunoreaction was evaluated using a score that reflected the changes in the extent and intensity of staining in the glomerular or cortical area. The PCNA reaction was quantified by counting the labeled cells of the glomeruli or renal cortex. The results, reported as median ± percentile (25th; 75th), showed that the a-SM-actin scores in the glomeruli and tubulointerstitium from the renal cortex were 2.0 (2.0; 4.0) and 3.0 (3.0; 4.0), respectively, in patients with FSGS, and 0.5 (0.0; 1.0) and 0.0 (0.0; 0.5) in the controls. The number of PCNA-positive cells per glomerulus and graded field of tubulointerstitium from the renal cortex was 0.2 (0.0; 0.4) and 1.1 (0.3; 2.2), respectively, for patients with FSGS, and 0.0 (0.0; 0.5) and 0.0 (0.0; 0.0) for controls. The present data showed an increase of a-SM-actin and PCNA expression in glomeruli and renal cortex from FSGS patients. The extent of immunoreaction for a-SM-actin in the tubulointerstitial area was correlated with the intensity of proteinuria. However, there was no correlation between the kidney expression of these proteins and the reciprocal of plasma creatinine level or renal fibrosis. These findings suggest that the immunohistochemical alterations may be reversible.
Keywords : a-smooth muscle actin; proliferating cell nuclear antigen; PCNA; focal segmental glomerulosclerosis; proteinuria; renal failure; renal disease progression; renal fibrosis.