Analysis of renal immunoexpression of cyclooxygenase-1 and cyclooxygenase-2 in lupus and nonlupus membranous glomerulopathy.

Recently a role of the upregulation ofcyclooxygenase isoforms in renal injury and modulation the severity of the inflammatory reactions is suggested. Cyclooxygenase exists as two isoforms COX-1 and COX-2 which are poorly understood with regard to their roles in renal function. Thereby, the present study was undertaken to ascertain the immunoexpression of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) in lupus (LMGN) and nonlupus (NLMGN) membranous glomerulopathy and to examine the possible relationship between this immunoexpresion and inflammatory infiltrates. Eleven renal biopsy specimens from patients with class V lupus glomerulopathy and 16 from patients with primary (nonlupus) membranous glomerulopathy were examined by percutaneous renal biopsy. As a control 10 biopsy specimens of the kidneys removed because of trauma were used. In each specimen staining intensity of COX-1 and COX-2 in glomeruli, tubuli, arterioles and interstitial cells were recorded semiquantitatively whereas CD68+ cells, CD3+ cells and CD20+ cells were assessed quantitatively using computer image analysis system. Our study revealed that the mean scores of COX-1 immunoexpression did not differ significantly in all groups investigated whereas immunoexpression of COX-2 in LMGN was significantly stronger as compared with both NLMGN and controls. Moreover, in LMGN a significant positive relationship was noted between COX-2 immunoexpression and CD 68+ cells. In NLMGN and controls the correlations between COX-2 immunoexpression and CD 68+ cells were positive, but they have not reached statistical significance. In conclusion, our findings point that glomerular inflammation in lupus and non-lupus membranous glomerulopathy have different signalling pathways and suggest that in lupus nephritis COX-2 and monocytes/ macrophages but not COX-1 isoform are involved in the inflammatory process.