Significance of P-selectin expression in human glomerulonephritis

To examine the relationship between P-selectin expression and human glomerulonephritis.

P-selectin expression was investigated in renal biopsies of glomerulonephritis patients (n = 133) by immunohistochemical and in situ hybridization analyses. They were divided into three groups based on the degrees of cells proliferation or sclerosis. Group I: histological lesions in glomeruli are mild (n = 23); Group II: glomerular cells proliferation is prominent (n = 91); Group III: glomerular sclerosis is severe (n = 19). The Kruskal-Wallis test, Chisquare test and Spearman's correlation were used in our study.

In normal controls, renal P-selectin expression was negative (n = 10). In glomerulonephritis, the up-regulated P-selectin expression on tubular epithelium was significantly higher than that on glomeruli and interstitium (P < 0.01). P-selectin was expressed predominantly on platelets in glomeruli, and glomerular P-selectin expression was more significantly up-regulated in Group II than in Group I or Group III (P < 0.05; and P < 0.01, respectively). There were strong correlations between the degree of tubulointerstitial lesions and the expression of P-selectin on tubular epithelium or within interstitium (rs = 0.395 and rs = 0.337, P < 0.01). Furthermore, P-selectin messenger RNA (mRNA) signals were also detected in the cytoplasm of glomerulus, tubular epithelial cells, interstitium and vascular endothelium.

P-selectin might mediate intraglomerular platelets aggregation, activation and leukocyte accumulation in the early stages of human proliferative glomerulonephritis. The up-regulation of P-selectin in interstitium was associated with interstitial fibrosis and tubular atrophy and may contribute to the progression of glomerulonephritis.