Effect of Adhesion Molecule P-selectin and Dendritic Cells on Tubulointerstitial Lesions in IgA Nephropathy

To observe the expression of P-selectin and the localization of dendritic cells (DCs) in human kidney with IgA nephropathy, and to evaluate their function in human renal tubulointerstitial lesions and renal dysfunction, 45 biopsy specimens of patients with IgA nephropathy were divided into 3 groups according to the degree of renal tubulointerstitial lesions: i. e. mild group ( n =29), moderate group ( n =10), severe group ( n =6). Ten normal renal tissues severed as control. The expression of P-selectin was analysed by immunohistochemistry. CD1a +CD80 +DCs were investigated by double immunostaining method and the images were analyzed with Axioplan 2 microscopy. The experimental results showed that (1) P-selectin was not expressed in normal controls, but presented mainly in renal tubular epithelial cells, which was greater in severe group than mild and moderate groups. The expression of P-selectin was associated with the degree of renal tubulointerstitial lesions. (2) CD1a +CD80 +DCs were hardly observed in nomal renal tissues, but in renal tissues of patients with IgA nephropathy, CD1a +CD80 +DCs were mostly found in renal tubulointerstitium. Also the distribution area, number and density of CD1a +CD80 +DCs in severe group was much more than other groups, which was associated with the degree of renal tubulointerstitial lesions and the lever of serum creatine. The distribution of CD1a +CD80 +DCs was associated with the expression of P-selectin in patient′s renal tubulointerstitium. The present study demonstrated that P-selectin and DCs might play an important role in renal tubulointerstitial lesions of IgA nephropathy, and DCs recruited into the renal tissues with IgA nephropathy might be mediated by P-selectin.

SIGNIFICANCE OF P-SELECTIN EXPRESSION INIGA NEPHROPATHY

Objective To investigate the role of P- selectin in Ig A nephropathy (IgAN). Methods PlasmaP-selectin level was measured by ELISA and P- selectin expression in renal tissue was detected byimmunohistochemistry and in situ hybridization in 45 patients with IgAN Results Plasma P-selectin levels inthe patients with IgAN were significantly higher than those in the controls. In IgAN the levels in the patientswith nephrotic syndrome or renal function insuffciency were much higher than those in the patients with grosshematuria, abnormal urine analyses or nephritis syndrome. P- selectin was widely expressed within renal tissue inIgAN. Glomerular P- selectin expression was remarkably up - regulated in grade IV and V of IgAN than that ingrade H and Ⅲ. Moreover, the expression of P- selectin on tubular epithelium or within interstitium was stronglyassociated with the degree of tubulointerstitial lesions. Conclusion The results suggested that P-selectin mightplay an important role in IgAN and the level of P- selectin in plasma and renal tissue might predict the progressof IgAN.