PECAM1 and IgA glomerulonephritis: In the IgA nephropathy group, there was no significant correlation between the expression of Gd-IgA1 in the kidney and the expression of CD31, α-SMA and vimentin both in glomerulus and tubulointerstitium regions (P > 0.05) (Table 2).Meanwhile, there was a significant negative correlation between glomerular CD31 surface density and glomerular α-SMA surface density (r=-0.505 P = 0.01) and a significant positive correlation between glomerular α-SMA surface density and glomerular vimentin surface density (r = 0.578 P = 0.002).