Cheng L, et al. - This study including patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) investigated the expression of complement regulatory proteins (CRPs) CD46, CD55, and CD59 in kidneys of these patients. Double immunofluorescence staining was performed that revealed expression of all the three CRPs on endothelial cells, podocytes, and mesangial cells in glomeruli. Also, in patients with AAV, expression levels of the three CRPs were disregulated in kidneys and were associated with the severity of renal injury.

Methods

• Researchers performed this study on 51 AVV patients.
• They used immunohistochemistry and double immunofluorescence staining to detect the expression of CD46, CD55 and CD59 in kidneys.

Results

• Expression of the three CRPs could be detected in the glomeruli and tubules of both AAV patients and normal controls, as revealed by immunohistochemical examination.
• In patients with AAV versus normal controls, the expression level of the three CRPs in glomeruli were significantly lower and the scores of CD46 and CD55 expression in the tubules were significantly lower.
• However, no significant difference was evident between the scores of CD59 expression in tubules of AAV patients and those of normal controls.
• Findings also demonstrated that among AAV patients, the expression level of CD46 in glomeruli correlated inversely with the proportion of normal glomeruli, while correlated with tubular atrophy in renal interstitium (r= -0.305, P=0.026; r=0.330, P= 0.023, respectively).
• Data also reported a correlation of the expression levels of CD55 and CD59 in glomeruli with the proportion of total crescents (r=0.384, P=0.006; r=0.351, P=0.011, respectively).