C5aR expression in kidney tubules, macrophages and fibrosis.

The anaphylatoxin C5a and its receptor C5aR (CD88) are complement pathway effectors implicated in renal diseases, including ANCA-associated vasculitis. We investigated the kidney expression of C5aR and a second C5a receptor C5L2 by using immunohistochemistry, in situ hybridization, and spatial gene expression on formalin-fixed, paraffin-embedded human and mouse kidney. C5aR was detected on interstitial macrophages and in multiple tubular regions, including distal and proximal; C5L2 had a similar expression pattern.