Native idiopathic membranous nephropathy (nIMN) is an established antibody-mediated glomerular disease. A recent work has identified the M-type phospholipase A2 receptor (PLA2R), a 185-kD glomerular glycoprotein as the target antigen in nIMN. Recent studies have identified C4d glomerular staining as a marker of negative progression of renal function in a primary glomerular disease like IgA nephropathy.
Kidney sections were stained using polyclonal rabbit IgG anti-human C4d antibodies. Normal renal tissue was obtained from heart-beating braindead donors before kidney harvesting. Positive control biopsy was a humoral kidney rejection with intense C4d staining.
Data are expressed as M ± SD. Data suggest that C4d glomerular capillary deposits in nIMN with a follow-up longer than 6 months might be a negative prognostic factor for both UPr and eGFR. Study has limitations like the relatively short term follow-up and the little number of biopsy analyzed. Nevertheless, the association between increasing UPr, worsening of renal function and glomerular deposits of C4d in nIMN patients might deserve reporting and eventually confirmation by further investigations.