Detection of immunoglobulin depositions by immunofluorescence and/or immunoperoxidase (P-AP method) in patients with IgA nephropathy.

Deposition of immunoglobulins in the glomeruli by immunoperoxidase (IP) and/or immunofluorescence (IF) using unfixed materials obtained from 25 patients with IgA nephropathy (IgAN) was evaluated. The results indicated that the deposition of IgA, IgM or IgG in the glomerular capillary walls using a peroxidase anti-peroxidase (P-AP) method was more prominently detected than by using IF. The results of double staining indicated that both P-AP and IF were able to stain mesangial and capillary depositions of IgA was more widely detected by P-AP than by IF. It is concluded that the P-AP method has the advantage of indicating the deposition of immunoglobulins in glomerular capillary walls, and evaluating the histopathological significance together with IF in patients with IgAN.