CD79A and staphylococcus aureus infection: Various IF staining patterns of IgA-dominant IRGN are described, with Nasr et al reporting 8 out of 48 IgA-dominant IRGN cases positive for C1q.[4] Moreover, Satoskar et al reported 4 out of 8 cases of IgA-dominant staphylococcus infection-associated glomerulonephritis were IgG positive.[12] Due to the variety of potential immunostaining patterns it is difficult to diagnose IgA-dominant IRGN.