CD79A and membranoproliferative glomerulonephritis: Assessment of renal biopsy specimens at second admission demonstrated membranoproliferative glomerulonephritis via light microscopy and positive stains for IgG, IgM, IgA, C3, and C1q in immunofluorescence studies, compatible with class IV + V lupus nephritis (Figs. 5, 6, 7).