In our patient, additional serum measurements included anti-streptolysin titer (AST) and anti-DNAse B titer, mycoplasma, hepatitis B and C serology, ANA, anti-PR3 ANCA, anti-MPO ANCA, anti-GBM measurements, and a full complement cascade for assessment of both the classical and alternative pathways (C3, C4, C3d, AP50, CH50, C3 nephritic factor, C5b-9). This evidence concerns the gene C3 and hepatitis A virus infection.