C3 and glomerulonephritis: Although most IgAN patients have undoubtedly had glomerulonephritis for years before a renal biopsy, it seems that a certain percentage of IgAN patients may go through a clinical period just after the onset, when neither IgA nor C3 is detectable in the renal biopsy but when there are histological lesions and aberrant urinary test results [7], [8].