C3 and Microscopic hematuria: The Yasuhiko T team also reported that the serum IgA/C3 ratio might be used to diagnose and predict prognostic grading in patients with IgAN [33], and combined with microscopic hematuria and/or persistent proteinuria, high serum IgA levels, and the serum IgA/C3 ratio could be used to distinguish IgAN from other primary renal diseases [34].