C3 and IgA glomerulonephritis: The results of retrospective analysis in this study showed that 21.85% of patients with IgA nephropathy had hypoc3-emia, and the mean value of BUN and serum creatinine in patients with reduced serum C3 were higher than those in the normal group, with significant statistical significance, suggesting that C3 consumption in IgAN patients was closely related to renal function damage.