Table 2. Optimal cutoff value of serum IgA/C3 ratio in children with IgAN for proteinuria ≥50 (mg/kg/day) group and proteinuria <50 (mg/kg/day) group.

	Cutoff	Sensitivity	Specificity	AUC	P value
IgA/C3	2.025	0.6	0.762	0.717	<0.01

AUC, area under the curve; IgA, immunoglobulin A; C3, complement 3.