CD79A and chronic kidney disease: In contrast, serum total IgA levels in children with IgAN ≥ 12 years (306 mg/dl, 199-444 mg/dl) were significantly elevated compared with those in HCs ≥ 12 years (210 mg/dl, 124-355 mg/dl) (p < 0.05), although those were not significantly elevated compared with those in patients with CKD ≥ 12 years (241 mg/dl, 97-455 mg/dl).