BackgroundPreviously, several studies have indicated that pediatric IgA nephropathy (IgAN) might be different from adult IgAN, and treatment strategies might be also different between pediatric IgAN and adult IgAN.MethodsWe analyzed two prospective cohorts established by pediatric and adult nephrologists, respectively. A comprehensive analysis was performed investigating the difference in clinical and pathological characteristics, treatment, and prognosis between children and adults with IgAN.ResultsA total of 1015 children and 1911 adults with IgAN were eligible for analysis. More frequent gross hematuria (88% vs. 20%, p < 0.0001) and higher proteinuria (1.8 vs. 1.3 g/d, p < 0.0001) were seen in children compared to adults. In comparison, the estimated glomerular filtration rate (eGFR) was lower in adults (80.4 vs. 163 ml/min/1.73 m2, p < 0.0001). Hypertension was more prevalent in adult patients. Pathologically, a higher proportion of M1 was revealed (62% vs. 39%, p < 0.0001) in children than in adults. S1 (62% vs. 28%, p < 0.0001) and T1–2 (34% vs. 8%, p < 0.0001) were more frequent in adults. Adjusted by proteinuria, eGFR, and hypertension, children were more likely to be treated with glucocorticoids than adults (87% vs. 45%, p < 0.0001). After propensity score matching, in IgAN with proteinuria > 1 g/d, children treated with steroids were 1.87 (95% CI 1.16–3.02, p = 0.01) times more likely to reach complete remission of proteinuria compared with adults treated with steroids.ConclusionsChildren present significantly differently from adults with IgAN in clinical and pathological manifestations and disease progression. Steroid response might be better in children.Graphical A higher resolution version of the Graphical abstract is available as Supplementary information