A clinicopathological comparison between IgA nephropathy and Henoch-Schönlein purpura nephritis in children: use of the Oxford classification.

BACKGROUND: There is controversy over whether IgA nephropathy (IgAN) and Henoch-Schönlein purpura nephritis (HSPN) are the same diseases. This study focuses on the clinicopathological comparison between HSPN and IgAN in children. METHODS: Children with IgAN and HSPN who had a diagnostic renal biopsy were enrolled. This study collected the clinical data of patients at biopsy, re-evaluated the pathological lesions of patients according to the Oxford Classification (MEST-C), and made a retrospective comparison between IgAN and HSPN on different stratifications of the course (Tc) and proteinuria. RESULTS: A total of 142 children with IgAN and 57 children with HSPN were enrolled. Various stratification showed the same result, which suggested that IgAN showed more mesangial proliferation (M). HSPN showed more segmental glomerulosclerosis in the Tc > 12 m group than IgAN (S 60.0% vs. 9.10%, P = 0.008). In the non-nephrotic-range and nephrotic-range proteinuria group, there were no significant differences in MEST-C scores between IgAN and HSPN. CONCLUSION: M is more common in IgAN. HSPN had more S than IgAN over the course of more than 12 months. These results indicate the differences in the pathogenesis in IgAN and HSPN. We propose early biopsy and active treatment of HSPN within 12 months to delay the development of chronic lesions.