Abstract: Background: The International Study of Kidney Diseases in Children (ISKDC) classification is often used clinically in purpura nephritis (HSPN), but it can only reflect active inflammation of the kidney at the onset, instead of chronic leisons. Objective: To investigate the application value of the Oxford classification of IgA nephropathy (MEST-C) scale in children with HSPN. Design: Case series report. Methods: Children aged ≤14 years who were hospitalized in the First Affiliated Hospital of Henan University of Traditional Chinese Medicine from January 2015 to December 2017, who met the diagnostic criteria for HSPN and underwent renal biopsy were retrospectively collected. General information, laboratory indicators of urine and blood samples before renal biopsy, clinical manifestations, ISKDC grading, and immunofluorescence typing based on pathology reports were collected. The renal pathology was re-evaluated based on the pathology report with reference to the MEST-C scale under the guidance of the pathologist. Since there were no T1/T2 lesions in this study, the renal tubulointerstitial lesions were classified into acute (Ta) and chronic (Tc) scores. All patients were divided into the groups of mesangial cell hyperplasia (M0/M1), endothelial cell hyperplasia (E0/E1), segmental sclerosis/adhesion (S0/S1), Ta0/Ta1, Tc0/Tc1, crescent formation (C0/C1 /C2). The kappa concordance test was performed for MEST-C and ISKDC grading and immunofluorescence pathology. Main outcome measures: The consistency of different pathological types of HSPN. Results: A total of 341 children with HSPN were analyzed incuding 191 males and 150 females, with a median age of onset of 9(8,11) years and an interval of 10 (3, 21) days between the first symptoms and abnormal urine test resutls. Clinical typing was most common for hematuria and proteinuria, with a higher proportion of hematuria and proteinuria in the C1 group, a higher proportion of nephrotic syndrome in the M1, E1, and Ta1 groups, and a higher proportion of chronic nephritis in the S1 and Tc1 groups (all with P < 0.05). M1, Ta1, and C2 groups were associated with more severe microscopic hematuria(P < 0.05). M1, E1, Ta1, and C2 groups were associated with large amounts of proteinuria(P < 0.05). M1, Ta1, C1/C2 groups were associated with decreased eGFR levels(P < 0.05). ISKDC grade II and III were the most common, and there were no cases of grade I, V, and VI. E1 and C1 pathological changes were more common in MEST-C score. MEST-C was correlated with ISKDC grading. M1, E1, Ta1, C1/C2 groups had higher ISKDC grading, and that of S1 and Tc1 groups were lower. Conclusions: The consistency of MEST-C scores with clinical manifestations and laboratory indicators of HSPN in children was in accordance with clinical expectations. All MEST-C pathological indices were consistent with ISKDC grading, and Ta and E indices were consistent with the severity of complement C3 deposition and fibrinogen, respectively.

Key words: Children, Purpura nephritis, IgA nephropathy Oxford classification, Clinical, Pathology