Endocapillary Proliferation was Associated with Unfavorable Outcomes in Children with Henoch-Schönlein Purpura Nephritis and IgA Nephropathy

Abstract Introduction: There are limited data on the outcomes in children with Henoch-Schönlein purpura nephritis (HSPN) and IgA nephropathy (IgAN) in limited-resource countries. This study was aimed to evaluate the outcome of HSPN and IgAN and to evaluate the pathological findings associated with unfavorable outcomes.Materials and methods: This was a retrospective study conducted in children (≤18 years) diagnosed with HSPN or IgAN, had estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m2 and underwent renal biopsy between year 2002 - 2018 at Ramathibodi Hospital, Bangkok, Thailand. Clinical outcomes were graded according to the outcome classification by Counahan, as follows: favorable [A, normal; B, minor urinary abnormalities (proteinuria < 1 g/1.73 m2/day)]; unfavorable [C, active renal disease (proteinuria > 1 g/1.73 m2/day and/or hypertension); D, renal insufficiency (eGFR < 60 mL/min/1.73 m2 or died)]. Pathologies were graded according to Oxford classification.Results: A total of 47 patients (28 HSPN and 19 IgAN) were included with means of age at 9.4 ± 2.8 vs 11.3 ± 4.3 years, respectively. After a median follow-up time of 50 months, proportions of favorable outcomes in the patients with HSPN and IgAN were 82.1% (23/28) and 89.5% (17/19), respectively (p-value = 0.685). In multivariate analysis, only endocapillary proliferation (E) was associated with unfavorable outcomes in both diseases with the odds ratio (95% CI) of 12.46 (1.36 - 114.51, p-value = 0.026).Conclusion: The clinical outcomes of most patients with HSPN and IgAN were favorable and comparable. Endocapillary proliferation (E) was the only factor associated with poor outcome in both diseases.