A retrospective analysis of children with Henoch-Schonlein purpura and re-evaluation of renal pathologies using Oxford classification

Background Henoch-Schonlein purpura (HSP) is the most common vasculitis in childhood. The long-term prognosis is variable and depends on renal involvement. The aims of this study were to investigate the clinical and laboratory characteristics of our HSP patients, to identify the risk factors for the development of Henoch-Schönlein purpura nephritis (HSPN) and to assess the efficacy of the Oxford Classification system for predicting renal outcomes. Methods We performed a retrospective review of HSP patients who admitted to our center between 2001 and 2016, and were < 18 years on admission. Results A total of 1120 children with HSP were analyzed. Their mean age was 7.4 ± 3.4 years. At onset, purpura was present in all cases, arthritis/arthralgia in 42.4%, abdominal involvement in 39% and renal involvement in 37%. Risk factors for the development of nephritis were age ≥ 8 years, atypical distribution of purpura, ESR > 20 mm/h and abdominal pain. Renal biopsy was performed on 75 patients before immunosuppressive treatment. The mesangial score was strongly associated with proteinuria. Segmental glomerulosclerosis, tubular atrophy/interstitial fibrosis, and crescent formation of ≥ 50% were associated with reduced eGFR at the time of biopsy. A Kaplan-Meier plot showed that segmental glomerulosclerosis and tubular atrophy/interstitial fibrosis significantly predict poor renal outcome. Conclusion The long-term morbidity of HSP is predominantly attributed to renal involvement. Patients with HSP, who have a high risk to develop nephritis, could be followed for longer periods of time. The Oxford classification is useful in predicting long-term outcomes of HSPN.