Risk factors for renal involvement and severe kidney disease in 2731 Chinese children with Henoch–Schönlein purpura: A retrospective study

To identify the risk factors for developing renal involvement and severe kidney disease in Chinese childhood Henoch–Schönlein purpura (HSP) patients. This was a retrospective study of 2731 children with HSP diagnosed between 2012 and 2015. We analyzed their demographic data, clinical manifestations, and laboratory tests retrospectively. Multivariate logistic regression analysis was used to assess the risk factors. Renal involvement occurred in 844 HSP patients (35.60%), and severe kidney disease occurred in 104 HSP patients (4.39%). Age over 6 years old at onset, colder season, more than 8 days interval between symptom onset and diagnosis, residence in rural, recurrence, angioedema, and the central nervous system (CNS) involvement were the significant risk factors for renal involvement. At the same time, age over 6 years at onset, more than 8 days interval between symptom onset and diagnosis, recurrence, angioedema, and CNS involvement were highly associated with severe kidney disease. Angioedema, longer interval between symptom onset and diagnosis, older age at HSP onset, and recurrence are prognostic indicators for renal involvement and severe kidney disease in children with HSP. The onset in colder season and rural residence associated with an increased risk for renal involvement, and the CNS involvement had an increased risk for severe kidney disease. HSP tends not to be self-limiting, and could progress into renal involvement or severe kidney disease for some of the HSP patients. Pediatricians should pay more attention to the children diagnosed with HSP, who also have these risk factors, for potential to develop renal involvement, and severe kidney disease, especially.