BackgroundOver the last 20 years, the prevalence of obesity is increased in the developed and developing countries. Adipose tissue has an effect on inflammatory processes and immune system besides metabolic and appetite regulating mechanisms. On this basis, it is now of major interest to clarify the relationship between obesity and autoimmune/inflammatory diseases (1,2).ObjectivesWe aimed to evaluate the role of obesity on the clinical course and response to treatment in patients with Henoch Shönlein Purpura (HSP).MethodsData charts of children with HSP followed in Dokuz Eylül University Childrens’ Hospital were reviewed retrospectively. Obesity was defined as BMI ≥95 percentile in conformity with Centers for Disease Control and Prevention (CDC) (3). Persistant purpura was defined as skin involvement persisting for ≥30 days. Mild nephropathy was defined by the presence of microscopical hematuria and/or nonnephrotic proteinuria, and severe nephropathy by nephrotic syndrome and/or acute nephritic syndrome and/or renal insufficiency (4). Patients were grouped as obese and non-obese depending on BMI. Two groups were compared for demographic, clinical and laboratory parameters.ResultsThere were 199 patients [M/F:104/95; presenting age 7.1 years (range 5.0-9.2); follow-up period 17.5 months (range 3-50)]. Obesity was present in 35 (17.5%) of children. These patients were determined to have significantly higher rate of persistent purpura (45.7% vs 20.7%), severe renal involvement (57.7% vs 30.8%), hypertension (28.6% vs 9.1%) and increased erythrocyte sedimentation rate (79.2% vs 55.9%). Obese patients also showed delayed improvement of skin (25 vs 14 days), joint (12.5 vs 10.0 days) and renal (280 vs 57 days) symptoms. While the rate of children requiring steroid treatment was not different between the two groups, obese children used steroids for significantly longer time (236 vs 40 days). Furthermore, need for immunosuppressive medications (azathioprine and cyclophosphamide) were higher in obese patients (40.0% vs 8.6%).ConclusionObese children with HSP seem to have higher ESR, hypertension and severe renal involvement; show delayed improvement of skin, joint and renal findings; need more immunosuppressive medications and longer period of immunosuppressive treatment. These findings may be associated with the effect of adipose tissue on inflammation.References[1] Versini M, Jeandel P-Y, Rosenthal E, Shoenfeld Y. Obesity in autoimmune diseases: not a passive bystander. Autoimmun Rev. 2014;13:981–1000.[2] Zhao Y, Liu Z, Bai X et all. Obesity increases the risk of renal involvement in children with Henoch–Schönlein purpura. Eur J Pediatr (2015) 174:1357–1363 [3] Styne DM, Arslanian SA, Connor EL et all. Pediatric Obesity—Assessment, Treatment, and Prevention: An Endocrine Society Clinical Practice Guideline. The Journal of Clinical Endocrinology & Metabolism, Volume 102, Issue 3, 1 March 2017, Pages 709–757[4] Trapani S, Micheli A, Grisolia F et all. Henoch Schonlein Purpura in childhood: epidemiological and clinical analy...