The study includes 19 patients with a previous history of HSP that were previously hospitalized in the pediatric department at Meyer Children’s Hospital, Rambam Medical Center in Israel and were followed in the pediatric rheumatology clinic. Their diagnosis was based on the clinical criteria for HSP . The minimal interval between the diagnosis of HSP and endothelial study was 5 months. Patients with chronic renal disease secondary to HSP or other chronic disease were excluded from the study.