Adult Henoch-Schönlein Purpura: Comprehensive Assessment of Demographic, Clinical, and Histopathological Features as Predictors for Systemic Involvement.

BACKGROUND: Henoch-Schönlein purpura (HSP) is a small-vessel IgA-predominant vasculitis. A major challenge in managing adult HSP is the difficulty assessing the risk of systemic involvement. There is currently a paucity of data in this area. OBJECTIVE: The objective of this study was to determine demographic, clinical, and histopathological features associated with systemic involvement in adult HSP. METHODS: In this retrospective study, we reviewed demographical features and clinical and pathology data of 112 adult HSP patients seen at Emek Medical Center between January 2008 and December 2020. RESULTS: Of these patients, 41 (36.6%) had renal involvement, 24 (21.4%) had gastrointestinal tract involvement, and 31 (27.7%) had joint involvement. Age >30 years (p = 0.006) at diagnosis was an independent predictor of renal involvement. Platelet count (<150 K/µL) (p = 0.020) and apoptosis of keratinocytes on skin biopsy (p = 0.031) were also associated with renal involvement. History of autoimmune disease (p = 0.001), positive c-antineutrophil cytoplasmic antibody (p = 0.018), positive rheumatoid factor (p = 0.029), and elevated erythrocyte sedimentation rate (p = 0.04) were associated with joint involvement. Female sex (p = 0.003), Arab race (p = 0.036), and positive pANCA (p = 0.011) were associated with gastrointestinal tract involvement. LIMITATIONS: This study is retrospective. CONCLUSION: These findings may serve as a guide to stratify risk in adult HSP patients so that those at higher risk can be monitored more closely.