SEARCH RESULTS FOR: iga-vasculitis-henoch-scholein-purpura-pathogenesis-and-clinical-findings

iga-vasculitis-henoch-scholein-purpura-pathogenesis-and-clinical-findings

IgA Vasculitis (Henoch-Schönlein purpura) : Pathogenesis and clinical findings Authors: Mia Koegler Nela Cosic Reviewers: Crystal Liu Yan Yu* Martin Atkinson* * MD at time of publication Infectious Agents 50% have preceding upper respiratory tract infections, i.e., influenza virus or Group A Strep Drugs I.e., antibiotics (penicillin, erythromycin), NSAIDs and biologics (tumor necrosis factor α inhibitors) Immunogenetic and cellular predisposition Various genetic polymorphisms alter cell- mediated immune response, IgA levels elevated in 50% of people ↑ Circulating galactose-deficient IgA1 (GD-IgA1). Deficiency in galactosylation of IgAà↓ IgA serum clearanceàadhesion of IgA complexes, which then deposit into the endothelial lining of blood vesselsàattraction of various inflammatory cells to the area: Formation of Secretion of Interleukin 8 (IL8) - cytokine that induces Neutrophils infiltrate Activation of complement immune complexes neutrophilic chemotaxis and macrophage phagocytosis the tissue site factors (C3, C4) Leukocytoclastic vasculitis (histopathologic term for small vessels inflamed by neutrophilic autoimmune response) Inflamed cutaneous vessels become enlarged in clusters Symmetrical palpable purpura (red/purple, non- blanchable papules) distributed on lower limbs and buttocks areas Cutaneous small vessel vasculitis (100%) Inflamed gastric vessels - hemorrhage and edema within bowel wall Gastrointestinal (85%) Colicky abdominal pain (commonly in the periumbilical region), nausea, vomiting Gastrointestinal GI bleeding (hematemesis, melena), Intussusception Glomerular mesangial proliferation and inflammation ↑ mast cell deposition in joints Joints (60-85%) Arthralgia's (common), arthritis (especially knees and ankles) Arthralgia often transient. No permanent sequelae Sympathetic nervous system activation Glomerulosclerosis, tubulointerstitial and podocyte damage Renal tissue ischemia ↑ Na sensitivity in renal tubules (↑ Na and water retention) Renal (10-50%) Increased renin secretion HTN, nephrotic/nephritic syndrome, renal insufficiency Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published September 1, 2019 on www.thecalgaryguide.com