SEARCH RESULTS FOR: Hypersensitivity-Pneumonitis

Hypersensitivity-Pneumonitis

Hypersensitivity Pneumonitis: Pathogenesis and clinical findings Authors: Zarrukh Baig, Zaini Sarwar Reviewers: Natalie Morgunov, Sadie Kutz, Laura Byford-Richardson, Ciara Hanly, Yonglin Mai (麦泳琳)*, Kerri Johannson* * MD at time of publication Farming and Compost Farmer’s Lung (Common) Bird and Animal Proteins Bird Fancier’s Lung (Common) Water Contamination and Ventilation Organic antigen identified by dendritic cells Manufacturing and Chemical Workers Grain and Flour Processors Notes: Immune complex - Production of IgG antibodies (Type III hypersensitivity) Cell mediated - Sensitization of helper T cells (Type IV hypersensitivity) • Thereare3typesofhypersensitivity pneumonitis: acute, subacute, chronic • InacuteHP,removalofincitingantigen results in resolution of symptoms within days. *Lymphoplasmocytic interstitial infiltrate with bronchiolocentric distribution on pathology Epithelial injury (exact mechanism unknown) *Organizing pneumonia Dyspnea, tachypnea, and crackles Abbreviations: • HP – Hypersensitivity Pneumonitis • PFT – Pulmonary Function Test ↑ Neutrophils, mast cells, macrophages, CD8+ T cells, & inflammatory cytokines • *TriadofmainfindingsforsubacuteHP Systemic release of cytokines disrupts hypothalamic regulation Fever Macrophages ingest antigens *Poorly formed granulomas on pathology Tissue breakdown from neutrophils activates fibroblasts, which deposit collagen CT: Normal or diffuse ground- glass opacity (acute) Chronic deposition of collagen replaces normal lung parenchyma by scar tissues (Chronic Findings) Neutrophil elastase breaks down lung elastic fibers Tissue destruction of alveolar walls creates larger air spaces CT: Emphysema CT: Honeycombing (End stage Iung disease) Pathology: Advanced interstitial fibrosis PFT: Restrictive pattern ↓FEV1, ↓FVC, and ↓ DLCO Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published September 1, 2016, updated October 5, 2021 on www.thecalgaryguide.com

过敏性肺炎-发病机制和临床发现

过敏性肺炎: 发病机制和临床发现