Lung-limited granulomatosis with polyangiitis and the importance of early treatment: a case report.

Introduction and importance: Granulomatosis with polyangiitis (GPA) is a rare systemic vasculitis causing necrotizing granulomatous inflammation, mostly affecting the respiratory tract and kidneys. It has an annual incidence of 0.3 to 1.4 per 100 000. Diagnosis is based on clinical presentation and serological findings. Treatment typically involves glucocorticoids and cyclophosphamide. This article describes a case of GPA in an elderly male with cough, hemoptysis, and bilateral hearing loss. Case Presentation: A 58-year-old man presented with hemoptysis, cough, fever, joint pain, and fatigue. Initially diagnosed with pneumonia, he showed improvements with prednisolone but experienced recurring symptoms. Examination revealed abnormal CBC, proteinuria, and positive cytoplasmic antineutrophil cytoplasmic antibodies (c-ANCA), indicating granulomatosis with polyangiitis. Due to hypoxia and alveolar hemorrhage, high-dose corticosteroid therapy was initiated, followed by rituximab, leading to significant improvement. Clinical Discussion: Granulomatosis with polyangiitis (GPA) is a rare autoimmune disease primarily affecting the upper respiratory tract, lungs, and kidneys. The disease's main inflammatory marker is c-ANCA. Treatment often involves steroids and immunosuppressants. This case emphasizes the necessity of early treatment, even without histological confirmation, due to severe symptoms like hemoptysis, hypoxia, and alveolar hemorrhage, but without renal involvement. Conclusion: Although GPA is systemic, it often appears in a limited form, affecting the respiratory system. While diagnosis requires a tissue biopsy, treatment should begin upon suspicion, especially in remote areas, to reduce morbidity and mortality and improve outcomes, which is the main purpose of working on this paper.