Pulmonary thromboembolism and diffuse alveolar hemorrhage in granulomatosis with polyangiitis vasculitis.

Granulomatosis with polyangiitis (GPA) is a small-vessel and medium-vessel vasculitis that affects mainly the respiratory tract and kidney. The main acute complications of GPA are diffuse pulmonary hemorrhage and acute renal failure. Renal involvement occurs in 17% of patients, with histological features of pauci-immune, focal, and segmental necrotizing crescentic glomerulonephritis.1 Diffuse alveolar hemorrhage (DAH) is the most severe complication in small-vessel and medium-vessel vasculitis, and immunosuppressive therapy alone is not sufficient to treat this condition. A recent study revealed that the incidence of DAH in anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) ranges from 8 to 36%, with 41% of these diagnosed as GPA.2 There is no consensus for the diagnostic criteria of DAH, but the presence of dyspnea, hemoptysis, PaO2/FIO2 300, a decrease in hemoglobin levels (between 1 and 2 g/dL), compatible bronchoscopy or bronchoalveolar lavage, and abnormal chest radiography or computed tomography have been reported in different studies.2 Respiratory failure due to DAH and sepsis are the most common reasons for ICU admission in these patients, with 28-d and 1-y mortality rates of 11% and 29%, respectively, in a retrospective cohort study including 26 subjects.3 Moreover, there is an increased incidence of thromboembolic disease in GPA vasculitis.4,5 Here, we report the case of a patient with active GPA, anticoagulated because of deep venous thrombosis and pulmonary emboli, who developed DAH and renal failure.