AB038. Isolated pauci-immune pulmonary capillaritis: rare case of diffuse alveolar hemorrhage

Abstract: As diffuse alveolar hemorrhage is defined the clinical pathological syndrome characterized by hemoptysis, diffuse alveolar infiltrates, acute respiratory failure and anemia. It is a life-threatening condition and a medical emergency. Causes are multiple and variable. A 75-year-old male, ex-smoker, with known coronary artery disease and paroxysmal atrial fibrillation treated with aspirin, presents due to low grade fever and bloody sputum. Hemodynamically stable, without respiratory failure, but with multiple alveolar infiltrates on chest imaging and anemia. Initially treated as lower respiratory tract infection with intravenous antibiotics while anticoagulant treatment was interrupted. Full laboratory testing for anemia, collagen vascular diseases and specific and nonspecific infections was performed. Anemia was normochromic, normocytic, without findings of hemolysis. Diffuse bilateral alveolar infiltrates were revealed on thorax computer tomography. Diagnostic bronchoscopy was performed with negative results for either infection or malignancy, while bronchoalveolar lavage analysis revealed siderophages 81% of alveolar macrophages. The patient underwent full pulmonary function testing, which revealed obstructive respiratory disease with a low diffusion capacity. Due to continuing life threatening anemia, despite blood transfusions, in combination with the results of the laboratory tests, the patient was started on high dose intravenous corticosteroids, followed by intravenous cyclophosphamide every 28 days for five cycles. Rapid improvement was achieved with elimination of chest CT infiltrates and normalization of blood tests and pulmonary function tests. At present peros treatment with azathioprine and low dose corticosteroids is given. Diffuse alveolar hemorrhage is a clinical pathological syndrome caused by different pathophysiological mechanisms, including capillary failure stress, diffuse alveolar damage and capillaritis. The most common cause is capillaritis associated with systemic autoimmune diseases, mostly ANCA-related vasculitides. The presence of diffuse alveolar hemorrhage, with pulmonary capillaritis without clinical or serological findings of a systemic autoimmune disease is known as isolated pauci-immune pulmonary capillaritis. The treatment is based on corticosteroids and cyclophosphamide.

Keywords: Diffuse alveolar hemorrhage; pulmonary capillaritis; immune pulmonary capillaritis