Tang S, Li X, Zhao KY, et al. - Researchers performed a retrospective study to analyze the clinical characteristics and prognostic factors of microscopic polyangiitis (MPA) with diffuse alveolar hemorrhage (DAH). The sample consisted of 92 patients diagnosed with MPA with DAH at the First Affiliated Hospital of Chongqing Medical University between March 1, 2012, and March 12, 2018. Data reported that the mean age at the onset of MPA with DAH was 66.32 years. It was noted that the cumulative survival rates of the 92 patients at 1, 3, and 5 years were 63.7%, 51.2%, and 47.3%, respectively. Findings revealed that the incidence and mortality of DAH in MPA patients are high. Independent prognostic factors for MPA with DAH include age > 65 years, sCr > 500 μmol/L, PaO ₂ /FiO₂ < 300 mmHg, and lung involvement area ≥ 50%.