Clinical characteristics and outcomes of diffuse alveolar hemorrhage in patients with systemic lupus erythematosus

ObjectiveTo identify the clinical characteristics of diffuse alveolar hemorrhage (DAH) compared to other types of acute diffuse lung infiltration in SLE patients, and the factors associated with mortality in these patients.MethodsWe studied a retrospective cohort including SLE patients with acute diffuse lung infiltration on thoracic CT between January 2004 and August 2014. We divided them into 2 groups, a DAH and a non-DAH group, and compared the clinical characteristics and outcomes in the 2 groups. We also evaluated the risk factors for mortality in SLE patients with diffuse lung infiltration.ResultsOf 47 patients with diffuse lung infiltration, 24 patients (51.1%) satisfied the criteria for DAH and the remaining 23 patients (48.9%) were assigned to the non-DAH group. There were no significant differences between the demographic features of the 2 groups. However, decreased hemoglobin (OR = 3.46; 95% CI: 1.38–8.67; p < 0.01) and C4 (OR = 1.21; 95% CI: 1.03–1.42; p = 0.02) levels, and presence of hypoxia (OR = 23.09; 95% CI: 1.47–365.34; p = 0.03) at the time of diagnosis were associated with SLE-DAH. In addition, severe conditions requiring mechanical ventilation (OR = 64.61; 95% CI: 1.98–2112.02; p = 0.02) were associated with increased mortality, whereas DAH did not increase mortality compared with non-DAH in SLE patients with diffuse lung infiltration.ConclusionsIn SLE patients with acute diffuse lung infiltration, it is important to promptly evaluate the DAH when patients have low levels of hemoglobin or C4, and symptoms of hypoxia. Mortality is associated with severe conditions requiring mechanical ventilation rather than with DAH in patients with diffuse lung infiltration.