Bronchoalveolar lavage fluid analysis and mortality risk in systemic lupus erythematosus patients with pneumonia and respiratory failure.

Abstract

Our aim was to characterize etiologic diagnoses obtained from bronchoalveolar lavage fluid (BALF) and blood specimens, and to identify risk factors for mortality in systemic lupus erythematosus (SLE) patients with pneumonia and respiratory failure. We conducted a retrospective analysis of SLE patients with pneumonia and respiratory failure. Clinical characteristics, laboratory profiles, and microbiology in BALF and blood samples were evaluated. We performed univariable analyses to identify mortality risk factors. All 24 patients (F:M=21:3, median age 46.5 years; disease duration 11 years) received mechanical ventilation (median duration: 11 days). Pathogens identified in BALF included Pneumocystis jiroveci (12 patients [50%]), cytomegalovirus (CMV, 7 patients [29.2%]), and bacteria (11 patients [45.8%]). Thirteen patients (54.2%) yielded pathogens in blood (CMV in 8 patients [33.3%] and Escherichia coli in 5 patients [20.8%]). Eight developed septic shock, and 9 died within 30 days. Univariable analysis identified thrombocytopenia (odds ratio [OR]: 8.0, 95% confidence interval [CI]: 1.23-52.25), bacteremia within 30 days before or after endotracheal intubation (OR: 8.0, 95% CI: 1.23-52.5), and P. jiroveci pneumonia (PJP, OR: 7.0, 95% CI: 1.04-46.95) as risk factors for 30-day mortality. Kaplan-Meier analysis confirmed an increased risk of 30-day mortality with thrombocytopenia and bacteremia. There are high prevalence rates of PJP and CMV infections as evidenced by BALF analyses in SLE patients with pneumonia and respiratory failure. BALF analysis can facilitate rescue therapy per pathogen. Thrombocytopenia, bacteremia, and PJP in SLE patients can increase their 30-day mortality, so warrant early and aggressive treatments.