Metagenomic next‐generation sequencing for <i>pneumocystis jirovecii</i> pneumonia in patients with connective tissue disease

Background Accurate diagnosis of Pneumocystis jirovecii pneumonia (PJP) is challenging, and the delayed PJP associated with high mortality in patients connective tissue disease (CTD). Metagenomic next-generation sequencing (mNGS) technology facilitates etiological various infectious diseases, promising application diagnosing PJP. This study aimed to investigate value mNGS using bronchoalveolar lavage fluid (BALF) for infection. Methods Data from 55 CTD suspected pulmonary infection was retrospectively collected analysed. A group non-PJP were formed. The clinical manifestations, laboratory test results, treatment methods, outcomes summarized. BALF results compared traditional pathogen tests (TPT) serum 1,3-beta-D-glucan (BDG) testing. Results mean age 54 years, 59% (10/17) female. significant difference found between average daily dose prednisone administered (25 mg vs. 16 mg, P < 0.001). had a significantly higher incidence dyspnoea (88% [15/17] 16% [6/38], 0.001) elevated BDG level (167.73 30.67 pg/mL, more sensitive than both TPT (100% [95% confidence interval {CI}: 77.1%–100%] 11.8% CI: 2.1%–37.7%], 85.7% 42%–99.2%], specific (89.5% 74.3%–96.6%] 46.7% 22.3%–72.6%], = 0.493). Co-infection cytomegalovirus (CMV) common (59% [10/17] 11% [4/38], respectively, Conclusion highly effective identifying co-infections.