Clinical application and evaluation of metagenomic next-generation sequencing in pulmonary infection with pleural effusion. Clinical application and evaluation of metagenomic next-generation sequencing in pulmonary infection with pleural effusion

Background Metagenomic next-generation sequencing (mNGS) is a novel technique of pathogens detection that plays an increasingly important role in clinical practice. In this study, we explored the application value of mNGS in pulmonary infection combined with pleural effusion applied to samples of pleural effusion fluid. Methods We retrospectively reviewed 80 pulmonary infection patients with pleural effusion from August 2020 to October 2021. Among them, 40 patients were placed into the mNGS group underwent both culture and mNGS testing, the other patients who were assigned to the control group were only culture test. We explored the application values of mNGS in microbial composition and diagnostic accuracy for the pleural effusion specimen types. Results We found the positive rate of mNGS was 70 % (28/40). The comparison between mNGS and culture method resulted that the sensitivity was 100% (95%CI: 29.2%-100%) and the specificity was 64.9% (95%CI: 47.5%-79.8%). The positive predictive value of mNGS was 18.8 %(95% CI, 13.0-26.3%), and the negative predictive value was 100%. The bacteria were the most commonly identified potential pathogens, such as Streptococcus, Prevotella, Parvimonas, Porphyromonas and Gemella. The most detected fungal infection was Candida and Pneumocystis. A total of 11 patients were identified as mixed infection by mNGS. The pattern of mixed infection was mainly bacteria and bacteria mixed infection, followed by bacteria and fungi mixed infection. Following adjustment of the treatment regimen according to the detection results of mNGS, the overall length of hospital stay in the mNGS group was lower than that of the control group. Conclusion In this study, mNGS has a higher positive rate than the culture method for detecting pathogens in pleural effusions specimens. mNGS technology can provide more diagnostic evidence, and reduced the length of stay in patients. mNGS showed a satisfying diagnostic performance in samples of pleural effusion from pulmonary infection combined with pleural effusion patients.