Clinical Value of Metagenomic Next-Generation Sequencing From Blood Samples to Identify Pneumocystis jirovecii Pneumonia in Patients With Human Immunodeficiency Virus.

Background: The aim of this study was to evaluate the clinical value of metagenomic next-generation sequencing (mNGS) of blood samples for identifying Pneumocystis jirovecii pneumonia (PJP) in patients with human immunodeficiency virus (HIV).

Methods: A total of 76 people with HIV (PWH) with suspected lung infections were enrolled in the study. The patients were divided into two groups: the PJP group and the non-PJP group.All patients underwent pulmonary computed tomography scans, and blood or respiratory tract specimens were subjected to mNGS and conventional microbiological tests. Patient characteristics were collected from their medical records.

Results: Thirty patients were diagnosed with PJP and 46 were confirmed to have non-P jirovecii (Pj) infectious pneumonia. mNGS was conducted on bronchoalveolar lavage fluid samples from 25 patients and on blood samples from 59 patients. Twenty-one of 22 (95.5%) blood samples from the PIP group contained sequences of Pi, with the number of specific reads for circulating Pj sequences ranging from 2 to 2035. In the non-PJP group, 4 blood samples exhibited low Pj sequences, ranging from 1 to 2 reads. The sensitivity and specificity for blood samples were 95.5% (95% confidence interval [CI], 91.2%-98.4%) and 90.0% (95% Cl, 89.5%-100%), respectively.

Conclusions: Our study indicates that mNGS of blood samples exhibits high sensitivity and specificity for diagnosing PJP in PWH. Caution should be exercised when interpreting low Pj mNGS read counts in blood samples; the definitive diagnosis of PJP relies on the synthesis of clinical data with Pj mNGS results. Further studies are necessary to validate this finding.