Metagenomics next-generation sequencing of plasma combined with blood cells for improving the prognosis of early infection in patients with hematologic disorders: a real-world cohort study in northern China

Introduction Infection is a leading cause of death in hematologic disorder patients. While plasma metagenomic next-generation sequencing (mNGS) is widely used, no studies have explored the clinical value of whole blood mNGS, combining plasma and blood cells, in these patients. Methods We retrospectively analyzed the results of whole blood mNGS testing from 231 blood samples of hematological disorders patients with suspected infections. The diagnostic performance of whole blood mNGS and its clinical impacts on treatment were assessed based on the final clinical diagnosis. Results mNGS testing in both plasma and whole blood showed significantly higher pathogen detection rates than blood culture (72.29%, 77.06% vs. 21.65%, P < 0.001). The total concordance rate of whole blood mNGS was also significantly higher than that of blood culture, conventional microbial testing, and plasma mNGS when compared to the final clinical diagnosis. Of the 101 pathogens detected by whole blood mNGS, 13 were missed by plasma mNGS. As a result, whole blood mNGS demonstrated a broad pathogen detection capability, especially in patients with non-hematologic malignancies or hematopoietic stem cell transplantation. Regarding treatment, whole blood mNGS had a positive impact on 72.73% of all patients, and 75.15% patients with pulmonary infections. It helped rule out infection in a timely manner, reduce or stop unnecessary antibiotic use, and enabled 77.88% of infected patients to benefit from whole blood mNGS sequencing. Discussion Whole blood mNGS assays, combining plasma and blood cells, significantly improved pathogen detection rates and optimized antibiotic therapy in patients with hematological diseases and pulmonary infections or bloodstream infection. This approach facilitates the early management of patients with hematologic disorders who are at risk of infection.