Metagenomic Next-Generation Sequencing Provides a Reliable Method for Early Diagnosis of Pneumocystis jirovecii Pneumonia After Kidney Transplant: A Single-Center Retrospective Cohort Study

Abstract

Objectives: Pneumocystis jirovecii pneumonia, a common pulmonary infection after kidney transplant, cannot be detected by conventional culture methods, and limitations have been shown with lung tissue biopsy, sputum collection, and sample smear staining. Early diagnosis is key as long-term survival is decreased in patients with Pneumocystis jirovecii pneumonia who are not treated in a timely and effective manner.

Materials and methods: From January 2018 to January 2023, our study enrolled 110 patients with pulmonary infection seen at the First Affiliated Hospital of Xi'an Jiaotong University (China). Of these patients, 46 had confirmed Pneumocystis jirovecii pneumonia per metagenomic next-generation sequencing or conventional detection methods. We compared percentages of positive tests, other pathogen species, and other factors between the 2 test methods. Clinical characteristics of patients with (n = 46) and without (n = 64) Pneumocystis jirovecii were analyzed retrospectively.

Results: Overall incidence of PJP was 2.3% (46/1977). Among 46 patients diagnosed with Pneumocystis jirovecii pneumonia, average time of onset post-transplant was 7.21 ± 2.55 months; 42 patients were cured, and 4 patients died. Thirty-three patients had mixed pulmonary infections, with Pneumocystis jirovecii and human cytomegalovirus being the most common pathogen combination, and 13 patients had monotypic pulmonary infections. Sixteen patients were Pneumocystis jirovecii positive according to conventional pathogen detection, for a detection rate of 34.8% (16/46), with significant difference shown between detection methods (χ2 = 92.0, P < .01). Patients who were treated with tacrolimus had insufficient use of sulfamethoxazole-trimethoprim and previous cytomegalovirus infection, and patients with acute rejection were more likely to develop Pneumocystis jirovecii pneumonia (P < .05).

Conclusions: Metagenomic next-generation sequencing showed more advantages in early diagnosis of Pneumocystis jirovecii pneumonia. Precision medicine can be adopted to reduce costs and improve cure rates based on results of metagenomic next-generation sequencing.