Single center clinical analysis of metagenomic next-generation sequencing for clinical diagnosis of Pneumocystis jirovecii Pneumonia after allogeneic hematopoietic stem cell transplantation
Objective:To explore the clinical characteristics of Pneumocystis jirovecii Pneumonia(PJP)patients diagnosed with metagenomic next-generation sequencing(mNGS)assisted by allogeneic hematopoietic stem cell transplantation(allo-HSCT).Methods:From October 2020 to March 2023,19 patients with fever were diagnosed with PJP through mNGS testing after allo-HSCT at our transplantation center,as routine microbiological and ima-ging examinations were unable to determine the diagnosis,and empirical anti-infective treatment was ineffective.The main clinical manifestations of the patients were analyzed,including mNGS results,cellular immune function,inflammatory factors,blood gas analysis,G-experiments,high-resolution CT and bronchoscopy results of the lungs,as well as clinical features such as treatment and prognosis.Results:The median time of occurrence of PJP after allo-HSCT was 6 months,and fever and dyspnea were the main clinical symptoms of PJP.All 19 patients experienced fever,with persistent moderate fever being the main cause.10 patients had difficulty breathing in a quiet state,and 3 patients had difficulty breathing after activity.The average CD4+T lymphocyte count was 148(34-394)/μL.Among them,12 cases had CD4+T lymphocyte counts＜200/μL.Blood gas analysis of 10 patients showed type 1 respiratory failure,with an average oxygen partial pressure of 59.5(36.8-74.0)mmHg.Bivariate correlation analysis showed a positive correlation between CD4+T lymphocyte count and patient oxygen partial pressure(r=0.468,P=0.043).9 PJP patients(47.37％)showed positive G-test results;The CT imaging of the lungs mainly shows multiple ground glass like high-density shadows;17 PJP patients underwent bronchoscopy and alveolar lavage fluid(BALF)to detect mNGS.The median nucleic acid sequence number of Pneumocystis jirovecii Pneumonia was 487(178-131 444),and the median relative abundance was 56.9％(26.0％-99.5％).Bivariate correlation analysis showed a significantly negative correlation between patient oxygen partial pressure and PJP se-quence number(r=-0.498,P=0.042).The number of nucleic acid sequences of Pneumocystis jirovecii pneu-monia in the peripheral blood of two patients was 2 and 4,respectively.Among the 19 patients,12 cases had cGVHD when PJP occurred,and 13 patients received varying doses of glucocorticoid therapy before PJP occurred.After the diagnosis of PJP,the patient mainly received treatment with compound sulfamethoxazole(SMZ)/trime-thoprim(TMP)combined with caspofungin or micafungin.One patient died of respiratory failure,and the remai-ning patients were cured.Conclusion:The main clinical manifestations of patients with PJP after allo-HSCT are fever and dyspnea.The CT imaging features are mainly ground glass shadows in both lungs,and early clinical di-agnosis is facilitated by BALF and whole blood mNGS.
万方数据
维普
