Clinical analysis and risk factors associated with poor prognosis in nontuberculous mycobacterial infection

Recently, the incidence and prevalence of NTM have been increasing nationwide in many countries. This study aimed to identify risk factors associated with the prognosis and mortality of non-HIV nontuberculous mycobacterial disease patients. This retrospective study was conducted at Peking Union Medical College Hospital. The electronic medical records in the hospital's database from January 2013 to December 2022 were retrospectively reviewed. Relevant data, including clinical characteristics, laboratory findings, microbiological tests, treatments, and outcomes were collected and subjected to statistical analyses. The search identified 745 patients diagnosed with NTM infection, of whom 147 met the inclusion criteria. NTM pulmonary disease was the most commonly observed (n = 93; 63.3%), followed by disseminated infection (n = 43; 29.3%). The most frequent NTM species was Mycobacterium avium complex (55.8%), followed by Mycobacterium abscessus (21.2%). The incidence of Aspergillus and Pseudomonas aeruginosa infection was significantly higher in the NTM pulmonary disease group than in the disseminated NTM group. Cumulative mortality in the total patients was 24.49% at 5 years. High Charlson Comorbidity Index (CCI), high neutrophil-to-lymphocyte-ratio (NLR), haematological disease, and disseminated infection were identified as independent predictors of unfavourable outcomes. The area under the curve (AUC) values for NLR and neutrophil-to-monocyte-plus-lymphocyte-ratio (NMLR) were 0.751 and 0.763 with optimal cut-off values of 9.50 and 3.83, respectively, for prediction of mortality in patients with NTM disease.