The Respiratory Mycobiome Dynamic is Associated With 3-Year Mortality in Severe COPD Patients During Exacerbation

Abstract Background Mortality rate was increased in AECOPD patients with lung infection. However, few studies had characterized the relationship between respiratory mycobiome and the outcome of AECOPD. The prognostic value of respiratory mycobiome was unclear in patients with AECOPD. Methods We collected sputum samples from 68 severe COPD patients during exacerbation needed to be admitted to hospital in 2016 to identified fungal species by using ITS sequencing. 44 patients were enrolled and 34 subjects were followed for three years after discharged. We performed microbiome analyses to find the relationship between mycobiome and the outcome of AECOPD. Results This is a 3-year retrospective observational cohort study. In our study, a total of 44 patients with AECOPD were enrolled and 34 patients were followed for 3 years. The patients were divided into two group according to 3-year mortality status: Non-Survival group (n=9, 26.47%) and Survival group (n=25, 73.53%). We found alpha diversity decreased in the Non-Survival group than the Survival group (PD_Whole Tree, p=0.033). Candida spp. was more abundant (p=0.009) while the blood lymphocyte counts was lower (p=0.030) in the Non-Survival group than the Survival group. Survival curve analysis showed higher mortality in patients with higher relative abundance of Candida spp. (HR: 5.273, 95% CI: 1.221-22.78, p=0.0083). Receiver operating characteristic (ROC) analysis showed the Candida spp. was a significantly strong predictor for disease outcome (urea under curve 0.7911). Conclusions The sputum mycobiome was associated with 3-year mortality in severe COPD patients during exacerbation. Among Non-Survival patients, the fungal alpha diversity was decreased and the relative abundance of Candida spp. was higher. It indicated lung mycobiome might be the prognostic marker of AECOPD patients.