Biblioteca Virtual en Salud

Objective:

To explore the airway pathogen characteristics and examine the correlation between donor-derived pathogens and post-transplant outcomes in patients after lung transplantation (LT).

Methods:

Between January 1, 2015 and December 31, 2019, retrospective review was conducted for clinical and microbiological data of 88 LT recipients.Airway pathogen percentage of different microorganisms and evolution of drug-resistance were examined.Drug-resistant pathogen positive group (n=71) and negative group (n=17) were assigned according to whether or not drug-resistant pathogens were detected.Survival analysis was conducted by Log-rank with 3-year follow-ups.Between April 11, 2020 and September 5, 2020, prospective study was conducted in 14LT recipients.The potential pathogenic bacteria from donor lungs were detected by metagenomic next generation sequencing and the impact of those bacteria was examined on 1-year post-transplantation outcome in 2020.Microbial diversity and richness were shown with Shannon index.The outcome variables included heart rate, neutrophil count, lymphocyte count, immunoglobulin level and pulmonary spirometry.ANOVA and Pearson's correlation analysis were performed for elucidating the relationship between airway microbiota and post-LT outcomes.

Results:

From 2015 to 2019, 88 recipients were recruited and 992 strains of airway pathogens were isolated, including bacteria 796 strains and fungi 196 strains.Gram-negative bacteria (704 strains) accounted for 88.4% of all bacteria.The detection rates of Gram-positive bacteria, Klebsiella pneumonia (Kp), Acinetobacter baumannii (Ab), Stenotrophomonas maltophilia and Candida increased in 2019 than that in 2015 (8.2% vs. 5.3%, 13.6% vs. 13.2%, 33.2% vs. 17.5%, 6.5% vs. 5.3%, 26.6% vs. 20.2%). Drug resistance rate of Kp to imipenem was 68.18% in 2019 and drug resistance rate of Ab to imipenem 98.44%.The 3-year survival rate was 46.3% and 35.3% in drug-resistance positive and negative groups and the difference was insignificant ( P=0.410). Fourteen recipients were enrolled in 2020.Potential pathogenic bacteria could be detected in all donor samples.Five recipients carried the same bacteria and two died during 1-year follow-up.Nine recipients did not carry the donor-derived pathogens and two died during 1-year follow-up.The diversity of donor/recipient-derived airway microbiota (Shannon index) showed no correlation with the outcomes of 1-year follow-up by Pearson's correlation test.

Conclusions:

Gram-negative bacteria predominated in airway pathogens of recipients post-LT.The drug resistance rate to imipenem remained high.The donor/recipient-derived pathogen isolates showed no correlation with immediate outcomes post-LT.