Pneumonia incidence and pathogen spectrum in liver transplant recipients a decade long retrospective analysis comparing pre coronavirus disease 2019 and pandemic era temporal patterns and risk 3 factors
35TH APASL, İstanbul, Türkiye, 22 - 25 Nisan 2026, ss.206-207, (Özet Bildiri)
- Yayın Türü: Bildiri / Özet Bildiri
- Basıldığı Şehir: İstanbul
- Basıldığı Ülke: Türkiye
- Sayfa Sayıları: ss.206-207
- Acıbadem Mehmet Ali Aydınlar Üniversitesi Adresli: Evet
Özet
Background/Hypothesis:Liver transplant recipients face substantially elevated pneumonia risk due to preexisting immune dysfunction from cirrhosis and intensive post-transplant immunosuppression, contributing significantly to morbidity and mortality. Pneumonia accounts for 15.5% of infection-related deaths in this population. Most studies lack detailed analysis of pre-transplant liver-specific risk factors, including severity scores (MELD, Child-Pugh) and metabolic status. This study examines whether pneumonia incidence and pathogen distribution vary across post-transplant periods and are influenced by these specific factors. The Coronavirus Disease 2019 (COVID-19) pandemic potentially altered infection epidemiology, and this research will assess whether the shift toward stricter infection control and altered antibiotic use is reflected in measurable changes in multidrug-resistant bacterial and fungal pneumonia rates. Materials and Methods:This retrospective cohort study includes 812 adult liver transplant recipients (≥18 years) at Acıbadem Atakent Hospital from September 2015 to September 2025. Pneumonia diagnosis will follow CDC criteria with clinical and radiological confirmation. Data will be stratified into pre-COVID (September 2015February 2020) and COVID-19 era (March 2020September 2025) periods. Variables extracted will include MELD/Child-Pugh scores, liver disease etiology, immunosuppression details, and viral serostatus. Pneumonia episodes will be classified by timing: early (0-30 days), intermediate (31-180 days), and late (>180 days), and by acquisition type (Community-Acquired, Healthcare-Associated, Nosocomial). Incidence rates per 1000 patient-years will be calculated and multivariable Cox regression with time-dependent covariates will be used to identify independent risk factors (p<0.05). Results:The large cohort of 812 patients will define dynamic shifts in pathogen distribution and antimicrobial resistance patterns across early, intermediate, and late periods. Results will define distinct pathogen profiles for each period, focusing on multidrug-resistant organisms. Key liver-specific risk factors, such as high pre-transplant MELD score and immunosuppressive regimen, will be identified with Hazard Ratios. Dedicated analysis will quantify changes in overall incidence and MDR organism and viral pneumonia rates between pre-COVID and COVID-19 eras. Conclusions:This study will fill important gaps in understanding post-transplant pneumonia through its decade-long, multi-dimensional analysis and COVID-19 era comparison. Findings will inform organ-specific infection prevention protocols, including targeted prophylaxis recommendations (e.g., fungal/viral agents), and refine antimicrobial stewardship programs. Results will guide therapy selection and management, ultimately improving safety and outcomes in liver transplant recipients. Keyword(s) : liver transplantation, pneumonia, pathogen spectrum, immunosuppression, infection .