Markers of inflammation and lung function in liver transplant recipients: results from a nationwide cohort study

Introduction In the general population elevated circulating inflammatory markers have been associated with impaired lung function in cross-sectional and longitudinal studies. No studies have investigated this association in liver transplant recipients, and we aimed to investigate if elevated inflammatory markers were associated with impaired lung function in this population. Methods Adult liver transplant recipients from The Danish Comorbidity in Liver Transplant Recipients (DACOLT) study, with available spirometry, high sensitivity (hs)-CRP, interleukin (IL)-1β, IL-2, IL-6, IL-10, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α were included. Outcomes were forced expiratory volume in one second (FEV 1 ), forced vital capacity (FVC), airflow limitation, and preserved ratio impaired spirometry (PRISm). Results We included 335 liver transplant recipients. The prevalence of airflow limitation and PRISm was 11.6% and 24.5%, respectively. The median FEV 1 was 2790 mL (IQR 2230–3505 mL) and the median FVC was 3680 mL (IQR 2980–3755 mL). When adjusted for age and sex, hs-CRP >3 mg/L was associated with increased odds of PRISm (aOR 2.08, 95% CI: 1.1; 3.9, p=0.02), lower FEV 1 (-209 mL 95% CI -340; -77 mL, p<0.01), and lower FVC (-290 mL 95% CI -448 mL; -132 mL, p<0.01). For FEV 1 and FVC, the associations were consistent when additionally adjusted for ethnicity, BMI, and smoking status. None of the remaining inflammatory markers were significantly associated with any of the outcomes across statistical models. Conclusion Elevated hs-CRP was associated with impaired lung function indicating that systemic inflammation may be part of the pathophysiology of impaired lung function in liver transplant recipients.