Invasive fungal infections after liver transplantation: Risk factors and impact on mortality in a retrospective single-center cohort with propensity score matching.

BACKGROUND: Invasive fungal infection (IFI) remains a serious complication after liver transplantation (LT). We evaluated IFI incidence within 180 days after LT, assessed the predictive performance of the neutrophil percentage-to-albumin ratio (NPAR) and MELD-Na for post-transplant IFI, and examined IFI-associated 1-year mortality. METHODS: We conducted a retrospective, single-center study of adult LT recipients between 2003 and 2024. Risk factors were analyzed using multivariable logistic regression. Survival was assessed with Kaplan-Meier curves and Cox proportional hazards models, including 1:1 propensity score matching. RESULTS: Among 426 LT recipients, 37 (9%) developed IFI, most commonly Candida species (n=25), followed by Aspergillus species (n=12). Risk factors were evaluated separately for Candida and Aspergillus infections. Compared with recipients without invasive Candida infection, those with Candida IFI had greater disease severity at transplant (MELD-Na≥19: 44% vs 29%), a higher prevalence of upper-tertile NPAR (56% vs 32%; p=0.023), increased need for postoperative renal replacement therapy (44% vs 7%; p<0.001), more frequent early reintervention (40% vs 10%; p<0.001), and higher rates of biliary complications (24% vs 8%; p=0.017). Recipients with invasive Aspergillus infection were more likely to have upper-tertile NPAR (67% vs 32%; p=0.018) compared with those without Aspergillus infection. Elevated NPAR independently predicted both Candida (OR 2.65, 95% CI 1.17-6.01) and Aspergillus IFI (OR 4.17, 95% CI 1.23-14.35), whereas MELD-Na was not associated with either infection. After matching, IFI was associated with significantly higher 1-year mortality (HR 6.73; 95% CI, 1.53-29.62). CONCLUSION: Pre-transplant NPAR was associated with an increased risk of post-transplant IFI, particularly Candida infection, and may contribute to risk stratification pending external validation.