Infectious complications in acute graft-versus-host disease after liver transplantation.

Graft-versus-hostdisease (GVHD) following liver transplantation (LT) is rare but can lead tosignificant mortality. The leading cause of death following GVHD diagnosis isinfectious complications. However, there is a lack of clear descriptions concerning infection and antimicrobial management patterns. Our study aims toprovide the focused details of all infectious complications of acute GVHDfollowing LT. We retrospectively reviewed all adult LT recipients with acute GVHD at Mayo Clinic's Transplant Centers from January 1, 2010, to December 31, 2021. Detailed characteristics of infection in each case were described. Among 4,585 LTs performed during this period, 12 (0.3%) patients developed acuteGVHD. The median time from transplantation to GVHD diagnosis was 49.0 days [IQR 31.5-99.0]. Ten (83.3%) patients developed severe infections leading tomortality. The most common cause of infection was nosocomial bacteremia fromenteric bacteria such as vancomycin-resistant enterococci and gram-negative bacilli. Other infections included breakthrough invasive fungal infections,cytomegalovirus (CMV) reactivation, and Clostridioides difficile colitis. Antimicrobial prophylaxis strategies in most cases were based on the degree of neutropenia-these include levofloxacin for bacterial prophylaxis, nebulized pentamidine for Pneumocystis jiroveci pneumonia prophylaxis, posaconazole for invasive fungal prophylaxis, and valganciclovir based on CMVstatus. All GVHD patients with severe infections succumbed to thesecomplications. Ourstudy reiterates that despite prophylaxis, infectious complications in GVHDfollowing LT are common and lead to exceptionally high mortality. Individualizedantimicrobial treatment, prophylaxis and monitoring strategies remain a criticalcomponent of GVHD management. Further study to optimize these practices isrequired.