Elevated alanine transaminase in liver transplant recipients after BNT162b2 vaccination: a cohort study.

Liver transplant (LTx) recipients risk severe COVID-19. Vaccination reduces this risk. However, there may be side effects, including elevated alanine transaminase (ALT) which could lead to increased use of liver biopsy. We aimed to describe prevalence and relative incidence of elevated ALT 90 days before and after BNT162b2 vaccination in LTx recipients. Furthermore, we aimed to describe changes in prevalence of liver biopsies before and after BNT162b2 vaccination. We included 393 LTx recipients from The Danish Comorbidity in Liver Transplant Recipients (DACOLT) study. We calculated prevalence of elevated ALT and liver biopsies before and after each BNT162b2 vaccine dose. We used self-control case series (SCCS) analysis to investigate whether vaccination was associated with higher relative incidence of elevated ALT. Prevalence of elevated ALT, around each vaccine dose, was comparable. We did not find higher relative incidence of elevated ALT after vaccination. The prevalence of liver biopsies around vaccination was comparable.