COVID-19 INFECTION AND BREAKTHROUGH INFECTION IN POST LIVER TRANSPLANT PATIENTS

ABSTRACT

Introduction: Solid organ transplant recipients have 2-5 times increased mortality after coronavirus disease 2019 (COVID-19) infection as compared to general population. These patients also have lower protection after vaccination against COVID-19. Therefore, the risk of breakthrough infection and hospitalization are also significantly higher in this patient population. Studies on efficacy of COVID-19 vaccination in post liver transplant (LT) patients are limited. We aimed to investigate the rate of mortality, hospitalization, and breakthrough infection and assess possible risk factors in COVID-19 infection mortality post LT. Methods: A retrospective chart review study. All post liver transplant patients at Carolinas Medical Center (CMC) who were tested positive for respiratory syndrome coronavirus 2 (SARS-CoV- 2) PCR test from Dec. 2020 (when first COVID-19 vaccine was approved in the US for emergency use authorization) until Nov. 2021 were included in this study. Breakthrough infection was defined as COVID-19 infection ≥14 days after full vaccination. Data was analyzed using Prism (GraphPad Software, San Diego, CA) and reported as mean ± SEM. T- test and chi square tests were applied for analyzing the data. Results: Thirty-six patients were identified and 66.1±9.6 months post liver transplantation (LT). Mean age was 61.2±1.6 years-old, male (72.2%) and Caucasian (91.6%). Ten patients (27.7%) expired. Chronic kidney disease (CKD) was present in 70.0% of expired patients as compared to 53.3% of recovered (p=0.0003). Type 2 diabetes (T2DM) was present in 70.0% vs. 25.0% of expired and recovered patients, respectively (p<0.0001). Hypertension (HTN) was present in 90.0% vs. 55.0% of expired and recovered patients, respectively (p<0.0001). No statistically significant difference was observed in weight of expired vs. recovered patients (50% vs. 65% obesity;p=0.4). Only 9 patients were vaccinated. Breakthrough infection rate was 25% and 2/9 (22.2%) died vs. 29.6% of non-vaccinated patients (p=0.4). COVID-19 infection occurred 4.9±0.86 months after vaccination. Hospitalization (44.4% vs. 55.5%) and ICU admission (22.2% vs. 37.0%) was not statistically different among vaccinated and non-vaccinated patients. Conclusion: T2DM and CKD were significantly higher among COVID-19 infected patients who expired, which are similar risk factors in patients who have not had a liver transplant. However, obesity was not significantly correlated with mortality as it was shown before in non-immunocompromised population. Although COVID-19 vaccine is effective in post LT patients, larger studies are warranted to evaluate its efficacy in this population. Our study also highlights that the efficacy of current COVID-19 vaccines decreases in 4-6 months after full vaccination, which warrants evaluating the efficacy of booster dose(s) in post LT patients