SARS-CoV-2 among liver transplant recipients: Clinical course and mutational analysis

•Majority of liver transplant recipients had mild COVID-19 infection.•Severe COVID- 19 infection was observed in recipient with post-transplant duration of more than 5 years.•Mortality was recorded in 23 % cases, and majority in non-vaccinated cases.•There was no significant difference in SARS-CoV-2 mutational load among transplant recipients when compared with the control group. Very limited literature on the clinical course of COVID-19 among liver transplant recipients (LT) is available from India. The present study aimed to evaluate the clinical and mutational profile of SARS-CoV-2 among LT. This was a retrospective study including LT cases in whom SARS-CoV-2 RT-PCR testing was requested between April 2020 and December 2022. Detailed mutational analysis was performed by comparing LT COVID-19 positive study group i.e. LT-CoV(+) with two control groups. One including COVID-19 positive with underlying chronic liver disease (CLD) i.e. CLD-CoV(+) and other including COVID-19 positive outpatients without any underlying LD i.e. NLD-CoV(+) Among 213 cases, 48 (22.5 %) were positive [LT-CoV(+)] and the remaining 165 (77.5 %) were negative [LT-CoV(-)] for SARS-CoV-2. Of these, 49 % had mild, 14 % moderate and 37 % had severe COVID-19. Mortality was recorded in 11 (23 %) cases, the majority being non-vaccinated. Severe COVID-19 with intensive care requirement was significantly higher among recipients with >5 years since transplant compared to recipients with ≤5 years (p = 0.02). Among 40 samples subjected to whole genome sequencing, 19 (47.5 %) were Delta, 15 (37.5 %) Omicron, and 6 (15 %) were other variants. COVID-19 severity was significantly higher in LT-CoV(+/D) with no significant difference in mortality (p = 0.122). No significant differences in mutational load and in fraction of deleterious mutations were observed between LT-/CLD-/NLD-CoV(+) groups for either Delta or Omicron. An overall fatality rate of 23 % was recorded among LT recipients. Longer duration since transplant was associated with severe clinical course. However, no significant difference in mutation load between studied groups was observed.