#1474 COVID-19-infection in kidney transplant recipients during the omicron surge, a sigh of relief

Abstract

Abstract Background and Aims The COVID-19 pandemic had a profound impact on global health, particularly affecting high-risk individuals such as solid organ transplant recipients (SOTRs). SOTRs have an elevated risk of severe COVID-19 disease and increased mortality. Kidney transplant recipients (KTRs) vaccinated with mRNA-based vaccines exhibit a lower response rate and shorter half-time of the serologic conversion. However, the percentage of serologic response improves with increasing number of vaccine doses. Studies also indicate that KTRs with prior COVID-19 infection demonstrate a more robust immune response post-immunization compared to COVID-19 naïve patients. Factors such as age, immunosuppressive regimen, eGFR, time since transplantation also impact vaccination response. This study aims to investigate COVID-19 infection outcome and vaccination response among KTRs during the Omicron surge. Method This study is a retrospective single-center cohort study at the Department of Nephrology and Transplantation at Skåne University Hospital in Malmö, Sweden. KTRs infected with COVID-19 during the Omicron surge were included (January 2022 until August 2023). Results 97 KTRs diagnosed with COVID-19 were included of whom 91 were vaccinated. In average, three doses of COVID-19-vaccine had been given to the patients. 67 KTRs showed seroconversion, 28 remained seronegative and the status of the remaining 2 KTRs was unknown. There was a significant association between lack of antibody production and mycophenolic acid (MPA) treatment (P = 0.019, Chi2 test), however the significance was not retained in a multivariate logistic regression analysis. Among the seroconverted (n = 67), 61 experienced mild infection, 5 moderate infection and 1 severe infection, according to the WHO clinical progression scale. In the seronegative group (n = 28), 25 had mild infection while the remaining three had moderate infection. The median time for viral clearance was examined in 79 KTRs and was 23 days (IQR 18-31). Immunosuppression was adjusted in 34% (n = 33) of cases. 2.1% (n = 2) of KTRs experienced graft rejection post infection. Conclusion While most patients experienced a mild infection, unlike during the first surges of the pandemic, the observed subsequent graft rejections emphasize the complexity of COVID-19´s potentially immunologic triggering effect and risk of graft loss in KTRs. The correlation between MPA treatment and a lower degree of serologic conversion after vaccination underscores the need for personalized immunologic follow up and treatment regimen in KTRs.