Patients who tested positive for SARS-CoV-2 antibodies prior to kidney transplantation continue to have persistent antibodies even after receiving high-dose immunosuppression in the early post-transplant period, investigators reported at the virtual American Transplant Congress 2021.
Of 78 patients transplanted from May 28, 2020 to October 1, 2020, 17 (22%) had a positive SARS-CoV-2 antibody test prior to surgery, including 10 with a positive PCR test or symptoms consistent with COVID-19 infection. At 30 to 60 days after transplant, 13 patients received follow-up antibody testing and 12 (92%) displayed persistent antibodies, Michelle Lubetzky, MD, of Weill Cornell Medicine in New York, New York, and colleagues reported.
Both SARS-CoV-2 IgM and IgG antibody levels declined within the 30 or 60 days but remained above the threshold for positivity, despite induction therapy with anti-thymocyte globulin followed by maintenance immunosuppression with calcineurin inhibitors and mycophenolate mofetil.
“Viral immunity is quite complex and may involve not just an antibody response but also cellular immune response,” Dr Lubetzky told Renal & Urology News. “What we and others have observed is that there is a reduction in circulating antibody titer. Whether that means the patients totally lack immunity to the virus and are at increased risk for severe illness or not remains to be determined.
“Our data in the early post-transplant period for patients with history of COVID-19 illness raise the question whether vaccinated patients undergoing transplantation should be monitored for vaccine titers and be considered for a booster vaccine post-transplant. The optimal timing for vaccination and measuring antibody titers as well as the risks and benefits of a third dose remain to be determined.”
The study population, which consisted of 45 male and 33 female patients, included 30 White, 19 Black, 16 Hispanic, and 11 Asian patients. Two patients were of other races. The mean age was 56 years. Half of patients received a living donor transplant.
None of the recipients experienced a new or recurrent SARS-CoV-2 infection.
“Our data provide a framework for future prospective studies on the kinetics and isotype of SARS-CoV-2 antibody response and as an essential reference to gauge immune response following vaccination,” according to Dr Lubetzky.
Lubetzky M, Sultan S, Zhao Z, et al. SARS-CoV-2 antibody response after induction therapy in kidney transplant recipients. Am J Transplant. 2021;21 (suppl 3). Presented at the virtual American Transplant Congress 2021, June 5-9, 2021. Abstract 61.