Antibody production after SARS-CoV-2 vaccine for kidney transplant recipients
The study identified factors affecting anti-S immunoglobulin G (IgG) production after vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in kidney transplant recipients. Anti-S IgG titers measured in serum samples were prospectively collected from kidney transplant recipients, live kidney donors, and healthy volunteers one month after receiving the second dose of SARS-CoV-2 vaccine. The mycophenolate mofetil (MMF) dose was reduced prior to vaccination in some immunologically low-risk recipients. A total of 151 kidney transplant recipients, 74 live kidney donors, and 50 healthy volunteers were included. Kidney transplant recipients had significantly lower titers of anti-S IgG than donors and healthy volunteers (1377 ± 246, 8310 ± 932, and 9908 ± 1040 AU/mL, respectively). Only 67.3% of kidney transplant recipients, compared with 100% of donors and healthy volunteers, were positive for anti-S IgG. Among kidney transplant recipients, the anti-S IgG titer was higher in younger recipients, those with higher peripheral blood lymphocyte counts and glomerular filtration rates, those without a history of antithymocyte globulin use, and those who had discontinued or received a reduced dose of MMF. Except for antithymocyte globulin, all factors were significantly associated with anti-S IgG >1000 AU/mL in nominal logistic regression analysis. There were no rejection episodes after MMF modification in kidney transplant recipients. Anti-S IgG production after vaccination was attenuated in kidney transplant recipients. Among the factors contributing to the intensity of IgG production, MMF cessation or reduction is a modifiable means to enhance IgG production in immunosuppressed kidney transplant recipients.