Temporary reduction of immunosuppression enhances production of anti-S antibody against severe acute respiratory syndrome coronavirus 2 after vaccination in kidney transplant recipients.

OBJECTIVES

The study identified factors affecting anti-S immunoglobulin G production after vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in kidney transplant recipients.

METHODS

Serum samples were prospectively collected from kidney transplant recipients, live kidney donors, and healthy volunteers 1 month after receiving the second dose of SARS-CoV-2 vaccine, and anti-S immunoglobulin G titers were measured. The mycophenolate mofetil dose was reduced before vaccination in some immunologically low-risk recipients.

RESULTS

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 immunoglobulin G than donors and healthy volunteers (1377 ± 246, 8310 ± 932, and 9908 ± 1040 AU/ml, respectively). Only 67.3% of kidney transplant recipients, compared to 100% of donors and healthy volunteers, were positive for anti-S immunoglobulin G. Among the kidney transplant recipients, the anti-S 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 mycophenolate mofetil. Younger age, higher lymphocyte count, glomerular filtration rate, and mycophenolate reduction were significantly associated with anti-S immunoglobulin G > 1000 AU/ml in nominal logistic regression analysis. There were no rejection episodes after mycophenolate modification in kidney transplant recipients.

CONCLUSIONS

Anti-S immunoglobulin G production after vaccination was attenuated in kidney transplant recipients. Mycophenolate mofetil cessation or reduction is a modifiable means to enhance anti-S immunoglobulin G production in immunosuppressed kidney transplant recipients.