Incidence and Severity of COVID-19 in Relation to Anti-Receptor-Binding Domain IgG Antibody Level after COVID-19 Vaccination in Kidney Transplant Recipients
A. Lianne Messchendorp,
Jan-Stephan F. Sanders,
Alferso C. Abrahams,
Frederike J. Bemelman,
Pim Bouwmans,
René M. A. van den Dorpel,
Luuk B. Hilbrands,
Céline Imhof,
Marlies E. J. Reinders,
Theo Rispens,
Maurice Steenhuis,
Marc A. G. J. ten Dam,
Priya Vart,
Aiko P. J. de Vries,
Marc H. Hemmelder,
Ron T. Gansevoort,
RECOVAC Investigators
Affiliations
A. Lianne Messchendorp
Department of Nephrology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands
Jan-Stephan F. Sanders
Department of Nephrology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands
Alferso C. Abrahams
Department of Nephrology and Hypertension, University Medical Center Utrecht, 3508 GA Utrecht, The Netherlands
Frederike J. Bemelman
Division of Nephrology, Department of Internal Medicine, Amsterdam University Medical Center, Location Amsterdam Medical Center, 1105 AZ Amsterdam, The Netherlands
Pim Bouwmans
Department of Internal Medicine, Division of Nephrology, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands
René M. A. van den Dorpel
Department of Nephrology, Maasstad Hospital, 3079 DZ Rotterdam, The Netherlands
Luuk B. Hilbrands
Department of Nephrology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
Céline Imhof
Department of Nephrology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands
Marlies E. J. Reinders
Erasmus MC Transplant Institute, Nephrology and Transplantation, Department of Internal Medicine, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands
Theo Rispens
Department of Immunopathology, Sanquin Research, 1006 AD Amsterdam, The Netherlands
Maurice Steenhuis
Department of Immunopathology, Sanquin Research, 1006 AD Amsterdam, The Netherlands
Marc A. G. J. ten Dam
Department of Internal Medicine, Canisius Wilhelmina Hospital, 6532 SZ Nijmegen, The Netherlands
Priya Vart
Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
Aiko P. J. de Vries
Leiden University Medical Center, Department of Nephrology and Leiden Transplant Center, 2333 ZA Leiden, The Netherlands
Marc H. Hemmelder
Department of Internal Medicine, Division of Nephrology, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands
Ron T. Gansevoort
Department of Nephrology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands
Kidney transplant recipients (KTRs) elicit an impaired immune response after COVID-19 vaccination; however, the exact clinical impact remains unclear. We therefore analyse the relationship between antibody levels after vaccination and the risk of COVID-19 in a large cohort of KTRs. All KTRs living in the Netherlands were invited to send a blood sample 28 days after their second COVID-19 vaccination for measurement of their IgG antibodies against the receptor-binding domain of the SARS-CoV-2 spike protein (anti-RBD IgG). Information on COVID-19 was collected from the moment the blood sample was obtained until 6 months thereafter. Multivariable Cox and logistic regression analyses were performed to analyse which factors affected the occurrence and severity (i.e., hospitalization and/or death) of COVID-19. In total, 12,159 KTRs were approached, of whom 2885 were included in the analyses. Among those, 1578 (54.7%) became seropositive (i.e., anti-RBD IgG level >50 BAU/mL). Seropositivity was associated with a lower risk for COVID-19, also after adjusting for multiple confounders, including socio-economic status and adherence to COVID-19 restrictions (HR 0.37 (0.19–0.47), p = 0.005). When studied on a continuous scale, we observed a log-linear relationship between antibody level and the risk for COVID-19 (HR 0.52 (0.31–0.89), p = 0.02). Similar results were found for COVID-19 severity. In conclusion, antibody level after COVID-19 vaccination is associated in a log-linear manner with the occurrence and severity of COVID-19 in KTRs. This implies that if future vaccinations are indicated, the aim should be to reach for as high an antibody level as possible and not only seropositivity to protect this vulnerable patient group from disease.
