#4301 OBSERVATIONAL STUDY OF HUMORAL RESPONSE TO SARS-COV-2 MRNA VACCINATION IN A COHORT OF RENAL TRANSPLANTS COMPARED TO PRIMARY IMMUNE DEFICIENCY
Authors: Hashemi Rahima , Shivakumar Kunigal , Nicholas Claire , Bhole Malini , Webber Caroline 
Published: June 2023

Abstract

Background and Aims
Uraemia in chronic kidney disease impairs both innate and adaptive immune response and is responsible for high failure of vaccination against infection [1]. With a rising global burden of CKD prevalence and mortality, [2] optimising humoral response is important part of management especially in the presence of immunosuppressants in renal transplant patients. There is lacking data in this group and immunosuppressants likely play a bigger role in impairing humoral response hence we compare a group of renal transplant patients (RTs) with a group of patients with primary immunodeficiency (PID).

Method
Non-randomised RTs were recruited between January 2021 to January 2022 and underwent voluntary SARS-CoV-2 vaccination and were tested for immune response. Abbott UK SARS-CoV-2 antibody test was used to identify previous SARS-CoV-2 infection with positive ‘N-antibody’ titre and immunity with positive ‘S-antibody’ titre prior to vaccination and 3-8 weeks after each vaccination. Results were analysed with Odds Ratios and Fisher Exact Probability.

Results
A total of 30/51 in the RT group were ‘S-antibody’ positive; 3 after first vaccination, 21 after second and additional 3 after third vaccination dose (3 patients were ‘S-antibody’ positive prior to vaccination from previous SARS-CoV-2 infection). In the PID group, 24/30 achieved a significantly positive ‘S-antibody’ after single vaccination and 27/30 after the second vaccination (Figure 1). No patient tested negative for ‘S-antibody’ on subsequent testing once they became positive. Compared to PID, transplant patients were much less likely to have positive ‘S-antibody’ after first vaccination (OR 0.03; 95% CI 0.01-0.11, p &lt; 0.0001) and second vaccination (OR 0.13; 95% CI 0.03 – 0.46, p = 0.0012). Within the transplant group, patients on mycophenolate mofetil (MMF) were less likely (OR 0.12; 95% CI 0.01 – 1.01, p = 0.036) to respond to vaccination (Figure 2). Conversely, the patients on azathioprine were more likely to have positive ‘S-antibody’ response (OR 7.27; 95% CI 0.83 – 63.4). Comparatively patients on tacrolimus were relatively less likely to respond (OR 0.35; 95% CI 0.06 – 1.86). There was no significant difference observed between patients on steroids (OR 0.82 95% CI 0.21 – 3.28), Ciclosporin (OR 1.9; 95% CI 0.33 – 10.88) or patients on two compared to three immunosuppressants (OR 1.6; 95% CI 0.45 – 5.63). Patients within the transplant group who only had single vaccination were less likely to be ‘S-antibody’ positive (OR 0.21; 95% CI 0.04 – 1.2). There were no significant differences within gender, age, ethnicity, primary renal pathology or co-morbidities.

Conclusion
Renal transplant patients, in particular those on MMF have impaired humoral response to SARS-CoV-2 vaccination compared to PID group which is similar to previous studies [3]. There is significant humoral response to second SARS-CoV-2 vaccination in renal transplant patients which was maintained for the observed study period.