Immune Response after SARS-CoV-2 Vaccination in Kidney Transplant Patients
Rūta Vaičiūnienė, Brigita Šitkauskienė, Inga Arūnė Bumblytė, Eglė Dalinkevičienė, Edita Žiginskienė, Dovydas Bagdonas, Rūta Auglienė, Kristina Petrulienė, Irmante Bagdziuniene, Inga Skarupskienė, Asta Stankuvienė, Jolanta Sauserienė, Šarūnas Mačinskas, Leonas Valius
Abstract
Background and Objectives: The prospective study was conducted to evaluate humoral and cellular immune responses after two doses of BNT162b2 (Pfizer-BioNTech) vaccine and possible relation with other factors (medication, etc.) in kidney transplant patients. Materials and Methods: Out of 167 vaccinated patients, 136 agreed to a follow-up visit three to six weeks after vaccination. Results: Only 39 patients (29%) developed antibody response against SARS-CoV-2 (≥35.2 binding antibody units (BAU)/mL) after full vaccination. Multivariate binary logistic regression analysis showed that predictive factors for good antibody response to the COVID-19 vaccine were better kidney function, higher hemoglobin level, and no use of mycophenolate mofetil for immunosuppression. For seropositive kidney transplant patients there was a significant negative correlation between anti-SARS-CoV-2 antibody titer and CD4/CD8 ratio (Spearman’s correlation coefficient −0.4, p = 0.02), percentage of CD19+ cells (r = −0.37, p = 0.02), and a positive correlation with percentage of CD8+ cells (r = 0.4, p = 0.01). There was an increase of total leucocyte count after vaccination in the total studied population, and in the group of responders. Conclusions: Only one third of kidney transplant patients develop sufficient antibody responses after full COVID-19 vaccination with Pfizer-BioNTech. Better kidney function, higher hemoglobin level, and no use of mycophenolate mofetil for immunosuppression increases the adequacy of response. The antibody titers correlated positively with relative number of CD8+ cells and negatively with CD4/CD8 ratio in responders.