Cinétique de la réponse humorale après administration d’un vaccin SARS-COV-2 mRNA dans une cohorte de patients transplantés et greffés rénaux

Introduction Kidney transplant recipients and patients on hemodialysis are immunocompromised populations, prioritized for COVID 19 vaccination, but excluded from vaccine trials. Data are lacking regarding humoral response to COVID vaccination in immunocompromised patients. Description We investigated early serological response after COVID 19 vaccination with Pfizer/BioNTech (BNT162b2) mRNA vaccine in groups of patients undergoing hemodialysis (n=78), kidney transplant recipients (n=74), and in healthy controls. Antibody titers against SARS-CoV-2 at days 0, 14, 28, 36 and 58 after the first injection were measured. Methods Antibody titers against SARS-CoV-2 at days 0, 14, 28, 36 and 58 after the first injection were measured. Results A total of 74 transplant recipients (mean age 64.8±11.5 years, 38.9% women), 78 hemodialysis patients (mean age 73.5±12.8 years, 40.2% women) and 7 healthy controls (mean age 51.6±6.8, 42% women) were included. In controls, antibodies were detected at a significant level (>13 AU/ml) at day 14 post-injection, and increased progressively, to peak at day 36 (median 1372 AU/mL [IQR 490.2-4540.5]). Patients undergoing hemodialysis had lower titers that peaked at day 58 (median 4.0 AU/mL [IQR: 1.85-12.2] at day 14; 6.6 AU/mL [IQR 2.1-19.0] at day 36; 276 AU/mL [IQR 83.4-526.0] at day 58). A significant antibody level was detected in only 3 kidney transplant recipients at day 36. In hemodialysis patients, age, serum albumin and Kt/V were positively correlated with serological response (P<0.043 and P<0.019 respectively); non responders to HBV vaccine had the lowest titers of anti-SARS-CovV-2 antibodies (Fig. 1). Conclusion Our results suggest that the post-vaccine humoral response is strongly inhibited by immunosuppressant therapy in kidney transplant recipients, while it is lowered by the uremic condition in patients undergoing hemodialysis.