RESUMEN
Serology studies provide limited information on immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This cross-sectional study aimed to assess prevalence and determinants of anti-SARS-CoV-2 cellular immunity in a cohort of heart transplant (HT) recipients. All consecutive HT recipients followed-up at our outpatient clinic between February and June 2022 providing informed consent were included in this observational cross-sectional study. We quantified SARS-CoV-2 Spike (S)-reactive and Nucleocapsid (N)-reactive T cells using enzyme-linked immunospot assay. A positive response was defined as S or N reactivity >8 spots/2 × 105 lymphocytes. Clinical characteristics, laboratory data, immunosuppressive regimen and vaccination status were compared between patients with and without SARS-CoV-2 S-reactive T cells. Categorical variables were described as number (%) and continuous variables with median [IQR]. Among 201 patients (age 58 [45-65] years, 77% males, time since transplantation 51 months [24-81]), 97 (48%) exhibit S-specific T cells, of which 58 had in addition N-reactive T cells. CD4 and CD8 T lymphocyte count, glomerular filtration rate, immunosuppressive regimen were associated with T cell response (Table). Among patients with detectable SARS-Co-V-2 cellular immunity, numbers of S-reactive T cells were higher in patients who had detectable N-reactive T cells (277 vs 93 /106 T cells) (Figure). Our study provides new information on cellular immunity against SARS-CoV-2 in HT recipients. [ FROM AUTHOR] Copyright of Journal of Heart & Lung Transplantation is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)
RESUMEN
Background: Recent studies reported poor to moderate humoral response after two vaccine doses in heart transplant recipients (HTR). Currently, French healthcare authorities recommend 2 and 3 vaccine injections for transplant recipients with and without prior SARS-CoV-2 infection, respectively. This study aimed to evaluate level and durability of humoral immunity with this vaccination strategy. Methods: This single-center cohort study included HTR followed at Paris Bichat hospital between January 2020 and September 2021. Analyses were performed using automated immunoassays (Abbot) to quantify anti-spike IgG (cut-off ≥ 7.1 BAU/mL) and anti-nucleocapsid IgG (cut-off index > 0.49), respectively. Categorical variables were described as number (%) and continuous variables with median (IQR). Results: A total of 181 HTR (75.7% males, age 58 y [47-66]) transplanted between June 1990 and June 2021, with cardiomyopathy (n=95), coronary artery disease (n=61), valvular cardiomyopathy (n=19) or other transplant indications were included. Median time from transplantation to first vaccine dose was 4.2 y [1.8-6.6]. 143 HTR (79%) had no SARS-CoV-2 infection history (HTRn) and 38 (21%) contracted the infection (HTRi) (56% before and 42% after vaccination initiation). After 2 vaccine injections, anti-S IgG seroconversion was observed for only 16% (n=12/76) of HTRn. Overall, anti-S IgG titers were lower in HTRn than in HTRi (0.5 [0.2-2.6] vs 578 [1.4-4449] BAU/mL, respectively, p=0.0001). The 3rd vaccine dose enabled to obtain 42% (n=33/72) of seroconversion among HTRn with median anti-S titers of 3.2 BAU/mL [0.4-35.0]. Only half seroconverters HTRn reached the 260 BAU/mL cut-off chosen by French authorities to define vaccination efficacy. Interestingly, these patients seem to have a sustained humoral response 4 months after the 3rd dose. Conclusion: This study gives new insights on the effect of the 3rd vaccine dose in HTR with low rate of seroconversion and low titers of anti-S IgG but sustained humoral response when seroconversion occurs. Studies on vaccine efficacy against SARS-CoV-2 variants and cell-mediated immune response in this cohort are ongoing.