ABSTRACT
Background: Kidney Transplant Recipients (KTRs) are a high-risk group as far as SARS-CoV-2 disease is concerned. The object of this study was to evaluate the immune response of a cohort of KTRs after 2 doses of mRNA BNT16b2 and to determine if there is any correlation between the immune response and immunosuppressive therapy.
Material – Methods: Our patient cohort consists of 83 KTRs of an Organ Transplant Unit of a General Hospital of Greece and included 60 men and 23 women (mean age 54,7 range 22-73 years). Two measurements of SARSCoV- 2 antibodies were conducted: a) after the initial 2dose vaccination (first measurement) and b) before the second booster dose (second measurement). The antibody response was measured using chemiluminescent microparticle immune assay (CMIA). Dividing line for the antibodies was value 50, KTRs with value ≥50 was considered fully immunized. Furthermore, structured interviews were conducted to obtain information about the medical history of KTRs, their treatment and vaccination’s adverse reactions.
Results: Even though the immune response increased after the second measurement it continued to be poor. A 39,8% (n=33) of KTRs had antibodies ≥50 after the first measurement and this percentage became 43,4% after the second measurement. This difference was not statistically important (p=0,664). As far as the immunosuppressive treatment is concerned, none of the medications affected the change in the antibody titers in the two measurements with p value for all medications being bigger than 0,05.
Conclusions: Immune response of KTRs decreased. For this reason, boosters are needed to protect this group.
Key words: BNT16b2 vaccine, immunosuppressive treatment, SARS–CoV-2
