Antibody response to double SARS-CoV-2 mRNA vaccination in Japanese kidney transplant recipients

Abstract

Immunocompromised patients, especially those who undergo kidney transplantation, have lower antibody levels following SARS-CoV-2 mRNA vaccination. The situation of transplant treatment, such as transplant source and immunosuppressive drugs, is different in Japan than that in other countries. Therefore, it is necessary to clarify whether antibody acquisition rates differ between Japan and other countries. This retrospective study included patients with post-kidney transplant who were attending at the Nagoya University Hospital. The anti-SARS-CoV-2 IgG antibody titers were measured between 3 weeks and 3 months after vaccination. Seventy-three patients (45 men and 28 women) were included. Of these, 23 (31.5%) showed antibody presence, and the rates of antibody acquisition were very low than those in the control group (100.0% vs. 31.5%, P < 0.05). Antibody acquisition rates were associated with body mass index (odds ratio [OR]: 1.21, 95% confidence interval [CI]: 1.04–1.39, P < 0.05) and the duration between transplantation and vaccination (OR: 1.01, 95% CI: 1.00–1.02, P < 0.05). The immunosuppressive drugs used were: prednisolone in all cases, tacrolimus in 89.0%, cyclosporine in 9.6%, and mofetil mycophenolate in 97.3%. None of the patients were excluded from receiving two doses of the vaccine due to adverse effects. The study indicated that vaccination-induced antibody acquisition rates against SARS-CoV-2 were extremely low in Japanese patients who underwent post-kidney transplantation. Thus, despite two doses of vaccination, it is necessary to closely monitor infection control in such patients.

Assessment of Antibody-Titer Changes after Second and Third Severe Acute Respiratory Syndrome Coronavirus 2 mRNA Vaccination in Japanese Post-Kidney-Transplant Patients

“…The trend was similar to that of healthy participants in that the highest antibody titer was obtained after the third vaccination. In kidney-transplanted patients, the results of this study revealed that the antibody-acquisition rate after the second vaccination (44.8%) was slightly higher than that reported in our previous study (31.5%) [ 16 ] and similar to that reported in other countries [ 17 , 18 ]. This may be because older adults, who are at a higher risk of severe SARS-CoV-2 infection, were prioritized for vaccination in Japan; therefore, the patients in the previous study were from an older age group than those in this study.…”

“…On comparing the group that acquired S-IgG after the third vaccination with the group that did not acquire S-IgG, significant differences in BMI and eGFR were observed. This was equally true for the rate of S-IgG acquisition after the second vaccination that we previously reported [16]. Regarding BMI, low BMI was associated with failure of antibody acquisition in our transplant patient data.…”

“…Therefore, particular attention should be focused on patients undergoing strong immunosuppressive therapy for rejection-related problems, among others, and those with impaired renal function. However, in our previous study [ 16 ], the longer the duration between transplantation and vaccination, the higher the antibody-acquisition rate tended to be. Conversely, in this study no correlation existed between the antibody-acquisition rate after the third vaccination and the duration between transplantation and vaccination.…”

“…In our previous study, we measured anti-S SARS-CoV-2 immunoglobulin G (S-IgG) titers between 3 weeks and 3 months after the first two doses of the SARS-CoV-2 mRNA vaccine in post-kidney-transplant patients in Japan [ 16 ]. The results revealed that 31.5% of post-kidney-transplant patients acquired antibodies, which was not only significantly lower than that of healthy participants but also lower than the antibody-acquisition rates reported in post-kidney transplant patients overseas [ 17 , 18 ].…”

Prevalence of COVID-19 in Kidney Transplant Patients in Relation to Their Immune Status after Repeated Anti-SARS-CoV-2 Vaccination

“…We acknowledge that a small group of subjects is a limitation that prevents general conclusions and strong recommendations. However, the results of our study add supplementary information to the data obtained from other centers [ 24 , 30 , 31 ] regarding anti-SARS-CoV-2 vaccination and bring new knowledge about the immune response after such vaccination in kidney transplant patients, at the same contributing to further recommendations on how to manage these patients. The main strength of our study is the assessment of COVID-19 morbidity in kidney transplant patients after social isolation due to the pandemic.…”