Serum titer of neutralizing antibodies after COVID-19 vaccination in Japanese patients with inflammatory bowel disease

Abstract

Vaccination is an important strategy to reduce the infection rate and adverse events of coronavirus disease 2019 (COVID-19). However, the effect of COVID-19 vaccination for Japanese patients with inflammatory bowel disease (IBD) has not been fully elucidated. In the present study, we investigated the serum titer of neutralizing antibodies after COVID-19 vaccination in patients with IBD, treated with and without immunosuppressive therapy. The study consisted of 108 patients with IBD [76 with ulcerative colitis (UC) and 32 with Crohn's disease (CD)] from the gastroenterology outpatient clinic at the Hospital of the Kyoto Prefectural University of Medicine who underwent anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. The control group included 64 healthy subjects who received the anti-SARS-CoV-2 vaccine. When 10 AU/ml of neutralizing antibodies was used as cut-off value, the positive rates of neutralizing antibodies of patients with UC, patients with DC, and the control group were 97.3%, 84.3%, and 100%, respectively. The neutralizing antibody titer showed no difference between patients treated with and without immunosuppressive therapy. These results indicate that COVID-19 vaccination may be useful in patients with IBD, treated with or without immunosuppressive therapy.

Keywords: COVID-19; Crohn’s disease; neutralizing antibody; ulcerative colitis; vaccination.

Fig. 1.

Boxplot of anti-SARS-CoV-2 neutralizing antibodies after vaccination and positive rate of anti-SARS-CoV-2 neutralizing antibody. Box and whisker plots are shown where the box contains 50% of the data, the bar represents the median value, and the upper and lower whiskers represent scores outside the middle 50%. (A) Boxplot of anti-SARS-CoV-2 neutralizing antibodies after vaccination of UC, CD, and control groups. Antibody titer not significantly different by multiple comparison test. (B) Positive rate of anti-SARS-CoV-2 neutralizing antibody of UC, CD, and control groups. 10 AU/ml of neutralizing antibody was used as cut off. *p<0.05 compared to control. (C) Boxplot of anti-SARS-CoV-2 neutralizing antibodies after vaccination according to immunosuppressive therapy. Antibody titer is not significantly different by multiple comparison test. (D) Positive rate of anti-SARS-CoV-2 neutralizing antibody according to immunosuppressive therapy. (E) Boxplot of anti-SARS-CoV-2 neutralizing antibodies after vaccination according to number of immunosuppressive therapies. (F) Positive rate of anti-SARS-CoV-2 neutralizing antibodies according to number of immunosuppressive therapies.

Fig. 2.

Anti-SARS-CoV-2 neutralizing antibody concentration over time. (A) Anti-SARS-CoV-2 neutralizing antibody concentration over time of UC, CD, and control groups. When we analysed CoV-2 Nab by patients’ category (as fixed factors) and days since vaccinated using ANCOVA, the analysis revealed no interaction between patients’ category and days since vaccination (p = 0.725). (B) Anti-SARS-CoV-2 neutralizing antibody concentration over time according to immunosuppressive therapy. When we analysed CoV-2 Nab by Immunosuppressive therapy and days since vaccinated using ANCOVA, the analysis revealed no interaction between Immunosuppressive therapy and days since vaccination (p = 0.313). (C) Anti-SARS-CoV-2 neutralizing antibody concentration over time according to number of immunosuppressive therapies. When we analysed CoV-2 Nab by Immunosuppressive therapy and days since vaccinated using ANCOVA, the analysis revealed no interaction between Immunosuppressive therapy and days since vaccination (p = 0.538).