Introduction: Both cellular and humoral responses are important for vaccine protection, but recommendations on immunosuppressants in dermatology are largely based on pre-pandemic experiences. This study aimed to investigate the impacts of immunosuppressants on humoral and cellular immunogenicity to COVID-19 vaccinations in pemphigus patients.
Methods: SARS-CoV-2-naïve pemphigus patients and age-, and sex-matched healthy controls were recruited from multiple tertiary medical centers during 2021-2023. Anti-spike protein-related T-cell responses, antibody titers, and high-parameter cell analysis of the peripheral blood were utilized to investigate the inhibitory effects of immunosuppressants, including rituximab and azathioprine.
Results: A total of 32 patients and 120 healthy controls were enrolled. COVID-19 vaccinations spaced at least six months after the last rituximab infusion did not cause a significant difference in anti-viral T-cell or antibody responses between rituximab-naïve and rituximab-treated patients. All pemphigus patients demonstrated improved antibody responses after the third vaccination and none of them suffered from severe COVID-19 illness. Intriguingly, we found that daily dosages of 100 mg or more of azathioprine were linked to significantly decreased anti-viral T-cell responses induced by the vaccination (mean of fold change [SD]; higher azathioprine dosage = 0.70 [0.61] folds vs. lower azathioprine dosage = 2.11 [1.03] folds; p = 0.044).
Conclusion: Except for a subset of patients with unrecovered B-cell deficiency, rituximab infusion with proper scheduling of vaccination preserved better anti-viral T-cell responses and did not lead to hindered antibody responses in pemphigus patients. All pemphigus patients benefited from receiving the third booster regardless of B-cell status.
Keywords: anti-viral humoral immunity; anti-viral t-cell response; azathioprine; pemphigus vulgaris; rituximab; vaccine immunogenicity.
Copyright © 2024 Lu, Lee, Chen, Hui, Chang, Lu, Wang and Chung.