{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T09:03:22Z","timestamp":1789635802917,"version":"4.0.0"},"reference-count":19,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T00:00:00Z","timestamp":1789603200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Rituximab induces prolonged B-cell depletion and may alter protective antibody levels, but longitudinal antibody to hepatitis B surface antigen (anti-HBs) patterns in pemphigus vulgaris remain poorly characterized. This study evaluated anti-HBs levels and seroprotection after rituximab and explored associated factors. Methods: This retrospective cohort included 84 patients with pemphigus vulgaris treated with rituximab between 2010 and 2026 who had baseline and post-treatment anti-HBs measurements. Longitudinal changes in log-transformed anti-HBs levels were analyzed using a linear mixed-effects model with categorical time and a patient-specific random intercept. The probability of anti-HBs &lt; 10 IU\/L was assessed using a binomial generalized estimating equation model. Paired Wilcoxon signed-rank tests were performed as sensitivity analyses. Results: The median baseline anti-HBs level was 49.7 IU\/L, and 34 patients (40.5%) had levels &lt; 10 IU\/L. Time was associated with longitudinal anti-HBs levels overall (p = 0.002). Compared with baseline, model-estimated levels were lower at month 6 (geometric mean ratio [GMR] 0.61, 95% CI 0.42\u20130.88), month 9 (GMR 0.64, 95% CI 0.45\u20130.89), and month 18 (GMR 0.50, 95% CI 0.32\u20130.78). Time was not significantly associated with the odds of anti-HBs &lt; 10 IU\/L (global p = 0.490). Positivity for antibody to hepatitis B core antigen (anti-HBc) IgG was associated with higher longitudinal anti-HBs levels (adjusted GMR 13.24, 95% CI 5.32\u201332.95; p &lt; 0.001). No clinically or biochemically evident hepatitis B virus (HBV) reactivation was documented, although HBV DNA was not routinely monitored. Conclusions: Quantitative anti-HBs levels varied significantly during follow-up; whereas, the probability of crossing below the conventional seroprotection threshold did not increase significantly. These findings support HBV serological assessment and cautious interpretation of serial anti-HBs measurements in rituximab-treated patients with pemphigus vulgaris.<\/jats:p>","DOI":"10.3390\/diagnostics16183004","type":"journal-article","created":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T08:03:17Z","timestamp":1789632197000},"page":"3004","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Longitudinal Anti-HBs Monitoring and Seroprotection Patterns in Rituximab-Treated Patients with Pemphigus Vulgaris: A Retrospective Cohort Study"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5837-377X","authenticated-orcid":false,"given":"Nur","family":"Ecer","sequence":"first","affiliation":[{"name":"Department of Dermatology and Venereology, Gazi Ya\u015fargil Training and Research Hospital, 21070 Diyarbak\u0131r, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"}]},{"given":"Mehmet","family":"Harman","sequence":"additional","affiliation":[{"name":"Department of Dermatology and Venereology, Faculty of Medicine, Dicle University, 21280 Diyarbak\u0131r, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"conceptualization","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,17]]},"reference":[{"key":"ref_1","unstructured":"Ingold, C.J., Sathe, N.C., and Khan, M.A.B. 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FDA Drug Safety Communication: Boxed Warning and New Recommendations to Decrease Risk of Hepatitis B Reactivation with the Immune-Suppressing and Anti-Cancer Drugs Arzerra (Ofatumumab) and Rituxan (Rituximab)."}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/18\/3004\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T08:26:56Z","timestamp":1789633616000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/18\/3004"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,17]]},"references-count":19,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["diagnostics16183004"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics16183004","relation":{},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,17]]}}}