20.500.12556/RUL-185261 Impaired booster-induced SARS-CoV-2 antibody responses in rituximab-treated B-cell lymphoma patients despite peripheral B-Cell Recovery Rituximab-treated patients with B-cell lymphoma exhibit profound B-cell depletion and impaired vaccine-induced antibody responses. However, it remains uncertain whether recovery of peripheral B-cell counts after rituximab is sufficient to restore effective humoral immunity following booster vaccination. Patients and methods In this prospective, single-center observational study at the Institute of Oncology Ljubljana, adult B-cell lymphoma patients treated with or previously exposed to rituximab received the Comirnaty® mRNA COVID-19 vaccine. Antibody responses to the SARS-CoV-2 spike and nucleoprotein were measured at baseline, 14 days after the second dose, and at 3, 6, 9, and 12 months. A third dose was administered at 6 months. T-cell responses (IFN-γ release) were assessed in patients before and after the primary series and booster dose. Lymphocyte subsets were analysed pre-vaccination. Adverse events and nutritional status were monitored. Results Patients undergoing anti-CD20 therapy showed absent antibody responses. Longer intervals since rituximab correlated with peripheral B-cell repopulation. However, even after reaching normal B-cell counts, patients’ antibody responses after revaccination remained significantly lower than in controls. Conclusions Rituximab is associated with impaired vaccine-induced antibody responses. Despite recovery of peripheral B-cell counts, patients with B-cell lymphoma show reduced humoral responses compared with healthy individuals following booster COVID-19 vaccination. lymphoma B-cell rituximab COVID-19 vaccines limfom B-celični limfom rituksimab cepljenje proti covid-19 true false true Angleški jezik Slovenski jezik Članek v reviji 2026-07-30 09:21:59 2026-07-30 09:22:04 2026-07-31 04:12:02 0000-00-00 00:00:00 2026 0 0 Str. 76-85 no. 1 Vol. 60 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 616-006 1318-2099 276354563 RAZ_Jurca_Tomaz_2026.pdf RAZ_Jurca_Tomaz_2026.pdf 1 1A22B7ED985869B5DBFBF8AC45BAD516 9450f4b50007727c2abf9f8ff1b147857983510dab72f6adca590890afa518de 6125641c-8be7-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=243607 https://www.radioloncol.com/index.php/ro/article/view/4845 0 80e15230-8be7-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=243608 Medicinska fakulteta 0 0 0