This study was conducted in compliance with ethical principles based on the Helsinki Declaration and was approved by the institutional review board of Aiiku Hospital. IgM level. The serologic response rates and median antibody titers were significantly different between diffuse large B-cell lymphoma (DLBCL) patients in whom anti-CD20 antibody treatment was completed within 9?months before vaccination and follicular lymphoma (FL) patients in whom anti-CD20 antibody treatment was completed within 15?months before vaccination. Moreover, the serologic response rates and median antibody titers were significantly different among FL patients in whom bendamustine treatment was completed within 33?months before vaccination. We demonstrated that B-NHL patients who were recently treated with anti-CD20 antibodies and bendamustine had a diminished humoral response to COVID-19 vaccination. UMIN 000,045,267. Supplementary Information The online version contains supplementary material available at 10.1007/s00277-023-05204-7. Keywords: COVID-19 vaccine, SARS-CoV-2, B-cell non-Hodgkin lymphoma (B-NHL), Anti-CD20 antibodies, Bendamustine Introduction The novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to a pandemic throughout the world and more than 5 million deaths. COVID-19 has an increased risk of mortality in patients with hematological malignancies, with a mortality rate of approximately 35% in hospitalized patients, probably due to impaired humoral and cellular immunity and therapy-related immunosuppression [1C11]. The results of several randomized trials for BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccines against SARS-CoV-2 have shown that the vaccines are safe and effective for preventing infection or attenuating disease severity [12, 13]. It was reported that seroconversion of SARS-CoV-2 immunoglobulin G (IgG) occurred in almost all healthy individuals, but the seroconversion rate was lower in patients with hematological malignancies [14C22]. Moreover, several studies have shown that the seroconversion rate was decreased in patients with B-cell lymphoma, especially those who had recently been treated with anti-CD20 monoclonal antibodies due to depletion of normal B cells and thus impairment of humoral response [23C30]. However, it is still unclear whether those patients develop an immune response following vaccination. In the current study, we investigated the antibody titers of SARS-CoV-2 in patients with B-cell non-Hodgkin lymphoma (B-NHL) who received two doses of an mRNA-based COVID-19 vaccine, either BNT162b2 or mRNA-1273, and compared them to those in healthy controls to identify factors affecting the response rate to the vaccine. Methods Patients and healthy controls Previously treated, actively treated at the time of vaccination, and treatment-na?ve B-NHL patients, including patients with diffuse large B-cell lymphoma (DLBCL) and patients with follicular lymphoma (FL), were enrolled in this prospective study (UMIN 000,045,267). Consistent with our previous report, all patients who had been vaccinated AZD8329 with two consecutive doses of an mRNA-based COVID-19 vaccine, either BNT162b2 or mRNA-1273, were recruited into this study between August 17 and December 31, 2021 [31]. The BNT162b2 and mRNA-1273 vaccines were administered 21?days and 28?days apart, respectively. Individuals with a known history of COVID-19 infection were excluded from both cohorts of patients and healthy controls. Demographic and clinical data including data for histological diagnosis, disease status, response to treatment, treatment AZD8329 regimen, complete blood count, and blood chemistry were obtained from medical records. The response criteria in patients with B-NHL were defined according to the Lugano response criteria for non-Hodgkins lymphoma [32]. The disease status in all patients was determined at the time of sample collection. We recruited healthcare workers at Aiiku Hospital who had no medical AZD8329 history of hematological disorders and who had received two doses of BNT162b2 vaccine as healthy controls. This study was conducted in compliance with ethical principles based on the Rabbit Polyclonal to ZAR1 Helsinki Declaration and was approved by the institutional review board of Aiiku Hospital. All participants provided written informed consent prior to enrollment in the study. Assessment of serological response Peripheral blood and serum samples were drawn 3?months?after administration of the second vaccine dose and were evaluated for anti-spike (S) SARS-CoV-2 antibodies using the Elecsys? Anti-SARS-CoV-2S immunoassay performed on the cobas e411 fully automated analyzer for the SARS-CoV-2 S protein receptor-binding domain [33C35]. This assay has a minimum measurement value of 0.4 U/mL, with a concentration of 0.8 U/mL or more considered to be a positive result. For individuals with an antibody titer to SARS-CoV-2 S protein of less than 0.4 U/mL, the antibody titer was calculated as 0 U/mL. Statistical analysis The chi-squared test or Fishers exact test was used to compare categorical variables and the MannCWhitney test or an analysis of variance test was used for continuous variables. values were adjusted using the Bonferroni.