scholarly journals Monitoring B-cell repopulation after depletion therapy in neurologic patients

2018 ◽  
Vol 5 (4) ◽  
pp. e463 ◽  
Author(s):  
Erik Ellwardt ◽  
Lea Ellwardt ◽  
Stefan Bittner ◽  
Frauke Zipp
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Depletion ◽  
Close Monitoring ◽  
B Cell Depletion ◽  
Cell Recovery ◽  
Cell Counts ◽  
White Blood Cell Counts ◽  
Anti Cd20 ◽  
Cell Repopulation

ObjectiveTo determine the factors that influence B-cell repopulation after B-cell depletion therapy in neurologic patients and derive recommendations for monitoring and dosing of patients.MethodsIn this study, we determined the association of body surface area (BSA; calculated by body weight and height with the Dubois formula), sex, pretreatment therapy, age, CSF data, and white blood cell counts with the risk and timing of B-cell repopulation, defined as 1% CD19+ cells (of total lymphocytes), following 87 B cell–depleting anti-CD20 treatment cycles of 45 neurologic patients (28 women; mean age ± SD, 44.5 ± 15.0 years).ResultsPatients with a larger BSA had a higher probability to reach 1% CD19+ cells than those with a smaller BSA (p < 0.05) following B-cell depletion therapy, although those patients had received BSA-adapted doses of rituximab (375 mg/m2). Sex, pretreatment, age, CSF data, or absolute lymphocyte and leukocyte counts during treatment did not significantly influence CD19+ B-cell recovery in the fully adjusted models. Intraindividual B-cell recovery in patients with several treatment cycles did not consistently change over time.ConclusionsB-cell repopulation after depletion therapy displays both high inter- and intra-individual variance. Our data indicate that a larger BSA is associated with faster repopulation of B cells, even when treatment is adapted to the BSA. A reason is the routinely used Dubois formula, underestimating a large BSA. In these patients, there is a need for a higher therapy dose. Because B-cell count–dependent therapy regimes are considered to reduce adverse events, B-cell monitoring will stay highly relevant. Patients' BSA should thus be determined using the Mosteller formula, and close monitoring should be done to avoid resurgent B cells and disease activity.

Sustained Depletion of B-Cells by a Humanized, Fc-Engineered Anti-CD20 Antibody, AME-133v, in Patients with Relapsed Follicular Lymphoma

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4977-4977
Author(s):  
Jennifer Wayne ◽  
Kristen N. Ganjoo ◽  
Andres Forero ◽  
Brad Pohlman ◽  
Sven de Vos ◽  
...  
Keyword(s):  
Clinical Trials ◽  
B Cells ◽  
Phase I ◽  
Follicular Lymphoma ◽  
B Cell ◽  
Cell Depletion ◽  
B Cell Depletion ◽  
Cell Counts ◽  
Evaluable Population ◽  
Anti Cd20

Abstract Abstract 4977 Sustained Depletion of B-Cells by a Humanized, Fc-Engineered Anti-CD20 Antibody, AME-133v, in Patients with Relapsed Follicular Lymphoma J Wayne,1 K Ganjoo,2 A Forero,3 B Pohlman,4 S de Vos,5 S Carpenter,6 J Wooldridge,6 S Marulappa,1 V Jain11Mentrik Biotech, LLC, Dallas, TX, 2Standford University Medical Center, Stanford, CA, 3Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL,4Cleveland Clinic Taussig Cancer Institute, Cleveland, OH, 5David Geffen School of Medicine at University of California, Los Angeles, CA, 6Eli Lilly and Company, Indianapolis, Indiana Introduction AME-133v is a humanized anti-CD20 monoclonal antibody that has a 13 to 20-fold increase in binding affinity and approximately 6-fold more potent effector function in antibody-dependent cell-mediated cytotoxicity (ADCC) compared to rituximab. Phase I/II clinical trials of AME-133v in patients with relapsed follicular lymphoma have demonstrated an overall response rate of greater than 30% with a complete response rate of 16%. The extent and duration of depletion of CD19+ B-cells in peripheral blood was used as a surrogate of therapeutic levels of AME-133v. Analysis from the Phase I/II clinical trials is presented in this report. Methods CD-19 positive B-cells in peripheral blood were measured in 77 patients with relapsed follicular lymphoma enrolled in two phase I/II clinical trials of AME-133v. These studies assessed five different doses of AME-133v (from 2 mg/m2 to 375 mg/m2). AME-133v was administered intravenously four times at weekly intervals in both trials. Blood samples were taken at multiple time points throughout the trial and a central lab measured levels of circulating CD19+ B-cells using fluorescence-activated cell sorting (FACS). Results Excluding the four patients enrolled in the 2 mg/m2 dose cohort, depletion of peripheral B-cells occurred in all patients and was sustained over time (Table 1). Baseline levels of B-cell counts ranged from 4 × 103 to 1,187 × 103 cells/μL, with an average of 102 × 103 cells/μL and a median of 60 × 103 cells/μL. Within 24 hours of the first infusion, all patients had depletion of circulating B-cells; ninety-six percent of patients had less than 10 × 103 cells/μL and two patients had less than 20 × 103 cells/μL. Interestingly, AME-133v was effective at depleting B-cells even at doses as low as 7.5 mg/m2. To assess sustainability of B-cell depletion after four doses of AME-133v, CD19+ cell counts were evaluated at nine weeks after the fourth infusion and every three months thereafter. Complete depletion of CD19+ lymphocytes was sustained for nine weeks. At five months after the last infusion of AME-133v, nearly two-thirds of patients had no detectable circulating B-cells. Sustained B-cell depletion lasted for at least eight months following the last infusion in 63% of patients. Table 1. B-cell counts for all patients in 7.5, 30, 100 and 375 mg/m2 cohorts. Percentages are cumulative Time Point Cell Count (x 103 cells/μL) 0 < 1 2 to 10 11 to 30 31 to 50 < 100 Day 1 (24 hours after last infusion) 62 % 66 % 96 % 100 % 100% 100% Day 7 (day of infusion 2) 75% 80% 95% 97% 97% 98% Day 28 (1 week after last infusion) 78 % 87% 95% 98% 98% 100% Day 84 (9 weeks after last infusion) 78% 87% 91% 96% 96% 98% Day 174 (5 months after last infusion) 60% 60% 70% 86% 93% 100% Day 264 (8 months after last infusion) 26% 26% 41% 63% 81% 89% Day 354 (11 months after last infusion) 0% 0% 15% 40% 55% 80% DEMOGRAPHIC CHARACTERISTICS (EVALUABLE POPULATION) “\f C \l 1 Demographic and Disease Characteristics on evaluable population (N=30) Conclusion The rapid and sustained effect of AME-133v on B-cell depletion, even in low-affinity FcγRIIIa patients, indicates a potentially relevant biological activity of the antibody in treating B-cell non-Hodgkin lymphoma. Notably, this depletion occurred even at very low doses of drug administration and persisted over time. This may be related to its higher affinity for CD20, increased ADCC, or both. The sustained B-cell depletion may result in prolonged clinical response and might mitigate the need for maintenance therapy. A randomized trial is being planned to compare efficacy of AME-133v vs. rituximab. Disclosures: No relevant conflicts of interest to declare.

scholarly journals B cell depletion with anti-CD20 mAb exacerbates anti-donor CD4+ T cell responses in highly sensitized transplant recipients

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Asuka Tanaka ◽  
Kentaro Ide ◽  
Yuka Tanaka ◽  
Masahiro Ohira ◽  
Hiroyuki Tahara ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
T Cell Responses ◽  
Cell Depletion ◽  
B Cell Depletion ◽  
Transplant Recipients ◽  
Cell Responses ◽  
Anti Cd20

AbstractPretransplant desensitization with rituximab has been applied to preformed donor-specific anti-human leukocyte antigen antibody (DSA)-positive recipients for elimination of preformed DSA. We investigated the impact of pretransplant desensitization with rituximab on anti-donor T cell responses in DSA-positive transplant recipients. To monitor the patients’ immune status, mixed lymphocyte reaction (MLR) assays were performed before and after desensitization with rituximab. Two weeks after rituximab administration, the stimulation index (SI) of anti-donor CD4+ T cells was significantly higher in the DSA-positive recipients than in the DSA-negative recipients. To investigate the mechanisms of anti-donor hyper responses of CD4+ T cells after B cell depletion, highly sensitized mice models were injected with anti-CD20 mAb to eliminate B cells. Consistent with clinical observations, the SI values of anti-donor CD4+ T cells were significantly increased after anti-CD20 mAb injection in the sensitized mice models. Adding B cells isolated from untreated sensitized mice to MLR significantly inhibited the enhancement of anti-donor CD4+ T cell response. The depletion of the CD5+ B cell subset, which exclusively included IL-10-positive cells, from the additive B cells abrogated such inhibitory effects. These findings demonstrate that IL-10+ CD5+ B cells suppress the excessive response of anti-donor CD4+ T cells responses in sensitized recipients.

Blinatumomab exposure and pharmacodynamic response in patients with non-Hodgkin lymphoma (NHL).

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 3051-3051 ◽  
Author(s):  
Youssef Hijazi ◽  
Matthias Klinger ◽  
Andrea Schub ◽  
Benjamin Wu ◽  
Min Zhu ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Phase 1 ◽  
Cell Depletion ◽  
B Cell Depletion ◽  
Dose Requirement ◽  
Time Curve ◽  
Cell Counts ◽  
Dose Dependent

3051 Background: Blinatumomab (AMG 103) is an investigational, bispecific, T cell engaging (BiTE) antibody targeting CD19-expressing B cells. We describe the exposure-pharmacodynamic (PD) response of blinatumomab in patients with NHL, using a quantitative pharmacology approach. Methods: In a phase 1 study, 76 patients with NHL received blinatumomab by continuous intravenous infusion (cIV) at doses of 0.5 to 90 μg/m2/d in 4- or 8-week cycles. Pharmacokinetics (PK) was determined. PD responses evaluated included lymphocytes and cytokines measured during treatment, and sum of the products of the greatest diameters of tumor size in lymph nodes (SPD) at the end of treatment. Blinatumomab concentration at steady state (Css) and the cumulative area under the concentration (AUCcum)–time curve over the period before the evaluation of SPD were used to evaluate the exposure-SPD relationship. Results: Blinatumomab showed linear PK. Early PD responses were characterized by B cell depletion, T cell redistribution, and transient cytokine release. Following cIV at doses from 0.5 to 90 μg/m2/d, B cells declined at a first-order rate with a dose-dependent rate constant, ranging from 0.16 to 1.0 h-1. Complete B cell depletion was achieved within 48 hours at doses ≥5 μg/m2/d. A dose-independent decrease in T cell counts was observed within 24 hours after dosing, and T cells returned to baseline within 2 weeks of treatment. Cytokine elevation occurred in some patients and was dose-dependent. Blinatumomab exposure-SPD relationship was best described by an inhibitory Emax model (E = E0-(Imax*C)/(IC50+C)). According to the model estimation, a 50% reduction in SPD would be achieved when Css is 2141 pg/mL and AUCcum is 1381 h*μg/L, equivalent to a blinatumomab dose of 54 µg/m2/d given over 27 days. Conclusions: B lymphocytes were completely depleted from the circulation at blinatumomab doses ≥5 μg/m2/d. Depletion was faster at higher doses. Higher blinatumomab Css and AUCcum were associated with better tumor reduction. Tissue accessibility may explain the higher dose requirement for SPD reduction versus peripheral B cell depletion. The PK/PD model has utility for the design of future studies of blinatumomab in NHL. Clinical trial information: NCT00274742.

B-cell-activating factor receptor expression on naive and memory B cells: relationship with relapse in patients with rheumatoid arthritis following B-cell depletion therapy

2010 ◽  
Vol 69 (12) ◽  
pp. 2181-2188 ◽  
Author(s):  
Inmaculada de la Torre ◽  
Rita A Moura ◽  
Maria J Leandro ◽  
Jonathan Edwards ◽  
Geraldine Cambridge
Keyword(s):  
Rheumatoid Arthritis ◽  
B Cells ◽  
B Cell ◽  
Memory B Cells ◽  
Receptor Expression ◽  
Cell Depletion ◽  
B Cell Depletion ◽  
B Cell Activating Factor ◽  
Significant Difference ◽  
Cell Repopulation

ObjectivesTo examine the expression of B-cell-activating factor receptor (BAFF-R) on naive CD27− and memory CD27+ B cells in normal individuals and patients with rheumatoid arthritis (RA) undergoing B-cell depletion therapy with rituximab.Patients and MethodsBAFF-R expression on B-cell subsets was determined in normal controls (NC; n=11), active patients with RA pre-rituximab (pre-RX; n=15), relapsing patients either concordant for B-cell repopulation (C-R, n=13) or discordant, with relapse more than 3 months after repopulation (D-R, n=11) and patients in remission over 3 months postrepopulation (discordant non-relapsing (D-NR), n=5). Serum BAFF was measured by ELISA and analysed using Mann–Whitney.ResultsThere was no significant difference between NC, pre-RX and D-NR patients in %BAFF-R-positive B cells or mean fluorescence intensity (MFI) in naive and memory B cells. Relapsing patients had significantly lower MFI and %BAFF-R-positive cells in both naive and memory compartments from NC and pre-RX (C-R and D-R; p<0.01). BAFF levels in pre-RX patients were within the normal range and did not correlate with BAFF-R expression in any patient group. D-NR patients had relatively lower proportions of pre and postswitch CD27+ B cells than pre-RX patients (D-NR vs pre-RX; p<0.05 for both) and also lower numbers of postswitch B cells than D-R patients (D-NR vs D-R, p<0.05).ConclusionBAFF-R expression was significantly reduced on both naive and memory B cells in patients at relapse, regardless of the relationship with B-cell repopulation or serum BAFF levels. Re-establishment of active disease was also associated with an increase in class-switch recombination. Factors responsible for lower levels of BAFF-R may relate to altered thresholds for autoreactive B-cell generation at relapse in patients with RA.

scholarly journals The Influence of B Cell Depletion Therapy on Naturally Acquired Immunity to Streptococcus pneumoniae

2021 ◽  
Vol 11 ◽  
Author(s):  
Giuseppe Ercoli ◽  
Elisa Ramos-Sevillano ◽  
Rie Nakajima ◽  
Rafael Ramiro de Assis ◽  
Algis Jasinskas ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
B Cells ◽  
B Cell ◽  
Respiratory Infections ◽  
Serum Levels ◽  
Cell Depletion ◽  
B Cell Depletion ◽  
Protein Antigens ◽  
Antibody Recognition ◽  
Anti Cd20

The anti-CD20 antibody Rituximab to deplete CD20+ B cells is an effective treatment for rheumatoid arthritis and B cell malignancies, but is associated with an increased incidence of respiratory infections. Using mouse models we have investigated the consequences of B cell depletion on natural and acquired humoral immunity to Streptococcus pneumoniae. B cell depletion of naïve C57Bl/6 mice reduced natural IgM recognition of S. pneumoniae, but did not increase susceptibility to S. pneumoniae pneumonia. ELISA and flow cytometry assays demonstrated significantly reduced IgG and IgM recognition of S. pneumoniae in sera from mice treated with B cell depletion prior to S. pneumoniae nasopharyngeal colonization compared to untreated mice. Colonization induced antibody responses to protein rather than capsular antigen, and when measured using a protein array B cell depletion prior to colonization reduced serum levels of IgG to several protein antigens. However, B cell depleted S. pneumoniae colonized mice were still partially protected against both lung infection and septicemia when challenged with S. pneumoniae after reconstitution of their B cells. These data indicate that although B cell depletion markedly impairs antibody recognition of S. pneumoniae in colonized mice, some protective immunity is maintained, perhaps mediated by cellular immunity.

HuMax-CD20 Fully Human Monoclonal Antibody in Follicular Lymphoma. First Human Exposure: Early Results of an Ongoing Phase I/II Trial.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1400-1400 ◽  
Author(s):  
Anton Hagenbeek ◽  
Torben Plesner ◽  
Jan Walewski ◽  
Andrzej Hellmann ◽  
Brian K. Link ◽  
...  
Keyword(s):  
B Cells ◽  
Adverse Events ◽  
B Cell ◽  
Cell Count ◽  
Peripheral Blood ◽  
Tumor Response ◽  
Cell Depletion ◽  
B Cell Depletion ◽  
Cell Counts ◽  
Grade 3

Abstract HuMax-CD20 is a fully human monoclonal IgG1 antibody targeting a unique extracellular epitope of the CD20 molecule on B-cells. HuMax-CD20 stops growth of engrafted B-cell tumors in SCID mouse tumor models more efficiently than Rituximab®, and i.v. infusion of HuMax-CD20 in cynomolgus monkeys has led to profound, long lasting, dose-dependent B-cell depletion. A total of 40 patients with CD20+ relapsed or refractory follicular non-Hodgkin’s lymphoma grade I-II will be enrolled in this open-label, dose-escalating, international, multi-center clinical trial. Cohorts of 10 patients will receive i.v. infusions at doses of either 300, 500, 700 or 1000 mg once weekly for 4 weeks. The patients are followed for 12 months. Patients receive oral acetaminophen and i.v. antihistamin before infusion. In case of adverse events of CTC grade 3 or higher, i.v. glucocorticosteroids are given. The endpoints are CT scan verified tumor response according to the Cheson criteria, B-cell depletion in peripheral blood and lymph nodes, time to next anti-lymphoma treatment, duration of response, BCL2 conversion, pharmacokinetics, and adverse events. Tumor and bone marrow biopsies and CT scans are assessed centrally. The first 17 patients treated with HuMax-CD20 are the subject of this report. Mean age is 60 years. In the 300 mg group all 10 patients have received all 4 infusions. Seven patients have been enrolled in the 500 mg group; three of them have received 4 infusions, two have received 3 infusions, and two patients have received 2 infusions. Baseline B-cell count was in the range of 11-382 x 106 cells per L with a median of 114 x 106. One week after the first infusion the median B-cell count available in 16 patients was 8 x 106 cells per L with a range of 0–19 x 106. In six of the 16 patients no B-cells were detected. B-cell counts measured one week after the 4th infusion are available for 10 patients. Eight patients had no detectable B-cells, one patient had 11 x 106 and one had 34 x 106 cells per L. B-cell counts eight weeks after the 4th infusion are available for two patients. No B-cells were detectable in these two patients. No dose limiting toxicity has been reported with administration of 300 or 500 mg. One serious adverse event assessed as not related to HuMax-CD20 has been reported in the 300 mg group. Infusion related adverse events have primarily been seen during the first infusion of HuMax-CD20. The events have, as expected, predominantly been signs and symptoms of cytokine release, e.g. pruritus, dyspnoea, rigors/chills, nausea, hypotension, urticaria, fatigue, fever and rash. In 15 of the 17 patients, 51 adverse events have been reported. Nine adverse events were CTC grade 3, 16 were grade 2, and 26 events were grade 1. In conclusion, this analysis based on preliminary data for the first 17 patients treated with HuMax-CD20 demonstrated significant depletion of peripheral blood B-cells and a favorable safety profile. An updated report of results for all 40 patients including preliminary tumor response data will be presented.

scholarly journals The Innate Mononuclear Phagocyte Network Depletes B Lymphocytes through Fc Receptor–dependent Mechanisms during Anti-CD20 Antibody Immunotherapy

2004 ◽  
Vol 199 (12) ◽  
pp. 1659-1669 ◽  
Author(s):  
Junji Uchida ◽  
Yasuhito Hamaguchi ◽  
Julie A. Oliver ◽  
Jeffrey V. Ravetch ◽  
Jonathan C. Poe ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Effector Cell ◽  
Fc Receptor ◽  
Cell Depletion ◽  
B Cell Depletion ◽  
Antibody Immunotherapy ◽  
Cd20 Antibody ◽  
Anti Cd20 ◽  
Cd20 Antibodies

Anti-CD20 antibody immunotherapy effectively treats non-Hodgkin's lymphoma and autoimmune disease. However, the cellular and molecular pathways for B cell depletion remain undefined because human mechanistic studies are limited. Proposed mechanisms include antibody-, effector cell–, and complement-dependent cytotoxicity, the disruption of CD20 signaling pathways, and the induction of apoptosis. To identify the mechanisms for B cell depletion in vivo, a new mouse model for anti-CD20 immunotherapy was developed using a panel of twelve mouse anti–mouse CD20 monoclonal antibodies representing all four immunoglobulin G isotypes. Anti-CD20 antibodies rapidly depleted the vast majority of circulating and tissue B cells in an isotype-restricted manner that was completely dependent on effector cell Fc receptor expression. B cell depletion used both FcγRI- and FcγRIII-dependent pathways, whereas B cells were not eliminated in FcR common γ chain–deficient mice. Monocytes were the dominant effector cells for B cell depletion, with no demonstrable role for T or natural killer cells. Although most anti-CD20 antibodies activated complement in vitro, B cell depletion was completely effective in mice with genetic deficiencies in C3, C4, or C1q complement components. That the innate monocyte network depletes B cells through FcγR-dependent pathways during anti-CD20 immunotherapy has important clinical implications for anti-CD20 and other antibody-based therapies.

P0286B CELL REPOPULATION AFTER REMISSION INDUCTION WITH RITUXIMAB IN NEWLY DIAGNOSED PATIENTS WITH ANCA-ASSOCIATED VASCULITIS: DOES ONE SIZE FIT ALL?

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Chiara Salviani ◽  
Alessandra Gina Gregorini ◽  
Guido Jeannin ◽  
Federico Alberici ◽  
Giovanni Cancarini ◽  
...  
Keyword(s):  
Maintenance Therapy ◽  
B Cell ◽  
Clinical Diagnosis ◽  
Cell Depletion ◽  
Remission Induction ◽  
B Cell Depletion ◽  
Cell Recovery ◽  
Anca Associated Vasculitis ◽  
Cell Repopulation

Abstract Background and Aims Rituximab (RTX) is one of the mainstays of ANCA-associated vasculitis (AAV) treatment. Nevertheless, studies specifically addressing the B cell repopulation in AAV patients after remission induction with RTX are still scanty and with conflicting results. Moreover, the role of B cell monitoring in the management of RTX-based maintenance therapy still remains to be fully elucidated. In this study, we evaluated B cell repopulation after a single course of RTX in treatment-naïve patients with AAV. Method We included all consecutive patients with new diagnosis of AAV from December 2009 to December 2017, treated with a single course of RTX for remission induction, with a follow-up ≥12 months. B cell recovery, re-treatment for relapse or rise in ANCA titer and scheduled re-treatment were considered as the termination of observation period. B cell count was performed by flow cytometry (Beckman Coulter Navios©) every 2 weeks during the 1st month, every 4 weeks until the 6th month, then every 12 weeks. B cell recovery was defined as CD19 count ≥10 cells/μl. Results Seventy-four patients (38% M, 62% F) met the inclusion criteria. Mean age was 63±21 years. MPA, GPA and EGPA were diagnosed in 49 (66%), 24 (33%) and 1 (1%) patients, respectively. ANCA were positive in 65 (88%) patients, with 50 (68%) anti-MPO and 15 (20%) anti-PR3. Overall median follow-up was 40 months (IQR 25-60). All patients achieved remission and complete B cell depletion after RTX. Twenty-two (31%) patients received plasma-exchange and 20 (29%) steroid pulses. Maintenance therapy with azathioprine or methotrexate was started in 10 (14%) patients. Seventeen (23%) patients received re-treatment with RTX (10 patients for relapses, the remaining cases for B cell recovery and/or a rise in ANCA titre or scheduled re-treatment). B cell recovery was observed in 39 (53%) patients, after a median time of 27 months (IQR 20-38). Particularly, only 7% of patients recovered B cells at 12 months (Figure 1). Univariate analysis showed significant correlation of persistent B-cell depletion with diagnosis of MPA vs GPA (p&lt;0.001), ANCA anti-MPO vs anti-PR3 (p=0.009), higher serum creatinine (p&lt;0.0001) and older age (p=0.004) (Figure 2). Sex, plasma-exchange at induction, steroid pulses, cumulative dose of RTX and maintenance therapy did not affect B cell recovery. Multivariate analysis confirmed significant association between B cell recovery and better renal function (RR 2.655, IC 1.254-5.615, p= 0.011) and clinical diagnosis of GPA (RR 2.466, IC 1.211-5.021, p=0.013). Conclusion After a single course of RTX for remission induction, we observed a very long-lasting B cell depletion in the large majority of our patients. Clinical diagnosis of MPA and a worse renal function were significantly correlated to persistent B cell depletion. These data question the need for scheduled RTX re-treatments in all AAV patients regardless of clinical diagnosis and features.

scholarly journals Determining the best window for BNT162b2 mRNA vaccination for SARS-CoV-2 in patients with multiple sclerosis receiving anti-CD20 therapy

2021 ◽  
Vol 7 (4) ◽  
pp. 205521732110621
Author(s):  
Audrey Rico ◽  
Laetitia Ninove ◽  
Adil Maarouf ◽  
Clémence Boutiere ◽  
Pierre Durozard ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
B Cells ◽  
B Cell ◽  
Serologic Response ◽  
Cell Counts ◽  
Anti Cd20 ◽  
Cell Proportion ◽  
Cell Repopulation

We studied the serologic response to the BNT162b2 mRNA vaccine at four weeks after the second dose in patients with RRMS treated with rituximab with extended-interval dosing ( n = 26). At four weeks, 73% of patients were seropositive. No patient without B cells at the first dose ( n = 4) was seropositive. Four of seven (57%) patients with B-cell proportion >0% and ≤5% were seropositive. All patients with B-cell proportion >5% ( n = 15) were seropositive. In all patients, quantitative ELISA measures after vaccination were correlated with B-cell counts measured before vaccination. In patients receiving rituximab, seropositivity after BNT162b2 mRNA vaccination emerged only after B-cell repopulation.

B-Cell Depletion Using IgG1 Anti-CD20 Spares MZ B Cells and Promotes Tolerance to Human FVIII In a Murine Model of Hemophilia A

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2206-2206
Author(s):  
Ai-Hong Zhang ◽  
Jonathan Skupsky ◽  
David W. Scott
Keyword(s):  
B Cells ◽  
B Cell ◽  
Hemophilia A ◽  
Tolerance Induction ◽  
Cell Depletion ◽  
High Dose ◽  
Marginal Effect ◽  
B Cell Depletion ◽  
Significant Difference ◽  
Anti Cd20

Abstract Abstract 2206 Preventing and reversing inhibitor formation remains one of the major challenges for hemophilia A therapy. Anti-CD20 mAb (Rituximab) has been reported to be beneficial for hemophilia A patients who failed immune tolerance induction (ITI). However, the evaluation of anti-CD20 therapy often is complicated in the clinical setting by concomitant use of other immune modulating drugs, such as hydrocortisone and IVIG. In this study, we tested the effect of B-cell depletion per se on tolerance induction to FVIII in a mouse model of hemophilia A. Two subclasses of anti-mouse CD20 monoclonal antibodies with differential effects were used. We previously showed that IgG1 anti-CD20 selectively depleted follicular (FO) B cells and spared marginal zone (MZ) B cells, while IgG2a anti-CD20 efficiently depleted both. In FVIII primed mice (inhibitor titer = 30.7 ± 4.8 BU/ml), a single dose of IgG1 anti-CD20 pretreatment prevented the increase in inhibitor formation in the majority of treated mice given daily, high dose FVIII i.v. injection as a model for ITI. Surprisingly, only a marginal effect was achieved when we repeated the same protocol using IgG2a anti-CD20 for B-cell depletion, which efficiently depletes both FO and MZ B cells. To examine tolerance to FVIII, we re-challenged the treated mice with 2 μg FVIII intraperitoneally three months after the initiation of B cell depletion using IgG1 anti-CD20 when the number of peripheral B cells had recovered 60 % or more. The inhibitor titers remained significantly lower in the IgG1 anti-CD20 group after this FVIII boost injection (60.9 ± 33.2 versus 190.3 ± 33.5 BU/ml in control IgG1 group; p = 0.02). Importantly, after the mice were subcutaneously challenged with an unrelated antigen, OVA in CFA, there was no significant difference in anti-OVA IgG titers between the two groups. Taken together, these results suggested that selectively depletion of FO B cells by IgG1 subtype anti-CD20 mAb treatment may facilitate the tolerance induction to FVIII. (Supported by NIH R01 HL061883 and a fellowship from the American Heart Association) Disclosures: No relevant conflicts of interest to declare.

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