Marginal Zone B-cell Research Articles

Marginal zone B cells produce 'natural' atheroprotective IgM antibodies in a T cell-dependent manner.

The adaptive immune response plays an important role in atherosclerosis. In response to a high-fat/high-cholesterol (HF/HC) diet, marginal zone B (MZB) cells activate an atheroprotective programme by regulating the differentiation and accumulation of 'poorly differentiated' T follicular helper (Tfh) cells. On the other hand, Tfh cells activate the germinal centre response, which promotes atherosclerosis through the production of class-switched high-affinity antibodies. We therefore investigated the direct role of Tfh cells and the role of IL18 in Tfh differentiation in atherosclerosis. We generated atherosclerotic mouse models with selective genetic deletion of Tfh cells, MZB cells, or IL18 signalling in Tfh cells. Surprisingly, mice lacking Tfh cells had increased atherosclerosis. Lack of Tfh not only reduced class-switched IgG antibodies against oxidation-specific epitopes (OSEs) but also reduced atheroprotective natural IgM-type anti-phosphorylcholine (PC) antibodies, despite no alteration of natural B1 cells. Moreover, the absence of Tfh cells was associated with an accumulation of MZB cells with substantially reduced ability to secrete antibodies. In the same manner, MZB cell deficiency in Ldlr-/- mice was associated with a significant decrease in atheroprotective IgM antibodies, including natural anti-PC IgM antibodies. In humans, we found a positive correlation between circulating MZB-like cells and anti-OSE IgM antibodies. Finally, we identified an important role for IL18 signalling in HF/HC diet-induced Tfh. Our findings reveal a previously unsuspected role of MZB cells in regulating atheroprotective 'natural' IgM antibody production in a Tfh-dependent manner, which could have important pathophysiological and therapeutic implications.

Marginal Zone B Cells Are Necessary for the Formation of Anti-donor IgG After Allogeneic Sensitization.

The formation of anti-major histocompatibility complex (MHC) antibodies is a significant barrier for many patients awaiting organ transplantation. Patients with preformed anti-MHC antibodies have limited options for suitable donors, and the formation of donor-specific anti-MHC antibodies after transplantation is a harbinger of graft rejection. Despite the recognized importance of anti-MHC antibodies, the mechanisms responsible for the differentiation of B cells after exposure to allogeneic antigens are poorly understood. To evaluate the differentiation of B cells in response to allogeneic antigen, we used a model of H-2 b C57Bl/6 sensitization with H-2 d antigen. We used a class I MHC tetramer-based approach to identify allogeneic B cells and flow cytometric crossmatch to identify allogeneic IgM and IgG. We found that although the formation of anti-H-2 d IgG was robust, few class-switched B cells and germinal center B cells were formed. Antigen-specific B cells did not express classical memory B-cell markers after sensitization but had an IgM + CD21 + marginal zone B-cell phenotype. The frequency of marginal zone B cells increased after sensitization. Depletion of marginal zone B cells before sensitization or skin grafting resulted in a significant diminution of anti-H-2 d IgG and fewer germinal center B cells. Adoptive transfer experiments revealed that marginal zone B cells more efficiently differentiated into germinal center B cells and anti-donor IgG-producing cells than follicular B cells. These results demonstrate an important role for marginal zone B cells as a reservoir of alloreactive B cells that are activated by allogeneic antigens.

An Unusual Occurrence of Immunoproliferative Small Intestinal Disease in Elderly Patient Presenting with Chronic Diarrhea - A Rare Case Report

Immunoproliferative small intestinal disease (IPSID) is a rare type of indolent B-cell lymphoma. It is a variant of extranodal marginal zone B-cell lymphoma of mucosa associated lymphoid tissue. It is commonly seen in older children and young adults in the age group of 10-35 years. It is more common in males with Male: Female ratio of 2.4:1. Duodenum and jejunum are the commonly involved areas in small intestine. Colicky abdominal pain and intermittent diarrhoea are the common symptoms. Here by, we report a rare case in a 74-year-old male patient presented with chief complaints of abdominal pain, diarrhea and weight loss for 3 months. CT scan findings revealed thickening of small intestinal wall and mesenteric lymphadenopathy. Upper gastrointestinal endoscopy findings revealed nodular and ulcerative mucosa in the duodenum. Histopathological examination revealed flattening of mucosa with villous atrophy, destruction of crypts and intraepithelial lymphocytic infiltrate is noted. Interstitium shows dense and diffuse collection of lymphoplasmacytic infiltrate. Immunohistochemistry was done and it showed CD20 positive lymphoid cells. Based on the above findings the case was reported as Immunoproliferative small intestinal disease. Clinicians should suspect IPSID in cases presenting with chronic diarrhea and abdominal pain refractory to treatment. Immunoproliferative small intestinal disease has indolent clinical course and it can be cured with antibiotics in early stages. Late stages have high mortality rate and has poor prognosis. Keywords: IPSID, Alphachain disease, B cell lymphoma, duodenum, villous atrophy, lymphoplasmacytic infiltrate

Socioeconomic status, individual behaviors and risk for Lymphomas: a Mendelian randomization study.

Background: The association of socioeconomic status and individual behavior (SES/IB) with human health is receiving increasing attention. However, the causal effects between SES/IB and lymphomas remain unclear. Methods: A two-sample Mendelian randomization (MR) study was used to assess the causal effects of 25 SES/IB traits (dietary habits, physical activity, smoking/drinking behaviors, sleeping behaviors, leisure sedentary behaviors, risky behaviors, and reproductive behaviors) on six distinct types of lymphomas, including Hodgkin lymphoma (HL), follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL), mature T/NK-cell lymphomas, marginal zone B-cell lymphoma (MZL), and mantle cell lymphoma (MCL). The inverse variance weighted (IVW) method was the primary approach used for the MR analysis. A series of sensitivity analyses were also conducted to ensure the robustness of the findings. Results: Two-sample MR revealed six SES/IB traits causally associated with lymphomas, including relative fat intake, drive time, television watching time, computer use time, vigorous physical activity, and number of children ever born. After false discovery rate (FDR) correction, the causal associations between longer television watching time and DLBCL (OR: 4.048, 95% CI: 1.688 to 9.708, P fdr=0.009), and the number of children ever born with both FL (OR: 0.008, 95% CI: 1.412E-04 to 0.484, P fdr=0.021) and DLBCL (OR: 0.001, 95% CI:1.587E-05 to 0.081, P fdr=0.002) were identified. Conclusions: These findings suggest that certain lifestyle and behavioral factors have a measurable impact on specific lymphoma types.

Spontaneous regression and rare relapse after excisional biopsy in long-term observation of 31 patients with primary conjunctival lymphoma.

To elucidate long-term outcome in primary conjunctival lymphoma, a review was conducted of 31 consecutive patients: 21 men and 10 women with an age range of 28 to 85 (median, 61) years at presentation and follow-up periods ranging from 1 to 19 (median, 7) years. Conjunctival lymphoma was on the right side in 10 patients, on the left side in 12, and on both sides in 9. Upper, lower, or both fornix lesions in 28 patients were all diagnosed as extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), while thick nasal bulbar conjunctival lesions in 3 patients were differently diagnosed as MALT lymphoma, diffuse large B-cell lymphoma, and follicular lymphoma, respectively. Seven patients underwent local radiation (30 Gy): as initial treatment in 5 patients and treatment for relapse in 2 patients. The remaining 24 patients were observed without additional treatment after excisional biopsy: 5 of these 24 patients showed relapse 0.5 to 6 years later and underwent excisional biopsy again that revealed MALT lymphoma. Of the 5 patients with relapse, only one with second-time relapse underwent radiation. Fluorodeoxyglucose positron emission tomography was performed in 18 patients and showed no systemic lesions: high uptake was noted in the residual conjunctival lesions of 4 patients and in the relapsed conjunctival lesions of 3 patients. One patient died of rectal cancer while no patients died of lymphoma. Observation is an option in patients with primary conjunctival lymphoma after excisional biopsy. Radiation is a treatment option in the case of relapse.

Excess BAFF May Impact HIV-1-Specific Antibodies and May Promote Polyclonal Responses Including Those from First-Line Marginal Zone B-Cell Populations.

We have previously shown that blood levels of B-cell Activating Factor (BAFF) rise relatively to disease progression status in the context of HIV-1 infection. Excess BAFF was concomitant with hyperglobulinemia and the deregulation of blood B-cell populations, notably with increased frequencies of a population sharing characteristics of transitional immature and marginal zone (MZ) B-cells, which we defined as marginal zone precursor-like" (MZp). In HIV-uninfected individuals, MZp present a B-cell regulatory (Breg) profile and function, which are lost in classic-progressors. Moreover, RNASeq analyses of blood MZp from classic-progressors depict a hyperactive state and signs of exhaustion, as well as an interferon signature similar to that observed in autoimmune disorders such as Systemic Lupus Erythematosus (SLE) and Sjögren Syndrome (SS), in which excess BAFF and deregulated MZ populations have also been documented. Based on the above, we hypothesize that excess BAFF may preclude the generation of HIV-1-specific IgG responses and drive polyclonal responses, including those from MZ populations, endowed with polyreactivity/autoreactivity. As such, we show that the quantity of HIV-1-specific IgG varies with disease progression status. In vitro, excess BAFF promotes polyclonal IgM and IgG responses, including those from MZp. RNASeq analyses reveal that blood MZp from classic-progressors are prone to Ig production and preferentially make usage of IGHV genes associated with some HIV broadly neutralizing antibodies (bNAbs), but also with autoantibodies, and whose impact in the battle against HIV-1 has yet to be determined.

Epidemiology and Clinical Features Analysis of Orbital and Adnexal Lymphoma in the Western Area of Gyeongsangnam-do

Purpose: We compared the epidemiology and clinical features of patients with orbital and adnexal lymphoma in western Gyeongsangnam-do with those reported previously, domestically and internationally.Methods: Of the 25 patients diagnosed with lymphoproliferative disorder, a retrospective analysis was conducted on 21 patients with orbital and adnexal lymphoma between January 2010 and December 2021.Results: In total, 21 patients were diagnosed with orbital and adnexal lymphoma, with an average annual incidence rate of 0.18 per 100,000 people, exceeding the national average in Korea. The median age of the patients was 57 years and the ratio of 1.1 to 1. The most common presenting symptoms included proptosis, conjunctival mass, conjunctival injection, eyelid swelling and epiphora. Primary and metastatic lesions accounted for 85.7% and 14.3% of cases, respectively. Histologically, the most common subtype was extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (90.4%). Furthermore, diffuse large B-cell lymphoma and NK/T-cell lymphoma of T-cell origin each accounted for 4.8% of cases.Conclusions: The reported incidence rate in the present study exceeded the national average in Korea. However, no significant differences were observed in clinical symptoms, primary and metastatic lesions, histological classification, or post-treatment effects compared to findings from domestic and international studies.

Mitoxantrone Hydrochloride Liposome Injection Combined with Carmustine, Etoposide, and Cytarabine As Conditioning of Autologous Hematopoietic Stem Cell Transplantation in NHL Patients：a Prospective Single-Arm Clinical Trial

Background：High-dose chemotherapy and autologous stem-cell transplantation (ASCT) is standard consolidation therapy for aggressive lymphoma.Choosing the most effective conditioning regimen prior to ASCT can lead to longer survival in these patients.Mitoxantrone liposome is an anthraquinone antibiotic anti-tumor drug. Previous studies have shown that mitoxantrone liposome monotherapy or combined with other drugs has achieved good efficacy for T-cell lymphoma, but there are no reports of its application in conditioning. Objective:This is a prospective single-arm clinical study to evaluate the efficacy and safety of mitoxantrone hydrochloride liposome injection combined with carmustine, etoposide, cytarabine (modified BEAM protocol) as conditioning of autologous hematopoietic stem cell transplantation for NHL patients (NCT05681403). Methods: Patients with non-Hodgkin lymphoma who planned to undergo ASCT were eligible to participate in the trial if they were 18 to 60 years of age.The patients received mitoxantrone hydrochloride liposome injection 24 mg/m 2,ivgtt,d-7, carmustine 300 mg/m 2,ivgtt,d-6, etoposide200 mg/m 2,ivgtt,d-5~ -2,cytarabine 200 mg/m 2 q12h,ivgtt,d-5~ -2 as conditioning regimen.The primary end point was the relapse rate within three years and the secondary end point was adverse events of modified BEAM protocol. Results：Twenty-five NHL patients (median age 39 years old,17 males and 8 females) were enrolled,including 40% DLBCL, 12% MCL, 4% primary mediastinal B-cell lymphoma,4%B lymphoblastic lymphoma,4%Marginal zone B-cell lymphoma,12% PTCL-NOS, 8% ALK +ALCL,8% NK/T lymphoma, 8% AITL,4% ALK -ALCL and 4% Sézary syndrome. 18 cases achieved complete remission before ASCT, while 7 cases received partial remission before ASCT. The median of neutrophil recovery time was 11 days(7-15) and the median of platelet recovery was 12days (7-60).Nausea,vomit,constipation,blue skin and cough were the most frequently reported conditioning related AEs (88%,16%,12%,12% and 8% of patients,respectively), and other AE included 1 case of hypoxemia, 1 case of hypotension, 1 case of palpitation, 1 case of rash. Except one patient experienced a grade 3 vomit ,the others were grade 1-2 and improved after symptomatic treatment. Nine patients experienced febrile neutropenia and 2 cases of sepsis, 4 cases of respiratory infection, and 3 cases of oral mucositis. All partial remission patients achieved complete remission post-HSCT and one of them relapsed 7 months after ASCT.The others were all in complete remission during follow-up. Conclusion:Mitoxantrone hydrochloride liposome injection combined with carmustine, etoposide, cytarabine (modified BEAM protocol) was a well-tolerated and effective conditioning regimen for NHL and the study is ongoing and updated results will be presented in the future.

Validation of a Composite Real-World Mortality Variable Among Patients with Hematologic Malignancies Treated in the United States

Introduction: Real-world data (RWD) is being increasingly used to support clinical and regulatory decisions where utilization of clinical trial data is difficult or impractical. With this expanded utilization comes a need to ensure RWD is of sufficient quality and completeness to adequately answer relevant research questions. Given the importance of overall survival (OS) for oncology research, treatment and care, complete and accurate real-world mortality data capture is of critical importance. Currently the industry standard practice aggregates mortality data across available data sources to maximize data capture. This study sought to validate and benchmark a composite real-world mortality variable against the gold standard data source from the National Death Index (NDI). Methods: This observational study was conducted using the COTA real-world database, a de-identified database derived from the electronic health records (EHRs) of partnered healthcare providers in the United States. Patients diagnosed with select cancers between January 1st, 2015 and December 31st, 2020 were included. Cancer types included in this study were: acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), marginal zone B-cell lymphoma (MZL), multiple myeloma (MM), and myelodysplastic syndrome (MDS). COTA's composite mortality variable utilizes structured and unstructured data from the EHRs of COTA partnered healthcare provider sites and commercially available obituary data including the Social Security Administration death master file. To conduct the validation study, COTA records were matched to NDI records using an NDI-developed matching algorithm. Patients without an NDI match were considered alive according to the NDI. Validation metrics were calculated in the overall population and by subgroup including cancer type and key demographic characteristics. Metrics assessed included sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and date concordance (exact, ± 7 days, ± 15 days, ± 30 days). Corresponding 95% confidence intervals were estimated using the Wilson method for calculating confidence intervals for proportions. Results: The final study population included 21,567 patients across 7 cancer types (AML N=2638, CLL N=2502, DLBCL N=6066, FL N=2835, MM N=4234, MDS N=2295, and MZL N=997). Within the overall study population, validation analysis comparing the real-world composite mortality variable to the NDI demonstrated high sensitivity (87.8), specificity (95.7), PPV (90.9) and NPV (94.1). (Table 1) Some variability in validation metrics by disease was observed with MM having the highest sensitivity (90.4) and FL having the highest specificity (99.0). Sensitivity and specificity across all cancer types were greater than 80%. Patients 18-29 years of age had the lowest sensitivity (75.0), while patients 90 years of age or greater had the highest sensitivity (92.7), but lowest specificity (77.1). Validation metrics were similar across sex, race, and year of diagnosis subgroups. Date concordance between the real-world composite mortality variable and NDI dates of death was high. In the study population (N=21,567), exact date concordance was observed in 88.0% of patients, and concordance rates for 7-, 15- and 30-day intervals were 93.1%, 93.8%, and 94.3%, respectively. (Table 2) Rates of concordance were consistent across disease subtypes, subgroups, and date intervals. Conclusions: This study found that a composite real-world mortality variable yielded strong performance in comparison to the gold-standard NDI database, as measured by the validation metrics of sensitivity, specificity, PPV and NPV. Additionally, high rates of date concordance were observed across the exact, 7-, 15- and 30-day intervals. These findings are critical to ensure the reliability of results generated using RWD, and further establish the use of a composite real-world mortality variable as best practice. Future research will expand this validation methodology to a cohort of patients with solid tumor cancers, as well as investigate the performance of overall survival using a composite real-world mortality variable.

Characteristics of Primary Cutaneous Lymphoma in Italy: A Tertiary Care, Single-Center Study.

Data on primary cutaneous lymphomas (PCLs) patients in the Italian population are limited, and, despite the existence of several treatment options, the management of those patients remains challenging. Our study aimed to investigate the clinical and therapeutic features of PCL patients in a referral center in Italy. We conducted a retrospective study on 100 consecutive PCL patients between January 2017 and December 2022. The mean (SD) age of our cohort was 70.33 (14.14) years. Cutaneous T-cell lymphomas (CTCLs) represented 65% of all cases; the majority were mycosis fungoides (42%), followed by cases of Sezary syndrome (10%) and primary cutaneous anaplastic large cell lymphoma (4%). Cutaneous B-cell lymphomas (CBCLs) accounted for 35 % of PCLs, with 15 cases of primary cutaneous follicle center lymphoma, 10 cases of primary cutaneous diffuse large B-cell lymphoma leg type, and 9 cases of marginal zone B-cell lymphoma. A higher frequency of pruritus (p = 0.008) and higher peripheral blood levels of beta-2 microglobulin (p ≤ 0.001) and lactate dehydrogenase (p = 0.025) were found in CTCLs compared to those of CBCLs. Considering all therapeutic lines performed, treatments were extremely heterogeneous and skin-directed therapies represented the most frequently used approach. Our study confirms the distribution of PCL subtypes formerly reported in the literature and highlights the utility of real-life data in treatments to improve the current management of PCL patients.

Epidemiology and Survival of Patients with Marginal Zone Lymphoma Treated at the National Cancer Institute of Peru. a Retrospective Analysis of 187 Cases

Background Marginal zone lymphoma (MZL) represents a heterogeneous subgroup, classified as extranodal, splenic and nodal lymphoma. Extranodal cases, also termed mucosa-associated lymphoid tissue (MALT), account for 70% of MZLs. Splenic marginal zone B-cell lymphoma (SMZL) accounts for <2% of all NHL. There is no data about marginal zone lymphoma in Latin American patients. Methods We evaluated retrospectively all patients diagnosed with marginal zone lymphoma at the National Cancer Institute from 2010 to 2019. Baseline characteristics, treatments and survival were retrieved from medical records. Kaplan Meier method was used to analyze the overall survival. The estimate of the survival curves was performed by the Kaplan-Meier method, and the differences were computed by the log-rank test. The Cox proportional hazard models were used to identify predictors of survival of MZL. A level of p <0.05 was considered for a statistical significance. Results During the study period 2010-2019, 4437 patients with B-cell non-Hodgkin lymphoma were evaluated at the INEN, 187 of them were marginal zone lymphomas, representing 4.2% of all cases. The most frequent marginal zone lymphoma was MALT, followed by nodal and splenic lymphoma with 89.8%, 5.3% and 4.8% of cases, respectively. The median age for the entire cohort was 59 years (range 17-89). The median age for the MALT, nodal and splenic MZL cohort were 58.5 years (range 17-89), 75 years (range 52-88), 68 years (range 43-87), respectively. 37.4% were male for the entire cohort, and 37%, 40%, 44% for the MALT, nodal and splenic MZL group. Elevated LDH was seen in 13% of the entire cohort and in 11% and 24% of the MALT and splenic MZL group. Transformed lymphoma was reported in 6.4% of the entire cohort, but in the 20% of nodal MZL and no one case of the splenic MZL. More data you can see in the table 1. The most frequent primary site locations for MALT lymphoma were gastric, ocular adnexal, parotid gland, cutaneous, intestinal and CNS with 36%, 30%, 7%, 5%, 5% and 5%, respectively. The median overall survival was 114 months (IQR 76-133) for the entire cohort and 133 months, 59 and 59 months for the MALT, nodal MZL, and splenic MZL, respectively (p=0.0011), see the figure 1. The 5-year OS was 81.4% (95% CI, 71.6-88.1) for the entire cohort and 85.7% (95% CI, 76.5-91.5) for the MALT lymphoma group. No one patients were alive at 5 years in both nodal and splenic lymphoma groups. Conclusion Marginal zone lymphoma is a relatively rare type of B-cell lymphoma. The most frequent type is MALT lymphoma, followed by nodal MZL. The median age for the entire group was 59 years, however patients with nodal MZL were older with a median age of 75 years. Transformed lymphoma was present in 6% of the entire cohort and in the 20% of the nodal MZL. Gastric, ocular adnexal and parotid gland were the most common primary site of MALT lymphoma. MALT lymphoma had long survival, but nodal and splenic MZL had shorter survival with no one surviving 5 years from diagnosis.

Human circulating CD24hi marginal zone B cells produce IgM targeting atherogenic antigens and confer protection from vascular disease.

IgMs that inactivate oxidation-specific epitopes (IgMOSE), which are secondary products of lipid peroxidization, protect against inflammatory diseases, including diet-induced atherosclerosis. However, the human B cell subtype that produces IgMOSE remains unknown. In this study, we used single-cell mass cytometry and adoptive transfer of B cell subtypes to NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice to identify B27+IgM+CD24hi cells as the major producers of IgMOSE in humans. Notably, these cells have characteristics of human circulatory marginal zone B (MZB) cells, which are known to be atheoroprotective IgM producers in mice. CD24 antibody treatment to reduce MZB cells and IgM in a hyperlipidemic humanized mouse model provides the evidence that MZB cells protect against vascular inflammation. Consistent with these findings, the frequency of B27+IgM+CD24hi cells (MZB) in patients inversely correlates with coronary artery disease severity.

MZB1-expressing cells are essential for local immunoglobulin production in chronic rhinosinusitis with nasal polyps

BackgroundThe expression of MZB1 genes is significantly elevated in patients who have chronic rhinosinusitis with nasal polyp (CRSwNP) disease compared with healthy controls. ObjectiveTo characterize MZB1-positive B cells in CRSwNP and to estimate the contribution of distinct subsets of B cells to the local overproduction of immunoglobulins. MethodsSingle-cell RNA-sequencing with Cellular Indexing of Transcriptomes and Epitopes by Sequencing technology, Switching Mechanism At the 5′ end of RNA Template sequencing, flow cytometry, immunohistochemistry and immunofluorescence staining, Western blot, QuantiGene Plex assay, B-cell ImmunoSpot assay, Luminex assay, and enzyme-linked immunosorbent assay were performed. ResultsSignificantly higher mRNA expression of MZB1 and HSP90B1 was found in type 2 CRSwNP compared with controls. In CRSwNP, MZB1 expression correlated with the local production of IgE. MZB1 could be colocalized with plasma and mature B cells, especially marginal zone (MZ) B cells. Single-cell transcriptome and epitope studies revealed prominent populations of B cells in type 2 CRSwNP with unexpectedly high MZB1 gene expression. The MZ B-cell population was significantly increased in CRSwNP compared with healthy controls in both peripheral blood mononuclear cells and nasal tissue single-cell suspensions. When those single cells were cultured overnight, the MZ B-cell numbers were positively correlated with local IgE production but negatively correlated with local IgM production. In vitro, MZB1 stimulation up-regulated the mRNA expression of IgE. ConclusionMZB1 was primarily expressed by plasma and mature B cells in nasal mucosa. MZB1 expression level was increased in CRSwNP compared with controls. MZB1 contributed to the local IgE production in type 2 CRSwNP.

MIgM-mediated splenic marginal zone B cells targeting of folic acid for immunological evasion

Folic acid is a fully oxidized synthetic folate with high bioavailability and stability which has been extensively prescribed to prevent congenital disabilities. Here we revealed the immunosuppressive effect of folic acid by targeting splenic marginal zone B (MZB) cells. Folic acid demonstrates avid binding with the Fc domain of immunoglobulin M (IgM), targeting IgM positive MZB cells in vivo to destabilize IgM-B cell receptor (BCR) complex and block immune responses. The induced anergy of MZB cells by folic acid provides an immunological escaping window for antigens. Covalent conjugation of folic acid with therapeutic proteins and antibodies induces immunological evasion to mitigate the production of anti-drug antibodies, which is a major obstacle to the long-term treatment of biologics by reducing curative effects and/or causing adverse reactions. Folic acid acts as a safe and effective immunosuppressant via IgM-mediated MZB cells targeting to boost the clinical outcomes of biologics by inhibiting the production of anti-drug antibodies, and also holds the potential to treat other indications that adverse immune responses need to be transiently shut off.

POSTER: IBCL-417 Primary Intracranial Marginal Zone B-Cell Lymphoma of Mucosa-Associated Lymphoid Tissue in Cerebral Localization: Case Report

POSTER: IBCL-417 Primary Intracranial Marginal Zone B-Cell Lymphoma of Mucosa-Associated Lymphoid Tissue in Cerebral Localization: Case Report

IBCL-417 Primary Intracranial Marginal Zone B-Cell Lymphoma of Mucosa-Associated Lymphoid Tissue in Cerebral Localization: Case Report

IBCL-417 Primary Intracranial Marginal Zone B-Cell Lymphoma of Mucosa-Associated Lymphoid Tissue in Cerebral Localization: Case Report

Intracranial hematolymphoid malignancies: A case series with molecular characterization

ObjectiveCentral nervous system (CNS) manifestations of hematologic malignancies are uncommon and often have a poor prognosis. As hematologic neoplasms are typically chemotherapy- and radiotherapy-sensitive, surgical resection is usually not indicated; thus, opportunities for in-depth characterization of CNS hematologic tumors are limited. Here, we report four cases of rare intracranial hematologic tumors requiring surgical intervention, allowing for histopathologic and genomic characterization. MethodsThe clinical course, genetic perturbations, and histopathological features are described for a case of 1) primary marginal zone B-cell lymphoma of the dura as well as cases of brain metastases of 2) cutaneous T-cell lymphoma, 3) acute myeloid leukemia/myeloid sarcoma, and 4) multiple myeloma. Targeted DNA sequencing, fluorescence in situ hybridization, cytogenetic analysis, flow cytometry and immunohistochemical staining were used to assess the lesions. ResultMolecular and histopathological characterizations of four unusual presentations of hematolymphoid diseases involving the CNS are presented. Genetic abnormalities were identified in each lesion, including chromosomal aberrations and single nucleotide variants resulting in missense or nonsense mutations in oncogenes. ConclusionsOur case series provides insight into unique pathological phenotypes of hematologic neoplasms with atypical CNS involvement. We offer targets for future studies by identifying potentially pathogenic genetic variants in these lesions, as the full implications of the novel molecular abnormalities described remain unclear.

Marginal Zone B (MZB) Cells: Comparison of the Initial Identification of Immune Activity Leading to Dacryoadenitis and Sialadenitis in Experimental Sjögren's Syndrome.

Although multiple mouse strains have been advanced as models for Sjögren's syndrome (SS), which is a human systemic autoimmune disease characterized primarily as the loss of lacrimal and salivary gland functions, the C57BL/6.NOD-Aec1Aec2 recombinant inbred (RI) mouse derived from the NOD/ShiLtJ line is considered one of the more appropriate models exhibiting virtually all the characteristics of the human disease. This mouse model, as well as other mouse models of SS, have shown that B lymphocytes are essential for the onset and development of observed clinical manifestations. Recently, studies carried out in the C57BL/6.IL14α transgenic mouse have provided clear evidence that the marginal zone B (MZB) cell population is directly involved in the early pathological events initiating the development of the clinical SS disease, as well as late-stage lymphomagenesis resulting in B-cell lymphomas. Since MZB cells are difficult to study in vivo and in vitro, we carried out a series of ex vivo investigations that utilize temporal global RNA transcriptomic analyses to profile differentially expressed genes exhibiting temporal upregulation during the initial onset and subsequent development of pathophysiological events within the lacrimal and salivary gland tissues per se or associated with the leukocyte cell migrations into these glands. The initial transcriptomic analyses revealed that while the upregulated gene expression profiles obtained from lacrimal and salivary glands overlap, multiple genetic differences exist between the defined activated pathways. In the current study, we present a concept suggesting that the initial pathological events differ between the two glands, yet the subsequent upregulated TLR4/TLR3 signal transduction pathway that activates the type-1 interferon signature appears to be identical in the two glands and indicates an autoimmune response against dsRNA, possibly a virus. Here, we attempt to put these findings into perspective and determine how they can impact the design of future therapeutic protocols.

Clinical Remission of Primary Cutaneous Marginal Zone B-Cell Lymphoma in a Patient With Crohn's Disease After Helicobacter pylori Quadruple Therapy and Vedolizumab.

Clinical Remission of Primary Cutaneous Marginal Zone B-Cell Lymphoma in a Patient With Crohn's Disease After Helicobacter pylori Quadruple Therapy and Vedolizumab.

Feasibility of oral doxycycline as first-line therapy for conjunctival mucosa-associated lymphoid tissue lymphoma.

To investigate the long-term outcomes of oral doxycycline as first-line treatment in patients with conjunctival extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). In this case series, the medical records of 67 patients with conjunctival MALT lymphoma who received doxycycline as their primary treatment and were followed up for at least 5 years were retrospectively reviewed. Progression-free survival (PFS) was analysed at 3, 5, and 10 years after the initial doxycycline treatment. A Cox proportional hazards model was used to assess the independent risk factors for progression. After the initial treatment, 25 patients (37.3%) achieved a complete response, 8 patients (11.9%) achieved a partial response, 30 patients (44.8%) showed stable disease, and 4 patients (6.0%) showed disease progression. The median PFS in all patients was 168 months, and the 3-, 5- and 10-year PFS rates for all patients were 70%, 65%, and 62%, respectively. No further progression was observed 6 years after the initial doxycycline treatment. Younger age and TNM stage T1c were significant risk factors for the time to progression in the multivariate Cox regression analysis (p < 0.05). Additional doxycycline (>2 cycles) showed no benefit. There were no serious adverse events associated with doxycycline therapy, and most patients were successfully salvaged by second-line treatments, including radiotherapy and chemotherapy. In this case series, oral doxycycline treatment yielded acceptable long-term PFS with minimal complications. Especially in patients with stage T1a or T1b conjunctival MALT lymphoma, first-line doxycycline treatment could be considered under close monitoring for at least 6 years.