Plasma Cells Research Articles

A case of diabetic mastopathy: An unusual breast lesion mimicking cancer in type 1 diabetes mellitus

Diabetic mastopathy is a rare fibroinflammatory disorder seen among middle aged and premenopausal age group. It is also called lymphocytic mastopathy or sclerosing lymphocytic mastitis. This is seen associated with type 1 diabetes mellitus and other autoimmune disorders specially related to endocrine disorders like thyroid. The definite diagnosis of diabetic mastopathy is truly based on biopsy and histopathological examination.A 33 year old female came to hospital with complaints of swelling in right breast since one month and pain since one week. She was a known case of type 1 diabetes mellitus since 10 years and on regular medications. Radiological Impression was possibilities of mastitis with abscess formation more likely to be considered. But infiltrating malignant neoplasm with areas of necrosis is also a differential diagnosis. Our histopathology laboratory, we received incision biopsy from right breast and microscopic examination from multiple tissue sections showed breast parenchyma with extensive fibrosis and periductal inflammatory infiltrate predominantly lymphocytes, plasma cells and a few neutrophils. Some of the ducts show epithelial proliferation forming bridges and micropapillae. Histopathological diagnosis was Lymphocytic Mastitis with features of Atypical Ductal Hyperplasia.: The diagnosis of Diabetic Mastopathy is based on clinical details, radiological evaluation and biopsy correlation. Sometimes it’s difficult to differentiate from carcinoma breast, so histopathological examination is indicated for a definitive diagnosis and management.

Four centrosome-related genes to predict the prognosis and drug sensitivity of patients with colon cancer

BACKGROUND As the primary microtubule organizing center in animal cells, centrosome abnormalities are involved in human colon cancer. AIM To explore the role of centrosome-related genes (CRGs) in colon cancer. METHODS CRGs were collected from public databases. Consensus clustering analysis was performed to separate the Cancer Genome Atlas cohort. Univariate Cox and least absolute shrinkage selection operator regression analyses were performed to identify candidate prognostic CRGs and construct a centrosome-related signature (CRS) to score colon cancer patients. A nomogram was developed to evaluate the CRS risk in colon cancer patients. An integrated bioinformatics analysis was conducted to explore the correlation between the CRS and tumor immune microenvironment and response to immunotherapy, chemotherapy, and targeted therapy. Single-cell transcriptome analysis was conducted to examine the immune cell landscape of core prognostic genes. RESULTS A total of 726 CRGs were collected from public databases. A CRS was constructed, which consisted of the following four genes: TSC1 , AXIN2 , COPS7A , and MTUS1 . Colon cancer patients with a high-risk signature had poor survival. Patients with a high-risk signature exhibited decreased levels of plasma cells and activated memory CD4+ T cells. Regarding treatment response, patients with a high-risk signature were resistant to immunotherapy, chemotherapy, and targeted therapy. COPS7A expression was relatively high in endothelial cells and fibroblasts. MTUS1 expression was high in endothelial cells, fibroblasts, and malignant cells. CONCLUSION We constructed a centrosome-related prognostic signature that can accurately predict the prognosis of colon cancer patients, contributing to the development of individualized treatment for colon cancer.

Elevated serum levels of soluble B-cell maturation antigen as a prognostic biomarker for multiple myeloma.

Serum B-cell maturation antigen (sBCMA) levels can serve as a sensitive biomarker in multiple myeloma (MM). In the research setting, sBCMA levels can be accurately detected by enzyme-linked immunosorbent assay (ELISA), but the approach has not been approved for clinical use. Here, we used a novel chemiluminescence method to assess sBCMA levels in 759 serum samples from 17 healthy donors and 443 patients with plasma cell (PC) diseases including AL amyloidosis, POEMS syndrome and MM. Serum BCMA levels were elevated 16.1-fold in patients with newly diagnosed MM compared to healthy donors and rare PC diseases patients. Specifically, the sBCMA levels in patients with progressive disease were 64.6-fold higher than those who showed partial response or above to treatment. The sBCMA level also correlated negatively with the response depth of MM patients. In newly diagnosed and relapsed MM patients, survival was significantly longer among those subjects whose sBCMA levels are below the median levels compared with those above the median value. We optimized the accuracy of the survival prediction further by integrating sBCMA level into the Second Revised International Staging System (R2-ISS). Our findings provide evidence that the novel chemiluminescence method is sensitive and practical for measuring sBCMA levels in clinical samples and confirm that sBCMA might serve as an independent prognostic biomarker for MM.

Iguratimod suppresses plasma cell differentiation and ameliorates experimental Sjögren's syndrome in mice by promoting TEC kinase degradation.

Primary Sjögren's syndrome (pSS) is a chronic inflammatory autoimmune disease with an unclear pathogenesis, and there is currently no approved drug for the treatment of this disease. Iguratimod, as a novel clinical anti-rheumatic drug in China and Japan, has shown remarkable efficacy in improving the symptoms of patients with pSS in clinical studies. In this study we investigated the mechanisms underlying the therapeutic effect of iguratimod in the treatment of pSS. Experimental Sjögren's syndrome (ESS) model was established in female mice by immunizing with salivary gland protein. After immunization, ESS mice were orally treated with iguratimod (10, 30, 100 mg·kg-1·d-1) or hydroxychloroquine (50 mg·kg-1·d-1) for 70 days. We showed that iguratimod administration dose-dependently increased saliva secretion, and ameliorated ESS development by predominantly inhibiting B cells activation and plasma cell differentiation. Iguratimod (30 and 100 mg·kg-1·d-1) was more effective than hydroxychloroquine (50 mg·kg-1·d-1). When the potential target of iguratimod was searched, we found that iguratimod bound to TEC kinase and promoted its degradation through the autophagy-lysosome pathway in BAFF-activated B cells, thereby directly inhibiting TEC-regulated B cells function, suggesting that the action mode of iguratimod on TEC was different from that of conventional kinase inhibitors. In addition, we found a crucial role of TEC overexpression in plasma cells of patients with pSS. Together, we demonstrate that iguratimod effectively ameliorates ESS via its unique suppression of TEC function, which will be helpful for its clinical application. Targeting TEC kinase, a new regulatory factor for B cells, may be a promising therapeutic option.

PMP22 duplication dysregulates lipid homeostasis and plasma membrane organization in developing human Schwann cells.

Charcot-Marie-Tooth disease type 1A (CMT1A) is the most common inherited peripheral neuropathy caused by a 1.5 megabase tandem duplication of chromosome 17 harboring the PMP22 gene. This dose-dependent overexpression of PMP22 results in disrupted Schwann cell myelination of peripheral nerves. To get better insights into the underlying pathogenic mechanisms in CMT1A, we investigated the role of PMP22 duplication on cellular homeostasis in CMT1A mouse models and in patient-derived induced pluripotent stem cells differentiated into Schwann cell precursors (iPSC-SCPs). We performed lipidomic profiling and bulk RNA sequencing on sciatic nerves of two developing CMT1A mouse models and on CMT1A patient derived iPSC-SCPs. For the sciatic nerves of the CMT1A mice, cholesterol and lipid metabolism was dose-dependently downregulated throughout development. For the CMT1A iPSC-SCPs, transcriptional analysis unveiled a strong suppression of genes related to autophagy and lipid metabolism. Gene ontology enrichment analysis identified disturbances in pathways related to plasma membrane components and cell receptor signaling. Lipidomic analysis confirmed the severe dysregulation in plasma membrane lipids, particularly sphingolipids, in CMT1A iPSC-SCPs. Furthermore, we identified reduced lipid raft dynamics, disturbed plasma membrane fluidity, and impaired cholesterol incorporation and storage, all of which could result from altered lipid storage homeostasis in the patient-derived CMT1A iPSC-SCPs. Importantly, this phenotype could be rescued by stimulating autophagy and lipolysis. We conclude that PMP22 duplication disturbs intracellular lipid storage and leads to a more disordered plasma membrane due to an alteration in the lipid composition, which ultimately may lead to impaired axo-glial interactions. Moreover, targeting lipid handling and metabolism could hold promise for the treatment of CMT1A patients.

Lymphocytoma Cutis - A Case Report

Without tissue biopsy and holistic review of presentation, histology, and immunohistochemistry, lymphocytoma cutis (LC) can often be misdiagnosed as other benign conditions or malignant pathologies such as cutaneous B cell lymphoma (CBCL). A 36-year-old female presented with a two-year history of a progressive indurated, edematous plaque in the preauricular area. At presentation, the patient also had labs significant for thrombocytopenia and eosinophilia. Original treatment with topical steroids did not lead to clinical improvement of the lesions. Punch biopsy revealed reactive lymphoid hyperplasia with polyclonal lymphoid infiltrates of small lymphocytes, histiocytes, eosinophils, and plasma cells. Diagnosis of LC was made and our patient was treated with serial 5 mg intralesional triamcinolone injections. Clinical improvement was seen beginning at 2 months. Diagnosing LC can be particularly difficult as the clinical presentation is ubiquitous and can resemble several other conditions such as CBCL, cutaneous lupus erythematosus, sarcoid, or hypersensitivity reactions. Recognition of the typical histologic findings of top-heavy dermal mixed-cellular infiltrates along with polyclonal kappa and lambda hybridization on immunohistochemistry is often essential in arriving at the correct diagnosis. Following diagnosis of LC, long-term surveillance is recommended as malignant transformation is a possibility.

Humoral responses are enhanced by facilitating B cell viability by Fcrl5 overexpression in B cells.

B cell initial activity is regulated through a balance of activation and suppression mediated by regulatory molecules expressed in B cells; however, the molecular mechanisms underlying this process remain incompletely understood. In this study, we investigated the function of the Fc receptor-like (Fcrl) family molecule Fcrl5, which is constitutively expressed on naïve B cells, in humoral immune responses. Our study demonstrated that B cell-specific overexpression of Fcrl5 enhanced antibody (Ab) production in both T cell-independent type 1 (TI1) and T cell-dependent (TD) responses. Additionally, it promoted effector B cell formation under competitive conditions in TD responses. Mechanistically, in vitro ligation of Fcrl5 by agonistic Abs reduced cell death and enhanced proliferation in lipopolysaccharide (LPS)-stimulated B cells. In the presence of anti-CD40 Abs and IL-5, the Fcrl5 ligation not only suppressed cell death but also enhanced differentiation into plasma cells. These findings reveal a novel role of Fcrl5 in promoting humoral immune responses by enhancing B cell viability and plasma cell differentiation.

Chronic Ileum Obstruction, Granulation, and Ulceration With IgG4-Positive Plasma Cell Infiltration in a Six-Year-Old Girl With 21trisomy

Chronic Ileum Obstruction, Granulation, and Ulceration With IgG4-Positive Plasma Cell Infiltration in a Six-Year-Old Girl With 21trisomy

Resolvin D1 inhibits T follicular helper cell expansion in systemic lupus erythematosus

Objective Resolvin D1 (RvD1) is one of the specialized pro-resolving lipid mediators, which control inflammation resolution and regulate immune responses. Previous research showed that RvD1 could block the progression of systemic lupus erythematosus (SLE). However, the detailed mechanism remains to be fully understood. Method Plasma RvD1 levels, and proportions of T follicular helper cells (Tfh cells) were measured in SLE patients and healthy controls. Plasma RvD1 levels and proportions of Tfh cells were quantitated in an MRL/lpr mouse model of lupus treated with RvD1. Naïve CD4+ T cells were purified from MRL/lpr mice to study the effect of RvD1 on Tfh cell differentiation in vitro. Results In patients, there were significant negative correlations between plasma RvD1 levels and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score, as well as between plasma RvD1 and anti-double-stranded DNA antibody levels, and numbers of peripheral Tfh cells and plasma cells. In MRL/lpr mice, the expected amelioration of disease phenotype and inflammatory response with RvD1 treatment correlated with decreased percentages of Tfh cells and plasma cells. In addition, the differentiation and proliferation of Tfh cells were markedly suppressed by RvD1 in vitro. Conclusion RvD1 may control SLE progression through the suppression of Tfh cell differentiation and subsequent inhibition of B-cell responses.

Reproducible Radiomics Features from Multi-MRI-Scanner Test-Retest-Study: Influence on Performance and Generalizability of Models.

Radiomics models trained on data from one center typically show a decline of performance when applied to data from external centers, hindering their introduction into large-scale clinical practice. Current expert recommendations suggest to use only reproducible radiomics features isolated by multiscanner test-retest experiments, which might help to overcome the problem of limited generalizability to external data. To evaluate the influence of using only a subset of robust radiomics features, defined in a prior in vivo multi-MRI-scanner test-retest-study, on the performance and generalizability of radiomics models. Retrospective. Patients with monoclonal plasma cell disorders. Training set (117 MRIs from center 1); internal test set (42 MRIs from center 1); external test set (143 MRIs from center 2-8). 1.5T and 3.0T; T1-weighted turbo spin echo. The task for the radiomics models was to predict plasma cell infiltration, determined by bone marrow biopsy, noninvasively from MRI. Radiomics machine learning models, including linear regressor, support vector regressor (SVR), and random forest regressor (RFR), were trained on data from center 1, using either all radiomics features, or using only reproducible radiomics features. Models were tested on an internal (center 1) and a multicentric external data set (center 2-8). Pearson correlation coefficient r and mean absolute error (MAE) between predicted and actual plasma cell infiltration. Fisher's z-transformation, Wilcoxon signed-rank test, Wilcoxon rank-sum test; significance level P < 0.05. When using only reproducible features compared with all features, the performance of the SVR on the external test set significantly improved (r = 0.43 vs. r = 0.18 and MAE = 22.6 vs. MAE = 28.2). For the RFR, the performance on the external test set deteriorated when using only reproducible instead of all radiomics features (r = 0.33 vs. r = 0.44, P = 0.29 and MAE = 21.9 vs. MAE = 20.5, P = 0.10). Using only reproducible radiomics features improves the external performance of some, but not all machine learning models, and did not automatically lead to an improvement of the external performance of the overall best radiomics model. Stage 2.

Antigen escape as a shared mechanism of resistance to BCMA-directed therapies in multiple myeloma

B-cell maturation antigen (BCMA)-targeting therapeutics have dramatically improved outcomes in relapsed/refractory multiple myeloma (RRMM). However, whether the mechanisms of resistance between these therapies are shared and how the identification of such mechanisms before therapy initiation could refine clinical decision-making remains undefined. We analyzed outcomes for 72 RRMM patients treated with teclistamab, a CD3 x BCMA bispecific antibody (BsAb), 42% (30/72) of whom had prior BCMA-directed therapy exposure. Malignant plasma cell BCMA expression was present in all BCMA therapy-naïve patients. Prior therapy-mediated loss of plasma cell BCMA expression before teclistamab treatment, measured by immunohistochemistry, was observed in 3 patients, none of whom responded to teclistamab, and one of whom also did not respond to ciltacabtagene autoleucel. Whole exome sequencing of tumor DNA from one patient revealed biallelic loss of TNFRSF17 following treatment with belantamab mafodotin. Low-to-undetectable peripheral blood soluble BCMA levels correlated with the absence of BCMA expression by bone marrow plasma cells. Thus, although rare, loss of BCMA expression following TNFRSF17 gene deletions can occur following any BCMA-directed therapy and prevents response to subsequent anti-BCMA-directed treatments, underscoring the importance of verifying the presence of a target antigen.

Single-cell analysis of anti-BCMA CAR T cell therapy in patients with central nervous system autoimmunity.

Chimeric antigen receptor (CAR) T cell immunotherapy for the treatment of neurological autoimmune diseases is promising, but CAR T cell kinetics and immune alterations after treatment are poorly understood. Here, we performed single-cell multi-omics sequencing of paired cerebrospinal fluid (CSF) and blood samples from patients with neuromyelitis optica spectrum disorder (NMOSD) treated with anti-B cell maturation antigen (BCMA) CAR T cells. Proliferating cytotoxic-like CD8+ CAR T cell clones were identified as the main effectors in autoimmunity. Anti-BCMA CAR T cells with enhanced features of chemotaxis efficiently crossed the blood-CSF barrier, eliminated plasmablasts and plasma cells in the CSF, and suppressed neuroinflammation. The CD44-expressing early memory phenotype in infusion products was potentially associated with CAR T cell persistence in autoimmunity. Moreover, CAR T cells from patients with NMOSD displayed distinctive features of suppressed cytotoxicity compared with those from hematological malignancies. Thus, we provide mechanistic insights into CAR T cell function in patients with neurological autoimmune disease.

Expression of Anoikis-Related Genes and Potential Biomarkers in Colon Cancer Based on RNA-seq and scRNA-seq.

Colon cancer (CC) is a malignant tumor in the colon. Despite some progress in the early detection and treatment of CC in recent years, some patients still experience recurrence and metastasis. Therefore, it is urgent to better predict the prognosis of CC patients and identify new biomarkers. Recent studies have shown that anoikis-related genes (ARGs) play a significant role in the progression of many tumors. Hence, it is essential to confirm the role of ARGs in the development and treatment of CC by integrating scRNA-seq and transcriptome data. This study integrated transcriptome and single-cell sequencing (scRNA-seq) data from CC samples to evaluate patient stratification, prognosis, and ARG expression in different cell types. Specifically, differential expression of ARGs was identified through consensus clustering to classify CC subtypes. Subsequently, a CC risk model composed of CDKN2A, NOX4, INHBB, CRYAB, TWIST1, CD36, SERPINE1, and MMP3 was constructed using prognosis-related ARGs. Finally, using scRNA-seq data of CC, the expression landscape of prognostic genes in different cell types and the relationship between important immune cells and other cells were explored. Through the above analysis, two CC subtypes were identified, showing significant differences in prognosis and clinical factors. Subsequently, a risk model comprising aforementioned genes successfully categorized all CC samples into two risk groups, which also exhibited significant differences in prognosis, clinical factors, involved pathways, immune landscape, and drug sensitivity. Multiple pathways (cell adhesion molecules (CAMs), and extracellular matrix (ECM) receptor interaction) and immune cells/immune functions (B cell naive, dendritic cell activate, plasma cells, and T cells CD4 memory activated) related to CC were identified. Furthermore, it was found that prognostic genes were highly expressed in various immune cells, and B cells exhibited more and stronger interaction pathways with other cells. The results of this study may provide references for personalized treatment and potential biomarker identification in CC.

Activated interferon response from DNA damage in multiple myeloma cells contributes to the chemotherapeutic effects of anthracyclines

IntroductionMultiple myeloma (MM) is a malignant plasma cell disease caused by abnormal proliferation of clonal plasma cells in bone marrow. Upfront identification of tumor subgroups with specific biological markers has the potential to improve biologically-driven therapy. Previously, we established a molecular classification by stratifying multiple myeloma into two subtypes with a different prognosis based on a gene module co-expressed with MCL-1 (MCL1-M).MethodsGene Ontology (GO) analysis with differentially expressed genes was performed to identify signal pathway. Drug sensitivity was analyzed using the OncoPredict algorithm. Drug sensitivity of different myeloma cell lines was detected by CCK8 and flow cytometry. RNA-seq was performed on drug-sensitive cell lines before and after adriamycin treatment. RT-qPCR was used to further verify the sequencing results. The expression of γ-H2AX and dsDNA in sensitive and resistant cell lines was detected by immunofluorescence method.ResultsIn our study, we demonstrated that MCL1-M low MM were more sensitive to anthracyclines. We treated different myeloma cell lines with doxorubicin in vitro and discovered the association of drug sensitivity with IFN signaling. Herein, we demonstrate that the doxorubicin-sensitive myeloma cell line showed significant DNA damage and up-regulated expression of genes related to the IFN response, which was not observed in drug-insensitive cell lines.DiscussionOur results suggest that the active IFN signaling pathway may serve as a marker for predicting chemotherapy sensitivity in patients with myeloma. With our MCL1-M molecular classification system, we can screen patients with a potentially good response to the interferon signaling pathway and provide individualized treatment for MM. We propose IFN-a as adjuvant therapy for patients with myeloma sensitive to anthracyclines to further improve the therapeutic effect and prolong the survival of patients.

Case report: A highly active refractory myasthenia gravis with treatment of telitacicept combined with efgartigimod

There is always a lack of effective treatment for highly active refractory generalized myasthenia gravis (GMG). Recently, telitacicept combined with efgartigimod significantly reduces circulating B cells, plasma cells, and immunoglobulin G, which brings promising therapeutic strategies. We report a case of a 37-year-old female patient with refractory GMG, whose condition got significant improvement and control with this latest treatment after multiple unsuccessful therapies of immunosuppressants. The new combination deserves further attention in the therapeutic application of myasthenia gravis.

Beyond BCMA: the next wave of CAR T cell therapy in multiple myeloma

Chimeric antigen receptor (CAR) T cell therapy has transformed the treatment landscape of relapsed/refractory multiple myeloma. The current Food and Drug Administration approved CAR T cell therapies idecabtagene vicleucel and ciltacabtagene autoleucel both target B cell maturation antigen (BCMA), which is expressed on the surface of malignant plasma cells. Despite deep initial responses in most patients, relapse after anti-BCMA CAR T cell therapy is common. Investigations of acquired resistance to anti-BCMA CAR T cell therapy are underway. Meanwhile, other viable antigenic targets are being pursued, including G protein-coupled receptor class C group 5 member D (GPRC5D), signaling lymphocytic activation molecule family member 7 (SLAMF7), and CD38, among others. CAR T cells targeting these antigens, alone or in combination with anti-BCMA approaches, appear to be highly promising as they move from preclinical studies to early phase clinical trials. This review summarizes the current data with novel CAR T cell targets beyond BCMA that have the potential to enter the treatment landscape in the near future.

The Use of Platelet-Rich Plasma and Stem Cell Injections in Musculoskeletal Injuries

The Use of Platelet-Rich Plasma and Stem Cell Injections in Musculoskeletal Injuries

Continuous and differential improvement in worldwide access to hematopoietic cell transplantation: activity has doubled in a decade with a notable increase in unrelated and non-identical related donors.

Promoting access to and excellence in hematopoietic cell transplantation (HCT) by collecting and disseminating data on global HCT activities is one of the principal activities of the Worldwide Network for Blood and Marrow Transplantation, a non-Governmental organization in working relations with the World Health Organization. HCT activities are recorded annually by member societies, national registries and individual centers including indication, donor type (allogeneic/autologous), donor match and stem cell source (bone marrow/peripheral blood stem cells/cord blood). In 2018, 1,768 HCT teams in 89 countries (six WHO regions) reported 93,105 (48,680 autologous and 44,425 allogeneic) HCT. Major indications were plasma cell disorders and lymphoma for autologous, and acute leukemias and MDS/MPN for allogeneic HCT. HCT number increased from 48,709 in 2007. Notable increases were seen for autoimmune diseases in autologous and hemoglobinopathies in allogeneic HCT. The number of allogeneic HCT more than doubled with significant changes in donor match. While HCT from HLA identical siblings has seen only limited growth, HCT from non-identical related donors showed significant increase worldwide. Strongest correlation between economic growth indicator of gross national income/capita and HCT activity/ten million population was observed for autologous HCT (r=0.79). HCT from unrelated donors showed strong correlation (r=0.68), but only moderate correlation (r=0.51) was detected from related donors. The use of HCT doubled in about a decade worldwide at different speed and with significant changes regarding donor match as a sign of improved access to HCT worldwide. Although narrowing, significant gaps remain between developing and non-developing countries.

AL amyloidosis: an overview on diagnosis, staging system, and treatment

Systemic light-chain (AL) amyloidosis is a monoclonal plasma cell disease characterized by the deposition of amyloidogenic monoclonal light-chain fragments in organs, causing their dysfunction. Clinical manifestations could be very aspecific, but the most frequent ones are proteinuria with or without renal failure or heart failure, with the kidney and the heart being the first two involved organs. Histological diagnosis with Congo red staining is the gold standard, but typing the amyloid with immunohistochemistry or mass spectrometry of the Congo red positive tissue is necessary to establish if an AL or ATTR amyloidosis could be diagnosed. Staging AL amyloidosis before treatment could help physicians to prognosticate the disease. Recently, staging systems were set separately for different involved organs, using biomarkers. Autologous stem cell transplant after a daratumumab-based induction treatment is the cornerstone of therapy in younger and fit patients, with the goal of reaching a deep and rapid disease hematological and organ response. Novel therapies, borrowed from a therapeutical model of multiple myeloma, are studied to optimize AL amyloidosis outcomes. In this review, we make an overview of diagnostic procedures, staging system, and therapies of AL amyloidosis.

A new perspective on therapies involving B-cell depletion in autoimmune diseases.

It has been rediscovered in the last fifteen years that B-cells play an active role in autoimmune etiology rather than just being spectators. The clinical success of B-cell depletion therapies (BCDTs) has contributed to this. BCDTs, including those that target CD20, CD19, and BAFF, were first developed to eradicate malignant B-cells. These days, they treat autoimmune conditions like multiple sclerosis and systemic lupus erythematosus. Particular surprises have resulted from the use of BCDTs in autoimmune diseases. For example, even in cases where BCDT is used to treat the condition, its effects on antibody-secreting plasma cells and antibody levels are restricted, even though these cells are regarded to play a detrimental pathogenic role in autoimmune diseases. In this Review, we provide an update on our knowledge of the biology of B-cells, examine the outcomes of clinical studies employing BCDT for autoimmune reasons, talk about potential explanations for the drug's mode of action, and make predictions about future approaches to targeting B-cells other than depletion.