Rituximab Resistance in Glomerular Diseases: A GlomCon Mini Review.

Resistance to rituximab B-cell depletion therapy is a clinically pertinent adverse sequela that can have significant implications for the treatment of immune-mediated glomerular diseases. The true incidence of rituximab resistance remains unknown; however, it is an increasingly recognized treatment complication. Resistance typically presents with suboptimal treatment response, rapid B-cell reconstitution, and a relapsing disease course. Although the diverse mechanisms resulting in rituximab resistance are ongoing topics of research, both primary and secondary mechanisms have been identified as key catalysts. The emergence of human antichimeric antibodies (HACAs) is a major cause of secondary resistance to rituximab therapy and typically appears following repeated drug exposure. Frequently, HACAs develop in the setting of underlying autoimmune disease and contribute to poor B-cell depletion, reduced rituximab therapeutic efficacy, and enhanced drug clearance. The clinical challenge of rituximab resistance necessitates heightened awareness among clinicians. Screening for HACAs should be considered in individuals with poor clinical response to rituximab, more rapid B-cell reconstitution, and relapsing disease. Detection of HACAs may guide treatment alterations, including addition of further immunosuppressive therapy and transitioning to a humanized B-cell depleting monoclonal antibody.

Subcutaneous epcoritamab monotherapy in Japanese adults with relapsed/refractory diffuse large B-cell lymphoma.

Epcoritamab is a subcutaneously administered CD3xCD20 bispecific Ab that showed deep, durable responses with a manageable safety profile in patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) in the global multicenter pivotal phase II trial EPCORE NHL-1. Here, we present results from the similar EPCORE NHL-3 phase I/II trial evaluating epcoritamab monotherapy in Japanese patients with R/R CD20+ B-cell non-Hodgkin's lymphoma previously treated with two or more lines of therapy. Epcoritamab was dosed subcutaneously in 28-day cycles; once weekly during cycles 1-3, every 2 weeks during cycles 4-9, and every 4 weeks from cycle 10 until disease progression or unacceptable toxicity. Step-up dosing and cytokine release syndrome (CRS) prophylaxis were used during treatment cycle 1. As of January 31, 2022, 36 patients received treatment with 48 mg epcoritamab monotherapy. At a median follow-up of 8.4 months, overall response and complete response rates by independent review committee were 55.6% and 44.4%, respectively. The median duration of response, duration of complete response, and overall survival were not reached at the time of data cut-off. The most common treatment-emergent adverse events of any grade were CRS (83.3%), injection-site reactions (69.4%), infections (44.4%), neutropenia (38.9%), hypokalemia (27.8%), and decreased lymphocyte count (25.0%). Cytokine release syndrome occurrence was predictable; events were primarily low grade (grade 1-2), all resolved, and none led to treatment discontinuation. These encouraging results are consistent with previous findings and support the ongoing clinical evaluation of epcoritamab for the treatment of R/R DLBCL, including in earlier treatment lines.

Patients with Classical Hodgkin Lymphoma with Less Than 10.5 CD20-Positive Reed-Sternberg Cells in 10 High-Power Fields Have Better Prognosis.

The CD20 immunoexpression in classical Hodgkin lymphoma (CHL) is variable and it may represent an intersection between the pathophysiology of CHL and the clinical prognosis of patients. Retrospective study with 174 patients with pathological diagnosis of CHL. Clinical data were reviewed from medical records. Immunophenotypic study with CD20 were performed in two ways: hotspot count and in 10 high-power fields (HPF). The data were tabulated and the p value less than 0.05 was considered significant. The CD20-positive phenotype was found in 45 (25.9%) of the total of 174 patients with available material. Patients with CD20 positivity on neoplastic cells tend to heal earlier, particularly those with less than 10.5 cells/10 HPF (p = 0.037). Patients with CHL with less than 10.5 CD20-positive Reed-Sternberg cells in 10 HPF have better prognosis.

Myositis with prominent B-cell aggregates causing shrinking lung syndrome in systemic lupus erythematosus: a case report.

BACKGROUND: Shrinking lung syndrome (SLS) is a rare manifestation of systemic lupus erythematosus (SLE) characterized by decreased lung volumes and diaphragmatic weakness in a dyspneic patient. Chest wall dysfunction secondary to pleuritis is the most commonly proposed cause. In this case report, we highlight a new potential mechanism of SLS in SLE, namely diaphragmatic weakness associated with myositis with CD20 positive B-cell aggregates. CASE PRESENTATION: A 51-year-old Caucasian woman was diagnosed with SLE and secondary Sjögren's syndrome based on a history of pleuritis, constrictive pericarditis, polyarthritis, photosensitivity, alopecia, oral ulcers, xerophthalmia and xerostomia. Serologies were significant for positive antinuclear antibodies, anti-SSA, lupus anticoagulant and anti-cardiolopin. Blood work revealed a low C3 and C4, lymphopenia and thrombocytopenia. She was treated with with low-dose prednisone and remained in remission with oral hydroxychloroquine. Seven years later, she developed mild proximal muscle weakness and exertional dyspnea. Pulmonary function testing revealed a restrictive pattern with small lung volumes. Pulmonary imaging showed elevation of the right hemidiaphragm without evidence of interstitial lung disease. Diaphragmatic ultrasound was suggestive of profound diaphragmatic weakness and dysfunction. Based on these findings, a diagnosis of SLS was made. Her proximal muscle weakness was investigated, and creatine kinase (CK) levels were normal. Electromyography revealed fibrillation potentials in the biceps, iliopsoas, cervical and thoracic paraspinal muscles, and complex repetitive discharges in cervical paraspinal muscles. Biceps muscle biopsy revealed dense endomysial lymphocytic aggregates rich in CD20 positive B cells, perimysial fragmentation with plasma cell-rich perivascular infiltrates, diffuse sarcolemmal upregulation of class I MHC, perifascicular upregulation of class II MHC, and focal sarcolemmal deposition of C5b-9. Treatment with prednisone 15 mg/day and oral mycophenolate mofetil 2 g/day was initiated. Shortness of breath and proximal muscle weakness improved significantly. CONCLUSION: Diaphragmatic weakness was the inaugural manifestation of myositis in this patient with SLE. The spectrum of myologic manifestations of myositis with prominent CD20 positive B-cell aggregates in SLE now includes normal CK levels and diaphragmatic involvement, in association with SLS.

CD20 role in pathophysiology of Hodgkin's disease / O papel do CD20 na fisiopatologia da doença de Hodgkin

Summary Hodgkin's lymphoma (HL) is a tumor comprising non-malignant and malignant B-cells. Classical HL expresses CD15+ and CD30+ antigens, and 20 to 40% of patients are CD20+. This antigen is a ligand free protein present in B lymphocyte cells and its function is not well known. Some studies suggest that expression of CD20 may play a major role in Hodgkin's disease pathophysiology and may affect the patients' treatment prognosis, as well as relapse and refractory response. In the past few years, development of monoclonal anti-CD20 antibodies changed drastically the treatment for non-Hodgkin lymphomas in which CD20 is expressed. HL treatment is essentially composed of radiotherapy and chemotherapy; however, monoclonal anti-CD20 antibodies applicability is not well delimitated due to lack of information about clinical outcomes with anti-CD20 monotherapy or combined drug therapy using a classic regimen, as well as about CD20 pathophysiology mechanisms in B-cells tumors. The objective of our review is to discuss CD20 function in Hodgkin's lymphoma development, its influence on disease evolution and outcomes, as well as its effects on therapeutics and patients' prognostic.

Resumo O linfoma de Hodgkin (LH) é um tumor composto por células B não malignas e malignas. O LH clássico expressa antígenos CD15+ e CD30+, mas apenas cerca de 20 a 40% dos pacientes expressa também antígeno CD20. Este antígeno é uma proteína sem ligante presente nas células de linfócitos B cuja função não é bem conhecida. Alguns estudos sugerem que a expressão de CD20 pode ter um papel importante na fisiopatologia da doença de Hodgkin e pode afetar o prognóstico dos pacientes ao tratamento, bem como recaída e refratariedade. Nos últimos anos, o desenvolvimento de anticorpos monoclonais anti-CD20 mudou drasticamente o tratamento para linfomas não Hodgkin em que o CD20 é expresso. O tratamento do LH é composto essencialmente de radio e quimioterapia; no entanto, o espaço dos anticorpos monoclonais anti-CD20 não está bem delimitado em decorrência de: falta de informação sobre o desfecho clínico, seja na monoterapia com anti-CD20, seja na terapêutica combinada com o regime clássico; falta de informação sobre os mecanismos de fisiopatologia CD20 em tumores de células B. O objetivo desta revisão é discutir sobre a função do CD20 no desenvolvimento do linfoma de Hodgkin, sua influência na evolução da doença e os resultados, bem como os efeitos sobre terapêutica e prognóstico dos pacientes.

CD3 and CD20 Immunohistochemical Staining Patterns of Bone Marrow-Infiltrating Malignant Lymphoma Cells.

OBJECTIVES: It is known that CD3 and CD20 are homogenously expressed in T lineage and B lineage lymphoma, respectively; however, there are no standard guidelines to interpret immunohistochemistry findings. In this study, we investigated CD3 and CD20 immunohistochemical staining patterns of bone marrow (BM)-infiltrating lymphoma cells. METHODS: Among 297 patients diagnosed with malignant lymphoma, the BM biopsy slides of all 39 cases found to have BM infiltration (T lineage: 11; B lineage: 28) were reviewed. We specifically investigated the immunohistochemical staining patterns of CD3 and CD20. RESULTS: All 11 T lineage lymphoma cases showed homogenous immunohistochemical staining patterns. In the 28 B lineage lymphoma cases, 15 (53.6%) showed a homogenous pattern while 13 (46.4%) showed a heterogeneous pattern. Ten cases in the latter group showed additional evidence of BM infiltration by lymphoma cells in separate laboratory analyses or imaging studies. There were no differences in overall or progression-free survival rates in patients exhibiting homogeneous vs. heterogeneous staining patterns (P=0.81 and P=0.59, respectively). CONCLUSIONS: A considerable number of B lineage cases showed heterogeneous patterns with evidence of BM infiltration. Thus, heterogeneous immunohistochemical staining patterns (particularly in B lineage lymphomas) may signify malignant lymphoma cell infiltration into the BM.

Anti-CD20 antibody treatment of non-Hodgkin lymphomas.

The CD20 antigen characteristic for mature B-cell is also expressed on B-cell Non-Hodgkin lymphomas (NHL). It thus presents a possible target for immunotherapy. NHL respond readily to radio- and/or chemotherapy but this standard treatment bears a high risk of relapse. The specific monoclonal anti-CD20-antibody Rituximab, the first to be approved for clinical use, could be shown to improve response rates, response duration, and survival in NHL when combined with standard therapy. This review details the development, clinical application, and future perspectives of anti-CD20-antibody treatment of NHL, thereby proving the efficiency of immunotherapy via targeting of a tumor associated antigen.

CD20-targeting in B-cell malignancies: novel prospects for antibodies and combination therapies.

Expression of CD20 antigen by the most of transformed B cells is believed to be the driving force for targeting this molecule by using anti-CD20 monoclonal antibodies. While it is true that most lymphoma/leukemia patients can be cured, these regimens are limited by the emergence of treatment resistance. Based on these observations, development of anti-CD20 monoclonal antibodies and combination therapies have been recently proposed, in particular with the aim to optimize the cytotoxic activity. Here we outline a range of new experimental agents concerning the CD20 positive B-cell tumors which provide high benefit from conventional therapy.

[Evolution of monoclonal antibodies in cancer treatment]. / Ewolucja przeciwcial monoklonalnych w leczeniu chorób nowotworowych.

Since late 90s of last century the new age of directed therapy began using mainly biological constructs produced in rodents called monoclonal antibodies. The side effects of monoclonal antibodies were a challenge for pharmaceutical companies to improve the biological properties of these biological drugs. The humanization of monoclonal constructs was an idea to improve monoclonal antibodies next generation activity cancer cell reduction in humans. Moreover for some other patients sensitive for monoclonal antibodies therapy could also potentially induce immunological differences that might imply on human health. The new idea related to monoclonal antibodies was to design a small molecule constructs of nanoantibodies with ability to enter into cells. Such small molecules could find their targets inside human cells, even in nuclei leading to differences in cancer cells expression. The existing knowledge on monoclonal antibodies as well as directed activity of nanoantibodies could improve anticancer treatment efficancy of diseases.

What is the status of novel anti-CD20 antibodies for chronic lymphocytic leukemia and are they set to leave rituximab in the shadows?

Chronic lymphocytic leukemia/small lymphocytic lymphoma is the most prevalent form of adult leukemia in western countries. Chemotherapy has been the mainstay of treatment for the last several decades. The introduction of biological, targeted agents (e.g., monoclonal antibodies) has dramatically improved treatment options. The addition of rituximab to fludarabine and cyclophosphamide has improved patient outcomes, as compared to fludarabine and cyclophosphamide. Nevertheless, chronic lymphocytic leukemia remains incurable, leaving considerable room for improvement. One approach would be to enhance the activity of the CD20 antibody. The next-generation monoclonal antibody ofatumumab has not demonstrated superiority over rituximab, whereas obinutuzumab-chlorambucil is superior to rituximab-chlorambucil. Recent efforts to combine anti-CD20 antibodies with new targeted therapies offer the potential to move toward alternative non-chemotherapy-based treatment approaches.

CD20 alternative splicing isoform generates immunogenic CD4 helper T epitopes.

Cancer-specific splice variants gain significant interest as they generate neo-antigens that could be targeted by immune cells. CD20, a membrane antigen broadly expressed in mature B cells and in B cell lymphomas, is subject to an alternative splicing named D393-CD20 leading to loss of membrane expression of the spliced isoform. D393-CD20 expression is detectable in transformed B cells and upregulated in various lymphoma B cells. In this study, we show that D393-CD20 is translated in malignant B cells and that D393-CD20 specific CD4 T cells producing IFN-γ are present in B-cell lymphoma patients. Then, we have investigated whether the 20mer D393-CD20 peptide spanning the splicing site might be targeted by the immune system and we have shown that D393-CD20-specific CD4 Th1 clones could directly recognize malignant B cell lines and kill autologous lymphoma B cells indicating that D393-CD20-derived epitopes are naturally processed and presented on tumor cells. Finally, D393-CD20 peptide-based vaccination induced specific CD8 and CD4 T cell responses in HLA-humanized transgenic mice suggesting the presentation of D393-CD20 derived peptides on both HLA Class-I and -II. These findings support further investigations on the potential use of D393-CD20 directed specific immunotherapy in B cell malignancies.

Expression of CD20 in B Cell Precursor Acute Lymphoblastic Leukemia.

CD20 is a B cell differentiation antigen with variable expression in B cell precursor acute lymphoblastic leukemia (BCP-ALL). The significance of CD20 expression has been evaluated in BCP-ALL with conflicting results. There is paucity of data regarding CD 20 expression in BCP-ALL in Indian patients. We retrospectively analyzed 100 patients of BCP-ALL for CD20 expression. CD20 positivity was defined as expression of CD20 to be more than or equal to 20 % in the blast population. 62 % patients expressed CD20 while 38 % patients were negative for CD20. The positivity ranged from negative to dim (35.5 % patients), moderately bright (19.3 % patients) to bright (45.2 % patients). Additional prospective studies are needed to determine the optimal use of rituximab in treatment of CD20-positive BCP-ALL.

Influência do CD 20 na refratariedade do linfoma de Hodgkin clássico ao tratamento inicial com o esquema ABVD, no Ceará, Brasil / Influence of CD 20 antigen expression in the refractoriness of classical Hodgkin lymphoma in the first line treatment with ABVD protocol in Ceará state, Brazil

INTRODUÇÃO: A significância prognóstica do marcador imunológico CD 20 no linfoma de Hodgkin clássico (LHc) ainda é incerta, particularmente no que se refere à refratariedade ao tratamento inicial. OBJETIVOS: Avaliar a influência da positividade do marcador CD 20 na refratariedade do LHc ao tratamento poliquimioterápico inicial, com o esquema doxorubicina 25 mg/m², bleomicina 10 mg/m², vinblastina 6 mg/m² e dacarbazina 375 mg/m² (ABVD), no Ceará, Brasil. MATERIAL E MÉTODOS: Estudo analítico incluindo 97 pacientes com diagnóstico de LHc firmado entre janeiro de 2000 e dezembro de 2004. A análise foi realizada avaliando variáveis demográficas, clínicas e laboratoriais. RESULTADOS: Foi evidenciada uma positividade do CD 20 em 38,1 por cento dos pacientes. Na análise bivariada, CD 20 positivo (razão de chance [RC] = 4,02; intervalo de confiança [IC] = 1,09 - 8,54; p = 0,02), a presença de sintomas B (RC = 4,02; IC = 1,18-17,51; p = 0,01) e a elevação da desidrogenase lática (mediana não-refratários 248,5 [200,5 - 389,5]; mediana refratários 356 [208,5 - 545]; p = 0,03) apresentaram relação de pior prognóstico quanto à refratariedade. Na regressão logística, o CD 20 positivo (RC ajustada = 3,6; IC = 0,99 - 13,09; p = 0,05) e a presença de sintomas B (RC ajustada = 5,41; IC = 1,16 - 25,34; p = 0,03) continuaram apresentando pior prognóstico. DISCUSSÃO: Esses dados coincidem com a literatura, em que a positividade do marcador CD 20 está relacionada com pior resposta ao tratamento com ABVD. CONCLUSÃO: Os nossos dados indicam que o tratamento com ABVD não é completamente adequado para a abordagem terapêutica inicial deste subgrupo de pacientes e novas pesquisas precisam ser realizadas no sentido de aperfeiçoar o tratamento destes pacientes.

INTRODUCTION: The prognostic value of CD20 antigen expression in classical Hodgkin lymphoma (cHL) is uncertain, particularly regarding the refractoriness to first-line treatment. OBJECTIVES: To assess the influence of CD20 positiveness on the refractoriness of cHL to first-line chemotherapy with ABVD protocol in Ceará State, Brazil. MATERIAL AND METHODS: Analytical study including 97 patients diagnosed with cHL between January/2000 and December/2004. The analysis was performed evaluating demographic, clinical and laboratory variables. RESULTS: CD20 antigen expression was positive in 38.1 percent of the patients. In the bivariate analysis, CD20 antigen expression (OR = 4.02; CI = 1.09 - 8.54; p = 0.02), the presence of B-symptoms (OR = 4.02; CI = 1.18-17.51; p = 0.01) and an elevated lactate dehydrogenase level (median not refractory 248.5 [200.5 - 389.5]; median refractory 356 [208.5-545]; p = 0.03) showed worse prognosis as to refractoriness. In the logistic regression analysis, the presence of CD 20 (OR = 3.6; CI = 0.99-13.09; p = 0.05) and B-symptoms (OR = 5.41; CI = 1.16-25.34; p = 0.03) continued to show worse prognosis. DISCUSSION: These findings coincide with literature data indicating that CD 20 antigen expression is associated with low response to treatment with ABVD. CONCLUSION: Our data show that the treatment with ABVD is not totally appropriate for the initial therapeutic approach in this subgroup of patients and that further studies are required to optimize their treatment.

Biological agents targeting beyond TNF-alpha.

Biological agents represent an important addition to the therapies for immuno-inflammatory conditions and have a great impact on the disease course and quality of life of these patients. However, recent reports of serious infections like tuberculosis, demyelinating and neurodegenerative diseases, pancytopenia, cardiovascular diseases, etc. after anti-TNF therapy raised questions on their safety. Hence, focus is shifted towards drugs targeting cytokine checkpoints in the inflammatory cascades beyond TNF-alpha. Existing therapeutic targets include the biological agents acting as antagonists of various inflammatory cytokines (Anakinra, Tocilizumab, Atlizumab) and modulators of CD80 or CD86-CD28 co-stimulatory signal (Abatacept), CD2 receptors on T-cells (Alefacept), CD11a, subunit of leukocyte function-associated antigen 1 (Efalizumab), vitronectin receptor and CD20 antigen on pre-B, immature and mature B cells (Rituximab). With the introduction of these novel molecules the future for immunomodulatory intervention in rheumatology, asthma, crohn's disease, septic shock etc. looks very promising. These novel therapeutic agents could truly give a new hope to the clinician to modify the disease and achieve tangible improvements in the lives of the patients.