Follow-up data of 10 patients with B-cell non-Hodgkin lymphoma with a CD20-negative phenotypic change after rituximab-containing therapy

Retrospective Study of CD20 Expression Loss in Relapsed or Refractory B-Cell Non-Hodgkin Lymphoma

Background

CD20-targeted therapies are widely used in the management of B-cell lymphomas. Re-treatment with CD20-directed agents is common; however, previous research has demonstrated loss of CD20 expression at relapse in a subset of patients.

Methods

In this single-center retrospective cohort of 243 patients, CD20 analysis was performed by immunohistochemistry (IHC) and/or flow cytometry at diagnosis and at relapse if a biopsy was performed.

Results

Of 109 patients with relapsed or refractory B-cell lymphoma, 59 patients with CD20-positive lymphoma at diagnosis underwent a biopsy at relapse for a total of 76 biopsies across all relapses. The rate of partial or complete CD20 expression loss was 11.9% (four patients with partial loss, three patients with complete loss). There were four cases of CD20 loss at first relapse (three IHC, one flow cytometry), two at second relapse (one IHC, one IHC and flow cytometry), and one at fifth relapse (IHC and flow cytometry). CD20 antigen escape was observed in marginal zone lymphoma, follicular lymphoma, and diffuse large B-cell lymphoma (DLBCL). All patients with CD20 expression loss previously received rituximab. Among patients with CD20 antigen escape, 85.7% had stage IV disease, and median overall survival after CD20 loss was 4 months. In the group of five patients with indolent lymphoma and CD20 expression loss, three patients (60%) had concurrent transformation to high-grade lymphoma.

Conclusions

This study, which reinforces the importance of repeating a biopsy at relapse before implementing CD20-directed therapy, is particularly relevant given the widespread use of rituximab along with the emerging significance of CD20-targeted bispecific antibodies in the management of B-cell lymphomas.

Loss of or decrease in CD30 expression in four patients with anaplastic large cell lymphoma after brentuximab vedotin-containing therapy

Brentuximab vedotin (BV), CD30 specific antibody drug conjugate, has been used to treat anaplastic large cell lymphoma (ALCL) and classic Hodgkin lymphoma (CHL); it is also used in the treatment of other CD30-positive peripheral T-cell lymphomas. We aimed to investigate the incidence and clinicopathological characteristics of patients with ALCL or CHL with loss of or decrease in CD30 expression after BV-containing therapy. Twelve and nine patients with refractory/relapsed CHL and ALCL, respectively, were analyzed after receiving BV-containing therapy. In four ALCL patients (44%), CD30 expression was lost/decreased in re-biopsy materials, including one with complete loss and three with a reduction of less than 20%. All 12 CHL patients showed consistent CD30 expression levels after BV treatment. Compared with five ALCL patients with consistent CD30 expression, four ALCL patients with a loss of/decrease in CD30 expression received a higher cumulative dose of BV (P = 0.014) and revealed a lower intensity of CD30 expression in initial biopsy materials (P = 0.017). The subtypes of ALCL (ALK positive, ALK negative, and primary cutaneous) were not related to the loss of/decrease in CD30 expression. In conclusion, 44% of ALCL patients, regardless of histological subtypes, showed a loss of/decrease in CD30 expression after receiving BV-containing therapy, but this phenomenon was not observed in CHL patients. A higher cumulative dose of BV and a lower amount of CD30 antigen in tumor cells in the initial biopsy materials might be predictors of a loss of/decrease in CD30 expression in ALCL patients.

Primary central nervous system CD20-negative diffuse large B-cell lymphoma: a case report

BACKGROUND

CD20-negative diffuse large B-cell lymphoma is a very rare and heterogeneous invasive cancer characterized by chemical resistance and poor prognosis. Primary CD20-negative diffuse large B-cell lymphoma of the central nervous system is even rarer, presenting great challenges in pathological diagnosis and clinical treatment.

CASE PRESENTATION

We report a case of primary CD20-negative diffuse large B-cell lymphoma of the CNS in a 54-year-old woman admitted to the hospital with a headache lasting more than 10 days. CT and MRI scans showed right temporal lobe lymphoma. Microscopically, large infiltrating lymphoid cells that induced brain tissue damage were observed. Immunohistochemistry showed that the tumor cells were CD79a⁺, PAX-5⁺, MUM1⁺, and CD20^-. The patient was diagnosed with lymphoma and transferred to an oncology hospital for chemotherapy. However, because the disease progressed rapidly, the patient died only after two rounds of chemotherapy.

CONCLUSIONS

To the best of our knowledge, this is one of the first reported cases of unclassifiable CD20-negative diffuse large B-cell lymphoma located in the CNS. This case report aims to deepen the understanding of clinicopathological features of this type of lymphoma and expand the scope of this disease.

Analysis of real-world data in patients with relapsed/refractory diffuse large B cell lymphoma who received salvage chemotherapy in the rituximab era

Although the overall clinical outcome of patients with diffuse large B cell lymphoma (DLBCL) has significantly improved, some patients still experience relapsed/refractory disease. In the rituximab era, real-world data about relapsed/refractory DLBCL are limited. To clarify the clinical outcome and prognostic factors in these patients, we conducted a retrospective analysis using data from the population-based Osaka Cancer Registry (OCR) from 2010 to 2015. In total, 189 adult patients aged up to 70 years who received CHOP or a CHOP-like regimen in combination with rituximab, as well as a subsequent second-line therapy, were included in the analysis. The median age was 63 years (range, 24-70). Age (> 63 years), the duration of first progression-free survival (PFS), and the use of rituximab in the second-line chemotherapy were prognostic factors for overall survival (OS) after the second-line treatment. In this cohort, 48 and 11 patients received autologous and allogeneic hematopoietic stem cell transplantation (HSCT), respectively. The probabilities of 3-year OS after autologous and allogeneic HSCT were 55.7% and 18.2%, respectively. In conclusion, we found that the clinical outcome of patients with relapsed/refractory DLBCL in the rituximab era was unsatisfactory. Further improvements in treatment strategies, including novel agents, are needed.

Clinical significance of the loss of CD20 antigen on tumor cells in patients with relapsed or refractory follicular lymphoma

Aim: Anti-CD20 monoclonal antibody is a cornerstone therapy for follicular lymphoma. Following anti-CD20 therapy, a potential decrease in CD20 antigen, and therefore a loss of the tumor target might be expected. However, the incidence and clinical significance of CD20 loss on tumor cells in patients with relapsed or refractory follicular lymphoma are unknown. This study aims to investigate the incidence and outcome of patients with relapsed or refractory follicular lymphoma patients harboring the loss of the tumor target, CD20. Methods: All consecutive adult patients with relapsed or refractory follicular lymphoma referred to the Early Drug Department at Gustave Roussy were included. The main objectives were to assess the incidence and prognosis of the loss in expression of CD20 antigen on the surface of tumor cells on patient outcome. Results: Over the study period 2013-2018, 131 patients were screened for clinical trials with B-cell malignancies in the early drug department of Gustave Roussy in France. Forty-four patients presented with relapsed or refractory follicular lymphoma and 32 had tumor biopsies at the time of relapse that were retained for analysis. The median (range) age was 67.5 years (55.3-75.3) and the median number of prior anti-cancer systemic therapies was 3 (2-4). At the time of relapse, CD20 expression was positive in 84% of tumors (n = 27) and negative in 16% of tumors (n = 5). At a median follow-up of 18.3 (0.6-83.3) months, CD20 negativity was associated with a poorer prognosis with a median overall survival of 8.9 months (95%CI: 2.4-19.1) in comparison to CD20 positive patients (28.3 months, 95%CI: 25.1-75.3 months, P = 0.019). Conclusion: The loss of the tumor target antigen, CD20, occurred in 16% of patients with relapse or refractory follicular lymphoma. Due to confounding factors in patients who received anti-CD20 immunotherapy, it was not possible to formally establish the prognostic significance of CD20 negativity. However, we suggest that a check for CD20 antigen positivity nevertheless be performed to adapt subsequent therapies for patients with relapsed or refractory follicular lymphoma.

Mechanism and Treatment of Rituximab Resistance in Diffuse Large Bcell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype B non-Hodgkin lymphoma in adults. After rituximab being introduced to treat DLBCL, the current first-line treatment is R-CHOP regimen. This regimen greatly improves patient's prognosis, however, relapsed or refractory cases are commonly seen, mainly due to the resistance to rituximab. Although a large number of experiments have been conducted to investigate rituximab resistance, the exac mechanisms and solutions are still unclear. This review mainly explores the possible mechanisms oft rituximab resistance and current new effective treatments for rituximab resistance in DLBCL.

Immunohistochemical CD20-negative change in B-cell non-Hodgkin lymphomas after rituximab-containing therapy

CD20^- change after rituximab-containing therapy is considered one of the main reasons of rituximab resistance of B-cell non-Hodgkin lymphomas (B-NHLs). However, the clinicopathological characteristics of B-NHL with CD20^- change are not entirely understood. In this study, 252 B-NHL patients who were CD20⁺ at initial diagnosis, whose diseases relapsed or were refractory after rituximab-containing therapy, and who were re-biopsied between 2000 and 2018, were included. The median number of rituximab administration was 11 (range, 1-48). Completely negative (cCD20^-) and partially negative (pCD20^-) change of CD20 was observed in 49 (20%) and 16 (6%) cases, respectively. Among cCD20^- and pCD20^- cases, 74% and 62% of the cases changed to CD20^- at the second relapse or later, respectively. Overall survival was significantly shorter in cCD20^- follicular lymphoma (FL) cases than in CD20⁺ FL cases. Seven histopathological patterns, such as CD20^- change without histological change, histological transformation (HT) to CD20^- diffuse large B-cell lymphoma, and proliferation of plasmablastic/plasmacytoid tumor cells, were associated with CD20^- change. HT occurred more frequently in FLs with CD20^- change than in FLs continuously expressing CD20 (P < 0.0001), regardless of the timing of HT. Nine out of 25 cases (36%) showed regain or heterogeneous regain of CD20 expression. In conclusion, 20% and 6% of the 252 B-NHL cases show cCD20^- and pCD20^- changes with 7 histological patterns after rituximab-containing therapy. Because changes in morphology and CD20 expression after rituximab-containing therapy vary, and recovery of CD20 expression is not rare, careful follow-up and re-biopsy in B-NHL patients are recommended.

CD20-negative primary middle ear diffuse large B-cell lymphoma coexpressing MYC and BCL-2 secondary to acute lymphoblastic leukemia: A case report

RATIONALE

Second diffuse large B-cell lymphoma (DLBCL) after treatment of acute lymphoblastic leukemia (ALL) is uncommon. To our knowledge, primary middle ear DLBCL which presents CD20-negative and coexpression of MYC and BCL-2 has not been reported yet.

PATIENT CONCERNS

A 20-year-old Chinese man complained fever and weakness for 2 months. Subsequently bone marrow morphology and flow cytometry immunophenotype suggested ALL. Administrated with 9 cycles of multiagent combined chemotherapy, he felt right ear progressive hearing loss, otalgia, aural fullness. Otoendoscopic examination revealed a pitchy mass obstructing the right external auditory canal. Then the mass resection was performed for biopsy and immunohistochemistry examination.

DIAGNOSIS

The mass was diagnosed as DLBCL which was negative for CD20 and double expression of MYC and BCL-2.

INTERVENTIONS

Chemotherapy.

OUTCOMES

The patient eventually gave up and died of severe infection.

LESSONS

Although intensive chemotherapy has markedly improved the survival of ALL, more and more secondary cancers have been reported. In addition, primary middle ear lymphoma is much rare; hence, it is easy to be misdiagnosed. Furthermore, DLBCL with negative CD20 and double expression of MYC and BCL-2 is aggressive, which is characterized by chemotherapy resistance and inferior survival rates. We discuss this case aiming at raising awareness of tumors secondary to ALL and exploring the appropriate treatment options for the rare DLBCL.

Effects of complement and serum IgG on rituximab-dependent natural killer cell-mediated cytotoxicity against Raji cells

Accumulating evidence indicates that the anti-CD20 monoclonal antibody rituximab significantly improves the clinical prognosis of patients with non-Hodgkin lymphoma and chronic lymphocytic leukemia. However, a number of patients relapse or fail to respond to rituximab. To further understand the cause of this, polymorphisms of FcγRIIIa were initially detected in healthy volunteers. Subsequently, the rituximab-dependent natural killer (NK) cell-mediated cytotoxicity of different FcγRIIIa genotypes was assessed by a cytotoxicity assay in vitro. Ultimately, the effect of human serum immunoglobulin (Ig) G and complement on rituximab-dependent NK cell-mediated cytotoxicity was evaluated in vitro. It was revealed that FcγRIIIa polymorphisms were associated with the antibody-dependent cell-mediated cytotoxicity (ADCC) of NK cells. In addition, the ADCC of NK cells with FcγRIIIa-158 V/V was increased compared with that of FcγRIIIa-158 V/F. The serum IgG and rituximab Fc segment was able to bind competitively with NK cell FcγRIIIa. It was observed that serum IgG inhibited, whereas complement enhanced rituximab-induced NK-cell mediated ADCC. Therefore, various agents administered synchronously with rituximab may modulate the efficacy of this agent and ultimately its toxicity against tumor cells.

There Are No Magic Bullets in Hematopathology: Even Immunostains for CD20 and CD3 Can Get You Into Trouble

Immunohistochemistry is a powerful tool for the diagnosis and subclassification of hematolymphoid neoplasms. However, the expression of certain markers is not always as expected, and unusual patterns of staining can lead to misdiagnosis. CD20 and CD3 are our most commonly used markers for identification of B cells and T cells, respectively, and they almost always yield reliable, specific staining. This discussion focuses on diagnostic pitfalls related to the use of immunohistochemistry for CD20 and CD3 in hematopathology, and specifically on diagnostic challenges that arise when (1) CD20 is not expressed in B-cell lymphomas, when (2) CD20 is expressed in plasma cell neoplasms and T-cell lymphomas, and when (3) CD3 is expressed in B-cell lymphomas and Hodgkin lymphoma.

Impact of obinutuzumab alone and in combination for follicular lymphoma

Although rituximab-based chemoimmunotherapy prolongs the survival of patients with follicular lymphoma (FL), this disease is considered incurable in most patients. Thus, new therapies are needed not only for those in the relapsed/refractory setting, but also for initial treatment. Obinutuzumab (G, GA101) is a third-generation, fully humanized type II glycoengineered, anti-CD20 monoclonal antibody that results in increased direct cell death and antibody-dependent, cell-mediated cytotoxicity/phagocytosis compared to rituximab. Obinutuzumab has significant antitumor activity when used alone or in combinations in untreated or relapsed refractory FL patients. Studies have demonstrated its ability to prolong progression-free survival and, in some cases, overall survival, and to eliminate minimal residual disease. Several ongoing trials are investigating combinations with chemotherapy, immunomodulators, targeted drugs, and immunotherapy agents. G is generally well tolerated, with associated adverse effects including infusion-related reactions, neutropenia, thrombocytopenia, and reactivation of hepatitis B virus. Future studies with this antibody should focus on identifying predictive markers and developing chemotherapy-free combinations that will improve the outcome of patients with FL.

Genetic and Epigenetic Modulation of CD20 Expression in B-Cell Malignancies: Molecular Mechanisms and Significance to Rituximab Resistance

CD20 is a differentiation related cell surface phosphoprotein that is expressed during early pre-B cell stages until plasma cell differentiation, and is a suitable molecular target for B-cell malignancies by monoclonal antibodies such as rituximab, ofatumumab, obinutuzumab and others. CD20 expression is confirmed in most B-cell malignancies; however, the protein expression level varies in each patient, even in de novo tumors, and down-modulation of CD20 expression after chemoimmunotherapy with rituximab, resulting in rituximab resistance, has been recognized in the clinical setting. Recent reports suggest that genetic and epigenetic mechanisms are correlated with aberrantly low CD20 expression in de novo tumors and relapsed/refractory disease after using rituximab. Furthermore, some targeting drugs, such as lenalidomide, bortezomib and ibrutinib, directly or indirectly affect CD20 protein expression. CD20-negative phenotypically-changed DLBCL after rituximab use tends to show an aggressive clinical course and poor outcome with resistance to not only rituximab, but also conventional salvage chemo-regimens. Understanding of the mechanisms of CD20-negative phenotype may contribute to establish strategies for overcoming chemo-refractory B-cell malignancies. In this manuscript, recent progress of research on molecular and clinical features of CD20 protein and CD20-negative B-cell malignancies was reviewed.

Medication-associated gastrointestinal tract injury

Medication-associated gastrointestinal (GI) tract injury has been known for centuries for some medications. The more recently introduced biologicals are a class of drugs that constantly increases, and as such, the spectrum of GI tract side effects is steadily growing. This review covers not only long-known GI tract side effects of drugs but also those more recently described. A comprehensive but concise list of medications used in daily practice and associated with GI tract injury is presented.

5-Azacytidine partially restores CD20 expression in follicular lymphoma that lost CD20 expression after rituximab treatment: a case report

BACKGROUND

The loss of CD20 protein expression after a rituximab-containing regimen is one of the resistance mechanisms in non-Hodgkin's lymphoma. Recently, it was reported that 5-azacitidine administration upregulates the expression of CD20 in CD20-negative B-cell acute lymphoblastic leukemia. Here we report a similar upregulation in a patient with follicular lymphoma who was treated with 5-azacitidine against secondary myelodysplastic syndrome.

CASE PRESENTATION

A 69-year-old Japanese woman with follicular lymphoma with treatment-related myelodysplastic syndrome was negative for the CD20 antibody at the time of her relapse. After treatment of 5-azacytidine for her myelodysplastic syndrome, CD20 expression was upregulated in the follicular lymphoma cells in her peripheral blood. We also observed follicular lymphoma cell stimulation in her peripheral blood due to 5-azacytidine.

CONCLUSIONS

Although partial, CD20 expression was upregulated after treatment with 5-azacitidine. However, CD20 expression was not re-upregulated after a second administration of 5-azacitidine and we also observed the risk of lymphoma cell stimulation due to 5-azacitidine.

New Immunohistochemistry for B-Cell Lymphoma and Hodgkin Lymphoma

Context

B-cell non-Hodgkin lymphoma is a heterogeneous group of lymphoproliferative malignancies with different clinical behaviors and treatments. It is important to differentiate individual B-cell lymphoma to apply the best treatment and management. Morphology and immunohistochemistry are the primary tools used for diagnosing lymphoma. There is a characteristic pattern of expression with immunohistochemical antibodies in most well-defined B-cell lymphomas. Some cases of B-cell lymphoma, however, show unusual morphologic and immunophenotypic features. The new and sometimes more specific antibodies have been developed recently, which may further define those lymphomas. Only with use of the antibodies over time does their true nature and specificity become evident.

Objectives

To present new antibodies for B-cell lymphoma that enhance the probability for diagnosis or can act as alternate markers in unusual cases, in which a B-cell lymphoma does not present with characteristic immunohistochemical staining, and to present prognostic markers that allow for better management of patients with specific B-cell lymphomas.

Data Sources

Data were obtained from literature review and figures from slides in personal practice.

Conclusions

The immunohistochemical antibodies presented in this article increase our ability to understand, diagnosis, and manage patients with B-cell lymphoma.