Comparison of the algorithms classifying the ABC and GCB subtypes in diffuse large B-cell lymphoma

Validation of LymphGen classification on a 400-gene clinical next-generation sequencing panel in diffuse large B-cell lymphoma: real-world experience from a cancer center

Not available.

Automatic subtyping of Diffuse Large B-cell Lymphomas (DLBCL): Raman-based genetic and metabolic classification

Diffuse large B-cell lymphoma (DLBCL), the most common non-Hodgkin's lymphoma in adults, is a genetically and metabolically heterogeneous group of aggressive malignancies. The complexity of their molecular composition and the variability in clinical presentation make clinical diagnosis and treatment selection a serious challenge. The challenge is therefore to quickly and correctly classify DLBCL cells. In this work, we show that Raman imaging is a tool with high diagnostic potential, providing unique information about the biochemical components of tumor cells and their metabolism. We present models of classification of lymphoma cells based on their Raman spectra. The models automatically and efficiently identify DLBCL cells and assign them to a given cell-of-origin (COO) subtype (activated B cell-like (ABC) or germinal center B cell-like (GCB)) or, respectively, to a comprehensive cluster classification (CCC) subtype (OxPhos/non-OxPhos). In addition, we describe each lymphoma subtype by its unique spectral profile, linking it to biochemical, genetic, or metabolic features.

The prognostic significance of programmed cell death protein 1 and its ligand on lymphoma cells and tumor-immune cells in diffuse large B-cell lymphoma, not otherwise specified

BACKGROUND

Diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS) is the most common type non-Hodgkin's lymphoma, where the treatment of relapsed/refractory cases is the major challenge. Programmed cell death protein 1 (PD-1) and its ligand PD-L1 play a crucial role in the negative regulation of the immune response against the disease. The aim of the study was to analyze the expression of PD-1 and PD-L1 on lymphoma cells (LCs) and tumor-immune cells (TICs) and to investigate their correlation with outcome.

PATIENTS AND METHODS

Samples from 283 patients diagnosed with DLBCL, NOS (both germinal center B cell like [GCB] and non-GCB subtypes) were included in the study. Expression of PD-1 and PD-L1 was determined using double immunohistochemical staining (D-IHC) for PD-1/PAX5 and PD-L1/PAX5 on tissue microarrays. LCs were highlighted by D-IHC to obtain more accurate results. Clinical data and histologic diagnoses were obtained from electronic data records. We correlated clinical characteristics, and PD-1 and PD-L1 expression on LCs and TICs with progression-free survival (PFS) and overall survival (OS).

RESULTS

Expression of PD-1 on TICs was observed in 38.4% and on LCs in 8.8% of cases, while PD-L1 was expressed on TICs in 46.8% and on LCs in 6.5% of cases. PD-L1 expression on LCs was more frequent in non-GCB subtype (p = 0.047). In addition, patients with PD-L1 expression on LCs had significantly shorter PFS (p = 0.015), and the expression retained significant in the multivariate model (p = 0.034).

CONCLUSIONS

PD-L1 was more frequently expressed in LCs of the non-GCB subtype. Additionally, PD-L1 in LCs may predict shorter PFS time. D-IHC staining for PD-L1/PAX5 is a feasible method to assess PD-L1 expression on LCs of DLBCL, NOS patients and can be used to identify patients who may benefit from targeted immunotherapy with checkpoint inhibitors.

Correlation between red blood cell distribution width/platelet count and prognosis of newly diagnosed diffuse large B-cell lymphoma

Background

Red blood cell distribution width/platelet count ratio (RPR) is a reliable prognostic assessment indicator for numerous diseases. However, no studies to date have examined the relationship between RPR and the prognosis of diffuse large B-cell lymphoma (DLBCL). Therefore, this study aimed to investigate the correlation between RPR and the clinical characteristics and prognosis of patients with diffuse large B-cell lymphoma.

Methods

We retrospectively studied 143 patients with newly diagnosed DLBCL and used the median value as the RPR threshold. We also investigated the correlation of pretreatment RPR level with clinical characteristics and its impact on DLBCL prognosis.

Results

Using the median value as the cut-off, patients with DLBCL were divided into a low RPR group (＜0.0549) and a high RPR group (≥0.0549). Patients in the high RPR group were older, had a later Ann Arbor stage, were prone to bone marrow invasion, and had a higher National Comprehensive Cancer Network International Prognostic Index score (P＜0.05). A survival analysis showed that progression-free survival (PFS) (P=0.003) and overall survival (OS) (P＜0.0001) were significantly shorter in the high versus low RPR group. A multifactorial Cox analysis showed that bone marrow invasion and elevated lactate dehydrogenase (LDH) were separate risk factors for PFS (P＜0.05), while an RPR ≥0.0549 and elevated LDH were separate risk factors for OS (P＜0.05).

Conclusion

A high RPR (≥0.0549) in patients with newly diagnosed DLBCL is an independent risk factor for a poor prognosis.

Activity of tafasitamab in combination with rituximab in subtypes of aggressive lymphoma

Background

Despite recent advances in the treatment of aggressive lymphomas, a significant fraction of patients still succumbs to their disease. Thus, novel therapies are urgently needed. As the anti-CD20 antibody rituximab and the CD19-targeting antibody tafasitamab share distinct modes of actions, we investigated if dual-targeting of aggressive lymphoma B-cells by combining rituximab and tafasitamab might increase cytotoxic effects.

Methods

Antibody single and combination efficacy was determined investigating different modes of action including direct cytotoxicity, antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) in in vitro and in vivo models of aggressive B-cell lymphoma comprising diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL).

Results

Three different sensitivity profiles to antibody monotherapy or combination treatment were observed in in vitro models: while 1/11 cell lines was primarily sensitive to tafasitamab and 2/11 to rituximab, the combination resulted in enhanced cell death in 8/11 cell lines in at least one mode of action. Treatment with either antibody or the combination resulted in decreased expression of the oncogenic transcription factor MYC and inhibition of AKT signaling, which mirrored the cell line-specific sensitivities to direct cytotoxicity. At last, the combination resulted in a synergistic survival benefit in a PBMC-humanized Ramos NOD/SCID mouse model.

Conclusion

This study demonstrates that the combination of tafasitamab and rituximab improves efficacy compared to single-agent treatments in models of aggressive B-cell lymphoma in vitro and in vivo.

CD56-positive diffuse large B-cell lymphoma: comprehensive analysis of clinical, pathological, and molecular characteristics with literature review

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma. The expression of CD56 in DLBCL is highly unusual. Little is known about its incidence and clinical importance. So far, no genetic profiling was performed in CD56 positive DLBCL.

PATIENTS AND METHODS

Tissue microarrays have been constructed, sectioned, and stained by H&E and immunohistochemistry for 229 patients with DLBCL diagnosed 2008-2017. For CD56 positive cases, clinical data was collected including age at diagnosis, stage of the disease, International Prognostic Index (IPI) score, treatment scheme and number of chemotherapy cycles, radiation therapy, treatment outcome, and possible relapse of the disease. Overall survival (OS) and progression-free survival (PFS) were calculated. For four patients, RNA was extracted and targeted RNA (cDNA) sequencing of 125 genes was performed with the Archer FusionPlex Lymphoma kit.

RESULTS

CD56 expression was found in 7 cases (3%). The intensity of expression varied from weak to moderate focal, to very intensive and diffuse. All patients had de novo DLBCL. The median age at the time of diagnosis was 54.5 years. Five of them were women and 2 males. According to the Hans algorithm, 6 patients had the germinal centre B cells (GBC) type and one non-GBC (activated B-cell [ABC]) type, double expressor. Genetic profiling of four patients according to Schmitz's classification showed that 1 case was of the BN2 subtype, 1 of EZB subtype, 2 were unclassified. The six treated patients reached a complete response and did not experience progression of the disease during the median follow-up period of 80.5 months.

CONCLUSIONS

We report on one of the largest series of CD56+DLBCL with detailed clinicopathological data and for the first time described genetical findings in a limited number of patients. Our results show that CD56 expression is rare, but seems to be present in prognostic favourable subtypes of DLBCL not otherwise specified (NOS) as tested by immunohistochemical or genetic profiling.

Tafasitamab mediates killing of B-cell non-Hodgkin's lymphoma in combination with γδ T cell or allogeneic NK cell therapy

Tafasitamab is an Fc-modified monoclonal antibody that binds to CD19, a cell-surface antigen that is broadly expressed on various types of B-cell non-Hodgkin’s lymphoma (NHL). Antibody-dependent cellular cytotoxicity (ADCC), a key mode of action of tafasitamab, is mediated through the binding of tafasitamab’s Fc region to FcγRIIIa receptors on immune effector cells and results in antitumor activity. Despite the proven clinical activity of tafasitamab in combination with lenalidomide in the treatment of diffuse large B-cell lymphoma (DLBCL), a higher number of immune cells in cancer patients may improve the activity of tafasitamab. Here, we characterized two ex vivo-expanded FcγRIIIa receptor—expressing cell types—γδ T and MG4101 natural killer (NK) cells—as effector cells for tafasitamab in vitro, and found that in the presence of these cells tafasitamab was able to induce ADCC against a range of NHL cell lines and patient-derived cells. We also explored the concept of effector cell supplementation during tafasitamab treatment in vivo by coadministering MG4101 NK cells in Raji and Ramos xenograft models of NHL. Combination treatment of tafasitamab and allogeneic MG4101 NK cells in these models demonstrated a survival benefit compared with tafasitamab or MG4101 monotherapy (Raji: 1.7- to 1.9-fold increase in lifespan; Ramos: 2.0- to 4.1-fold increase in lifespan). In conclusion, adoptive cell transfer of ex vivo-expanded allogeneic NK or autologous γδ T cells in combination with tafasitamab treatment may potentially be a promising novel approach to increase the number of immune effector cells and enhance the antitumor effect of tafasitamab.

Cell-blocks and hematolymphoid lesions

Cell-blocks are an important component for evaluation for hematolymphoid lesions. They are especially critical for immunocharacterization of the lymphoid population especially when flow cytometry is not available or cannot be performed. In addition, cell-blocks allow various molecular pathology tests including gene rearrangement studies and FISH, proteomics analysis, and microbiology/histochemical special stains. Fine-needle aspiration (FNA) for mass lesions, lymphadenopathy, and effusion fluids are common cytopathology specimens which are frequently cell-blocked. The differential diagnosis of enlarged lymph nodes (LNs) and mass lesions is broad and includes reactive processes, granulomatous lesions and malignancies including solid tumor metastases and various types of hematological malignancies, of which lymphoma would be most common. Depending on the patient population, most lymphomas may be diagnosed with immunocharacterization on cell-block or/and flow cytometry in concert with excellent cytomorphology in Diff-Quik stained FNA aspirate smears. However, a proportion of lymphoma cases (up to 12-30%) may still require an excisional LN biopsy to evaluate architectural parameters. Similarly, various effusion fluids suspicious for lymphoma can be immunocharacterized by immunostaining of cell-block sections (or/and by flow cytometry). Availability of quantitatively and qualitatively optimum cell-blocks of specimens to be evaluated for hematolymphoid processes is critical for immunohistochemistry, polymerase chain reaction, in situ hybridization (FISH), and gene expression profiling studies.

Artificial Intelligence and Digital Microscopy Applications in Diagnostic Hematopathology

Digital Pathology is the process of converting histology glass slides to digital images using sophisticated computerized technology to facilitate acquisition, evaluation, storage, and portability of histologic information. By its nature, digitization of analog histology data renders it amenable to analysis using deep learning/artificial intelligence (DL/AI) techniques. The application of DL/AI to digital pathology data holds promise, even if the scope of use cases and regulatory framework for deploying such applications in the clinical environment remains in the early stages. Recent studies using whole-slide images and DL/AI to detect histologic abnormalities in general and cancer in particular have shown encouraging results. In this review, we focus on these emerging technologies intended for use in diagnostic hematology and the evaluation of lymphoproliferative diseases.

Primary Central Nervous System Lymphoma in an Immunocompetent Patient Presenting as Multiple Cerebellar Lesions: A Case Report and Review of Literature

Primary central nervous system (CNS) lymphoma (PCNSL) is an uncommon extranodal non-Hodgkin lymphoma often presenting as a single brain lesion within the CNS. On histopathological evaluation of PCNSL a positive CD10, which is frequently observed in systemic diffuse large B-cell lymphoma, is present in approximately 10% of PCNSL. We describe a case of CD10-positive PCNSL presenting with multiple posterior fossa enhancing lesions in an immunocompetent older woman with a history of breast cancer successfully treated by the RTOG 0227 protocol consisting of pre-irradiation chemotherapy with high-dose methotrexate, rituximab, and temozolomide for 6 cycles, followed by low-dose whole-brain radiation and post-irradiation temozolomide.