BCL3 rearrangements in B-cell lymphoid neoplasms occur in two breakpoint clusters associated with different diseases.

The t(14;19)(q32;q13) often juxtaposes BCL3 with immunoglobulin heavy chain (IGH) resulting in overexpression of the gene. In contrast to other oncogenic translocations, BCL3 rearrangement (BCL3-R) has been associated with a broad spectrum of lymphoid neoplasms. Here we report an integrative whole-genome sequence, transcriptomic, and DNA methylation analysis of 13 lymphoid neoplasms with BCL3-R. The resolution of the breakpoints at single base-pair revealed that they occur in two clusters at 5' (n=9) and 3' (n=4) regions of BCL3 associated with two different biological and clinical entities. Both breakpoints were mediated by aberrant class switch recombination of the IGH locus. However, the 5' breakpoints (upstream) juxtaposed BCL3 next to an IGH enhancer leading to overexpression of the gene whereas the 3' breakpoints (downstream) positioned BCL3 outside the influence of the IGH and were not associated with its expression. Upstream BCL3-R tumors had unmutated IGHV, trisomy 12, and mutated genes frequently seen in chronic lymphocytic leukemia (CLL) but had an atypical CLL morphology, immunophenotype, DNA methylome, and expression profile that differ from conventional CLL. In contrast, downstream BCL3-R neoplasms were atypical splenic or nodal marginal zone lymphomas (MZL) with mutated IGHV, complex karyotypes and mutated genes typical of MZL. Two of the latter four tumors transformed to a large B-cell lymphoma. We designed a novel fluorescence in situ hybridization assay that recognizes the two different breakpoints and validated these findings in 17 independent tumors. Overall, upstream or downstream breakpoints of BCL3-R are mainly associated with two subtypes of lymphoid neoplasms with different (epi)genomic, expression, and clinicopathological features resembling atypical CLL and MZL, respectively.

Expert consensus on the integrated diagnosis of idiopathic multicentric Castleman disease / Consenso de expertos sobre el diagnóstico integrado de la enfermedad de Castleman idiopática multicéntrica

Idiopathic multicentric Castleman disease (iMCD) is rare. The differential diagnosis includes inflammatory, autoimmune and neoplastic disease. The identification of the histopathological features of Castleman disease in the lymph node is the main diagnostic criterion.Fifty-three experts from three medical societies (SEMI, SEHH and SEAP) have created a multi-disciplinary consensus document in order to standardise the diagnosis of Castleman disease. Using the Delphi method, specific recommendations for the initial clinical, laboratory and imaging studies have been made for an integrated diagnosis of iMCD as well as for the best way to obtain samples for histopathological confirmation, correct laboratory procedure and interpretation and reporting of results.(AU)

La enfermedad de Castleman multicéntrica idiopática (ECMi) es una patología infrecuente. El diagnóstico diferencial incluye patología inflamatoria, autoinmune y neoplásica. El estudio anatomopatológico del ganglio linfático y la identificación de las características histopatológicas de la enfermedad de Castleman constituyen un criterio principal para el diagnóstico.Con el objetivo de estandarizar el proceso diagnóstico de esta patología, se ha desarrollado un documento de consenso multidisciplinario con la participación de 53 expertos de tres sociedades médicas (Sociedad Española de Medicina Interna [SEMI], Sociedad Española de Hematología y Hemoterapia [SEHH] y Sociedad Española de Anatomía Patológica [SEAP]). Mediante el método Delphi se han validado las recomendaciones específicas para el diagnóstico integrado de la ECMi con respecto a los estudios clínicos, de laboratorio y de imagen necesarios en el abordaje inicial del paciente y las recomendaciones acerca de la mejor obtención de muestras para confirmación histopatológica, así como procedimientos de laboratorio para el estudio de las muestras, interpretación de resultados y emisión de un informe anatomopatológico.(AU)

Characterization and Factors Associated with Poor Asthma Control in Adults with Severe Eosinophilic Asthma.

A study was conducted in 98 adult patients diagnosed with severe eosinophilic asthma (73.5% women, mean age 47.2 years) and followed prospectively for 1 year. The aim of the study was to characterize this population and to identify factors associated with poor prognosis at 1 year of follow-up. At the initial visit, uncontrolled severe asthma was diagnosed in 87.7% of patients. Allergic sensitization was observed in 81.7% (polysensitization in 17.3%), with clinically significant allergic asthma in 45%. The mean percentage of sputum eosinophils was 4.7% (standard deviation(SD) 6.3%) and the mean (SD) blood eosinophil count 467 (225) cells/µL. Almost half of the patients (48.3%) had sputum eosinophilia (>3% eosinophils). Sputum eosinophils correlated significantly with peripheral eosinophilia (p = 0.004) and, to a lesser extent, with fractional exhaled nitric oxide (FeNO) (p = 0.04). After 1 year, 48 patients (49%) had uncontrolled asthma in all visits, and 50 (51%) had controlled asthma in some visits. Airway obstruction (FEV1 < 80% predicted) was the main reason for uncontrolled asthma. In the multivariate analysis, an obstructive pattern (odds ratio (OR) 7.45, 95% confidence interval (CI) 2.41-23.03, p < 0.0001) and the patient's age (OR 1.045, 95% CI 1.005-1.086, p = 0.026) were independent predictors of poor asthma control. In adult-onset and long-standing asthma, serum interleukin (IL) IL-17 was higher in the uncontrolled asthma group. This study contributes to characterizing patients with severe eosinophilic asthma in real-world clinical practice.

Expert consensus on the integrated diagnosis of idiopathic multicentric Castleman disease.

Idiopathic multicentric Castleman disease (iMCD) is rare. The differential diagnosis includes inflammatory, autoimmune and neoplastic disease. The identification of the histopathological features of Castleman disease in the lymph node is the main diagnostic criterion. Fifty-three experts from three medical societies (SEMI, SEHH and SEAP) have created a multi-disciplinary consensus document in order to standardise the diagnosis of Castleman disease. Using the Delphi method, specific recommendations for the initial clinical, laboratory and imaging studies have been made for an integrated diagnosis of iMCD as well as for the best way to obtain samples for histopathological confirmation, correct laboratory procedure and interpretation and reporting of results.

Diffuse Large B-Cell Lymphoma in the HIV Setting.

Despite the widespread use of combined antiretroviral therapy (cART) and the subsequent decrease in AIDS-defining cancers, HIV-related lymphomas remain a leading cause of morbidity and mortality in people with HIV (PWH). Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma (NHL) subtype in PWH. This lymphoma is a heterogeneous disease including morphological variants and molecular subtypes according to the cell of origin or the mutation profile. In the pre-cART era, treatment with standard-dose chemotherapy induced high rates of toxicity and outcomes were very poor. The introduction of cART and the incorporation of infection prophylaxis allowed the use of conventional intensive chemotherapy regimens used in the general population, such as R-CHOP or R-EPOCH. The use of cART during chemotherapy treatment was initially controversial due to the potential risk of adverse drug-drug interactions. However, the availability of current cART regimens with less potential to cause drug interactions and evidence that cART improves survival rates in NHL strongly support the use of cART in PWH with DLBCL. Consequently, interdisciplinary collaboration between HIV specialists and hemato-oncologists for the management of potential interactions and overlapping toxicities between antiretroviral and antineoplastic drugs is crucial for the optimal treatment of PWH with NHL.

HHV8 and EBV-negative primary effusion-based lymphoma: A case report of a new provisional entity and review of literature.

Key Clinical Message: HHV8- and EBV-negative primary effusion lymphoma is an extremely rare neoplasm involving body cavities without detectable tumor mass. It usually presents in elderly patients without known immunodeficiency. Compared to primary effusion lymphoma, it has a better prognosis.Primary effusion lymphoma (PEL) is a rare non-Hodgkin lymphoma confined exclusively to body cavities without detectable tumor masses. The term PEL-like is an entity similar to PEL in clinical presentation but without relation to human herpesvirus 8 (HHV8). We report a case of HHV8- and EBV-negative primary effusion-based lymphoma.

Optimization of monocyte gating to quantify monocyte subsets for the diagnosis of chronic myelomonocytic leukemia.

BACKGROUND: The presence of >94% classical monocytes (MO1, CD14++/CD16-) in peripheral blood (PB) has an excellent performance for the diagnosis of chronic myelomonocytic leukemia (CMML). However, the monocyte gating strategy is not well defined. The objective of the study was to compare monocyte gating strategies and propose an optimal one. METHODS: This is a prospective, single center study assessing monocyte subsets in PB. First, we compared monocyte subsets using 13 monocyte gating strategies in 10 samples. Then we developed our own 10 color tube and tested it on 124 patients (normal white blood cell counts, reactive monocytosis, CMML and a spectrum of other myeloid malignancies). Both conventional and computational (FlowSOM) analyses were used. RESULTS: Comparing different monocyte gating strategies, small but significant differences in %MO1 and percentually large differences in %MO3 (nonclassical monocytes) were found, suggesting that the monocyte gating strategy can impact monocyte subset quantification. Then, we designed a 10-color tube for this purpose (CD45/CD33/CD14/CD16/CD64/CD86/CD300/CD2/CD66c/CD56) and applied it to 124 patients. This tube allowed proper monocyte gating even in highly abnormal PB. Computational analysis found a higher %MO1 and lower %MO3 compared to conventional analysis. However, differences between conventional and computational analysis in both MO1 and MO3 were globally consistent and only minimal differences were observed when comparing the ranking of patients according to %MO1 or %MO3 obtained with the conventional versus the computational approach. CONCLUSIONS: The choice of monocyte gating strategy appears relevant for the monocyte subset distribution test. Our 10-color proposal allowed satisfactory monocyte gating even in highly abnormal PB. Computational analysis seems promising to increase reproducibility in monocyte subset quantification.

Accuracy and prognostic impact of FDG PET/CT and biopsy in bone marrow assessment of follicular lymphoma at diagnosis: A Nation-Wide cohort study.

BACKGOUND: In the workup of follicular lymphoma (FL), bone marrow biopsy (BMB) assessment is a key component of FLIPI and FLIPI2, the most widely used outcome scores. During the previous decade, several studies explored the role of FDG-PET/CT for detecting nodal and extranodal disease, with only one large study comparing both techniques. METHODS: The aim of our study was to evaluate the diagnostic accuracy and the prognostic impact of both procedures in a retrospective cohort of 299 FL patients with both tests performed at diagnosis. In order to avoid a collinearity bias, FLIPI2 was deconstructed in its founding parameters, and the bone marrow involvement (BMI) parameter separately included as: a positive BMB, a positive PET/CT, the combined "PET/CT and BMB positive" or "PET/CT or BMB positive". These variables were also confronted independently with the POD24 in 233 patients treated with intensive regimens. RESULTS: In the total cohort, bone marrow was involved in 124 and 60 patients by BMB and PET/CT, respectively. In terms of overall survival, age > 60 y.o. and the combined "PET/CT or BMB positive" achieved statistical independence as a prognostic factor. In patients treated with an intensive regimen, only the combined "PET/CT or BMB positive" added prognostic value for a shorter overall survival, when confronted with the POD24. CONCLUSION: Our results show that in FL both BMB and PET/CT should be considered at diagnosis, as their combined assessment provides independent prognostic value in the context of the most widely use clinical scores.

Flow cytometry to detect bone marrow involvement by follicular lymphoma.

BACKGROUND: High-quality data on bone marrow involvement (BMI) assessed by flow cytometry (FC) in follicular lymphoma (FL) is lacking. AIMS: We set up a prospective protocol with a 10-color tube and acquisition of 500.000 leukocytes on a Nav flow cytometer for evaluation of BMI in FL by FC. MATERIALS AND METHODS: FC was compared with a combination of histopathology and IGH gene rearrangement, which were considered the gold standard. We also compared BMI by FC with PET. RESULTS: Fifty-two patients were included (median 67 years, 54% female). BMI by FC was seen in 35 (67%), with a median involvement of 1.2% (interquartile range: 0.3%-7%) of leukocytes. Comparison with the gold standard revealed two false negatives and two false positives (potentially true involvement undetected by the gold standard). BMI by PET was seen in 14/46 (30%). Immunophenotype of FL in the bone marrow was highly heterogeneous. The most common phenotypic abnormality was dim expression of CD19 (>0.5 log loss in 30% of patients). CD10 was negative in 13 (37%) and incompletely positive (overlap with the negative population) in a further 8 (28%) while entirely positive only in 14 (48%). Other abnormalities (loss of CD20, gain or loss of CD79b, expression of CD43, and substantial loss of CD45) were rare. Computational analysis by means of FlowSOM confirmed the heterogeneous phenotype, with FL from different patients clustering in unrelated metaclusters. CONCLUSION: BMI by FL was frequent and immunophenotype was heterogeneous. However, this protocol enabled detection of FL in bone marrow in the vast majority of patients with bone marrow involvement by the gold standard.

Genetic and phenotypic characterisation of HIV-associated aggressive B-cell non-Hodgkin lymphomas, which do not occur specifically in this population: diagnostic and prognostic implications.

The frequency of aggressive subtypes of B-cell non-Hodgkin lymphoma (B-NHL), such as high-grade B-cell lymphomas (HGBL) with MYC and BCL2 and/or BCL6 rearrangement (HGBL-DH/TH) or Burkitt-like lymphoma (BL) with 11q aberration, is not well known in the HIV setting. We aimed to characterise HIV-associated aggressive B-NHL according to the 2017 WHO criteria, and to identify genotypic and phenotypic features with prognostic impact. Seventy-five HIV-associated aggressive B-NHL were studied by immunohistochemistry (CD10, BCL2, BCL6, MUM1, MYC, and CD30), EBV-encoded RNAs (EBERs), and fluorescence in situ hybridisation (FISH) to evaluate the status of the MYC, BCL2, and BCL6 genes and chromosome 11q. The 2017 WHO classification criteria and the Hans algorithm, for the cell-of-origin classification of diffuse large B-cell lymphomas (DLBCL), were applied. In DLBCL cases, the frequencies of MYC and BCL6 rearrangements (14.9 and 27.7%, respectively) were similar to those described in HIV-negative patients, but BCL2 rearrangements were infrequent (4.3%). MYC expression was identified in 23.4% of DLBCL cases, and coexpression of MYC and BCL2 in 13.0%, which was associated with a worse prognosis. As for BL cases, the expression of MUM1 (30.4%) conferred a worse prognosis. Finally, the prevalence of HGBL-DH/TH and BL-like with 11q aberration are reported in the HIV setting. The phenotypic and genotypic characteristics of HIV-associated aggressive B-NHL are similar to those of the general population, except for the low frequency of BCL2 rearrangements in DLBCL. MYC and BCL2 coexpression in DLBCL, and MUM-1 expression in BL, have a negative prognostic impact on HIV-infected individuals.

BCL2 translocation in high grade B cell lymphoma (NOS, DH/TH) is associated with reduced progression free survival.

High Grade B Cell Lymphoma, NOS, and High Grade B Cell Lymphoma with Dual Hit or Triple Hit have been recently recategorized in the 2016 revision of the WHO classification of lymphoid neoplasms. In this study we have characterized the genetic, histopathological, and clinical features of a series of this type of lymphoid neoplasia (17 HGBCL NOS and 53 HGBCL DH/TH).HGBCL NOS showed better response to first line treatment than HGBCL with DH/TH but no significant differences in PFS or OS were found between the two categories. Survival analysis in the whole cohort of cases found that only the presence of BCL2 translocation was significantly associated with PFS. Other clinical features such as IPI, LDH or stage were equivalent in both categories. Furthermore, both high grade and DLBCL morphological patterns showed equivalent PFS and OS in this set of High grade BCL NOS/DH/TH.Key pointsBCL2 translocation in High Grade B Cell Lymphoma NOS and High Grade B Cell Lymphoma with DH/TH is associated with reduced progression free survival.Both high grade and DLBCL morphological patterns showed equivalent outcome regarding PFS and OS in HGBCL.

Clinical and Therapeutic Implications of Epstein-Barr Virus in HIV-Related Lymphomas.

The incidence of lymphomas is increased in people living with HIV (PLWH). Aggressive B-cell non-Hodgkin lymphomas (NHLs) are the most common and are considered an AIDS-defining cancer (ADC). Although Hodgkin lymphoma (HL) is not considered an ADC, its incidence is also increased in PLWH. Among all HIV-related lymphomas (HRL), the prevalence of Epstein-Barr virus (EBV) is high. It has been shown that EBV is involved in different lymphomagenic mechanisms mediated by some of its proteins, contributing to the development of different lymphoma subtypes. Additionally, cooperation between both HIV and EBV can lead to the proliferation of aberrant B-cells, thereby being an additional lymphomagenic mechanism in EBV-associated HRL. Despite the close relationship between EBV and HRL, the impact of EBV on clinical aspects has not been extensively studied. These lymphomas are treated with the same therapeutic regimens as the general population in combination with cART. Nevertheless, new therapeutic strategies targeting EBV are promising for these lymphomas. In this article, the different types of HRL are extensively reviewed, focusing on the influence of EBV on the epidemiology, pathogenesis, clinical presentation, and pathological characteristics of each lymphoma subtype. Moreover, novel therapies targeting EBV and future strategies to treat HRL harboring EBV are discussed.

Molecular and functional profiling identifies therapeutically targetable vulnerabilities in plasmablastic lymphoma.

Plasmablastic lymphoma (PBL) represents a rare and aggressive lymphoma subtype frequently associated with immunosuppression. Clinically, patients with PBL are characterized by poor outcome. The current understanding of the molecular pathogenesis is limited. A hallmark of PBL represents its plasmacytic differentiation with loss of B-cell markers and, in 60% of cases, its association with Epstein-Barr virus (EBV). Roughly 50% of PBLs harbor a MYC translocation. Here, we provide a comprehensive integrated genomic analysis using whole exome sequencing (WES) and genome-wide copy number determination in a large cohort of 96 primary PBL samples. We identify alterations activating the RAS-RAF, JAK-STAT, and NOTCH pathways as well as frequent high-level amplifications in MCL1 and IRF4. The functional impact of these alterations is assessed using an unbiased shRNA screen in a PBL model. These analyses identify the IRF4 and JAK-STAT pathways as promising molecular targets to improve outcome of PBL patients.