Advances in understanding of angioimmunoblastic T-cell lymphoma

Recurrence of Angioimmunoblastic T-cell Lymphoma in a Patient Successfully Treated for Hodgkin's Lymphoma: A Case Report

Hodgkin's lymphoma (HL) is a common and potentially curable malignancy that has an overall good prognosis when timely treatment with chemoradiation is delivered. Recurrence of malignancy is one complication seen in patients successfully treated for HL. In most cases, the recurring malignancy can be a solid tumor or leukemia. While recurrence of a non-HL (NHL) has been reported, this is relatively uncommon. Angioimmunoblastic T-cell lymphoma (AITL) is a rare nodal appearing, peripheral T-cell lymphoma and represents 2% of all NHLs. Its clinical features include generalized lymphadenopathy, varying constitutional symptoms, and autoimmune-related hematologic findings, such as hemolytic anemia and or thrombocytopenia. Diagnosis is made based on histological and immunohistochemical (IHC) findings, which show evidence of T-cells, follicular T-cell markers, and characteristic genomic features including mutations of T-cell receptor or T-cell receptor signaling genes. It is a characteristically aggressive cancer with a poor prognosis if untreated and therefore requires prompt diagnosis. While sporadic AITL is rare on its own, data on AITL occurrence in patients previously treated for HL is lacking. We present a peculiar case of an 80-year-old patient who was diagnosed and treated for stage IV Hodgkin's disease only to be later diagnosed with AITL.

Molecular Diagnostic Testing for Hematopoietic Neoplasms: Linking Pathogenic Drivers to Personalized Diagnosis

Molecular diagnostics inhabit an increasingly central role in characterizing hematopoietic malignancies. This brief review summarizes the genomic targets important for many major categories of hematopoietic neoplasia by focusing on disease pathogenesis. In myeloid disease, recurrent mutations in key functional classes drive clonal hematopoiesis, on which additional variants can specify clinical presentation and accelerate progression. Lymphoblastic leukemias are frequently initiated by oncogenic fusions that block lymphoid maturation while, in concert with additional mutations, driving proliferation. The links between genetic aberrations and lymphoma patient outcomes have been clarified substantially through the clustering of genomic profiles. Finally, the addition of next-generation sequencing strategies to cytogenetics is refining risk stratification for plasma cell myeloma. In all categories, molecular diagnostics shed light on the unique mechanistic underpinnings of each individual malignancy, thereby empowering more rational, personalized care for these patients.

Case Report: Immune Microenvironment and Mutation Features in a Patient With Epstein–Barr Virus Positive Large B-Cell Lymphoma Secondary to Angioimmunoblastic T-Cell Lymphoma

On rare occasions, secondary Epstein–Barr virus (EBV)-associated B-cell lymphoma can develop in patients with angioimmunoblastic T-cell lymphoma (AITL). Here, we describe the tumor microenvironment and mutation features of a patient with EBV + large B-cell lymphoma (LBCL) secondary to AITL. He was admitted to hospital due to a 1-year history of fever and enlarged right inguinal lymph nodes. A biopsy of the right inguinal lymph node demonstrated that numerous diffuse medium-sized atypical lymphocytes proliferated, together with increased extrafollicular follicular dendritic cell meshwork, and the lymphocytes expressed CD3, CD4, BCL6, CD10, PD-1, CXCL13, and Ki-67 (75%). Thus, a diagnosis of AITL was made. However, the disease progressed following treatment by CHOP regimen (cyclophosphamide, adriamycin, vincristine, and prednisone). Biopsy showed that most of the cells were positive for CD20 staining and IgH rearrangement. Analysis of 22 kinds of immune cells showed that the numbers of activated NK cells and activated memory T cells increased, while the T-follicular helper population decreased in the transformed sample. In addition, compared with the primary sample, RHOA (G17V) mutation was not detected, while JAK2 and TRIP12 gene mutations were detected in the transformed sample. Overall, we described the immune microenvironment and mutation features of a patient with EBV + LBCL secondary to AITL. This study will help us to understand the mechanisms by which AITL transforms to B-cell lymphoma.

Case Report: Pathogenesis With a Rare RHOA A161E Mutation in a Patient With Angioimmunoblastic T-Cell Lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) genomic abnormalities are highly disease-specific, and the ras homology family member A (RHOA) gene is one of the most recurrent mutated genes, especially for RHOA G17V mutation site. Here, we identified a rare RHOA A161E mutation in an AITL patient through gene sequencing platforms. The patient presented with persistent hypereosinophilia, asymptomatic or symptomatic mildly for over 3 years. At diagnosis, this patient manifested night sweats, weight loss, multiple lymphadenopathies, and enlargement of the liver and spleen. We performed a retrospective genetic mutation analysis by whole-exome sequencing (WES) and droplet digital PCR (ddPCR) on serial gastric, intestinal, and lymph node specimens. The genetic mutation testing result demonstrated that a rare RHOA A161E mutation was found, which was elevated significantly on diagnosis related to AITL pathogenesis. Our case confirms that genetic mutation testing is helpful for diagnostic classification in AITL and dynamic monitoring of gene mutations at multiple time points may facilitate early detection of disease diagnosis.

Indispensable role of microbes in anticancer drugs and discovery trends

Recent years have seen an increased focus on the advancement of naturally derived products for the treatment of cancer. Since the beginning of recorded history, nature has provided a variety of medicinal agents, and an overwhelming number of drugs that we have today are derived from natural sources. Such natural agents are prominently used to treat several diseases such as diabetes, malaria, Alzheimer's, pulmonary disorders, etc. with cancer being the highlight of this review. Due to the rapid development of resistance to chemotherapeutic drugs, the hunt for effective novel drugs is still a paramount concern in cancer treatment. Moreover, many chemotherapy drugs typically have high toxicity and adverse side effects, which necessitates the need to develop anti-tumor drugs that can be employed to treat deadly tumors with fewer negative effects on health and better efficacy. Isolation of several chemotherapeutic drugs has been conducted from a wide range of natural sources which include plants, microbes, fungi, and marine microorganisms. Considering the trends of previous decades, microbial diversity has grown to play a significant role in the formulation of pharmaceuticals and drugs, especially antibiotics and anti-cancer medications. Microbe-derived antitumor antibiotics such as anthracycline, epothilones, bleomycin, actinomycin, and staurosporine are amongst the widely used cancer chemotherapeutic agents. This review deals majorly with microbe-derived anticancer drugs taking into account their derivatives, mechanism of action, isolation procedures, limitations, and tumors targeted by them. This article also reports the phase of clinical study these drugs are undergoing. Moreover, it intends to portray the indispensable part that these microbes have been playing since time immemorial in the odyssey of chemotherapeutic agents. KEY POINTS: • Microbial diversity contributes heavily towards the formulation of anticancer drugs. • Polypeptides, carbohydrates, and alkaloids are prevalent microbe-based drug classes. • Microbe-derived anticancer agents target various sarcomas, carcinomas, and lymphomas.

Neoplasms of follicular helper T-cells: an insight into the pathobiology

T-follicular helper cells (TFH) are a unique subset of T-cells with varied transcriptional profiles and functions. In the last 2016 WHO classification, lymphomas arising from TFH were included as a broad category and emphasis was given to separating them from other peripheral T cell lymphomas. The neoplasms derived from these mainly comprise angioimmunoblastic T-cell lymphoma, peripheral T-cell lymphoma with T-follicular helper cell phenotype, follicular T-cell lymphoma, and cutaneous CD4+ small-medium sized lymphoproliferative disorders. The TFH lymphomas comprise both indolent and aggressive forms. Additional immunohistochemistry to identify TFH cells like CD10, BCL6, ICOS, PD1, CXCL13 and mutations like RHOA, IDH2 is required for diagnosis and prognostication. The understanding of these has evolved over the years, and currently we review the updates and pathobiology of the above.

Chidamide plus prednisone, etoposide, and thalidomide for untreated angioimmunoblastic T-cell lymphoma in a Chinese population: A multicenter phase II trial

Angioimmunoblastic T‐cell lymphoma (AITL) is a common type of peripheral T‐cell lymphoma (PTCL) with a poor prognosis, and an effective first‐line therapy is lacking. Chidamide is a selective histone deacetylase inhibitor and has been approved by the China Food and Drug Administration for relapsed or refractory PTCL. We conducted a multicenter phase II clinical trial combining chidamide with prednisone, etoposide, and thalidomide (CPET regimen) for a total of eight cycles in untreated AITL patients in China. The primary objectives were the overall response rate (ORR) and complete remission (CR) rate after eight cycles of the CPET regimen. The secondary endpoints were progression‐free survival (PFS) and safety. Of the 71 enrolled patients, 51 completed the eight cycles of the CPET regimen. The ORR and CR of the 51 patients were 90.2 and 54.9%, respectively. After a median follow‐up of 11.4 months (95% confidence interval [CI], 9.9–17.0), the median PFS of the 51 patients was 42.6 months (95% CI, 27.7—not reached) and the median overall survival (OS) was not reached. The 2‐year PFS rate and OS rate were 66.5 and 82.2%, respectively. Sixty‐eight patients received at least one cycle of CPET regimen and were included as the safety assessment population. The most common grade 3/4 adverse event was neutropenia (n = 22, 32.3%). Twelve patients showed treatment‐related infections and recovered from antibiotic therapy; the other adverse events were mostly mild and reversible. The oral CPET regimen is an effective, tolerable, and economical choice for untreated AITL in a Chinese population. This trial was registered in www.clinicaltrials.gov as NCT03273452.

Parallel evolution of two distinct lymphoid proliferations in clonal haematopoiesis

AIMS

Angioimmunoblastic T-cell lymphoma (AITL) is genetically characterized by TET2 and DNMT3A mutations occurring in haematopoietic progenitor cells, and late events (e.g. the RHOA-G17V mutation) associated with malignant transformation. As TET2/DNMT3A-mutated progenitor cells can differentiate into multilineage progenies and give rise to both AITL and myeloid neoplasms, they may also have the potential to lead to other metachronous/synchronous neoplasms. We report two cases showing parallel evolution of two distinct potentially neoplastic lymphoid proliferations from a common mutated haematopoietic progenitor cell population.

METHODS AND RESULTS

Both cases presented with generalized lymphadenopathy. In case 1 (a 67-year-old female), an initial lymph node (LN) biopsy was dismissed as reactive, but a repeat biopsy showed a nodal marginal zone lymphoma (NMZL)-like proliferation with an increase in the number of T-follicular helper (TFH) cells. Immunohistochemistry, and clonality and mutational analyses by targeted sequencing of both whole tissue sections and microdissected NMZL-like lesions, demonstrated a clonal B-cell proliferation that harboured the BRAF-G469R mutation and shared TET2 and DNMT3A mutations with an underlying RHOA-G17V-mutant TFH proliferation. Review of the original LN biopsy showed histological and immunophenotypic features of AITL. In case 2 (a 66-year-old male), cytotoxic T-cell lymphoma with an increase in the number of Epstein-Barr virus-positive large B cells was diagnosed on initial biopsy. On review together with the relapsed biopsy, we identified an additional occult neoplastic TFH proliferation/smouldering AITL. Both T-cell proliferations shared TET2 and DNMT3A mutations while RHOA-G17V was confined to the smouldering AITL.

CONCLUSIONS

In addition to demonstrating diagnostic challenges, these cases expand the potential of clonal haematopoiesis in the development of different lineage neoplastic proliferations.

Critical Role of Flow Cytometric Immunophenotyping in the Diagnosis, Subtyping, and Staging of T-Cell/NK-Cell Non-Hodgkin's Lymphoma in Real-World Practice: A Study of 232 Cases From a Tertiary Cancer Center in India

Background

T-cell/NK-cell non-Hodgkin’s lymphoma (T/NK-NHL) is an uncommon heterogeneous group of diseases. The current classification of T/NK-NHL is mainly based on histopathology and immunohistochemistry. In practice, however, the lack of unique histopathological patterns, overlapping cytomorphology, immunophenotypic complexity, inadequate panels, and diverse clinical presentations pose a great challenge. Flow cytometric immunophenotyping (FCI) is a gold standard for the diagnosis, subtyping, and monitoring of many hematological neoplasms. However, studies emphasizing the role of FCI in the diagnosis and staging of T/NK-NHL in real-world practice are scarce.

Methods

We included T-cell non-Hodgkin’s lymphoma (T-NHL) patients evaluated for the diagnosis and/or staging of T/NK-NHL using FCI between 2014 and 2020. We studied the utility of FCI in the diagnosis and subtyping of T/NK-NHL and correlated the FCI findings with the results of histopathology/immunohistochemistry. For correlation purposes, patients were categorized under definitive diagnosis and subtyping, inadequate subtyping, inadequate diagnosis, and misdiagnosis based on the findings of each technique.

Results

A total of 232 patients were diagnosed with T/NK-NHL. FCI findings provided definitive diagnoses in 198 patients and subtyping in 187/198 (95.45%) patients. The correlation between FCI and histopathological/immunohistochemistry results (n = 150) demonstrated an agreement on the diagnosis and subtyping in 69/150 (46%) patients. Of the remaining cases, the diagnosis and subtyping were inadequate in 64/150 (42.7%), and 14/150 (9.33%) were misdiagnosed on histopathology/immunohistochemistry results. FCI provided definitive diagnosis and subtyping in 51/64 (79.7%) patients. Among these, 13 patients diagnosed with peripheral T-cell lymphoma not-otherwise-specified were reclassified (angioimmunoblastic T-cell lymphoma (AITL)-11 and prolymphocytic leukemia-2) on FCI. It corrected the diagnosis in 14 patients that were misdiagnosed (6 B-cell NHL (B-NHL), 3 Hodgkin’s lymphoma, 1 acute leukemia, and 1 subcutaneous panniculitis-like T-cell lymphoma) and misclassified (3 T-NHL) on histopathological results. AITL was the commonest T-NHL misclassified on histopathological results. FCI also confirmed the definite involvement in 7/83 (8.4%) and 27/83 (32.5%) bone marrow (BM) samples reported as suspicious and uninvolved, respectively, on histopathological evaluation.

Conclusion

AITL was the most frequently diagnosed T/NK-NHL in this study. FCI provided a distinct advantage in detecting BM involvement by T/NK-NHL, especially in patients with low-level involvement. Overall, our study concluded that FCI plays a critical role in the diagnosis, subtyping, and staging of T/NK-NHL in real-world practice.

Genetic Landscape of Peripheral T-Cell Lymphoma

Peripheral T-Cell lymphoma (PTCL) comprises a heterogenous group of uncommon lymphomas derived from mature, post-thymic or “peripheral” T- and natural killer cells. The World Health Organization (WHO) emphasizes a multiparameter approach in the diagnosis and subclassification of these neoplasms, integrating clinical, morphologic, immunophenotypic, and genetic features into the final diagnosis. Clinical presentation is particularly important due to histologic, immunophenotypic and genetic variations within established subtypes, and no convenient immunophenotypic marker of monoclonality exists. In recent years, widespread use of gene expression profiling and next-generation sequencing (NGS) techniques have contributed to an improved understanding of the pathobiology in PTCLs, and these have been incorporated into the 2016 revised WHO classification of mature T- and NK-cell neoplasms which now encompasses nearly 30 distinct entities. This review discusses the genetic landscape of PTCL and its role in subclassification, prognosis, and potential targeted therapy. In addition to discussing T-Cell lymphoma subtypes with relatively well-defined or relevant genetic aberrancies, special attention is given to genetic advances in T-Cell lymphomas of T follicular helper cell (TFH) origin, highlighting genetic overlaps between angioimmunoblastic T-Cell lymphoma (AITL), follicular T-Cell lymphoma, and nodal peripheral T-Cell lymphoma with a TFH phenotype. Furthermore, genetic drivers will be discussed for ALK-negative anaplastic large cell lymphomas and their role in differentiating these from CD30+ peripheral T-Cell lymphoma, not otherwise specified (NOS) and primary cutaneous anaplastic large cell lymphoma. Lastly, a closer look is given to genetic pathways in peripheral T-Cell lymphoma, NOS, which may guide in teasing out more specific entities in a group of T-Cell lymphomas that represents the most common subcategory and is sometimes referred to as a “wastebasket” category.

The Safety of Anti-SARS-CoV-2 Vaccines: Vigilance Is Still Required

The opinion I put forward in this paper is that attention must continue to be paid to clinical observations compatible with a detrimental effect of anti-SARS-CoV-2 in certain diseases of immunological nature. Using the example of the atypical thrombocytopenic thromboses caused by adenoviral-vector-based vaccines, I argue that usual post-marketing pharmacovigilance programs may fail in identifying very rare vaccine-related disorders. Since the robust protective immunity induced by mRNA vaccines is related to their distinct capacity to induce strong stimulation of T follicular helper cells, I suggest that the safety of mRNA vaccines should be further assessed by appropriately designed epidemiological and mechanistic studies focusing on lymphoproliferative and autoimmune diseases in which T follicular helper cells were found to play a key role.

T‐cell lymphoma, B‐cell lymphoma, and myelodysplastic syndrome harboring common mutations: Trilineage tumorigenesis from a common founder clone

A 64‐year‐old man with angioimmunoblastic T‐cell lymphoma (AITL) subsequently developed diffuse large B‐cell lymphoma (DLBCL) and myelodysplastic syndrome (MDS). Genomic profiling of AITL, DLBCL, and MDS samples revealed that the tumor cells from all samples shared common mutations in TET2 and DNMT3A. In addition, the IDH2 mutation was observed in AITL, and TP53 mutation was observed in DLBCL and MDS. These findings illustrate the clonal relationship between AITL and DLBCL in addition to AITL and MDS, with the latter being increasingly reported. The present findings strongly support the theory of multistep and multilineage tumorigenesis from a common founder clone.

Recent Advances in Diagnosis and Therapy of Angioimmunoblastic T Cell Lymphoma

Angioimmunoblastic T cell lymphoma (AITL) is a common subtype of mature peripheral T cell lymphoma (PTCL). As per the 2016 World Health Organization classification, AITL is now considered as a subtype of nodal T cell lymphoma with follicular helper T cells. The diagnosis is challenging and requires a constellation of clinical, laboratory and histopathological findings. Significant progress in the molecular pathophysiology of AITL has been achieved in the past two decades. Characteristic genomic features have been recognized that could provide a potential platform for better diagnosis and future prognostic models. Frontline therapy for AITL was mainly depending on chemotherapy and the management of relapsed or refractory AITL is still unsatisfactory with a very poor prognosis. Upfront transplantation offers better survival. Novel agents have been introduced recently with promising outcomes. Several clinical trials of combinations using novel agents are underway. Herein, we briefly review recent advances in AITL diagnosis and the evolving treatment landscape.

Update on recurrent mutations in angioimmunoblastic T-cell lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) is a subtype of peripheral T cell lymphoma (PTCL), defined by genetic alterations that induce abnormal immune activity and inflammatory disorders. Through recent discoveries using genomic studies, the identification of various recurrent mutations has provided greater insight and changed our understanding of the molecular genetics of the disease. By acknowledging these recurrent mutations and their affected pathways, the diagnosis, prognosis, treatment, and survival of AITL can be improved. In this review, we summarize the known recurrent mutations present in the molecular pathogenesis of AITL by emphasizing the effects of mutations on signaling pathways and genes, as well as the multistep process of AITL development.

Recent advances in T-cell lymphoid neoplasms

T Cells comprise many subtypes of specified lymphocytes, and their differentiation and function take place in different tissues. This cellular diversity is also observed in the multiple ways T-cell transformation gives rise to a variety of T-cell neoplasms. This review covers the main types of T-cell malignancies and their specific characteristics, emphasizing recent advances at the cellular and molecular levels as well as differences and commonalities among them.

Cancer-associated mutations in VAV1 trigger variegated signaling outputs and T-cell lymphomagenesis

Mutations in VAV1, a gene that encodes a multifunctional protein important for lymphocytes, are found at different frequencies in peripheral T‐cell lymphoma (PTCL), non‐small cell lung cancer, and other tumors. However, their pathobiological significance remains unsettled. After cataloguing 51 cancer‐associated VAV1 mutations, we show here that they can be classified in five subtypes according to functional impact on the three main VAV1 signaling branches, GEF‐dependent activation of RAC1, GEF‐independent adaptor‐like, and tumor suppressor functions. These mutations target new and previously established regulatory layers of the protein, leading to quantitative and qualitative changes in VAV1 signaling output. We also demonstrate that the most frequent VAV1 mutant subtype drives PTCL formation in mice. This process requires the concurrent engagement of two downstream signaling branches that promote the chronic activation and transformation of follicular helper T cells. Collectively, these data reveal the genetic constraints associated with the lymphomagenic potential of VAV1 mutant subsets, similarities with other PTCL driver genes, and potential therapeutic vulnerabilities.

Cytomorphological characterisation of angioimmunoblastic T cell lymphoma: a case-control study

AIMS

Angioimmunoblastic T cell lymphoma (AITL) is often misdiagnosed in cytology. Hence, the present study was conducted to identify the distinctive cytomorphological features of AITL in lymph node fine-needle aspirates (LN-FNA).

METHODS

This was a 4-year retrospective case-control study. Cases included LN-FNAs from patients with histopathologically confirmed AITL. The controls included LN-FNAs from patients with histopathologically confirmed reactive lymphoid hyperplasia (RLH; n=25). Eleven cytomorphological features were assessed in all the aspirates; the strength of association was determined by OR, Cramer's V and multiple correspondence analysis (MCA).

RESULTS

Of a total of 22 cases of AITL reported on histopathology, 19 adequate aspirates from 14 patients (63.6%) were available for review. On univariate analysis, 5 of 11 cytomorphological variables were found to be significant for AITL; however, on MCA, 3 of these parameters, viz absence of tingible body macrophages (OR=0.014; V=0.74), presence of atypical lymphoid cells (OR=10.8; V=0.41) and singly scattered epithelioid cells (OR=19.3; V=0.31), were found to be the strongest predictors of AITL.

CONCLUSIONS

The absence of tingible body macrophages, presence of atypical lymphoid cells and singly scattered epithelioid cells in polymorphic LN-FNAs are significant cytomorphological predictors of AITL in comparison with RLH. Knowledge of these diagnostic predictors, supplemented by clinicoradiological correlation and appropriate ancillary studies, can help diagnose AITL on aspiration cytology.

Uncommon Variants of Mature T-Cell Lymphomas (MTCLs): Imaging and Histopathologic and Clinical Features with Updates from the Fourth Edition of the World Health Organization (WHO) Classification of Lymphoid Neoplasms

Simple Summary

Familiarity with the updated fourth edition WHO classification of lymphoid malignancies released in 2016, and the new terminology introduced, is crucial for oncologists, pathologists and radiologists. It is mandatory to be aware of rare variants of T-cell lymphomas, specifically mature T-cell lymphomas, including clinicopathologic keys and the most common imaging features and sites of involvement for each subtype. Even though some of these disorders may have perceptible clinical and imaging features, they may overlap with more common disorders, causing delay in diagnosis and treatment. Understanding the appropriate clinical setting and imaging findings will help radiologists to include these disorders in their differential diagnosis. Imaging plays a pivotal role in subclassifying these subtypes of MTCLs, affecting prognosis and treatment implications. Many of these disorders if diagnosed early can be potentially treatable, and early, aggressive intervention may be lifesaving.

Abstract

Understanding the pathogenesis and molecular biology of malignant lymphomas is challenging, given the complex nature and incongruity of these disorders. The classification of lymphoma is continually evolving to account for advances in clinical, pathological, molecular biology and cytogenetic aspects, which impact our understanding of these disorders. The latest fourth edition of the WHO classification of lymphoid malignancies was released in 2016 to account for these changes. Additionally, unlike B-cell lymphomas (BCL), T-cell lymphomas (TCL) are uncommon, and may be sporadically experienced in clinical practice. These disorders are rare, thus early diagnosis is challenging for both physicians and radiologists, owing to the overlap in clinical and imaging features with other, more common disorders. We aim to discuss some rare variants of T-cell lymphomas, including clinicopathologic and imaging features, as well as to give a glimpse of the updates contained within the new 2016 WHO classification.

Tet2 deficiency in immune cells exacerbates tumor progression by increasing angiogenesis in a lung cancer model

Immune cells harboring somatic mutations reportedly infiltrate cancer tissues in patients with solid cancers and accompanying clonal hematopoiesis. Loss‐of‐function TET2 mutations are frequently observed in clonal hematopoiesis in solid cancers. Here, using a mouse lung cancer model, we evaluated the activity of Tet2‐deficient immune cells in tumor tissues. Myeloid‐specific Tet2 deficiency enhanced tumor growth in mice relative to that seen in controls. Single‐cell sequencing analysis of immune cells infiltrating tumors showed relatively high expression of S100a8/S100a9 in Tet2‐deficient myeloid subclusters. In turn, treatment with S100a8/S100a9 promoted Vegfa production by cancer cells, leading to a marked increase in the tumor vasculature in Tet2‐deficient mice relative to controls. Finally, treatment of Tet2‐deficient mice with an antibody against Emmprin, a known S100a8/S100a9 receptor, suppressed tumor growth. These data suggest that immune cells derived from TET2‐mutated clonal hematopoiesis exacerbate lung cancer progression by promoting tumor angiogenesis and may provide a novel therapeutic target for lung cancer patients with TET2‐mutated clonal hematopoiesis.

SOHO State of the Art Updates and Next Questions: Pathology and Pathogenesis of Nodal Peripheral T-Cell Lymphomas

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous and often clinically aggressive group of neoplasms derived from mature post-thymic T-lymphocytes. These neoplasms are rare and usually diagnostically challenging. Our understanding of the pathogenesis of PTCL is increasing and this improved knowledge is leading us to better molecular characterization, more objective and accurate diagnostic criteria, more effective risk assessment, and potentially better treatments. The focus of this paper is to present a brief overview of the current pathology criteria and molecular and genetic features of nodal peripheral T-cell lymphomas focusing on distinct genetically and molecularly defined subgroups that are being recognized within each major nodal PTCL category. It is expected that the molecular stratification will improve the diagnosis and will provide novel therapeutic opportunities (biomarker-driven and targeted therapies) that might benefit and change the outcomes of patients with these neoplasms.

The Conspicuousness of High Endothelial Venules in Angioimmunoblastic T-cell Lymphoma Is Due to Increased Cross-sectional Area, Not Increased Distribution Density

Angioimmunoblastic T-cell lymphoma (AITL) is a T-cell lymphoma of follicular helper T-cell origin. Histologically, neoplastic T-cells proliferate to form clusters adjacent to or between arborizing high endothelial venules (HEVs). HEVs in normal lymph nodes express sulfated glycans called peripheral lymph node addressin (PNAd); however, it remains unclear whether PNAd is also expressed on HEVs in AITL. Furthermore, although it is widely accepted that HEVs are conspicuous in AITL due to their proliferation, quantitative histological support for this concept is lacking. To investigate these issues, we employed monoclonal antibodies recognizing PNAd, namely, MECA-79, HECA-452, and 297-11A, and performed quantitative immunohistochemical analysis of HEVs in 36 AITL-affected and 67 normal lymph nodes. Staining with all three antibodies confirmed that AITL HEVs express PNAd. Moreover, AITL HEVs were bound calcium-dependently by L-selectin-IgM fusion proteins, indicating that they function in the recruitment of L-selectin-expressing lymphocytes. Unexpectedly, HEV distribution density was not increased but rather decreased in AITL compared with normal lymph nodes, but HEV cross-sectional area in AITL was significantly greater than that seen in normal lymph nodes. Overall, these results indicate that the prominence of AITL HEVs is likely due to increased cross-sectional area rather than increased distribution density.

Mutation analysis links angioimmunoblastic T-cell lymphoma to clonal hematopoiesis and smoking

Background

Although advance has been made in understanding the pathogenesis of mature T-cell neoplasms, the initiation and progression of angioimmunoblastic T-cell lymphoma (AITL) and peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), remain poorly understood. A subset of AITL/PTCL-NOS patients develop concomitant hematologic neoplasms (CHN), and a biomarker to predict this risk is lacking.

Methods

We generated and analyzed the mutation profiles through 537-gene targeted sequencing of the primary tumors and matched bone marrow/peripheral blood samples in 25 patients with AITL and two with PTCL-NOS.

Results

Clonal hematopoiesis (CH)-associated genomic alterations, found in 70.4% of the AITL/PTCL-NOS patients, were shared among CH and T-cell lymphoma, as well as concomitant myeloid neoplasms or diffuse large B-cell lymphoma (DLBCL) that developed before or after AITL. Aberrant AID/APOBEC activity-associated and tobacco smoking-associated mutational signatures were respectively enriched in the early CH-associated mutations and late non-CH-associated mutations during AITL/PTCL-NOS development. Moreover, analysis showed that the presence of CH harboring ≥2 pathogenic TET2 variants with ≥15% of allele burden conferred higher risk for CHN (p=0.0006, hazard ratio = 14.01, positive predictive value = 88.9%, negative predictive value = 92.1%).

Conclusions

We provided genetic evidence that AITL/PTCL-NOS, CH, and CHN can frequently arise from common mutated hematopoietic precursor clones. Our data also suggests smoking exposure as a potential risk factor for AITL/PTCL-NOS progression. These findings provide insights into the cell origin and etiology of AITL and PTCL-NOS and provide a novel stratification biomarker for CHN risk in AITL patients.

Funding

R01 grant (CA194547) from the National Cancer Institute to WT.

The Anticancer Potential of Maslinic Acid and Its Derivatives: A Review

Cancer is still an insurmountable problem for humans and critically attacking human health. In recent years, natural products have gained increasing attention in the field of anti-tumor due to their extensive sources and minimal side effects. Maslinic acid (MA), a pentacyclic triterpene acid mainly derived from the olive tree (Olea europaea L.) has been confirmed to possess great anti-cancer effects. This paper reviewed the inhibitory effect of MA and its derivatives on lung cancer, colon cancer, ovarian cancer, gastric cancer, lymphatic, leukemia, breast cancer, pancreatic cancer, melanoma, prostate cancer, renal cell carcinoma, gallbladder cancer, and bladder cancer, among others. MA inhibited the proliferation of various tumor cells and showed lower IC50 values in melanoma 518A2 cells and gastric cancer MKN28 cells compared with other cell lines. A series of semi-synthetic derivatives obtained by modifying MA chemical structure have been shown to have high cytotoxicity to human tumor cell lines, but low cytotoxicity to non-malignant cells, which is conducive to developing its potential as a chemotherapeutic agent. These studies suggest that MA derivatives have broad prospects in the development of antitumor therapeutics in the future and warrant further study.

Aggressive T-cell lymphomas: 2021 Updates on diagnosis, risk stratification and management

INTRODUCTION

Aggressive T-cell lymphomas continue to have a poor prognosis. There are over 27 different subtypes of peripheral T-cell lymphoma (PTCL), and we are now beginning to understand the differences between the various subtypes beyond histologic variations.

MOLECULAR PATHOGENESIS OF VARIOUS SUBTYPES OF PTCL

Gene expression profiling (GEP) can help in diagnosis and prognostication of various subtypes including PTCL-nos and anaplastic large cell lymphoma (ALCL). In addition, mutational analysis is now being incorporated in clinical trials of novel agents to evaluate various biomarkers of response to allow better therapeutic choices for patients.

TARGETED THERAPIES

There are many targeted agents currently in various stages of clinical trials for PTCL that take advantage of the differential expression of specific proteins or receptors in PTCL tumors. This includes the CD30 directed antibody drug conjugate brentuximab vedotin. Other notable targets are CD25, CCR4, inhibition of PI3kinase - m TOR and JAK/STAT pathways. The ALK inhibitors are promising for ALK expressing tumors.

IMMUNOTHERAPIES

Allogeneic stem cell transplant continues to be the curative therapy for most aggressive subtypes of PTCL. The use of checkpoint inhibitors in the treatment of PTCL is still controversial. The most promising results have been seen in cases of extranodal natural killer cell/T-cell (ENK/T) lymphomas and cutaneous T-cell lymphomas (CTCL). Bispecific antibody based treatments as well as CAR-T cell based therapies are in clinical trials.

The Early Diagnostic Dilemma in Angioimmunoblastic T Cell Lymphoma with Excessive Plasma Cells Proliferation

Background

Angioimmunoblastic T cell lymphoma (AITL) is an aggressive Epstein–Barr virus-associated T cell lymphoma. Clinical syndromes of AITL are not confined to fever and lymphadenopathy, and patients may initially present with polyclonal plasma cell proliferation, which may obscure the underlying disease of AITL, delaying diagnosis. Case Presentation. Here, we report two AITL patients with excessive plasma cell proliferation in the bone marrow, peripheral blood, and ascites even mimicking plasma cell leukemia. Both of them had poor endings.

Conclusions

Our report emphasizes the complexity of the clinical manifestations of AITL, which aims to increase the alertness of physicians and improve the rate of early diagnosis. Integrated diagnostic approaches such as histopathology, flow cytometry, cytogenetics, and molecular biology are essential for accurate diagnosis and precise therapy.

Prognostic value of baseline total metabolic tumour volume of 18F-FDG PET/CT imaging in patients with angioimmunoblastic T-cell lymphoma

Purpose

The aim of this study was to explore the prognostic value of baseline metabolic parameters of ¹⁸F-FDG PET/CT imaging in patients with angioimmunoblastic T-cell lymphoma (AITL).

Materials and methods

Fifty-six AITL patients (average age 64.0 ± 1.3 years) diagnosed pathologically from August 2009 to August 2019 were enrolled in this retrospective study. The total metabolic tumour volume (TMTV), total lesion glycolysis (TLG), maximum standardized uptake value (SUVmax), and correlated clinical characteristics were collected and analysed. TMTV was computed with the 41% SUVmax threshold method. The chi-square test or Fisher’s exact probability method was used to compare clinical characteristics. Kaplan–Meier curves were used to describe progression-free survival (PFS) and overall survival (OS). The log-rank test was used to analyse the difference within groups. The statistically significant factors in the univariate regression analysis were incorporated into the Cox risk proportional regression model for multivariate survival analysis.

Results

The TMTV cut-off value was 514.6 cm³ from the ROC curve analysis. Forty (71.4%) patients progressed and 31 (55.4%) patients died within a median follow-up time of 19.1 (interquartile range 7.8–34.6) months. The 1-year and 3-year PFS rates were 42.9% and 30.1%, and the 3-year and 5-year OS rates were 45.9% and 34.4%, respectively. Univariate survival analysis showed that high TMTV and TLG may be the factors contributing to poor PFS and OS. Multivariate analysis showed that TMTV and prognostic index for T-cell lymphoma (PIT) were independent parameters for PFS and OS in AITL patients. TMTV, combined with PIT, may have better risk stratification performance than TMTV alone.

Conclusions

Baseline TMTV and PIT were independent prognostic predictors in AITL patients. The combination of TMTV and PIT can facilitate prognostic stratification and contribute to personalized therapy.

High-dimensional and single-cell transcriptome analysis of the tumor microenvironment in angioimmunoblastic T cell lymphoma (AITL)

Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive lymphoid malignancy associated with a poor clinical prognosis. The AITL tumor microenvironment (TME) is unique, featuring a minority population of malignant CD4+ T follicular helper (TFH) cells inter-mixed with a diverse infiltrate of multi-lineage immune cells. While much of the understanding of AITL biology to date has focused on characteristics of the malignant clone, less is known about the many non-malignant populations that comprise the TME. Recently, mutational consistencies have been identified between malignant cells and non-malignant B cells within the AITL TME. As a result, a significant role for non-malignant populations in AITL biology has been increasingly hypothesized. In this study, we have utilized mass cytometry and single-cell transcriptome analysis to identify several expanded populations within the AITL TME. Notably, we find that B cells within the AITL TME feature decreased expression of key markers including CD73 and CXCR5. Furthermore, we describe the expansion of distinct CD8+ T cell populations that feature an exhausted phenotype and an underlying expression profile indicative of dysfunction, impaired cytotoxicity, and upregulation of the chemokines XCL2 and XCL1.

Virus-Driven Carcinogenesis

Cancer arises from the accumulation of genetic and epigenetic alterations. Even in the era of precision oncology, carcinogens contributing to neoplastic process are still an important focus of research. Comprehensive genomic analyses have revealed various combinations of base substitutions, referred to as the mutational signatures, in cancer. Each mutational signature is believed to arise from specific DNA damage and repair processes, including carcinogens. However, as a type of carcinogen, tumor viruses increase the cancer risk by alternative mechanisms, including insertional mutagenesis, viral oncogenes, and immunosuppression. In this review, we summarize virus-driven carcinogenesis to provide a framework for the control of malignant cell proliferation. We first provide a brief overview of oncogenic viruses and describe their implication in virus-related tumors. Next, we describe tumor viruses (HPV, Human papilloma virus; HBV, Hepatitis B virus; HCV, Hepatitis C virus; EBV, Epstein-Barr virus; Kaposi sarcoma herpesvirus; MCV, Merkel cell polyoma virus; HTLV-1, Human T-cell lymphotropic virus, type-1) and tumor virus-related cancers. Lastly, we introduce emerging tumor virus candidates, human cytomegalovirus (CMV), human herpesvirus-6 (HHV-6) and adeno-associated virus-2 (AAV-2). We expect this review to be a hub in a complex network of data for virus-associated carcinogenesis.

Comprehensive analysis of clinical, pathological, and genomic characteristics of follicular helper T-cell derived lymphomas

Background

The 2016 World Health Organization (WHO) classification introduced nodal lymphomas of T follicular helper (Tfh) cell origin, such as angioimmunoblastic T-cell lymphoma (AITL), follicular peripheral T-cell lymphoma (F-PTCL), and nodal peripheral T-cell lymphoma with T follicular helper phenotype (nodal PTCL with TFH phenotype). However, the accurate incidence rate and clinical characteristics of F-PTCL and nodal PTCL with TFH are unstudied.

Methods

Between February 2012 to June 2020, a total of 207 cases diagnosed with nodal lymphomas of T follicular helper (Tfh) cell origin and PTCL-NOS were reviewed for clinical and histopathologic data. PTCL-NOS was defined to not correlate to any of the specific entities of mature T cell lymphoma in the WHO 2016 classification. We attempted to classify PTCL-GATA3 and PTCL-TBX21 by IHC staining. Target gene analysis was performed on a few patients with sufficient blood and tissue samples additionally.

Results

Among 207 patients, 111 patients (53.6%) had AITL, 67 patients (32.4%) had PTCL-NOS, 19 patients (9.2%) had F-PTCL, and 10 patients (4.8%) had nodal PTCL with TFH phenotype. We re-defined and analyzed F-PTCL and nodal PTCL with TFH phenotype into other TFH lymphomas. AITL (N = 101/111, 91.0%) was found to have a higher frequency of stage III/IV cancers compared to other TFH lymphomas (N = 22/29, 75.0%) and PTCL-NOS (N = 53/67, 79.1%; p-value = 0.03). The OS of AITL and other TFH lymphomas was similarly superior to PTCL-NOS (p-value = 0.02). AITL and other TFH lymphomas showed the TBX21 subtype more commonly than the GATA3 subtype. Mutations related to the RAS family (RHOA) and those related to epigenetic regulators (IDH2, DNMT3A, and TET2) were shown mainly in AITL and other TFH lymphomas.

Conclusions

Other TFH lymphomas appear to be a rare disease entity around one-quarter in nodal lymphomas of T follicular helper (Tfh) cell origin. Their less aggressive clinical feature than we did not expect is utterly different from PTCL-NOS and AITL. On the other hand, other TFH lymphomas share some characteristics, such as the cell of origin, a more common TBX21 subtype, and genetic variation such as RAS family mutation and epigenetic regulators, with AITL.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40164-021-00224-3.

CD94 expression patterns in reactive and neoplastic T-cell and NK-cell proliferations

Lymphomas and leukemias of T-cell and NK-cell lineages are highly heterogeneous disorders and lack effective therapeutic strategies. Targeted therapies including anti-CD94 agents are currently under clinical investigation, but studies of CD94 expression on mature T/NK-cell neoplasms are limited. In this study, we investigated the landscape of CD94 protein expression in 15 patients with reactive T/NK-cell proliferations and 124 patients with various T/NK cell neoplasms. CD94 expression was detected at a high level in reactive NK-cells, with a lower level of expression in a subset of reactive CD8 + T-cells; reactive CD4 + T-cells were negative for CD94 expression. All NK-cell neoplasms surveyed had high-level CD94 expression, which was significantly higher than that in T cell neoplasms (p = 0.0174). In neoplastic T-cell proliferations, CD94 expression was positive in all 10 hepatosplenic T-cell lymphoma cases tested, with a high mean fluorescence intensity. Fifty-six percent of T-cell large granular lymphocytic leukemia cases were positive for CD94 expression in a subset of neoplastic cells. All T-cell prolymphocytic leukemia and 97 % of peripheral T-cell lymphoma cases showed no CD94 expression. Our findings demonstrate a broad range of CD94 expression among T/NK-cell neoplasms, in some at levels that suggest therapeutic vulnerability to CD94-targeted therapies.

Clinicopathological Implications of RHOA Mutations in Angioimmunoblastic T-Cell Lymphoma: A Meta-analysis: RHOA mutations in AITL

BACKGROUND

Studies have recently shown that RHOA mutations play a crucial role in angioimmunoblastic T-cell lymphoma (AITL) pathogenesis. We aimed to pool data from these studies to provide a comparison of clinicopathological features between the RHOA mutant and RHOA wild-type groups in the AITL population.

METHODS

We searched PubMed and Web of Science for the keywords "RHOA AND lymphoma" and selected only studies reporting the clinical significance of RHOA mutations in AITL. We calculated the odds ratios (OR) or the mean difference with 95% CI using a random effect model.

RESULTS

Our pooled results showed a significant association between RHOA mutations and a T-follicular helper cell (TFH) phenotype, especially CD10 (OR, 5.16; 95% CI, 2.32-11.46), IDH2 mutations (OR, 10.70; 95% CI, 4.22-27.15), and TET2 mutations (OR, 7.03; 95% CI, 2.14-23.12). Although DNMT3A together with TET2 and IDH2 mutations are epigenetic gene alterations, we found an insignificant association between RHOA and DNMT3A mutations (OR, 1.72; 95% CI, 0.73-4.05). No significant associations of RHOA mutations with other clinicopathological features and overall survival were found.

CONCLUSIONS

RHOA mutations are strongly correlated with a T-follicular helper cell phenotype and epigenetic mutations such as TET2 and IDH2. Further studies with large AITL samples should be conducted to validate the relationship of TET2, DNMT3A, and RHOA co-mutations.

Comprehensive Epstein-Barr Virus Transcriptome by RNA-Sequencing in Angioimmunoblastic T Cell Lymphoma (AITL) and Other Lymphomas

The Epstein-Barr virus (EBV) is associated with angioimmunoblastic T cell lymphoma (AITL) in more than 80% of cases. Few studies have focused on this association and it is not clear now what role the virus plays in this pathology. We used next-generation sequencing (NGS) to study EBV transcriptome in 14 AITLs compared to 21 other lymphoma samples and 11 cell lines including 4 lymphoblastoid cell lines (LCLs). Viral transcripts were recovered using capture probes and sequencing was performed on Illumina. Bam-HI A rightward transcripts (BARTs) were the most latency transcripts expressed in AITLs, suggesting they may play a role in this pathology. Thus, BARTs, already described as highly expressed in carcinoma cells, are also very present in AITLs and other lymphomas. They were poorly expressed in cell lines other than LCLs. AITLs showed a latency IIc, with BNLF2a gene expression. For most AITLs, BCRF1, which encodes a homologous protein of human interleukin 10, vIL-10, was in addition expressed. This co-expression can contribute to immune escape and survival of infected cells. Considering these results, it can be assumed that EBV plays a pathogenic role in AITLs.

Novel tumour-infiltrating lymphocyte-related risk stratification based by flow cytometry for patients with de novo angioimmunoblastic T cell lymphoma

Tumour-infiltrating lymphocytes (TILs) account for a large proportion of tumour microenvironment (TME) in angioimmunoblastic T cell lymphoma (AITL), and at present the significance of TIL in TME of AITL remains unclear. Overall, 50 de novo AITL patients undergoing lymph node flow cytometry from 2014 to 2019 were retrospectively analysed to assess the relationship between TILs and AITL prognosis. We found that high TIL-Bs (≥ 42.4%, p = 0.004) and high CD4:CD8 (≥ 0.85, p = 0.024) were independent favourable prognostic factors for de novo AITL in univariate or multivariate analyses. New TIL-related risk stratification was established based on TIL-Bs and CD4:CD8 factors. Patients in the low-risk group (TIL-Bs ≥ 42.4% and CD4:CD8 ≥ 0.85) had significantly better overall survival than the high-risk (TIL-Bs < 42.4% and CD4:CD8 < 0.85) (p < 0.001) or intermediate-risk group (TIL-Bs ≥ 42.4% and CD4:CD8 < 0.85 or TIL-Bs < 42.4% and CD4:CD8 ≥ 0.85) (p = 0.011). To our knowledge, our cohort is the largest one focusing on the TILs in de novo cases of AITL by analysing lymph node samples using flow cytometry, which is the first time to comprehensively consider humoral immunity and cellular immunity influence on AITL. Our new risk stratification was valuable and useful in evaluating prognosis of AITL and guiding immunotherapy strategies.

Molecular insights into pathogenesis and targeted therapy of peripheral T cell lymphoma

Peripheral T-cell lymphomas (PTCLs) are biologically and clinically heterogeneous diseases almost all of which are associated with poor outcomes. Recent advances in gene expression profiling that helps in diagnosis and prognostication of different subtypes and next-generation sequencing have given new insights into the pathogenesis and molecular pathway of PTCL. Here, we focus on a broader description of mutational insights into the common subtypes of PTCL including PTCL not other specified type, angioimmunoblastic T-cell lymphoma, anaplastic large cell lymphoma, and extra-nodal NK/T cell lymphoma, nasal type, and also present an overview of new targeted therapies currently in various stages of clinical trials.