Angioimmunoblastic T-cell lymphoma: the many-faced lymphoma. Blood. 2017;129:1095-1102. [PMID: 28115369 DOI: 10.1182/blood-2016-09-692541]

A combination of 5-azacytidine and nivolumab is a potentially effective rescue therapy in relapsed/refractory AITL

Introduction

Angioimmunoblastic T-cell lymphoma (AITL) is a peripheral T-cell lymphoma characterized by a T follicular helper cell phenotype expressing PD-1 (programmed cell death-1). AITL exhibits a poor response to conventional chemotherapy, with a median 5-year overall survival of 44% and a progression-free survival of 32%. Relapse is common, resulting in a median overall survival of 6 months. Recurrent mutations are detected in genes regulating DNA methylation, including TET2, DNMT3A, and IDH2 variants, along with the prevalent RHOA G17V mutation. In this context, patients treated with the hypomethylating agent 5-azacytidine achieved overall response and complete response rates of 75% and 41%, respectively. We hypothesized that targeted therapies combining anti-PD-1 checkpoint blockers with hypomethylating agents could be efficient in AITL patients and less toxic than standard chemotherapy.

Methods

Here, we report the efficacy of a regimen combining 5-azacytidine and nivolumab in nine relapsed or refractory AITL patients.

Results

This regimen was well-tolerated, especially in elderly patients. The overall response rate was 78%, including four partial responses (44%) and three complete responses (33%). Allogeneic hematopoietic stem cell transplantation was performed in two patients who reached complete response.

Discussion

These preliminary favorable results may serve as a basis for further investigation in prospective studies.

Tubulointerstitial nephritis with storiform fibrosis in a patient with angioimmunoblastic T-cell lymphoma

We present a case of an angioimmunoblastic T-cell lymphoma (AITL) and tubulointerstitial nephritis with storiform fibrosis in a 76-year-old man. The patient exhibited lymphadenopathy, polyclonal hypergammaglobulinemia, and renal dysfunction and was diagnosed with AITL on the basis of lymph node biopsy findings. The serum IgG4 level was highly elevated. Renal biopsy revealed IgG4-positive plasma cells and storiform fibrosis without infiltration of AITL, and the findings indicated IgG4-related kidney disease (IgG4-RKD). Following THPCOP therapy for AITL, the renal function improved. While diagnosing IgG4-RKD in a patient with AITL poses challenges, follicular helper T cell involvement appeared crucial in AITL and renal tubulointerstitial lesions in this case.

Dependence on mitochondrial respiration of malignant T cells reveals a new therapeutic target for angioimmunoblastic T-cell lymphoma

Cancer metabolic reprogramming has been recognized as one of the cancer hallmarks that promote cell proliferation, survival, as well as therapeutic resistance. Up-to-date regulation of metabolism in T-cell lymphoma is poorly understood. In particular, for human angioimmunoblastic T-cell lymphoma (AITL) the metabolic profile is not known. Metabolic intervention could help identify new treatment options for this cancer with very poor outcomes and no effective medication. Transcriptomic analysis of AITL tumor cells, identified that these cells use preferentially mitochondrial metabolism. By using our preclinical AITL mouse model, mimicking closely human AITL features, we confirmed that T follicular helper (Tfh) tumor cells exhibit a strong enrichment of mitochondrial metabolic signatures. Consistent with these results, disruption of mitochondrial metabolism using metformin or a mitochondrial complex I inhibitor such as IACS improved the survival of AITL lymphoma-bearing mice. Additionally, we confirmed a selective elimination of the malignant human AITL T cells in patient biopsies upon mitochondrial respiration inhibition. Moreover, we confirmed that diabetic patients suffering from T-cell lymphoma, treated with metformin survived longer as compared to patients receiving alternative treatments. Taking together, our findings suggest that targeting the mitochondrial metabolic pathway could be a clinically efficient approach to inhibit aggressive cancers such as peripheral T-cell lymphoma.

Plasmacytosis mimicking multiple myeloma in angioimmunoblastic T-cell lymphoma: A case report and review of literature

BACKGROUND

Angioimmunoblastic T-cell lymphoma (AITL) is a common subtype of peripheral T-cell lymphoma. Approximately half of patients with AITL may concurrently present with hypergammaglobulinemia. Increased numbers of plasma cells in the bone marrow are commonly observed at diagnosis. These tumors mimic plasma cell myelomas, hindering a conundrum of clinical diagnoses and potentially delaying appropriate treatment.

CASE SUMMARY

A 78-year-old woman experienced poor appetite, weight loss of 5 kg, fatigue 2 months before presentation, and shortness of breath 2 d before presentation, but no fever or night sweats. Physical examination revealed splenomegaly and many palpable masses over the bilateral axillary regions, approximately > 2 cm in size, with rubbery consistency and no tenderness. Blood tests revealed anemia and thrombocytopenia, lactate dehydrogenase level of 153 U/L, total protein level of 10.9 g/dL, albumin to globulin ratio of 0.2, and immunoglobulin G level more than the upper limit of 3000 mg/dL. The free kappa and lambda light chain concentrations were 451 and 614 mg/L, respectively. A pathological examination confirmed the diagnosis of AITL. The initial treatment was the cyclophosphamide, epirubicin, vincristine, and prednisolone regimen. Following this treatment, pleural effusion was controlled, and the patient was discharged in a stable condition and followed up in our outpatient department.

CONCLUSION

This report highlights the importance of differentiating reactive plasmacytosis from plasma cell myeloma in patients with hypergammaglobulinemia. A precise diagnosis of AITL requires a comprehensive evaluation, involving clinical, immunophenotypic, and histological findings conducted by a multidisciplinary team to ensure appropriate treatment.

Molecular Pathology of Mature Lymphoid Malignancies

Lymphoid malignancies are a broad and heterogeneous group of neoplasms. In the past decade, the genetic landscape of these tumors has been explored and cataloged in fine detail offering a glimpse into the mechanisms of lymphomagenesis and new opportunities to translate these findings into patient management. A myriad of studies have demonstrated both distinctive and overlapping molecular and chromosomal abnormalities that have influenced the diagnosis and classification of lymphoma, disease prognosis, and treatment selection.

A Case Report on a Rare Type of Lymphoma: Angioimmunoblastic T-cell Lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) is a rare type of non-Hodgkin lymphoma (NHL). We present a case of a 60-year-old female who attended the emergency department (ED) with fatigue, recurrent fever, weight loss, and adenopathy for six months. Laboratory findings showed anemia, lymphocytosis, eosinophilia, thrombocytosis, cholestasis, hypoproteinemia, and hypoalbuminemia. Abdominopelvic computed tomography (CT) revealed multiple adenopathies. A lymph node biopsy yielded inconclusive results in the outpatient clinic. Later, during admission, the patient underwent a positron emission tomography-computed tomography (PET-CT), revealing a cervical adenopathy cluster that was excised en bloc. Histology confirmed the diagnosis of AITL. The medical team initiated chemotherapy but opted for exclusive symptomatic treatment due to disease progression. The patient died six months after diagnosis. The fluctuating and nonspecific presentation of AITL can hinder and delay definitive diagnosis, therefore impacting treatment and prognosis.

cyTRBC1 evaluation rapidly identifies sCD3-negative peripheral T-cell lymphomas and reveals a novel type of sCD3-negative T-cell clone with uncertain significance

The flow cytometry-based evaluation of TRBC1 expression has been demonstrated as a rapid and specific method for detecting T-cell clones in sCD3-positive TCRαβ+ mature T-cell lymphoma. The aim of the study was to validate the utility of surface (s) TRBC1 and cytoplastic (cy) TRBC1 assessment in detecting clonality of sCD3-negative peripheral T-cell lymphomas (PTCLs), as well as exploring the existence and characteristics of sCD3-negative clonal T-cell populations with uncertain significance (T-CUS). Evaluation of sTRBC1 and cyTRBC1 were assessed on 61 samples from 37 patients with sCD3-negative PTCLs, including 26 angioimmunoblastic T-cell lymphoma (AITL) patients and 11 non-AITL patients. The sCD3-negative T-CUS were screened from 1602 patients without T-cell malignancy and 100 healthy individuals. Additionally, the clonality of cells was further detected through T-cell gene rearrangement analysis. We demonstrated the monotypic expression patterns of cyTRBC1 in all sCD3-negative PTCLs. Utilizing the cyTRBC1 evaluation assay, we identified a novel and rare subtype of sCD3-negative T-CUS for the first time among 13 out of 1602 (0.8%) patients without T-cell malignancy. The clonality of these cells was further confirmed through T-cell gene rearrangement analysis. This subset exhibited characteristics such as sCD3-cyCD3 + CD4 + CD45RO+, closely resembling AITL rather than non-AITL. Further analysis revealed that sCD3-negative T-CUS exhibited a smaller clone size in the lymph node and mass specimens compared to AITL patients. However, the clone size of sCD3-negative T-CUS was significantly lower than that of non-AITL patients in both specimen groups. In conclusion, we validated the diagnostic utility of cyTRBC1 in detecting sCD3-negative T-cell clonality, provided a comprehensive analysis of sCD3-negative T-CUS, and established a framework and provided valuable insights for distinguishing sCD3-negative T-CUS from sCD3-negative PTCLs based on their phenotypic properties and clone size.

Comparison of chemotherapy and chidamide combined with chemotherapy in patients with untreated angioimmunoblastic T-cell lymphoma

Background

Angioimmunoblastic T-cell lymphoma (AITL) is characterized by high recurrence rates and poor prognosis, and effective first-line treatment is lacking. Recently, histone deacetylase inhibitors (HDACi), such as chidamide, have been found to induce durable remissions in AITL patients.

Methods

Patients with untreated AITL from March 2015 to March 2023 were retrospectively collected and divided into chemotherapy (ChT) group and chidamide combined with chemotherapy (C-ChT) group based on the first-line treatment received. The comparison of efficacy and safety between the two groups was conducted.

Results

86 patients with newly diagnosed AITL were enrolled, in which 35 patients were in the ChT group and 51 in the C-ChT group. The objective response rate (ORR) of C-ChT group was significantly higher than that of ChT group (84.3% vs. 60%, P= 0.011), and had superior progression-free survival (PFS) (27 months vs. 12 months, P= 0.025). However, no significant difference in overall survival (OS) was observed between the two groups (P= 0.225). In addition, the responding patients who received autologous stem cell transplantation (ASCT) had superior PFS compared to those who did not (P= 0.015).

Conclusions

Compared with ChT regimen, C-ChT regimen was well tolerated and had superior ORR and PFS in patients with untreated AITL. ASCT may contribute to longer PFS in remission patients.

Long-term successful use of belinostat in a patient with relapsed-refractory angioimmunoblastic lymphoma who has previously been heavily treated

ABSTRACT

Angioimmunoblastic T-cell lymphoma (AITL) is one of the sub-types of peripheral T-cell lymphomas (PTCLs) that are remarkably refractory and has the potential to have a poor prognosis. The treatment process includes a wide range of treatment modalities, from anthracycline-based regimens that have been used for years to novel agents, such as histone deacetylase inhibitor romidepsin and belinostat. Increased treatment response rates and prolonged survival have been reported in studies with belinostat. Similarly, in this case report, we wanted to share a patient of an advanced age and with a high IPI score, whom we had treated in many treatment lines and maintained a long-term treatment response by administering belinostat.

Clinicopathological features of adult T-cell leukemia/lymphoma with T-follicular helper phenotype

AIMS

T-follicular helper (TFH) cells are effector T-cells that are crucial for B-cell selection and differentiation. T-cell lymphomas derived from TFH cells have distinct characteristics. Additionally, in the World Health Organization (WHO) classification 5th edition, three lymphomas were introduced as independent disease entities with TFH cell origin. We aimed to investigate the clinicopathological features of adult T-cell leukemia/lymphoma (ATLL) with a TFH phenotype (TFHP).

METHODS AND RESULTS

We performed TFH immunohistochemistry analysis of five biomarkers for the biopsy specimen, with TFHP being indicated by a positive result for more than two markers. Among 75 cases of ATLL, 37.3% of them showed TFHP. Compared with cases of ATLL without TFHP, cases of ATLL with TFHP showed higher C-reactive protein levels (p = 0.0219) and increased high endothelial venule proliferation (p = 0.024). However, there were no significant between-group differences in overall survival as well as other clinical and morphological findings. Furthermore, there was no significant between-group difference in TFH markers and FOXP3 expression.

CONCLUSION

Some patients with ATLL may present a TFHP, which should not preclude the diagnosis of ATLL. Although presenting a TFHP does not affect prognosis, it is important to identify cases of ATLL with a TFHP since it may inform future treatment strategies.

Spatially Exploring RNA Biology in Archival Formalin-Fixed Paraffin-Embedded Tissues

Spatial transcriptomics has emerged as a powerful tool for dissecting spatial cellular heterogeneity but as of today is largely limited to gene expression analysis. Yet, the life of RNA molecules is multifaceted and dynamic, requiring spatial profiling of different RNA species throughout the life cycle to delve into the intricate RNA biology in complex tissues. Human disease-relevant tissues are commonly preserved as formalin-fixed and paraffin-embedded (FFPE) blocks, representing an important resource for human tissue specimens. The capability to spatially explore RNA biology in FFPE tissues holds transformative potential for human biology research and clinical histopathology. Here, we present Patho-DBiT combining in situ polyadenylation and deterministic barcoding for spatial full coverage transcriptome sequencing, tailored for probing the diverse landscape of RNA species even in clinically archived FFPE samples. It permits spatial co-profiling of gene expression and RNA processing, unveiling region-specific splicing isoforms, and high-sensitivity transcriptomic mapping of clinical tumor FFPE tissues stored for five years. Furthermore, genome-wide single nucleotide RNA variants can be captured to distinguish different malignant clones from non-malignant cells in human lymphomas. Patho-DBiT also maps microRNA-mRNA regulatory networks and RNA splicing dynamics, decoding their roles in spatial tumorigenesis trajectory. High resolution Patho-DBiT at the cellular level reveals a spatial neighborhood and traces the spatiotemporal kinetics driving tumor progression. Patho-DBiT stands poised as a valuable platform to unravel rich RNA biology in FFPE tissues to study human tissue biology and aid in clinical pathology evaluation.

Inhibition of choline metabolism in an angioimmunoblastic T-cell lymphoma preclinical model reveals a new metabolic vulnerability as possible target for treatment

BACKGROUND

Angioimmunoblastic T-cell lymphoma (AITL) is a malignancy with very poor survival outcome, in urgent need of more specific therapeutic strategies. The drivers of malignancy in this disease are CD4+ follicular helper T cells (Tfh). The metabolism of these malignant Tfh cells was not yet elucidated. Therefore, we decided to identify their metabolic requirements with the objective to propose a novel therapeutic option.

METHODS

To reveal the prominent metabolic pathways used by the AITL lymphoma cells, we relied on metabolomic and proteomic analysis of murine AITL (mAITL) T cells isolated from our established mAITL model. We confirmed these results using AITL patient and healthy T cell expression data.

RESULTS

Strikingly, the mAITL Tfh cells were highly dependent on the second branch of the Kennedy pathway, the choline lipid pathway, responsible for the production of the major membrane constituent phosphatidylcholine. Moreover, gene expression data from Tfh cells isolated from AITL patient tumors, confirmed the upregulation of the choline lipid pathway. Several enzymes involved in this pathway such as choline kinase, catalyzing the first step in the phosphatidylcholine pathway, are upregulated in multiple tumors other than AITL. Here we showed that treatment of our mAITL preclinical mouse model with a fatty acid oxydation inhibitor, significantly increased their survival and even reverted the exhausted CD8 T cells in the tumor into potent cytotoxic anti-tumor cells. Specific inhibition of Chokα confirmed the importance of the phosphatidylcholine production pathway in neoplastic CD4 + T cells, nearly eradicating mAITL Tfh cells from the tumors. Finally, the same inhibitor induced in human AITL lymphoma biopsies cell death of the majority of the hAITL PD-1high neoplastic cells.

CONCLUSION

Our results suggest that interfering with choline metabolism in AITL reveals a specific metabolic vulnerability and might represent a new therapeutic strategy for these patients.

Lymphoma-associated hemophagocytic lymphohistiocytosis (LA-HLH): a scoping review unveils clinical and diagnostic patterns of a lymphoma subgroup with poor prognosis

Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory syndrome driven by pathologic activation of cytotoxic T-lymphocytes and macrophages. Despite advances in diagnostics and management, adult patients with lymphoma-associated HLH (LA-HLH) harbor particularly poor prognosis and optimal treatment remains challenging. As systematic data on LA-HLH are scarce, we aimed to synthesize research evidence by thorough analysis of the published literature in PubMed (MEDLINE-database) within the context of a scoping review. Of 595 search results, 132 articles providing information on 542 patients were reviewed and analyzed. Median patient age was 60 years (range, 18-98) with male predominance (62.7%). B- and T-NHL were equally represented (45.6% and 45.2%), Hodgkin's lymphoma was reported in 8.9% of the cases. The majority of patients (91.6%) presented in Ann-Arbor-Stages III and IV, and bone marrow infiltration was observed in a significant proportion of patients (61.5%). Soluble CD25 levels were markedly elevated (median 10,000 U/ml), with levels beyond 10,000 U/ml indicating unfavorable prognosis for 30-day and overall survival. 66.8% of the patients died after median 5.1 months. LA-HLH remains a clinical challenge requiring specialized management. Timely diagnosis and appropriate lymphoma-specific treatment are of utmost importance to enhance patient outcomes.

Case report: Good response to CMOP regimen containing mitoxantrone hydrochloride liposome (PLM60) as induction chemotherapy in patients with angioimmunoblastic T-cell lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) is a highly aggressive subtype of peripheral T-cell lymphoma. The current prognosis with the first-line standard of care remains unsatisfactory, necessitating the exploration of more effective treatment options. We reported 5 cases of AITL receiving CMOP (mitoxantrone hydrochloride liposome, cyclophosphamide, vincristine, and prednisone). Cases 1 and 2 initially received CHOP as first-line induction therapy but switched to CMOP due to inadequate efficacy and cardiac adverse events. Cases 3, 4, and 5 were newly diagnosed and received CMOP. All patients achieved complete remission with acceptable cardiotoxicities and hematologic toxicities. After study treatment discontinuation, Cases 1 and 3 underwent autologous stem cell transplantation, and Cases 4 and 5 received oral maintenance agents. At the last follow-up, 4 patients remained in remission and 1 (Case 2) exhibited tumor recurrence. CMOP showed promise as a potential treatment option for AITL patients. Further research is essential to identify its efficacy and safety.

Therapeutic challenges in peripheral T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) is a rare and heterogeneous group of hematological malignancies. Compared to our knowledge of B-cell tumors, our understanding of T-cell leukemia and lymphoma remains less advanced, and a significant number of patients are diagnosed with advanced stages of the disease. Unfortunately, the development of drug resistance in tumors leads to relapsed or refractory peripheral T-Cell Lymphomas (r/r PTCL), resulting in highly unsatisfactory treatment outcomes for these patients. This review provides an overview of potential mechanisms contributing to PTCL treatment resistance, encompassing aspects such as tumor heterogeneity, tumor microenvironment, and abnormal signaling pathways in PTCL development. The existing drugs aimed at overcoming PTCL resistance and their potential resistance mechanisms are also discussed. Furthermore, a summary of ongoing clinical trials related to PTCL is presented, with the aim of aiding clinicians in making informed treatment decisions.

A case of angioimmunoblastic T-cell lymphoma presenting with migration of lung shadows

A 62-year-old woman presented with chronic cough. Chest CT showed multiple nodules and consolidation. Bronchoscopy could not confirm a specific diagnosis. Because her symptoms and lung opacities improved spontaneously, she was followed without treatment. Seven months later, chest radiography showed worsening of consolidation and a tumorous shadow. After performing cervical lymph node and lung tissue biopsies, we diagnosed her as having angioimmunoblastic T-cell lymphoma (AITL). Cases of AITL showing migration of lung shadows have not been reported. AITL development is influenced by immunodeficiency and reactivation of EBV, and migration of lung opacities may be related to the patient's immune status.

Advances in the pathogenesis and therapeutic strategies of angioimmunoblastic T-cell lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive subtype of peripheral T-cell lymphomas with its cell origin determined to be follicular helper T-cells. AITL is characterized by a prominent tumor microenvironment involving dysregulation of immune cells, signaling pathways, and extracellular matrix. Significant progress has been made in the molecular pathophysiology of AITL, including genetic mutations, immune metabolism, hematopoietic-derived microenvironment, and non-hematopoietic microenvironment cells. Early diagnosis, detection of severe complications, and timely effective treatment are crucial for managing AITL. Treatment typically involves various combination chemotherapies, but the prognosis is often poor, and relapsed and refractory AITL remains challenging, necessitating improved treatment strategies. Therefore, this article provides an overview of the pathogenesis and latest advances in the treatment of AITL, with a focus on potential therapeutic targets, novel treatment strategies, and emerging immunotherapeutic approaches.

Detection of HHV-6 Virus in specimen of a ductal pancreatic adenocarcinoma with comparison in tumor and normal tissue

AIMS

The association of human herpesvirus 6 (HHV-6) species with pancreatic cancer is controversially discussed. The aim of this study was to further investigate the postulated association and to identify the basis of HHV-6 DNA positivity reported for pancreatic cancer tissue.

METHODS

All samples of patients with pancreatic cancer (cancer and surrounding tissue) were analyzed for presence of HHV-6 DNA by PCR and then selected cases by immunohistochemistry.

RESULTS

Sixty eight per cent (68% = 52/77) of all patients were HHV-6 DNA positive in any of the samples, 49% (38/77) were positive in tumor tissue. Specimens of just one patient were HHV-6A DNA positive, all other patients were positive for HHV-6B. Immunohistochemical analysis of HHV-6 DNA positive samples did not reveal any specific HHV-6B protein positive tumor cell. In contrast, supposed immune cells presented intra- and peritumorally expressed HHV-6B-protein. The cause of presence of these cells in the tumor stroma is unknown, as of yet.

CONCLUSIONS

HHV-6 DNA-positivity of pancreatic cancer tissue described by us and others is probably not due to the infection of pancreatic cells by HHV-6, but rather due to the migration of HHV-6 positive immune cells into the pancreas. Based on our data, we suppose that there is no direct evidence for HHV-6 as a causative agent of pancreatic cancer, but further in-depth studies (including investigation of immune status of patients) are necessary to make definitive conclusions.

Clinical features and prognostic outcomes of angioimmunoblastic T cell lymphoma in an Asian multicenter study

In our Asian multicenter retrospective study, we investigated the clinical prognostic factors affecting the outcomes of AITL patients and identified a novel prognostic index relevant in the Asian context. In our 174-patient cohort, the median PFS and OS was 1.8 years and 5.6 years respectively. Age > 60, bone marrow involvement, total white cell count >12 × 109/L and raised serum lactate dehydrogenase were associated with poorer PFS and OS in multivariate analyses. This allowed for a prognostic index (AITL-PI) differentiating patients into low (0-1 factors, n = 64), moderate (2 factors, n = 59) and high-risk (3-4 factors, n = 49) subgroups with 5-year OS of 84.0%, 44.0% and 28.0% respectively (p < 0.0001). POD24 proved to be strongly prognostic (5-year OS 24% vs 89%, p < 0.0001). Exploratory gene expression studies were performed and disparate immune cell profiles and cell signaling signatures were seen in the low risk group as compared to the intermediate and high risk groups.

First-in-class small molecule inhibitors of ICOS/ICOSL interaction as a novel class of immunomodulators

The interaction of the inducible co-stimulator (ICOS) with its ligand (ICOSL) plays key roles in T-cell differentiation and activation of T-cell to B-cell functions. The ICOS/ICOSL pathway is a validated target for T-cell lymphomas induced by the proliferation of T-follicular helper (Tfh) cells. Moreover, the inhibition of ICOS/ICOSL interaction can decrease the enhancement of immunosuppressive regulatory T cells (Tregs) in both hematologic malignancies and solid tumors. However, targeting ICOS/ICOSL interaction is currently restricted to monoclonal antibodies (mAbs) and there are no small molecules in existence that can block ICOS/ICOSL. To fill this gap, we report herein the first time-resolved fluorescence resonance energy transfer (TR-FRET) assay to evaluate the ability of small molecules to inhibit ICOS/ICOSL interaction. Implementation of the developed TR-FRET assay in high-throughput screening (HTS) of a focused chemical library resulted in the identification of AG-120 as a first-in-class inhibitor of ICOS/ICOSL interaction. We further employed docking studies and molecular dynamics (MD) simulations to identify the plausible mechanism of blocking ICOS/ICOSL complex formation by AG-120. Using the structure-activity relationship (SAR) by catalog approach, we identified AG-120-X with an IC50 value of 4.68 ± 0.47 μM in the ICOS/ICOSL TR-FRET assay. Remarkably, AG-120-X revealed a dose-dependent ability to block ICOS/ICOSL interaction in a bioluminescent cellular assay based on co-culturing Jurkat T cells expressing ICOS and CHO-K1 cells expressing ICOSL. This work will pave the way for future drug discovery efforts aiming at the development of small molecule inhibitors of ICOS/ICOSL interaction as potential therapeutics for cancer as well as other diseases.

High CD8+tumor-infiltrating lymphocytes indicate severe exhaustion and poor prognosis in angioimmunoblastic T-cell lymphoma

Background

Exhaustion of CD8+ tumor-infiltrating lymphocytes (TILs), characterized by the overexpression of immune checkpoints (IC), is a major impediment to anti-tumor immunity. However, the exhaustion status of CD8+TILs in angioimmunoblastic T cell lymphoma (AITL) remains unclear. Therefore, we aimed to elucidate the exhaustion status of CD8+TILs in AITL and its influence on prognosis.

Methods

The correlation between CD8+TILs and IC expression in AITL was analyzed using single-cell RNA sequencing (n = 2), flow cytometry (n = 20), and RNA sequencing (n = 20). Biological changes related to CD8+TILs exhaustion at different cytotoxic T lymphocyte (CTL) levels (mean expression levels of CD8A, CD8B, GZMA, GZMB, and PRF1) in AITL were evaluated using RNA sequencing (n = 20) and further validated using the GEO dataset (n = 51). The impact of CD8 protein expression and CTL levels on patient prognosis was analyzed using flow cytometry and RNA sequencing, respectively.

Results

Our findings demonstrated that the higher the infiltration of CD8+TILs, the higher was the proportion of exhausted CD8+TILs characterized by the overexpression of multiple IC. This was accompanied by extensive exhaustion-related biological changes, which suggested severe exhaustion in CD8+TILs and may be one of the main reasons for the poor prognosis of patients with high CD8+TILs and CTL.

Conclusion

Our study comprehensively reveals the exhaustion status of CD8+TILs and their potential negative impact on AITL prognosis, which facilitates further mechanistic studies and is valuable for guiding immunotherapy strategies.

Role of cytokine in malignant T-cell metabolism and subsequent alternation in T-cell tumor microenvironment

T cells are an important component of adaptive immunity and T-cell-derived lymphomas are very complex due to many functional sub-types and functional elasticity of T-cells. As with other tumors, tissues specific factors are crucial in the development of T-cell lymphomas. In addition to neoplastic cells, T- cell lymphomas consist of a tumor micro-environment composed of normal cells and stroma. Numerous studies established the qualitative and quantitative differences between the tumor microenvironment and normal cell surroundings. Interaction between the various component of the tumor microenvironment is crucial since tumor cells can change the microenvironment and vice versa. In normal T-cell development, T-cells must respond to various stimulants deferentially and during these courses of adaptation. T-cells undergo various metabolic alterations. From the stage of quiescence to attention of fully active form T-cells undergoes various stage in terms of metabolic activity. Predominantly quiescent T-cells have ATP-generating metabolism while during the proliferative stage, their metabolism tilted towards the growth-promoting pathways. In addition to this, a functionally different subset of T-cells requires to activate the different metabolic pathways, and consequently, this regulation of the metabolic pathway control activation and function of T-cells. So, it is obvious that dynamic, and well-regulated metabolic pathways are important for the normal functioning of T-cells and their interaction with the microenvironment. There are various cell signaling mechanisms of metabolism are involved in this regulation and more and more studies have suggested the involvement of additional signaling in the development of the overall metabolic phenotype of T cells. These important signaling mediators include cytokines and hormones. The impact and role of these mediators especially the cytokines on the interplay between T-cell metabolism and the interaction of T-cells with their micro-environments in the context of T-cells lymphomas are discussed in this review article.

Involvement of spleen is associated with shorter survival in patients with angioimmunoblastic T cell lymphoma

BACKGROUND

The prognosis of patients with angioimmunoblastic T cell lymphoma (AITL) remains dismal, with their 5-year overall survival (OS) and progression-free survival (PFS) rates of 32-41% and 18-38%, respectively. Spleen involvement occurs in a proportion of patients with AITL. But still, it is unclear whether spleen involvement impacts the prognosis of AITL patients. In this study, we aim to establish new prognostic indicators for the identification of high-risk patients to draft optimal treatment regimens.

METHODS

We collected and counted the clinical data of 54 patients with AITL treated with CHOP-based first-line chemotherapy regimen between 2010 and 2021 at Hubei Cancer Hospital and Hunan Cancer Hospital. In addition, all patients received PET-CT scan prior to receiving treatment. We performed univariate and multivariate analyses to assess the predictive role of tumor characteristics, laboratory, and radiographic data for the prognosis of AITL.

RESULTS

We observed that PFS and OS are worse in patients with high ECOG scores, spleen involvement, and low serum albumin levels in patients with AITL. In univariate analysis, stage (HR 3.515 [1.142-10.822], p = 0.028) and spleen involvement (HR 8.378 [1.085-64.696, p = 0.042) were correlated with PFS in patients with AITL. Besides, stage (HR 3.439 [1.108-10.674], p = 0.033) and spleen involvement (HR 11.002 [1.420-85.254], p = 0.022) were significantly correlated with OS. Consistently, spleen involvement was correlated with OS (HR 16.571 [1.350-203.446], p = 0.028) and PFS (HR 10.905 [1.037-114.690], p = 0.047) in AITL patients in a multivariate analysis.

CONCLUSION

This study demonstrates that spleen involvement might be used as a prognostic indicator for AITL patients.

Clonal haematopoiesis and dysregulation of the immune system

Age-related diseases are frequently linked to pathological immune dysfunction, including excessive inflammation, autoreactivity and immunodeficiency. Recent analyses of human genetic data have revealed that somatic mutations and mosaic chromosomal alterations in blood cells - a condition known as clonal haematopoiesis (CH) - are associated with ageing and pathological immune dysfunction. Indeed, large-scale epidemiological studies and experimental mouse models have demonstrated that CH can promote cardiovascular disease, chronic obstructive pulmonary disease, chronic liver disease, osteoporosis and gout. The genes most frequently mutated in CH, the epigenetic regulators TET2 and DNMT3A, implicate increased chemokine expression and inflammasome hyperactivation in myeloid cells as a possible mechanistic connection between CH and age-related diseases. In addition, TET2 and DNMT3A mutations in lymphoid cells have been shown to drive methylation-dependent alterations in differentiation and function. Here we review the observational and mechanistic studies describing the connection between CH and pathological immune dysfunction, the effects of CH-associated genetic alterations on the function of myeloid and lymphoid cells, and the clinical and therapeutic implications of CH as a target for immunomodulation.

Spontaneous remission of angioimmunoblastic T-cell lymphoma in a child with ataxia-telangiectasia: a case report

BACKGROUND

Angioimmunoblastic T-cell lymphoma is an uncommon subtype of peripheral T-cell lymphoma in children with fewer than 20 cases reported in literature.

CASE PRESENTATION

A 3-year-old Omani boy was diagnosed with ataxia-talengectasia presenting with fever and generalized lymphadenopathy. His biopsy revealed atypical lymphocytic infiltrate consistent with the diagnosis of angioimmunoblastic T-cell lymphoma. Within 3 weeks from the initial presentation and without any neoadjuvant therapy, he showed complete recovery of symptoms with absence of fever and regression of all previously affected lymph nodes. He has remained in remission ever since.

CONCLUSION

This is the first report of spontaneous improvement of angioimmunoblastic T-cell lymphoma in a patient with ataxia-telangiectasia who was 3 years old at presentation. Owing to the paucity of similar cases, this report adds valuable diagnostic, therapeutic, and monitoring data.

Hemoglobin-platelet index as a prognostic factor in patients with peripheral T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of aggressive lymphomas with a poor prognosis. The International Prognostic Index (IPI) and the Prognostic Index for PTCL-unspecified (PIT) is used to predict the prognosis of PTCL. The hemoglobin-platelet index (HPI), based on anemia and thrombocytopenia status, is associated with the prognosis of diffuse large B-cell lymphoma. However, its significance in terms of predicting the prognosis of PTCL has not been fully investigated. We herein retrospectively analyzed 100 patients with newly diagnosed PTCL in our department. At a median follow-up of 3.2 years, the median progression-free survival (PFS) and overall survival (OS) was 0.72 (95% confidence interval [CI]: 0.56-1.2) years and 2.0 (95% CI: 1.5-4.7) years, respectively. Multivariate analysis revealed that elevated lactic dehydrogenase (LDH) and hypoalbuminemia were independent adverse variables for PFS. The HPI showed significant predictive value for both PFS and OS. As a new prognostic model comprising the HPI, LDH, and albumin, the LA-HPI allowed the stratification of patients into four distinct risk subgroups: low risk (zero risk factors), low-intermediate risk (one risk factors), high-intermediate risk (two or three risk factors), or high risk (four risk factors). The PFS and OS differed significantly among the patients by the LA-HPI score. The LA-HPI demonstrated better predictive performance compared to the IPI, PIT, and HPI. Our data demonstrated the prognostic utility of the HPI in patients with PTCL. The LA-HPI, incorporating four readily obtainable parameters, exhibited superior performance compared to traditional indices.

Immune infiltration and drug specificity analysis of different subtypes based on functional status in angioimmunoblastic T-cell lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) is a subtype of peripheral T-cell lymphoma (PTCL) strongly correlated with worse clinical outcomes. However, the role of characteristic pathway-related genes in patients with AITL (e.g., subtype typing and pathogenesis) remains unknown. In this study, we intended to understand the potential role and prognostic value of characteristic pathways in AITL and identified a model for subtype identification based on pathway-related functional status. Transcriptomic (RNA-seq) data were obtained from the Gene Expression Omnibus database for three sets of tumor tissues from AITL patients. AITL was divided into three clusters based on the pathway profile of patients and the best clustering k = 3, and differentially expressed genes (DEGs) in the three clusters were analyzed. The top 45 important variables associated with characteristic pathways, such as Huntington's disease, VEGF signaling pathway, nucleotide excision repair, ubiquitin-mediated proteolysis, purine metabolism, olfactory transduction, etc., were used to construct a subtype identification model. The model was experimentally validated and proved to possess good predictive efficacy. In addition, pathway-related subtype typing was significantly associated with different immune cell infiltration in AITL. Further analysis revealed that the drug IC50 values predicted also differed markedly among the different subtypes, thus further identifying some subtype-specific drugs. Our study indicates a potential role of characteristic pathways in AITL staging for the first time, provides novel insights for future research targeting AITL, and points to potential therapeutic options for patients with different subtypes of AITL.

A preliminary investigation of the relationship between 18F-FDG PET/CT metabolic parameters and prognosis in angioimmunoblastic T-cell lymphoma

Purpose

The goal of the study was to determine the prognostic significance of metabolic parameters in baseline ¹⁸F-FDG PET/CT images obtained from patients with angioimmunoblastic T-cell lymphoma (AITL).

Methods

Forty patients with pathologically diagnosed AITL who had baseline ¹⁸F-FDG PET/CT between May 2014 and May 2021 were assessed as part of this study. Maximum standardized uptake value (SUVmax), total lesion glycolysis (TLG), and total metabolic tumor volume (TMTV) were obtained and analyzed. In addition, many relevant features were evaluated, including sex, age, staging, International Prognostic Index (IPI), prediction index for T-cell lymphoma (PIT), Ki-67, and so on. Estimates of progression-free survival (PFS) and overall survival (OS) were determined using the log-rank test and Kaplan-Meier.

Results

The median follow-up was 30.2 months (interquartile range 9.82-43.03). Throughout the follow-up period, 29 (72.5%) deaths occurred and 22 (55.0%) patients made progress. The rates for 2- and 3-year PFS were 43.6% and 26.4%, respectively. The 3- and 5-year OS were 42.6% and 21.5%. For TMTV, TLG, and SUVmax, the cut-off values were 87.0 cm3, 711.1, and 15.8, respectively. Poorer PFS and OS were substantially correlated with high SUVmax and TLG. An increased TMTV suggested a shorter OS. TLG performed independently as OS predictors in multivariate analysis. The risk score for predicting the prognosis of AITL includes the TMTV, TLG, SUVmax, and IPI scores, with 4.5 for TMTV, 2 for TLG, 1.5 for IPI scores, and 1 for SUVmax. Three risk categories of patients with AITL had 3-year OS rates of 100.0%, 43.3%, and 25.0%, respectively.

Conclusion

Baseline TLG was a strong predictor of OS. Here a new prognostic scoring system for AITL based on the clinical indicators and PET/CT metabolic parameters was constructed, which might make stratification of prognosis easy and also help to individualize treatment.

Misdiagnosis of angioimmunoblastic T‑cell lymphoma: A case report

Angioimmunoblastic T-cell lymphoma (AITL) is a specific subtype of peripheral T-cell lymphoma that is challenging to diagnose due to the lack of specific pathological characteristics. This report describes the case of a 56-year-old man with Hodgkin lymphoma in whom the gene rearrangement results were positive for TCRβDB+Jβ1/2. Pathological and immunochemical examinations revealed a diagnosis of lymphoma that was a composite of AITL and focal classical Hodgkin lymphoma. Unfortunately, he died soon after the correct diagnosis was made. This case shows that a combination of immunohistochemistry and gene rearrangement analysis can increase the diagnostic accuracy for AITL. A review of the literature on the misdiagnosis of AITL indicates that this disease progresses rapidly with a high mortality rate. Our experience, in this case, highlights the need for early diagnosis.

Angioimmunoblastic T-cell lymphoma and correlated neoplasms with T-cell follicular helper phenotype: from molecular mechanisms to therapeutic advances

Angioimmunoblastic T-cell lymphoma (AITL) is the second most frequent subtype of mature T-cell lymphoma (MTCL) in the Western world. It derives from the monoclonal proliferation of T-follicular helper (TFH) cells and is characterized by an exacerbated inflammatory response and immune dysregulation, with predisposition to autoimmunity phenomena and recurrent infections. Its genesis is based on a multistep integrative model, where age-related and initiator mutations involve epigenetic regulatory genes, such as TET-2 and DNMT3A. Subsequently, driver-mutations, such as RhoA G17V and IDH-2 R172K/S promote the expansion of clonal TFH-cells ("second-hit"), that finally begin to secrete cytokines and chemokines, such as IL-6, IL-21, CXCL-13 and VEGF, modulating a network of complex relationships between TFH-cells and a defective tumor microenvironment (TME), characterized by expansion of follicular dendritic cells (FDC), vessels and EBV-positive immunoblasts. This unique pathogenesis leads to peculiar clinical manifestations, generating the so-called "immunodysplastic syndrome", typical of AITL. Its differential diagnosis is broad, involving viral infections, collagenosis and adverse drug reactions, which led many authors to use the term "many-faced lymphoma" when referring to AITL. Although great advances in its biological knowledge have been obtained in the last two decades, its treatment is still an unmet medical need, with highly reserved clinical outcomes. Outside the setting of clinical trials, AITL patients are still treated with multidrug therapy based on anthracyclines (CHOP-like), followed by up-front consolidation with autologous stem cell transplantation (ASCT). In this setting, the estimated 5-year overall survival (OS) is around 30-40%. New drugs, such as hypomethylating agents (HMAs) and histone deacetylase inhibitors (HDAi), have been used for relapsed/refractory (R/R) disease with promising results. Such agents have their use based on a biological rationale, have significant potential to improve the outcomes of patients with AITL and may represent a paradigm shift in the therapeutic approach to this lymphoma in the near future.

An update on genetic aberrations in T-cell neoplasms

T-cell neoplasms are a highly heterogeneous group of leukaemias and lymphomas that represent 10-15% of all lymphoid neoplasms. Traditionally, our understanding of T-cell leukaemias and lymphomas has lagged behind that of B-cell neoplasms, in part due to their rarity. However, recent advances in our understanding of T-cell differentiation, based on gene expression and mutation profiling and other high throughput methods, have better elucidated the pathogenetic mechanisms of T-cell leukaemias and lymphomas. In this review, we provide an overview of many of the molecular abnormalities that occur in various types of T-cell leukaemia and lymphoma. Much of this knowledge has been used to refine diagnostic criteria that has been included in the fifth edition of the World Health Organization. This knowledge is also being used to improve prognostication and identify novel therapeutic targets, and we expect this progress will continue, eventually resulting in improved outcomes for patients with T-cell leukaemias and lymphomas.

Emerging predictive biomarkers for novel therapeutics in peripheral T-cell and natural killer/T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) and natural killer/T-cell lymphoma (NKTCL) are rare subtypes of non-Hodgkin's lymphoma that are typically associated with poor treatment outcomes. Contemporary first-line treatment strategies generally involve the use of combination chemoimmunotherapy, radiation and/or stem cell transplant. Salvage options incorporate a number of novel agents including epigenetic therapies (e.g. HDAC inhibitors, DNMT inhibitors) as well as immune checkpoint inhibitors. However, validated biomarkers to select patients for individualized precision therapy are presently lacking, resulting in high treatment failure rates, unnecessary exposure to drug toxicities, and missed treatment opportunities. Recent advances in research on the tumor and microenvironmental factors of PTCL and NKTCL, including alterations in specific molecular features and immune signatures, have improved our understanding of these diseases, though several issues continue to impede progress in clinical translation. In this Review, we summarize the progress and development of the current predictive biomarker landscape, highlight potential knowledge gaps, and discuss the implications on novel therapeutics development in PTCL and NKTCL.

Best Practices in CD30 Immunohistochemistry Testing, Interpretation, and Reporting: An Expert Panel Consensus

CONTEXT.—

Although CD30 testing is an established tool in the diagnostic workup of lymphomas, it is also emerging as a predictive biomarker that informs treatment. The current definition of CD30 positivity by immunohistochemistry is descriptive and based on reactivity in lymphomas that are defined by their universal strong expression of CD30, rather than any established threshold. Challenges include inconsistencies with preanalytic variables, tissue processing, pathologist readout, and with the pathologist and oncologist interpretation of reported results.

OBJECTIVE.—

To develop and propose general best practice recommendations for reporting CD30 expression by immunohistochemistry in lymphoma biopsies to harmonize practices across institutions and facilitate assessment of its significance in clinical decision-making.

DESIGN.—

Following literature review and group discussion, the panel of 14 academic hematopathologists and 2 clinical/academic hematologists/oncologists divided into 3 working groups. Each working group was tasked with assessing CD30 testing by immunohistochemistry, CD30 expression readout, or CD30 expression interpretation.

RESULTS.—

Panel recommendations were reviewed and discussed. An online survey was conducted to confirm the consensus recommendations.

CONCLUSIONS.—

CD30 immunohistochemistry is required for all patients in whom classic Hodgkin lymphoma and any lymphoma within the spectrum of peripheral T-cell lymphoma are differential diagnostic considerations. The panel reinforced and summarized that immunohistochemistry is the preferred methodology and any degree of CD30 expression should be reported. For diagnostic purposes, the interpretation of CD30 expression should follow published guidelines. To inform therapeutic decisions, report estimated percent positive expression in tumor cells (or total cells where applicable) and record descriptively if nontumor cells are positive.

Incidence, Survival Outcome, and Prognostic Nomogram of Patients with Angioimmunoblastic T-cell Lymphoma: a Population-based Analysis

OBJECTIVE

Due to the rarity of angioimmunoblastic T-cell lymphoma (AITL), very limited data concerning its incidence patterns and prognostic factors are available. This study aimed to explore the incidence, characteristics, survival outcomes, and prognostic factors of AITL.

METHODS

Age-adjusted incidence and temporal trends were calculated based on 1247 AITL patients from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER)-13 database. A total of 1525 AITL patients from the SEER-18 database and 43 patients from our single center were included for survival analysis and nomogram construction.

RESULTS

The age-adjusted incidence for overall cohort was 0.123 [95% confidence interval (CI), 0.117-0.131) per 100 000 during 1992-2017. The overall incidence increased steeply at the rate of 15.3% (95%CI 11.0%-19.8%, P<0.001) per year during 1992-2004, but remained stable during 2004-2017 (P=0.200). Similar incidence trends were observed in age, sex, and stage subgroups. The final nomograms consisted of four variables: age at diagnosis, sex, Ann Arbor stage, and primary site. The concordance index (C-index) of the nomogram for 5-year overall survival prediction was 0.717, 0.690 and 0.820 in the training cohort, validation cohort-1 and cohort-2, respectively. Regarding the disease-specific survival (DSS), the nomogram also demonstrated a good discrimination level, with the C-index for predicting the probability of DSS at 5 years of 0.716, 0.682 and 0.813 for the three cohorts, respectively. The calibration displayed good concordance between the nomogram-predicted and actual observed outcomes.

CONCLUSION

The age-adjusted incidence for AITL was low during 1992-2017. The incidence continuously increased during 1992-2004, but remained stable during 2004-2017. The nomograms as proposed may provide a favorable and accurate prognostic survival prediction in AITL.

The added prognostic values of baseline PET dissemination parameter in patients with angioimmunoblastic T-cell lymphoma

To explore the prognostic values of baseline 2-deoxy-2-[¹⁸F] fluoro-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) dissemination parameter in angioimmunoblastic T-cell lymphoma (AITL) and its added values to total metabolic tumour volume (TMTV). Eighty-one AITL patients with at least two FDG-avid lesions in baseline PET/CT were retrospectively included. PET parameters including TMTV and the distance between the two lesions that are the furthest apart (Dmax) were obtained. Univariate Cox analysis showed that both Dmax and TMTV were risk factors for progression-free survival (PFS) and overall survival (OS). Multivariate Cox analysis models of different combinations showed that high Dmax (> 65.7 cm) could independently predict both PFS and OS, while high TMTV (>456.6 cm³) was only significant for OS. A concise PET model based on TMTV and Dmax can effectively risk-stratify patients. PFS and OS rates were significantly lower in patients with high Dmax and high TMTV than in patients with low Dmax and low TMTV (3-year PFS rate: 15.0% vs. 48.7%, p = 0.001; 3-year OS rate: 27.6% vs. 79.0%, p < 0.001). Dmax can directly reflect the disease dissemination characteristic and has a significant prognostic value for FDG-avid AITL patients. It has the potential to be introduced into new risk stratification models for tailored treatment.

A phase I dose-escalation study of neoantigen-activated haploidentical T cell therapy for the treatment of relapsed or refractory peripheral T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) is a type of highly heterogeneous non-Hodgkin lymphoma with a poor prognosis and lack of effective targeted therapies. Adoptive T-cell therapy has been successfully used in the treatment of B-cell malignancies. We first used adoptive transfer of haploidentical T cells activated by patient-specific neoantigens in vitro to treat an elderly patient with refractory angioimmunoblastic T-cell lymphoma (AITL) in 2017, and the patient achieved long-term complete remission (CR). Here we report on early results from this first-in-human phase 1 clinical trial that aims to assess the safety and tolerability of neoantigen-activated haploidentical T cell therapy (NAHTC) for relapsed/refractory PTCL.

CLINICAL TRIAL REGISTRATION

http://www.chictr.org.cn/index.aspx, identifier [ChiCTR1800017440].

Real-World Efficacy of 5-Azacytidine as Salvage Chemotherapy for Angioimmunoblastic T-cell Lymphoma

BACKGROUND

Based on specific epigenetic mutation in AITL such as TET2, DNMT3A, IDH2, and RHOA, hypomethylating agents are emerging as a promising treatment option for AITL.

METHOD

The efficacy and safety of 5-azacytidine as salvage chemotherapy were retrospectively analyzed in 15 patients with RR-AITL from 2019 to 2022.

RESULTS

During the median 6.0 months of follow-up, the overall response rate (ORR) was 40% (n = 6/15) with 2 CRs and 4 PRs. The patients who previously had received ≤2 prior chemotherapies showed higher ORR than subjects with >2 prior chemotherapies (80% vs. 20%). The 10 patients who received 5-azacitidine at the late chemotherapy lines (>2 prior chemotherapy lines) usually received less dose 5-azacitidine. And these patients discontinued treatment due to disease progression (n = 6/10, 60%) or neutropenic fever (n = 4/10, 40%). The patients who received a full dose (75 mg/m² for 7 days) of 5-azacitidine seemed to show better ORR than subjects (100 mg for 7 days) who did not receive an optimal dose (60.0% vs. 30.0%). The median progression-free survival (PFS) was 1.6 months, and the patients who previously had undergone ≤2 chemotherapies had better PFS compared with subjects who previously received >2 chemotherapies (P-value = .04).

CONCLUSION

5-azacitidine shows reasonable efficacy and manageable toxicities for patients with RR-AITL, especially those who previously received ≤2 chemotherapy lines.

Angioimmunoblastic T-cell lymphoma with predominant CD8+ tumor-infiltrating T-cells is a distinct immune pattern with an immunosuppressive microenvironment

Background

Angioimmunoblastic T-cell lymphoma (AITL) has a rich tumor microenvironment (TME) that typically harbors plenty of CD4+tumor infiltrating lymphocytes, (TIL)-T-cells (so called common AITL). Nonetheless, AITL with large numbers of CD8+TIL-Ts that outnumber CD4+cells have been observed (CD8-predominant AITL). However, detailed comparison of CD8-predominant AITL and common AITL are still lacking.

Methods

We compared clinicopathological features, TIL subsets, TME T cell receptor-β (TRB), and immunoglobulin heavy chain (IGH) repertoires, and gene expression profiles in six CD8-predominant and 12 common AITLs using case-control matching (2014 to 2019).

Results

Comparing with common AITLs, CD8-predominant AITLs showed more frequent edema (P = 0.011), effusion (P = 0.026), high elevated plasma EBV-DNA (P = 0.008), and shorter survival (P = 0.034). Moreover, they had more pronounced eosinophil increase (P = 0.004) and a higher Ki67 index (P = 0.041). Flow cytometry revealed an inverted CD4/CD8 ratio in TIL-Ts and lower TIL-B proportions (P = 0.041). TRB repertoire metrics deteriorated, including lower productive clones (P = 0.014) and higher clonality score (P = 0.019). The IGH repertoire was also narrowed, showing a higher proportion of the top 10 clones (P = 0.002) and lower entropy (P = 0.027). Gene expression analysis showed significant enrichment for upregulated negative regulation of immune system processes and downregulated T-cell activation and immune cell differentiation.

Conclusion

Our findings demonstrated that CD8-predominant AITL is a distinct immune pattern of AITL characterized by anti-tumor immunity impairment and an immunosuppressive microenvironment. These characteristics can interpret its severe clinical manifestations and poor outcomes.

Plasmacytic Pleural Effusion as a Major Presentation of Angioimmunoblastic T-Cell Lymphoma: A Case Report

Angioimmunoblastic T-cell lymphoma is one of the peripheral T-cell lymphomas. Reactive plasma cells can occasionally be observed in AITL patients' peripheral blood and bone marrow. Plasmacytic pleural effusion as the presentation of AITL has not been reported before. The mechanisms of plasmacytic pleural effusion are not fully understood. Here we present an 82-year-old male with exuberant plasma cells in his pleural effusion in addition to his peripheral blood and bone marrow aspiration. By presenting this case, we would like to expand the spectrum of disease presentations in AITL and discuss the significance of flow cytometry in the differential diagnosis of pleural effusion. To our knowledge, this is the first case report in the literature, which will be crucial to assist the hematopathologist in accurate diagnosis and treatment.

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.

PD-1 combined with TRBC1 and pan-T cell antibodies for robustly monitoring angioimmunoblastic T-cell lymphoma

Background

The diagnosis of AITL is challenging. It may be delayed or even missed due to critical clinical conditions and its histologic and immunophenotypic overlap with other neoplastic and reactive lymphoid proliferations.

Objective

The key objective is to obtain an efficient diagnosis, sensitive disease monitoring and treatment efficacy assessment of AITL using multiparameter flow cytometry (MFC).

Methods

In total, 167 de novo AITL patients were immunophenotypically profiled using sensitive MFC. We precisely identified the aberrant T-cell populations of AITL and performed an in-depth description of their phenotypic characteristics in comparison with their residual normal CD4+ T cells. A comparison of Programmed death receptor-1 (PD-1) expression was performed among AITL and other T-cell lymphomas.

Results

MFC detected a neoplastic T-cell population in 94.1% (80/85) of tissue, 71.5% (108/151) of bone marrow (BM), 100% (8/8) of peripheral blood (PB) and 78.6% (11/14) of body fluid samples. The most frequent immunophenotypic aberrations included the absence and diminished expression of CD3 (71.25% in tissues, 71.3% in BM, 75% in PB, 81.8% in hydrothorax and ascites specimens), followed by the loss or partial loss of CD7 (71.25% in LN, 67.6% in BM, 50% in PB, 81.8% in hydrothorax and ascites specimens). The immunophenotyping of neoplastic T-cell populations showed a high degree of similarity among different sites of the same patient and they might change over time but were relatively stable. Bright PD-1 expression showed high sensitivity and specificity in differentiating AITL from other T-cell lymphomas. In 14 AITL patients, neoplastic T-cell populations were initially missed by T-cell screening tube but were successfully discovered by bright PD-1 expression.

Conclusion

T-cell screening tube can reliably screen neoplastic T-cell populations in AITL patients with typical immunophenotyping, such as loss of surface CD3 and loss of CD7 with a relatively high ratio. Bright PD-1 expression is essential for identifying aberrant T cells in almost all AITLs. The clonality assessment antibody TRBC1 is efficient for robustly and cheaply assessing T-cell clonality. Using PD-1 and TRBC1 combined with pan-T cell antibodies can make a precise diagnosis of AITL and also sensitively monitor minimal residual disease regardless of the antigenic drift of the neoplastic T cells.

A High Programmed Cell Death Protein 1 Hormone Receptor Score on Skin Biopsy is Associated with Sézary Syndrome Diagnosis: A Study of 91 Patients with Erythroderma

Erythroderma is challenging to diagnose. The aim of this single-centre retrospective study was to identify factors that can be used to improve the diagnosis of erythroderma. Among 91 patients with erythroderma, 21 were diagnosed with eczema, 17 with psoriasis, 20 with drug-induced erythroderma, 13 with erythrodermic mycosis fungoides and 20 with Sézary syndrome. Nail alterations, ear involvement, and severe scaling were significantly associated with psoriasis (p = 0.044). Fever and hypereosinophilia were associated with drug-induced erythroderma. Expression of programmed cell death protein 1 was observed in all skin biopsies. However, with Sézary syndrome, programmed cell death protein 1 expression was significantly higher than with other aetiologies. A programmed cell death protein 1 hormone receptor score (H-score) >50 was associated with Sézary syndrome (p < 0.001, sensitivity 75%, specificity 92%) as well as CXCL13 expression (p < 0.044). CD7 loss was more frequent with erythrodermic mycosis fungoides and Sézary syndrome (p = 0.022). This study reports the importance of programmed cell death protein 1 expression for the differential diagnosis of Sézary syndrome and other aetiologies, including erythrodermic mycosis fungoides.

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.

Bortezomib Use for a Critically Ill Patient with Angioimmunoblastic T-Cell Lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) accounts for 18.5% of all peripheral T-cell lymphomas. There is still no gold standard chemotherapy for treating newly diagnosed AITL. This case describes the use of bortezomib in newly diagnosed AITL. A 53-year-old man with no previous illness presented with erythema and swelling in the left neck. A diagnosis of AITL was made based on the results of lymph node biopsies. AITL progression led the patient to a severely deteriorated general condition. Bortezomib was thus administered, which resulted in a reduction in lymphadenopathies, the disappearance of tumor fever, and a decrease in serum lactate dehydrogenase levels. Subsequently, the patient’s general condition gradually improved. Despite the patient’s poor condition, bortezomib was well tolerated. After bortezomib administration, the patient did not require chemotherapy for approximately 10 months. The present case indicates that bortezomib is a possible treatment option for patients with AITL.

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.

Tet2 coordinates with Foxo1 and Runx1 to balance T follicular helper cell and T helper 1 cell differentiation

In response to various types of infection, naïve CD4+ T cells differentiate into diverse helper T cell subsets; however, the epigenetic programs that regulate differentiation in response to viral infection remain poorly understood. Demethylation of CpG dinucleotides by Tet methylcytosine dioxygenases is a key component of epigenetic programing that promotes specific gene expression, cellular differentiation, and function. We report that following viral infection, Tet2-deficient CD4+ T cells preferentially differentiate into highly functional germinal center T follicular helper (TFH) cells that provide enhanced help for B cells. Using genome-wide DNA methylation and transcription factor binding analyses, we find that Tet2 coordinates with multiple transcription factors, including Foxo1 and Runx1, to mediate the demethylation and expression of target genes, including genes encoding repressors of TFH differentiation. Our findings establish Tet2 as an important regulator of TFH cell differentiation and reveal pathways that could be targeted to enhance immune responses against infectious disease.

Epstein-Barr Virus (EBV) Is Mostly Latent and Clonal in Angioimmunoblastic T Cell Lymphoma (AITL)

The Epstein-Barr virus (EBV) is associated with angioimmunoblastic T cell lymphoma (AITL), a peripheral T lymphoma of poor prognosis in at least 90% of cases. The role of EBV in this pathology is unknown. Using next-generation sequencing, we sequenced the entire EBV genome in biopsies from 18 patients with AITL, 16 patients with another EBV-associated lymphoma, and 2 controls. We chose an EBV target capture method, given the high specificity of this technique, followed by a second capture to increase sensitivity. We identified two main viral strains in AITL, one of them associated with the mutations BNRF1 S542N and BZLF1 A206S and with mutations in the EBNA-3 and LMP-2 genes. This strain was characterized in patients with short post-diagnosis survival. The main mutations found during AITL on the most mutated latency or tegument genes were identified and discussed. We showed that the virus was clonal in all the AITL samples, suggesting that it may be involved in this pathology. Additionally, EBV was latent in all the AITL samples; for one sample only, the virus was found to be latent and probably replicative, depending on the cells. These various elements support the role of EBV in AITL.

A preclinical model of peripheral T-cell lymphoma GATA3 reveals DNA damage response pathway vulnerability

Peripheral T-cell lymphoma (PTCL) represents a rare group of heterogeneous diseases in urgent need of effective treatments. A scarcity of disease-relevant preclinical models hinders research advances. Here, we isolated a novel mouse (m)PTCL by serially transplanting a lymphoma from a germinal center B-cell hyperplasia model (Cγ1-Cre Blimp1fl/fl ) through immune-competent mice. Lymphoma cells were identified as clonal TCRβ+ T-helper cells expressing T-follicular helper markers. We also observed coincident B-cell activation and development of a de novo B-cell lymphoma in the model, reminiscent of B-cell activation/lymphomagenesis found in human PTCL. Molecular profiling linked the mPTCL to the high-risk "GATA3" subtype of PTCL, showing GATA3 and Th2 gene expression, PI3K/mTOR pathway enrichment, hyperactivated MYC, and genome instability. Exome sequencing identified a human-relevant oncogenic β-catenin mutation possibly involved in T-cell lymphomagenesis. Prolonged treatment responses were achieved in vivo by targeting ATR in the DNA damage response (DDR), a result corroborated in PTCL cell lines. This work provides mechanistic insight into the molecular and immunological drivers of T-cell lymphomagenesis and proposes DDR inhibition as an effective and readily translatable therapy in PTCL.

Rapidly progressive glomerulonephritis in a patient with angioimmunoblastic T-cell lymphoma: a rare autopsy case showing IgA vasculitis and cylinder-like deposits

Angioimmunoblastic T-cell lymphoma (AITL), a hematological malignancy, originates from follicular helper T cells. The primary site of AITL is the lymph nodes, but extranodal presentation is frequent in patients with advanced stages. Here, we report a rare case of a patient with AITL presenting with rapidly progressive glomerulonephritis (RPGN). The patient underwent computed tomography, which showed systemic lymph node swelling. RPGN was noted at the time of admission. Livedo was observed in the lower limbs with purpura on the foot. The patient was diagnosed with AITL based on lymph node biopsy. Skin biopsy revealed vasculitis with immunoglobulin A (IgA) deposits. Renal biopsy revealed endocapillary proliferative glomerulonephritis with massive subendothelial deposits and intraluminal thrombi. Immunofluorescence showed IgA, IgG, and complement component 3c-predominant granular staining pattern in the capillary and mesangial areas. Electron micrographs demonstrated dense cylindrical-like deposits in the subendothelial space. Chemotherapy drugs were administered, but the patient's respiratory distress increased until death. Upon autopsy, membranoproliferative glomerulonephritis and extensive necrotizing cellular crescent formation were observed in the glomeruli. Taken together, this case is a rare combination of AITL and RPGN showing both cylinder-like deposits suggestive of cryoglobulinemic glomerulonephritis (CN) and IgA vasculitis.