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

An exploratory study on the differential diagnostic indicators between adult systemic EBV-positive T-cell lymphoproliferative disorders and angioimmunoblastic T-cell lymphoma with multiple EBV infections

BACKGROUND

The differential diagnosis between adult systemic EBV-positive T-cell lymphoproliferative disorders (EBV+ T-LPD) and angioimmunoblastic T-cell lymphoma (AITL) with multiple EBV infections is difficult, and distinguishing between the two has become a diagnostic challenge for pathologists. Given that the clinical treatment plans are different, an accurate diagnosis is a prerequisite to ensure effective treatment, therefore, it is extremely necessary and meaningful to find effective pathological indicators for distinguishing between two diseases.

METHODS

We present a retrospective study comparing 7 cases of adult EBV+ T-LPD and 16 cases of AITL with multiple EBV infections diagnosed at our institution from 2017 to 2022. Differences in immunophenotype, type of EBV-infected cells, clonality and gene mutations between the two groups of cases were compared by immunohistochemical staining, double-label staining, TCR gene rearrangement and next-generation sequencing analysis.

RESULTS

7 cases of adult EBV+ T-LPD: all cases had no more than 1 T follicular helper (THF) marker was expressed, and there were significantly more EBER+/CD3 + cells than EBER+/CD20 + cells; 5 cases had mutation detection results, in which only 1 had the characteristic KMT2D mutation, 2 had TET2 mutations, and no common mutations such as DDX3X were detected.16 cases of AITL with multiple EBV infections: all cases were found to express at least 2 TFH markers, with 87% of them expressing at least 3 TFH markers., and had significantly more EBER+/CD20 + cells than EBER+/CD3 + cells; 4 cases had mutation test results, with mutated high-frequency genes being TET2 (100%, and all of them had 2 or more TET2 mutations) and RHOA G17V (100%), DNMT3A mutation occurred in 2 cases (50%), and IDH2 R172 mutation occurred in 1 case (25%).

CONCLUSIONS

We found that the expression pattern of TFH markers, the types of cells predominantly infected by EBV and the different mutations can all be used as effective pathological indicators for distinguishing between two diseases.

When the mask slips: A peripheral T-cell lymphoma disguised as lupus with myelofibrosis in a patient with May-Hegglin syndrome

We describe the case of a female patient with May-Hegglin syndrome who developed peripheral T-cell lymphoma not otherwise specified. The patient presents with systemic lupus erythematous phenotype and myelofibrosis secondary to T-cell lymphoma. Peripheral T-cell lymphoma not otherwise specified, represents 25 % of all peripheral T-cell lymphoma. Its diagnosis remains challenging due to the polymorphous clinical presentation and pathological heterogeneity. Myelofibrosis associated with malignant lymphomas is rare and peripheral T-cell lymphoma is even rarer. To our knowledge, this is the first case to describe an association between May-Hegglin syndrome and a peripheral T-cell lymphoma.

Sustained yet non-curative response to lenalidomide in relapsed angioimmunoblastic T-cell lymphoma with acquired chidamide resistance: a case report with 10-year follow-up, genetic insights and literature review

Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive subtype of peripheral T-cell lymphoma (PTCL) characterized by its T-follicular helper (TFH) phenotype. Relapsed and refractory disease is common in AITL and often associated with a poor prognosis. The presence of epigenetic abnormalities, immune dysregulation, hyperinflammation and active angiogenesis in AITL offers potential targets for histone deacetylase (HDAC) inhibitors and immunomodulatory drugs (IMiDs). Herein, we present a case of AITL with multiple relapses over a decade. Following intensive chemotherapy and autologous stem cell transplantation (ASCT), the patient relapsed with extensive nodal and extranodal involvement, particularly pulmonary lesions, and subsequently pursued chemo-free treatments. Initially, the patient exhibited a remarkable response to single-agent chidamide, the first oral HDAC inhibitor. Soon after developing resistance to chidamide, continuous treatment with lenalidomide led to an impressive sustained complete remission lasting 64 months, followed by a diminished response for an additional 11 months. Genetic profiling of the patient revealed mutations in KMT2D and ARID1A, along with chromosomal aberrations such as del(5q). Notably, genes commonly mutated in AITL, including RHOA, TET2, DNMT3A, and IDH2, were absent in this case. A review of the literature highlights the heterogeneous genomic landscape of AITL and the diversity of treatment options available, underscoring the importance of tailored approaches to overcome resistance and improve outcomes in this distinct lymphoma subtype.

Deciphering the multifaceted roles and clinical implications of 2-hydroxyglutarate in cancer

Increasing evidence indicates that 2-hydroxyglutarate (2HG) is an oncometabolite that drives tumour formation and progression. Due to mutations in isocitrate dehydrogenase (IDH) and the dysregulation of other enzymes, 2HG accumulates significantly in tumour cells. Due to its structural similarity to α-ketoglutarate (αKG), accumulated 2HG leads to the competitive inhibition of αKG-dependent dioxygenases (αKGDs), such as KDMs, TETs, and EGLNs. This inhibition results in epigenetic alterations in both tumour cells and the tumour microenvironment. This review comprehensively discusses the metabolic pathways of 2HG and the subsequent pathways influenced by elevated 2HG levels. We will delve into the molecular mechanisms by which 2HG exerts its oncogenic effects, particularly focusing on epigenetic modifications. This review will also explore the various methods available for the detection of 2HG, emphasising both current techniques and emerging technologies. Furthermore, 2HG shows promise as a biomarker for clinical diagnosis and treatment. By integrating these perspectives, this review aims to provide a comprehensive overview of the current understanding of 2HG in cancer biology, highlight the importance of ongoing research, and discuss future directions for translating these findings into clinical applications.

Clinical trial: Chidamide plus CHOP improve the survival of newly diagnosed angioimmunoblastic T-cell lymphoma

Background

Angioimmunoblastic T-cell lymphoma (AITL) is known for its unfavorable survival prognosis. Chidamide has shown efficacy in relapsed/refractory AITL, but its efficacy in newly diagnosed AITL is uncertain.

Objective

This retrospective research aimed to evaluate the effectiveness and safety of chidamide when used with doxorubicin, cyclophosphamide, prednisone, and vincristine (CHOP) in comparison to CHOP by itself for individuals newly diagnosed with AITL, and to examine the impact of transplantation.

Method

This was an analysis that compared outcomes among patients who received chidamide + CHOP on a clinical trial vs. historical controls who received CHOP alone, enrolling a total of sixty-six treatment-naive AITL patients between April 2014 and November 2022. Among them, thirty-three received chidamide in addition to CHOP (chidamide group), while thirty-three received CHOP alone (control group). The clinical characteristics were balanced between the two groups. All patients were scheduled to undergo up to six courses of treatment before transplantation.

Results

The chidamide group had a significantly longer median overall survival (OS) compared to the control group, with a median OS that was not reached, as opposed to 20 months in the control group (p = 0.002). In the control group, the median progression-free survival (PFS) was 11 months, while in the chidamide group, it was 22 months (p = 0.080). In the high-risk group (IPI ≥ 3), the chidamide group demonstrated notably superior complete response (CR) and overall response rate (ORR) compared to the control cohort (p = 0.002, p = 0.034). The PFS and OS in the chidamide group were not reached, and there were significant differences compared to the control group (p = 0.007, p = 0.003). The median OS of the transplanted group was longer than the non-transplanted group (p = 0.004). On multivariate analysis, chidamide group reduced the hazards of death in the total cohort.

Conclusion

As the study was non-random and retrospective, Chidamide combined with chemotherapy should be tested in randomized trials given its potential to improve prognosis in treatment-naive AITL patients. Furthermore, autologous hematopoietic stem cell transplantation (auto-HSCT) has demonstrated enhanced overall survival in individuals with AITL.

Clinical trial registration

https://clinicaltrials.gov/, NCT03268889.

Complete hematologic response in a patient with multiple pretreated angioimmunoblastic T-cell lymphoma after belinostat therapy followed by allogeneic stem cell transplantation: A case report

Key Clinical Message

Belinostat therapy followed by hematopoietic stem cell transplantation is a promising salvage strategy for heavily pretreated patients with peripheral T-cell lymphoma.

Abstract

Effective treatments for peripheral T-cell lymphoma in the relapsed and refractory (r/r) setting are limited. However, with the development and approval of innovative therapies, effective therapeutic options are becoming available for this patient population. This case report describes the treatment course of a patient with multiple r/r nodal follicular T-helper cell lymphoma of angioimmunoblastic type. Treatment with the histone deacetylase inhibitor belinostat as bridging, enabled allogeneic stem cell transplantation and resulted in a durable complete hematologic response for at least 21 months post-transplantation.

Romidepsin Plus Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone Versus Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone in Patients With Previously Untreated Peripheral T-Cell Lymphoma: Final Analysis of the Ro-CHOP Trial

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The primary analysis of the Ro-CHOP phase III randomized controlled trial (ClinicalTrials.gov identifier: NCT01796002) established that romidepsin (Ro) plus cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) did not yield an increased efficacy compared with CHOP alone as first-line treatment of peripheral T-cell lymphoma. We report the planned final analysis 5 years after the last patient enrolled. With a median follow-up of 6 years, median progression-free survival (PFS) was 12.0 months compared with 10.2 months (hazard ratio [HR], 0.79 [95% CI, 0.62 to 1.005]; P = .054), while median overall survival was 62.2 months (35.7-86.6 months) and 43.8 months (30.1-70.2 months; HR, 0.88 [95% CI, 0.68 to 1.14]; P = .324) in the Ro-CHOP and CHOP arms, respectively. In an exploratory analysis, the median PFS in the centrally reviewed follicular helper T-cell lymphoma subgroup was significantly longer in the Ro-CHOP arm (19.5 v 10.6 months, HR, 0.703 [95% CI, 0.502 to 0.985]; P = .039). Second-line treatments were given to 251 patients with a median PFS2 and OS2 after relapse or progression of 3.3 months and 11.5 months, respectively. Within the limits of highly heterogeneous second-line treatments, no specific regimen seemed to provide superior disease control. However, a potential benefit was observed with brentuximab vedotin in association with chemotherapy even after excluding anaplastic large-cell lymphoma subtype or after adjusting for histology and international prognostic index in a multivariate model (HR for PFS, 0.431 [95% CI, 0.238 to 0.779]; P = .005).

Enteric associated T-cell lymphoma in a mule

A 25-year-old female mule weighing 336 kg was referred with a history of lethargy, abdominal discomfort, anorexia, and constipation in the previous 24 hours. On admission, decreased intestinal borborygmi and distended small intestinal loops were detected by auscultation and rectal palpation, respectively. On rectal examination a firm, irregular surface, and pedunculated mass were detected in the middle-caudal region of the abdomen. Transrectal ultrasonography revealed the mass was highly vascularized with heterogeneous tissue density. On exploratory celiotomy two neoplastic masses were observed, one in the jejunoileal junction obstructing the intestinal flow and the second in the dorsal part of the jejunal mesentery, unable to be exposed and resected. An enterectomy was conducted, and the intestinal mass was removed. The mass was pale with hemorrhagic areas and 12 cm in diameter. Histopathology and immunohistochemistry confirmed a diagnosis of enteric associated T cell lymphoma subtype 2. The mule died suddenly 43 days later.

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.