Search Results (29)

Introduction: Immune evasion through inhibition of effector T cells is a key survival mechanism of lymphoma cells. We hypothesized that reinstating effector T cell activity through concurrent inhibition of the PD1/PD-L1 axis and of Treg activity will result in a synergistic anti-tumor effect with an acceptable toxicity profile. Methods: Phase I multi-institutional NCI-ETCTN trial aimed to evaluate the safety and tolerability of the combination of mogamulizumab and pembrolizumab in relapsed or refractory non-Hodgkin lymphoma. The study used a 3 + 3 design. Treatment consisted of mogamulizumab 1 mg/kg on days 1, 8, and 15 of cycle 1, followed by 1.5 mg/kg on day 1 of each subsequent 21-day cycle in combination with pembrolizumab 200 mg on day 1 of each cycle. A de-escalation level was defined as a 50% reduction in the dose of mogamulizumab (registered in clinicaltrials.gov NCT03309878). Results: The study was discontinued early, after treating seven patients (two angioimmunoblastic T cell lymphoma, four transformed follicular lymphoma, and one diffuse large B cell lymphoma of germinal center subtype) for concerns of futility and non-tolerability. Only two patients completed the first two cycles of treatment. Three patients presented with an early progression and three withdrew consent in the setting of general deterioration with clinically suspected progression. All six patients expired shortly after withdrawal from the study. The remaining patient experienced stress cardiomyopathy during the third cycle and was taken off the study. Discussion: In striking difference to the observation in solid malignancies, the combination of mogamulizumab with pembrolizumab was associated with low tolerability and suspected hyper-progression in patients with lymphoma. Full article

Background: Angioimmunoblastic T-cell lymphoma (AITL) and peripheral T-cell lymphomas (PTCL), not otherwise specified (NOS), share overlapping histology and T-follicular helper (TFH) biology but often show divergent outcomes and treatment needs. The clinical significance of KMT2A rearrangement (KMT2A-r) in nodal PTCL remains undefined. We aimed to investigate the clinicogenomic features and prognostic impact of KMT2A-r in AITL and PTCL-NOS. Methods: We retrospectively analyzed consecutive patients diagnosed with AITL or PTCL-NOS between 2021 and 2024 at two centers. All patients underwent 523-gene DNA/RNA next-generation sequencing. Gene co-variation and diagnostic splits were summarized using network and decision-tree analyses. Results: Overall, 37 patients were included (AITL: 14; PTCL-NOS: 23), with similar baseline clinical characteristics. In AITL, TFH markers were more frequently expressed, and RHOA mutations were enriched. KMT2A-r occurred in 24% of cases without histology-specific enrichment. AITL showed better 2-year overall survival (OS) than PTCL-NOS (70.7% vs. 38.8%; p = 0.040) but similar progression-free survival (PFS). Univariate analysis revealed that KMT2A-r, lactate dehydrogenase elevation, and bone-marrow involvement predicted inferior PFS (Hazard ratio for KMT2A-r: 2.56). Median PFS was 5.9 versus 12.5 months in the KMT2A-r and non-KMT2A-r groups, respectively (p = 0.039). Brentuximab vedotin (BV) plus cyclophosphamide, doxorubicin, and prednisone did not significantly improve OS or PFS overall; however, exploratory analysis indicated improved PFS in the KMT2A-r subset. Conclusions: KMT2A-r delineates an adverse-risk biology in nodal PTCL, aligns with non-TFH genomic hubs and markers of tumor burden, and may serve as a stratifier and hypothesis-generating target for BV-based strategies. Full article

Background/Objectives: Angioimmunoblastic T-cell lymphoma (AITL) is a rare peripheral T-cell lymphoma of follicular helper T-cell (TFH) origin, often associated with immune dysregulation and EBV-positive B-cell proliferation. Kaposi sarcoma (KS) is a vascular neoplasm caused by human herpesvirus 8 (HHV-8), typically arising in immunocompromised individuals. The synchronous occurrence of AITL and KS in HIV-negative patients is exceptionally rare, with only three cases previously reported worldwide. Case Presentation: We describe an 81-year-old HIV-negative Korean woman presenting with progressive generalized edema and dyspnea. Imaging revealed multifocal lymphadenopathy. Excisional biopsy of the inguinal lymph node showed two distinct but adjacent neoplastic processes. The AITL component demonstrated a polymorphous infiltrate of atypical TFH cells expressing CD3, CD4, CD10, PD-1, and Bcl-6, with monoclonal TCR-γ rearrangement and TET2 and RHOA mutations. The KS component comprised spindle cells with slit-like vascular spaces, red blood cell extravasation, and immunoreactivity for HHV-8, CD31, CD34, and ERG. The findings were consistent with a collision tumor. Despite supportive care, the patient’s condition deteriorated, and she was discharged with palliative care. Discussion: The coexistence of AITL and KS in an HIV-negative setting raises important pathogenetic considerations. AITL is characterized by profound immune dysregulation, with depletion of normal T-cell subsets, abnormal B-cell activation, and cytokine milieu changes that may favor latent viral reactivation. This immunologic environment may permit HHV-8 reactivation, thereby facilitating the development of KS even in the absence of overt immunodeficiency due to HIV infection. Our findings support the hypothesis that AITL-related immune dysfunction may create a permissive niche for HHV-8-driven neoplasia. Conclusions: This is the first reported case in Asia and the fourth worldwide of a collision tumor comprising AITL and KS in an HIV-negative patI dient. The case suggests that AITL-associated immune dysregulation may facilitate HHV-8 reactivation and KS development even in the absence of HIV infection. Awareness of this association is critical for accurate diagnosis and optimal patient management. Full article

Angioimmunoblastic T-cell lymphoma (AITL) is a rare and aggressive subtype of non-Hodgkin lymphoma, the monitoring of which is largely restricted to radiological methods. Diagnosis relies on identifying characteristic clinicopathological features, supported by the detection of recurrent somatic mutations in RHOA, TET2, IDH2 and DNMT3A. The characteristic molecular profile of AITL and the high levels of circulating tumour DNA (ctDNA) measurable in AITL before treatment makes this an attractive lymphoma subtype in which to further investigate the role of ctDNA monitoring. The detection of somatic mutations in pre-treatment AITL-containing tissue samples was compared to those detected in pre-treatment ctDNA samples in a cohort of 12 patients. Changes in ctDNA somatic mutation burden over time were then correlated with radiological response. All six paired pre-treatment ctDNA and tissue samples had variants in common. All (8/8) previously ctDNA-detectable IDH2 and RHOA variants were undetectable in ctDNA samples at the time of end-of-treatment complete metabolic response (CMR). In comparison, the majority of both previously ctDNA-detectable DNMT3A variants (3/4) and TET2 variants (6/11) were detectable in ctDNA samples at the time of end-of-treatment CMR. These observations suggest that IDH2/RHOA variants may be more reliable markers of measurable residual disease in AITL than DNMT3A/TET2 variants. Full article

Background: T-cell lymphomas (TCLs) are rare and aggressive malignancies associated with poor outcomes, often because of the development of acquired drug resistance as well as intolerance to the established and often toxic chemotherapy regimens in elderly and frail patients. The many subtypes of TCL are well established to exhibit marked geographic variation. The epidemiology, clinical presentation, diagnosis, prognosis, and treatment of TCLs in the Middle East (ME) are yet to be explored; hence, limited data are available about these entities in this part of the world. Aim: Therefore, in this review article, we aim to discuss the available data regarding the T-cell neoplasms in the ME, including the incidence of specific subtypes of peripheral T-cell lymphoma (PTCL), as well as the trends in survival and treatment, all in an effort to understand the natural history of these complex entities across the ME. Full article

Romidepsin is an important therapeutic option for patients with peripheral T-cell lymphoma (PTCL). However, the timing of romidepsin administration remains controversial. The objective of this study was to characterize the safety and efficacy of romidepsin as consolidation therapy after gemcitabine, dexamethasone, and cisplatin (GDP) therapy (GDPR). This study of patients treated between March 2019 and March 2021 was registered with the Japan Registry of Clinical Trials (registration number: jRCT0000000519). If complete response, partial response, or stable disease was confirmed after 2–4 GDP cycles, romidepsin was administered every 4 weeks for 1 year. Seven patients with relapsed/refractory (R/R) PTCL (T-follicular helper phenotype [n = 1] and angioimmunoblastic T-cell lymphoma [n = 6]) were included in this prospective study (PTCL-GDPR). After a median follow-up of 34 months of patients in PTCL-GDPR, the 2-year overall survival rate was 71%, and the overall response rate after treatment was 57%. Common adverse events in patients with PTCL-GDPR included hematological toxicities such as neutropenia, which improved with supportive treatment. There were no treatment-related mortalities. GDPR might be safe and effective in elderly transplant-ineligible patients with R/R PTCL; however, further investigation is required. Full article

Although trophoblast cell surface antigen 2 (Trop2)-targeting drugs are already approved or under investigation in various solid tumors, the significance of Trop2 in lymphoma is unknown. Thus, our objective was to investigate the expression of Trop2 in diffuse large B-cell lymphoma (DLBCL) through a systemic immunohistochemistry screening. We constructed a tissue microarray comprising tissue from 92 DLBCL patients, each diagnosed at the University Medical Center Hamburg-Eppendorf (2020–2022). Trop2-immunohistochemistry was carried out, and positive staining was deemed a specific membranous positivity. Four samples were derived from Epstein-Barr virus (EBV)-positive DLBCL, with one case of EBV-positive DLBCL following angioimmunoblastic T-cell lymphoma (AITL). Strong Trop2 immunostaining was detectable in 1 of 91 analyzable samples, originating from a patient with a composite EBV-positive DLBCL emerging from AITL. Therefore, we performed an additional database search to identify all cases of composite EBV-positive DLBCL emerging from AITL since 2015. Five additional cases were identified and stained for Trop2, revealing two cases with strong B-blast positivity. Our preliminary data imply that Trop2 appears absent in de novo DLBCL, whereas Trop2 is strongly expressed in cases of a rare variant of EBV-positive DLBCL. Further investigations are needed to confirm our results, particularly on the subset of EBV-positive DLBCL emerging from AITL. Full article

Peripheral T-cell lymphomas (PTCLs) expressing multiple follicular T helper (TFH) cell-related antigens are now classified as TFH lymphomas (TFHL), including angioimmunoblastic, follicular, and not otherwise specified (NOS) types. CXCR5 is the TFH cell-defining chemokine receptor that, together with its ligand CXCL13, plays a critical role in the development of follicles and the positioning of TFH and B cells within follicles. A comprehensive immunomorphologic study was performed to investigate the expression pattern of CXCR5 in a large cohort of nodal PTCLs, particularly those with a TFH cell phenotype, and to compare its expression with six other TFH cell-related antigens. We found that CXCR5 is widely expressed in neoplastic TFH cells, except in TFHL-NOS, and represents a specific marker of this lymphoma entity. Our results suggest that CXCR5 directs the distribution of neoplastic T cells in the affected lymph nodes and may influence the formation of the pathognomic pathological FDC network. Full article

We report a case of a 24-year-old man who developed angioimmunoblastic T-cell lymphoma (AITL) after treatment for refractory lymphocyte-rich classic Hodgkin lymphoma (LR-CHL). This patient was treated with the BV+AVD (brentuximab vedotin, doxorubicin, vinblastine, and dacarbazine) protocol for LR-CHL but progressed before completing chemotherapy. The pathological imaging showed the typical findings of LR-CHL at the first onset and first progression. Rescue chemotherapy and high-dose chemotherapy combined with autologous hematopoietic stem cell transplantation (AHSCT) were performed for refractory LR-CHL, and complete remission was achieved. However, the recurrence was suspected 6 months after AHSCT. The pathological findings of the lymph node biopsy at this time were different from those of the previous two lymph node biopsies, demonstrating findings of AITL. The finding of the immunohistochemical staining and polymerase chain reaction results supported the diagnosis. Although it has been reported that the risk for the development of non-Hodgkin lymphoma after treatment for Hodgkin lymphoma is increased, most are B-cell lymphomas, and few cases of AITL have been reported. AITL is a type of peripheral T-cell lymphoma that generally occurs in middle-aged and elderly people and that rarely occurs in young people. Here, we were able to make an accurate diagnosis by performing re-examination even when recurrence of LR-CHL was suspected. As there are no detailed case reports of AITL developing into secondary non-Hodgkin lymphoma, here we report on an identified case. Full article

Diffuse large B-cell lymphoma (DLBCL) and angioimmunoblastic T-cell lymphoma (AITL) are two subtypes of non-Hodgkin lymphoma (NHL). The simultaneous occurrence of DLBCL and AITL in a composite lymphoma is very rare, and there are no established treatment regimens. We present the case of an 85-year-old male admitted to the intensive care unit with distributive shock, lymphocytosis, and lymphadenopathy, who was subsequently diagnosed with composite AITL and DLBCL, and treated with brentuximab vedotin (BV) and rituximab. To our knowledge, this is the first case of composite lymphoma presenting with distributive shock and treated with BV and rituximab, with successful resolution of shock. Full article

Peripheral T-cell lymphomas (PTCLs) are a group of diseases with a low incidence, high degree of heterogeneity, and a dismal prognosis in most cases. Because of the low incidence of these diseases, there have been few therapeutic novelties developed over time. Nevertheless, this fact is changing presently as epigenetic modifiers have been shown to be recurrently mutated in some types of PTCLs, especially in the cases of PTCLs not otherwise specified (PTCL-NOS), T follicular helper (TFH), and angioimmunoblastic T-cell lymphoma (AITL). These have brought about more insight into PTCL biology, especially in the case of PTCLs arising from TFH lymphocytes. From a biological perspective, it has been observed that ten-eleven translocators (TET2) mutated T lymphocytes tend to polarize to TFH, while Tregs lose their inhibitory properties. IDH2 R172 was shown to have inhibitory effects on TET2, mimicking the effects of TET2 mutations, as well as having effects on histone methylation. DNA methyltransferase 3A (DNMT3A) loss-of-function, although it was shown to have opposite effects to TET2 from an inflammatory perspective, was also shown to increase the number of T lymphocyte progenitors. Aside from bringing about more knowledge of PTCL biology, these mutations were shown to increase the sensitivity of PTCLs to certain epigenetic therapies, like hypomethylating agents (HMAs) and histone deacetylase inhibitors (HDACis). Thus, to answer the question from the title of this review: We found the Achilles heel, but only for one of the Achilles. Full article

Nodal T-follicular helper cell lymphoma, angioimmunoblastic-type (AITL), is characterized by constitutional symptoms, advanced-stage disease, and generalized lymphadenopathy. A genetic hallmark of this lymphoma is the frequent occurrence of the RHOA mutation G17V in neoplastic cells, which is observed in around 60% of patients. Because RHOA is involved in both T-cell receptor downstream signalling and cell migration, we hypothesized that the characteristic presentation of AITL could be the result of enhanced tumor cell migration. Therefore, this study aimed to elucidate the impact of the RHOA variant G17V on the migration of neoplastic T cells. We transfected the T-cell lymphoma cell lines HH and HuT78 to stably express the RHOA-G17V variant. RHOA-G17V-expressing T cells did not exhibit enhanced motility compared to empty-vector-transfected cells in microchannels, a 3D collagen gel, or primary human lymphatic tissue. Cells of the HH cell line expressing RHOA-G17V had an increased number of cells with cleaved collagen compared with the empty-vector-transfected cells. Therefore, we hypothesized that the early spread of AITL tumor cells may be related to remodelling of the extracellular matrix. Accordingly, we observed a significant negative correlation between the relative area of collagen in histological sections from 18 primary AITL and the allele frequency of the RHOA-G17V mutation. In conclusion, our results suggest that the characteristic presentation of AITL with early, widespread dissemination of lymphoma cells is not the result of an enhanced migration capacity due to the RHOA-G17V mutation; instead, this feature may rather be related to extracellular matrix remodelling. Full article

Angioimmunoblastic T-cell lymphoma (AITL), a type of malignant lymphoma with unique genomic aberrations, significant clinicopathological features, and poor prognosis, is characterized by immune system dysregulation. Recent sequencing studies have identified recurrent mutations and interactions in tet methylcytosine dioxygenase 2 (TET2), ras homology family member A (RHOA), DNA methyltransferase 3 alpha (DNMT3A), and mitochondrial isocitrate dehydrogenase II (IDH2). Notably, since B-cell lymphomas are frequently observed along with AITL, this review first summarizes its controversial mechanisms based on traditional and recent views. Epigenetic regulation represented by TET2 plays an increasingly important role in understanding the multi-step and multi-lineage tumorigenesis of AITL, providing new research directions and treatment strategies for patients with AITL. Here, we review the latest advances in our understanding of AITL and highlight relevant issues that have yet to be addressed in clinical practice. Full article

Nodal peripheral T cell lymphoma (PTCL) with T follicular helper (TFH) cell phenotype is a provisional entity added to the 2016 revised WHO classification of haematological malignancies. These lymphomas have an aggressive clinical course and respond poorly to conventional treatments. Distinct histological features have not been well described. Additionally, the minimum criteria for diagnosis is not well established but detection of at least two TFH markers in addition to CD4 is suggested to assign a TFH cell phenotype. Some pathological features of angioimmunoblastic T cell lymphoma (AITL) such as recurrent molecular alterations are commonly found. As the name suggests, these lymphomas are nodal in origin with patients presenting with widespread lymphadenopathy. We describe the first documented case of nodal PTCL with a TFH phenotype presenting as an isolated mesenteric mass with no nodal involvement. Full article

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. Full article