Impact of rituximab on treatment outcomes of patients with angioimmunoblastic T-cell lymphoma; a population-based analysis

TP53 and CDKN2A alterations define a poor prognostic subgroup in patients with nodal T follicular helper cell lymphoma

Nodal T follicular helper cell lymphoma (nTFHL) exhibits unique immunophenotypes and somatic alterations, while the prognostic value of these alterations remains unclear. By analyzing 173 nTFHL cases, we identified 36 driver genes, including 4 novel ones (TET3, HLA-C, NRAS, and KLF2). Then, we classified nTFHL cases into four molecular subgroups by major driver alterations. TR-I (+) and TR-I (-) were characterized by TET2 and/or RHOA mutations with and without IDH2 mutations; AC53 by TP53 and/or CDKN2A alterations and aneuploidy; and NSD with no subgroup-defining alterations (namely without any of the above alterations). AC53 exhibited the worst survival, while NSD, particularly those lacking driver alterations, showed the best prognosis. nTFHL had a better prognosis than peripheral T-cell lymphoma, not otherwise specified, when TP53 and/or CDKN2A alterations were absent. Multivariable analyses showed that AC53, the presence of driver alterations, and international prognostic index high-risk were independently associated with worse survival. Finally, we developed a simple prognostic index (mTFHL-PI), which classified patients into three risk categories with a median OS of 181, 67, and 20 months, respectively. Our study identifies novel prognostic factors, namely TP53 and/or CDKN2A alterations and the presence of driver alterations, demonstrating the clinical relevance of molecular classification in nTFHL.

Angioimmunoblastic T-cell lymphoma: Current Diagnostic Insights and Advances

Angioimmunoblastic T-cell lymphoma (AITL), or nodal T-follicular helper cell lymphoma, angioimmunoblastic type, is a rare and aggressive type of T-cell lymphoma characterized by a spectrum of clinical and histopathological features that can present diagnostic challenges. Derived from T-follicular helper cells, the genesis of AITL is thought to be a multistep process involving mutations in epigenetic regulatory genes such as TET2 and DNMT3A, followed by driver mutations in RHOAG17V and IDH2R172 which promote clonal expansion as well as a characteristic inflammatory milieu. This review aims to provide a comprehensive overview of AITL, including its clinical presentation, epidemiology, pathogenesis, histomorphology and treatment options. Despite advancements in the understanding of AITL biology and the development of novel treatment strategies, the prognosis for patients with AITL remains poor.

Role of the Crosstalk B:Neoplastic T Follicular Helper Cells in the Pathobiology of Nodal T Follicular Helper Cell Lymphomas

Angioimmunoblastic T-cell lymphoma (AITL), the most common form of peripheral T-cell lymphoma, originates from follicular helper T (Tfh) cells and is notably resistant to current treatments. The disease progression and maintenance, at least in early stages, are driven by a complex interplay between neoplastic Tfh and clusters of B-cells within the tumor microenvironment, mirroring the functional crosstalk observed inside germinal centers. This interaction is further complicated by recurrent mutations, such as TET2 and DNMT3A, which are present in both Tfh cells and B-cells. These findings suggest that the symbiotic relationship between these 2 cell types could represent a therapeutic vulnerability. This review examines the key components and signaling mechanisms involved in the synapses between B-cells and Tfh cells, emphasizing their significant role in the pathobiology of AITL and potential as therapeutic targets.

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.

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.