Retrospective analysis of prognostic factors for angioimmunoblastic T-cell lymphoma: a multicenter cooperative study in Japan

Novel clinical risk stratification and treatment strategies in relapsed/refractory peripheral T-cell lymphoma

Peripheral T cell lymphoma (PTCL) represents a group of heterogeneous hematological malignancies, which are notoriously challenging to treat and outcomes are typically poor. Over the past two decades, clinical prognostic indices for patient risk stratification have evolved, while several targeted agents are now available to complement combination chemotherapy in the frontline setting or as a salvage strategy. With further understanding of the molecular pathobiology of PTCL, several innovative approaches incorporating immunomodulatory agents, epigenetic therapies, oncogenic kinase inhibitors and immunotherapeutics have come to the forefront. In this review, we provide a comprehensive overview of the progress in developing clinical prognostic indices for PTCL and describe the broad therapeutic landscape, emphasizing novel targetable pathways that have entered early phase clinical studies.

What is new in the 5th edition of the World Health Organization classification of mature B and T/NK cell tumors and stromal neoplasms?

The classification of tumors is essential in the diagnosis and clinical management of patients with malignant neoplasms. The World Health Organization (WHO) provides a globally applicable classification scheme of neoplasms and it was updated several times. In this review, we briefly outline the cornerstones of the upcoming 5th edition of the World Health Organization Classification of Haematolymphoid Tumours on lymphoid neoplasms. As is adopted throughout the 5th edition of the WHO classification of tumors of all organ systems, entities are listed by a hierarchical system. For the first time, tumor-like lesions have been included in the classification, and modifications of nomenclature for some entities, revisions of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities are presented along with mesenchymal lesions specific to the stroma of lymph nodes and the spleen. In addition to specific outlines on constitutional and somatic genetic changes associated with given entities, a separate chapter on germline predisposition syndromes related to hematologic neoplasms has been added.

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.

The 5th edition of the World Health Organization Classification of mature lymphoid and stromal tumors - an overview and update

The purpose of this review is to give an overview on the conceptual framework and major developments of the upcoming 5th edition of the World Health Organization (WHO) Classification of Haematolymphoid tumours (WHO-HAEM5) and to highlight the most significant changes made in WHO-HAEM5 compared with the revised 4th edition (WHO-HAEM4R) of lymphoid and stromal neoplasms. The changes from the revised 4th edition include the reorganization of entities by means of a hierarchical system that is realized throughout the 5th edition of the WHO classification of tumors of all organ systems, a modification of nomenclature for some entities, the refinement of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities. For the first time, tumor-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms are included in the classification.

Angioimmunoblastic T-cell lymphoma involving the nasopharynx: An easily misdiagnosed disease with atypical histopathological features

OBJECTIVES

To explore the clinicopathologic features, treatment, and survival outcomes of angioimmunoblastic T-cell lymphoma (AITL) involving the nasopharynx.

METHODS

We retrospectively analyzed 73 cases of AITL. Among them, 64 cases with complete pre-treatment 18F-FDG positron emission tomography/computed tomography (PET/CT) images were integrated into the analysis of clinical characteristics and PET/CT findings of AITL involving the nasopharynx; 14 cases with both biopsies from lymph node and nasopharynx were included in the comparison of pathological characteristics of AITL in the two areas. Forty-six of the 73 patients who received first-line systemic treatment at our institute were included in the treatment efficacy and survival analyses.

RESULTS

Nasopharyngeal involvement was seen in 44/64 (68.8%) patients. Histologically, lymph node and nasopharyngeal biopsies in 14 patients both showed small to medium-sized tumor cells, complex inflammatory infiltration, and Reed-Sternberg-like cells or B immunoblasts. However, tumor cells with clear cytoplasm, significant high endothelial venule (HEV) hyperplasia, and perivascular infiltration were observed in 5/14, 3/14, and 2/14 nasopharyngeal biopsies, respectively, but in all fourteen lymph node biopsies (P < 0.05). Immunophenotypic profiles and gene rearrangements were highly concordant. Treatment efficacy and survival were similar between patients with nasopharyngeal involvement and those without (P > 0.05), indicating nasopharyngeal involvement is not a prognostic factor for AITL patients.

CONCLUSIONS

Nasopharyngeal involvement is common in AITL but can be easily misdiagnosed because of its atypical pathologic pattern, especially when a lymph node biopsy is unavailable. However, the patient's clinical presentation, PET/CT manifestations, the typical immunophenotype, and gene rearrangements help the diagnosis.

Clinical and histological study of follicular helper T-cell lymphomas with indolent evolution

INTRODUCTION

Follicular helper T-cell lymphomas (TFHL) have an aggressive course with a poor outcome. European and US guidelines recommend anthracycline-based chemotherapy as a first-line treatment, but the 5-year overall survival rate is still approximately 30%. We describe here the features of a cohort of TFHL patients who experienced prolonged survival despite the absence of specific treatment or the initiation of steroid-based therapy.

PATIENTS AND METHODS

In our study, we describe 15 adult patients who suffered from TFHL and had not received intensive chemotherapy at diagnosis for any reason. Biopsies of these cases were centrally reviewed, and the mutational pattern was determined using next-generation sequencing.

RESULTS

These 15 patients had the classic clinical, biological and pathological features of TFHL, angioimmunoblastic-type. TET2 mutations were found in 83% of patients; RHOA G17V, IDH2 R172 and DNMT3A mutations were found in 67%, 42% and 33% of the patients, respectively. Among the 15 patients, 8 did not receive any treatment, and 7 received steroid-based treatment. Ten patients had progression (5 in each group). Four patients died (3 of them from the progression of their lymphoma). The median follow-up in our cohort was 53 months. The 5-year OS was 66%, 100% for untreated patients and 29% for the others. In those 2 groups, the median time to treatment initiation was 22 months from diagnosis.

CONCLUSION

We described a series of 15 well-characterized TFHL patients with an indolent outcome, suggesting that a watch-and-wait approach can be proposed in selected patients. Identifying factors predicting such evolution is warranted.

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.

The Role of Epigenetic Modifier Mutations in Peripheral T-Cell Lymphomas

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.

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.

The clinical features, treatment, and prognostic factors for peripheral T-cell lymphomas: A single-institution analysis of 240 Chinese patients

AIM

This study aimed to analyze the clinical features, treatment, survival, and prognostic factors of Chinese patients with peripheral T-cell lymphoma (PTCL) excluding natural killer/T-cell lymphoma (NKTCL).

METHODS

Data on patients with newly diagnosed PTCLs between January 1, 2006 and December 31, 2017 at our hospital were retrospectively reviewed. Patients with NKTCL were excluded.

RESULTS

A total of 240 patients were included. PTCL, not otherwise specified (PTCL-NOS), was the most frequent subtype (42.5%), followed by angioimmunoblastic T-cell lymphoma (AITL) (21.3%), anaplastic lymphoma kinase (ALK)-negative anaplastic large-cell lymphoma (ALK-ALCL) (16.7%), ALK-positive ALCL (ALK+ALCL) (10.8%) and others (8.8%). With a median follow-up of 81.1 months, the 5-year progression-free survival (PFS) and overall survival (OS) rates for all patients were 30.4% (95% CI 25.0%-37.0%) and 48.8% (95% CI 42.6%-55.7%), respectively. On multivariate analysis, no consolidative autologous stem cell transplantation (ASCT) and not achieving complete response after first-line chemotherapy retained independently prognostic value for inferior PFS and OS. Besides, bone marrow involvement and serum albumin level were independent factors for PFS, and Eastern Cooperative Oncology Group performance status ≥2 was significantly predictive of inferior OS. Compared with PTCL-NOS, significantly superior PFS and OS were observed for ALK+ALCL and ALK-ALCL.

CONCLUSION

The survival outcomes with current treatment for most PTCL subtypes are still unsatisfactory. Prospective randomized studies are needed to establish the value of consolidative ASCT in PTCL, and novel therapeutic approaches should be explored.

Correlation of low numbers of intratumoral FOXP3+ cells with worse progression-free survival in angioimmunoblastic T cell lymphoma

AIMS

Angioimmunoblastic T cell lymphoma (AITL) is a T cell lymphoma with aberrant immune activity. It is characterised by inflammatory and immune reactions. However, the impact of regulatory T (Treg) cells on AITL remains unclear.

METHODS

We retrospectively collected 46 AITL cases and performed immunohistochemical analysis of forkhead box P3 (FOXP3) expression. The number of immunostained FOXP3 cells was determined using a digital pathology system with whole-slide imaging. The average number of FOXP3+ cells per high-power field (HPF) was determined by randomly counting 20 HPFs. AITL cases were categorised into high-expression and low-expression groups based on the median count of FOXP3+ cells in all analysed samples. The relationship between FOXP3 expression and clinicopathological features was assessed.

RESULTS

Among the studied patients, 14 (30.4%) were females and 32 (69.6%) were males, and the median age at diagnosis was 64.1 years. The median expression of FOXP3 was 84.9 positive cells/HPF. FOXP3 expression negatively correlated with Epstein-Barr virus-encoded small RNA positivity in tumour (p=0.041). The patients with low FOXP3 expression presented with aggressive clinical behaviour, including advance-staged diseases (p=0.043), splenomegaly (p=0.008), B symptoms (p=0.019) and extranodal involvement (p=0.019). The neutrophil-to-lymphocyte ratio was higher in the patients with low FOXP3 expression, compared with those with high FOXP3 expression. Low FOXP3 expression had an adverse effect on progression-free survival (PFS, p=0.033), and increased the risk of recurrence 2.320-fold (HR 2.320 (95% CI 1.109 to 4.856); p=0.025).

CONCLUSIONS

Patients with AITL with low FOXP3 expression tend to have aggressive clinical presentation and shortened PFS. These findings may help with risk stratification and determination of new treatment strategy.

Circulating tumor DNA in NK/T and peripheral T cell lymphoma

Natural killer (NK)/T-cell lymphomas (NK/TCL) and peripheral T-cell lymphomas (PTCL) are aggressive hematological malignancies. With the development of next-generation sequencing, circulating tumor DNA (ctDNA) can be detected by several techniques with clinical implications. So far, the effect of ctDNA in pretreatment prognosis prediction, longitudinal monitoring of treatment response and surveillance of long-term remission or relapse in NK/TCL and PTCL has been reported in several researches.

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.

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.

Current Concepts in Nodal Peripheral T-Cell Lymphomas

This review summarizes the current understanding of mature T-cell neoplasms predominantly involving lymph nodes, including ALK-positive and ALK-negative anaplastic large cell lymphomas, nodal T-follicular helper cell lymphoma, Epstein-Barr virus-positive nodal T/NK-cell lymphoma, and peripheral T-cell lymphoma (PTCL), not otherwise specified. These PTCLs are clinically, pathologically, and genetically heterogeneous, and the diagnosis is made by a combination of clinical information, morphology, immunophenotype, viral positivity, and genetic abnormalities. This review summarizes the pathologic features of common nodal PTCLs, highlighting updates in the fifth edition of the World Health Organization classification and the 2022 International Consensus Classification.

Follicular Helper T-Cell-derived Nodal Lymphomas: Study of Histomorphologic, Immunophenotypic, Clinical, and RHOA G17V Mutational Profile

The study was designed to review the demographic, clinical, and pathologic characteristics of follicular helper T cells (TFH)-derived nodal PTCL in India including angioimmunoblastic T-cell lymphoma (AITL), peripheral T-cell lymphoma (PTCL) with follicular helper T cell phenotype (P-TFH), and follicular T-cell lymphoma with additional immunohistochemistry (IHC) and RHOAG17V mutational analysis, as well as their impact on survival. This retrospective study included 88 cases of PTCL that were reclassified using IHC for TFH markers (PD1, ICOS, BCL6, and CD10) and dendritic-meshwork markers (CD21, CD23). Cases of TFH cell origin were evaluated for RHOAG17V mutation using Sanger sequencing and amplification-refractory mutation system-polymerase chain reaction (PCR) (validated using cloning and quantitative PCR) with detailed clinicopathologic correlation. Extensive re-evaluation with added IHC panel resulted in a total of 19 cases being reclassified, and the final subtypes were AITL (37 cases, 42%), PTCL-not otherwise specified (44, 50%), P-TFH (6, 7%), and follicular T-cell lymphoma (1, 1%). The presence of at least 2 TFH markers (>20% immunopositivity) determined the TFH origin. AITL patients tended to be male and showed increased presence of B-symptoms and hepatosplenomegaly. Histomorphology revealed that 92% of AITL cases had pattern 3 involvement. Sanger sequencing with conventional PCR did not yield any mutation, while RHOAG17V was detected by amplification-refractory mutation system-PCR in AITL (51%, P =0.027) and P-TFH (17%), which was validated with cloning followed by sequencing. Cases of RHOAG17V-mutant AITL had a worse Eastern Cooperative Oncology Group performance status initially but fared better in terms of overall outcome ( P =0.029). Although not specific for AITL, RHOAG17V mutation shows an association with diagnosis and requires sensitive methods for detection due to low-tumor burden. The mutant status of AITL could have prognostic implications and translational relevance.

Pathologic and molecular insights in nodal T-follicular helper cell lymphomas

T-follicular helper (TFH) cells are one of the T-cell subsets with a critical role in the regulation of germinal center (GC) reactions. TFH cells contribute to the positive selection of GC B-cells and promote plasma cell differentiation and antibody production. TFH cells express a unique phenotype characterized by PD-1^hi, ICOS^hi, CD40L^hi, CD95^hi, CTLA^hi, CCR7^lo, and CXCR5^hi . Three main subtypes of nodal TFH lymphomas have been described: 1) angioimmunoblastic-type, 2) follicular-type, and 3) not otherwise specified (NOS). The diagnosis of these neoplasms can be challenging, and it is rendered based on a combination of clinical, laboratory, histopathologic, immunophenotypic, and molecular findings. The markers most frequently used to identify a TFH immunophenotype in paraffin-embedded tissue sections include PD-1, CXCL13, CXCR5, ICOS, BCL6, and CD10. These neoplasms feature a characteristic and similar, but not identical, mutational landscape with mutations in epigenetic modifiers (TET2, DNMT3A, IDH2), RHOA, and T-cell receptor signaling genes. Here, we briefly review the biology of TFH cells and present a summary of the current pathologic, molecular, and genetic features of nodal lymphomas. We want to highlight the importance of performing a consistent panel of TFH immunostains and mutational studies in TCLs to identify TFH lymphomas.

Cardiac Tamponade as a Recurrence of Angioimmunoblastic T-Cell Lymphoma with the Detection of a p.Gly17Val RHOA Mutation in the Pericardial Effusion

Angioimmunoblastic T-cell lymphoma (AITL) is an intractable type of T-cell lymphoma. We and others have identified that the p.Gly17Val RHOA mutation is specifically identified in AITL. We herein report a patient whose condition deteriorated, resulting from massive pericardial effusion one month after undergoing autologous transplantation for AITL. He was diagnosed with cardiac tamponade caused by AITL recurrence in the presence of the p.Gly17Val RHOA mutation as well as T-lineage cells with an aberrant immune-phenotype in the pericardial effusion. This case suggests that a precision medicine approach by detecting the presence of a p.Gly17Val RHOA mutation is useful for the management of AITL.

Clinicopathologic characteristics, outcomes, and prognostic factors of angioimmunoblastic T-cell lymphoma in China

BACKGROUND

This study aimed to better characterize the clinicopathologic characteristics, outcomes, and prognostic factors of AITL in China.

METHODS

We retrospectively analyzed 312 patients with AITL enrolled between January 2011 and December 2020 from five institutions in China.

RESULTS

The median age was 65 years, with 92.6% advanced stage, 59.7% elevated LDH, 46.1% anemia, and 44.0% hypergammaglobulinemia. The majority of patients (84.9%) received anthracycline-based regimens with or without etoposide, and only 6.1% underwent autologous stem cell transplantation following first remission. The 5-year OS and PFS estimates were 43.4% and 25.0% with no significant improvement of survival between patients treated during 2011-2015 and 2016-2020, respectively. Both the International Prognostic Index (IPI) and the prognostic index for PTCL, not otherwise specified (PIT), were predictive for OS. In multivariate analysis, age >70 years, elevated LDH, and albumin level <35 g/L were independent prognostic factors for OS. Combining these three factors, a novel prognostic model (the Chinese AITL score) was constructed, which stratified patients into low-, intermediate-, and high-risk groups, with 5-year OS rates of 69.0%, 41.5%, and 23.7%, respectively. This new model was successfully validated in an independent cohort.

CONCLUSIONS

Patients with AITL were mainly treated with anthracycline-based regimens, and the outcomes were still unsatisfactory in China. Our novel prognostic model may improve our ability to identify patients at different risks for alternative therapies.

Distinct and overlapping features of nodal peripheral T-cell lymphomas exhibiting a follicular helper T-cell phenotype: a multicenter study emphasizing the clinicopathological significance of follicular helper T-cell marker expression

Nodal peripheral T-cell lymphoma (PTCL) is a heterogeneous category including angioimmunoblastic T-cell lymphoma (AITL), PTCL of follicular helper T-cell (Tfh) phenotype (PTCL-Tfh), and PTCL, not otherwise specified (PTCL-NOS). We explored Tfh marker profiles in nodal PTCL. Nodal PTCLs (n = 129) were reclassified into AITL (58%; 75/129), PTCL-Tfh (26%; 34/129), and PTCL-NOS (16%; 20/129). Histologically, clear cell clusters, high endothelial venules, follicular dendritic cell proliferation, EBV+ cells, and Hodgkin-Reed-Sternberg (HRS)-like cells were more common in AITL than PTCL-Tfh (HRS-like cells, P = .005; otherwise, P < .001) and PTCL-NOS (HRS-like cells, P = .028; otherwise, P < .001). PTCL-NOS had a higher Ki-67 index than AITL (P = .001) and PTCL-Tfh (P = .002). Clinically, AITL had frequent B symptoms (versus PTCL-Tfh, P = .010), while PTCL-NOS exhibited low stage (versus AITL + PTCL-Tfh, P = .036). Positive Tfh markers were greater in AITL (3.5 ± 1.1) than PTCL-Tfh (2.9 ± 0.9; P = .006) and PTCL-NOS (0.5 ± 0.5; P < .001). Tfh markers showed close correlations among them and AITL-defining histology. By clustering analysis, AITL and PTCL-NOS were relatively exclusively clustered, while PTCL-Tfh overlapped with them. Survival was not different among the PTCL entities. By Cox regression, sex and ECOG performance status (PS) independently predicted shorter progression-free survival in the whole cohort (male, P = .001, HR = 2.5; PS ≥ 2, P = .010, HR = 1.9) and in 'Tfh-lymphomas' (ie, AITL + PTCL-Tfh) (male, P = .001, HR = 2.6; PS ≥ 2, P = .016, HR = 2.1), while only PS predicted shorter overall survival (OS) in the whole cohort (P = .012, HR = 2.7) and in 'Tfh-lymphomas' (P = .001; HR = 3.2). ICOS predicted favorable OS in 'Tfh-lymphomas' (log-rank; P = .016). Despite the overlapping features, nodal PTCL entities could be characterized by Tfh markers revealing clinicopathologic implications.

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.

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

BACKGROUND

Patients with angioimmunoblastic T-cell lymphoma (AITL) are treated with cyclophosphamide, doxorubicin, vincristine and prednisone with or without etoposide (CHO(E)P). In the majority of cases, Epstein-Barr virus (EBV)-positive B-cells are present in the tumour. There is paucity of research examining the effect of rituximab when added to CHO(E)P. In this nationwide, population-based study, we analysed the impact of rituximab on overall response rate (ORR), progression-free survival (PFS) and overall survival (OS) of patients with AITL.

METHODS

Patients with AITL diagnosed between 2014 and 2020 treated with ≥one cycle of CHO(E)P with or without rituximab were identified in the Netherlands Cancer Registry. Survival follow-up was up to 1st February 2022. Baseline characteristics, best response during first-line treatment and survival were collected. PFS was defined as the time from diagnosis to relapse or to all-cause-death. OS was defined as the time from diagnosis to all-cause-death. Multivariable analysis for the risk of mortality was performed using Cox regression.

FINDINGS

Out of 335 patients, 146 patients (44%) received R-CHO(E)P. Rituximab was more frequently used in patients with a B-cell infiltrate (71% versus 89%, p < 0·01). The proportion of patients who received autologous stem cell transplantation (ASCT) was similar between CHO(E)P and R-CHO(E)P (27% versus 30%, respectively). The ORR and 2-year PFS for patients who received CHO(E)P and R-CHO(E)P were 71% and 78% (p = 0·01), and 40% and 45% (p = 0·12), respectively. The 5-year OS was 47% and 40% (p = 0·99), respectively. In multivariable analysis, IPI-score 3-5, no B-cell infiltrate and no ASCT were independent prognostic factors for risk of mortality, whereas the use of rituximab was not.

INTERPRETATION

Although the addition of rituximab to CHO(E)P improved ORR for patients with AITL, the PFS and OS did not improve.

Angioimmunoblastic T-cell Lymphoma Presenting as a Methotrexate-associated Lymphoproliferative Disorder with Extreme Peripheral Blood Plasmacytosis

A 74-year-old man was admitted to our hospital because of systemic lymphadenopathy, weight loss, and a fever at night that had persisted for approximately 1 month. Blood tests revealed extreme peripheral blood plasmacytosis and hypergammaglobulinemia. A lymph node biopsy showed angioimmunoblastic T-cell lymphoma (AITL). Based on the history of methotrexate (MTX) administration, the established diagnosis was MTX-associated lymphoproliferative disorder (MTX-LPD). After MTX was discontinued, the lymphadenopathy spontaneously regressed and the plasmacytosis disappeared. He had no disease progression for three years. We found that AITL as an MTX-LPD can cause plasmacytosis, and the prognosis of this disease may not be poor.

Pathological and Molecular Features of Nodal Peripheral T-Cell Lymphomas

Peripheral T-cell lymphomas (PTCLs) are uncommon neoplasms derived from mature T cells or NK cells. PTCLs comprise numerous disease entities, with over 30 distinct entities listed in the latest WHO classification. They predominantly affect adults and elderly people and usually exhibit an aggressive clinical course with poor prognosis. According to their presentation, PTCLs can be divided into nodal, extranodal or cutaneous, and leukemic types. The most frequent primary sites of PTCLs are lymph nodes, with over half of cases showing nodal presentation. Nodal PTCLs include ALK-positive and ALK-negative anaplastic large cell lymphoma; nodal T-cell lymphoma with T follicular helper cell origin; and PTCL, not otherwise specified. Adult T-cell leukemia/lymphoma also frequently affects lymph nodes. Recent pathological and molecular findings in nodal PTCLs have profoundly advanced the identification of tumor signatures and the refinement of the classification. Therefore, the therapies and pathological diagnosis of nodal PTCLs are continually evolving. This paper aims to provide a summary and update of the pathological and molecular features of nodal PTCLs, which will be helpful for diagnostic practice.

Genetic alterations and oxidative stress in T cell lymphomas

T cell lymphomas encompass a diverse group of Non-Hodgkin lymphomas with a wide spectrum of clinical, immunological and pathological manifestations. In the last two decades there has been a progress in our understanding of the cell of origin, genetic abnormalities and their impact on behaviour in T cell lymphomas. Genetic alterations are one of the critical drivers of the pathogenesis of T cell lymphoma. Disease progression has been correlated with multiple genetic abnormalities where malignant clones arise primarily out of the host immune surveillance arsenal. There are many cellular processes involved in disease development, and some of them are T cell signaling, differentiation, epigenetic modifications, and immune regulation. Modulation of these crucial pathways via genetic mutations and chromosomal abnormalities possessing either point or copy number mutations helps tumor cells to develop a niche favourable for their growth via metabolic alterations. Several metabolic pathways especially regulation of redox homeostasis is critical in pathogenesis of lymphoma. Disruption of redox potential and induction of oxidative stress renders malignant cells vulnerable to mitochondrial damage and triggers apoptotic pathways causing cell death. Targeting genetic abnormalities and oxidative stress along with current treatment regime have the potential for improved therapeutics and presents new combination approaches towards selective treatment of T cell lymphomas.

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.

Peripheral T-Cell Lymphomas: Therapeutic Approaches

Simple Summary

Peripheral T-cell lymphomas are a group of rare cancers of T cells or natural killer cells, most often with a poor prognosis. In recent years, significant progress has been made through the development of more specific therapies. This review aims to provide an up-to-date overview of current treatments in nodal PTCL.

Abstract

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of rare neoplasms of mature T cells or natural killer (NK) cell. PTCLs usually have an aggressive course and a poor outcome. In recent years, significant progress has been made in the knowledge of the molecular lymphomagenesis of PTCLs, and through the development of new, more specific therapeutic molecules, one can hope in the coming years for more personalized medicine and improved patient prognosis. This review aims to provide an up-to-date overview of the current therapeutic approaches in nodal PTCLs.

CD56-positive Angioimmunoblastic T-cell Lymphoma Complicated by Chylothorax

A 77-year-old woman presented with systemic lymphadenopathy and bilateral pleural effusion. Angioimmunoblastic T-cell lymphoma (AITL) was diagnosed based on the results of a lymph node biopsy. AITL cells expressed the aberrant antigen of CD56. The bilateral pleural effusion was attributed to chylothorax, not the infiltration of lymphoma cells into the pleura, as determined by the pleural fluid analysis. We therefore diagnosed her with CD56-positive AITL complicated by chylothorax. She achieved complete remission by multidrug chemotherapy. AITL is commonly complicated by pleural effusion, but rarely by chylothorax. This is the first case of CD56-positive AITL complicated by chylothorax.

Angioimmunoblastic T-cell lymphoma: treatment strategies and prognostic factors from a retrospective multicenter study in China

Angioimmunoblastic T-cell lymphoma (AITL) is a unique sub-type of peripheral T-cell lymphoma (PTCL). We aimed to evaluate treatment programs and prognostic factors of 121 newly diagnosed patients with AITL in China from January 2001 to December 2018. The median age was 58 years with male predominance. Bone marrow involvement appeared in only 8.3% of patients, which was different from the previously published literature. The 5-year progression-free survival (PFS) and 5-year overall survival (OS) were 29.7% and 44.0%, respectively. Univariate and multivariate analyses showed that involvement of >5 nodal areas, age and Beta-2 microglubulin were highly predictive of OS but only the involvement of fewer than five nodal areas was significant for PFS. We identified a novel prognostic model including the three factors that may be applied in clinical practice and offer an alternative to IPI and PIT.

Recent Advances in Diagnosis and Therapy of Angioimmunoblastic T Cell Lymphoma

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

Epigenetic focus on angioimmunoblastic T-cell lymphoma: pathogenesis and treatment

PURPOSE OF REVIEW

Angioimmunoblastic T-cell lymphoma (AITL) is a frequent peripheral T-cell lymphoma affecting elderly patients with a poor outcome when treated with conventional chemotherapy. Molecular studies revealed a homogenous mutational landscape gathering anomalies in genes regulating the DNA methylation and hydroxymethylation and anomalies in T-cell signalling.

RECENT FINDINGS

Recent studies indicate that AITL emerges from a TET2 and/or DNMT3A mutated clonal haematopoiesis. This clonal haematopoiesis bearing mutations altering DNA hydroxymethylation can explain the observed coexistence of AITL with myeloid neoplasms. In addition, AITL development requires AITL-specific mutations, such as the RHOAG17V mutations. Combination of TET2 and RHOAG17V alterations results in the development of AITL-like disease in mouse models. The impact of the presence of these mutations on patient outcome seems limited and new biological factor predicting treatment response and survival remains to be determined. At the therapeutic level, therapies targeting epigenetic changes, such as histone deacetylase inhibitors and the hypomethylating 5-azacytidine agent, could have efficacy in this disease and gave promising results. Recent progress in mouse model development should allow development of new treatments.

SUMMARY

Epigenetic changes are frequent in AITL and could be a promising target.

A Case of Angioimmunoblastic T-cell Lymphoma That Mimics As Autoimmune Diseases and Infections

Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive malignancy with a presentation like either autoimmune diseases, drug reactions, or infections. We hereby present a unique case of AITL. A 61-year-old Caucasian male with a past medical history of chronic obstructive pulmonary disease (COPD) presented to the emergency department with a rash over his bilateral knees, shortness of breath, and productive cough of few days. He was managed for suspected COPD exacerbation associated with community-acquired pneumonia. On the day of admission patient was having an itchy maculopapular rash, ecchymosis on the left flank, and generalized lymphadenopathy. Physical exam showed generalized lymphadenopathy. Laboratory tests revealed leukocytosis, thrombocytopenia and were positive for multiple autoantibodies. Epstein-Barr virus polymerase chain reaction and hepatitis B virus core antibody were positive. Skin biopsy revealed findings suggestive of a small vessel vasculitis. Inguinal lymph node biopsy showed AITL. The patient recovered with chemotherapy. The case illustrates that clinical presentation of AITL mimics rheumatologic disorders and infections. This complexity could arise from the follicular T helper cell, which is an important checkpoint for B cell activation and differentiation. Additionally, skin involvement is one of the important findings of AITL and a variety of lesions have been reported as skin manifestations.

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

Background

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

Conclusions

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

A novel prognostic model for angioimmunoblastic T-cell lymphoma: A retrospective study of 55 cases

Objective

To explore prognostic factors and develop an accurate prognostic prediction model for angioimmunoblastic T-cell lymphoma (AITL).

Methods

Clinical data from Chinese patients with newly diagnosed AITL were retrospectively analysed. Overall survival (OS) and progression-free survival (PFS) were estimated using Kaplan-Meier method survival curves; prognostic factors were determined using a Cox proportional hazards model. The sensitivity and specificity of the predicted survival rates were compared using area under the curve (AUC) of receiver operating characteristic (ROC) curves.

Results

The estimated 5-year OS and PFS of 55 eligible patients with AITL were 22% and 3%, respectively. Multivariate analysis showed that the presence of pneumonia, and serous cavity effusions at initial diagnosis were significant prognostic factors for OS. Based on AUC ROC values, our novel prognostic model was superior to IPI and PIT based models and suggested better diagnostic accuracy.

Conclusions

Our prognostic model based on pneumonia, and serous cavity effusions at initial diagnosis enabled a balanced classification of AITL patients into different risk groups.

Management of Angioimmunoblastic T-Cell Lymphoma (AITL) and other T Follicular Helper Cell lymphomas (TFH PTCL)

Despite the remarkable improvements in the treatment and outcome of patients with aggressive B-cell lymphoma, the peripheral T-cell lymphomas (PTCL) continue to carry a poor prognosis with the presently available treatment options. The PTCL are very rare diseases that account for only 10,000 to 15,000 new cases per year in the United States. The World Health Organization's 2016 classification describes 29 distinct subtypes of PTCL, thus making these both rate and incredibly heterogenous. The 2 most common forms of PTCL, for example, peripheral T-cell lymphoma-not otherwise specified and angioimmunoblastic T-cell lymphoma , have an incidence of only 2500 and 1800 cases per year respectively, in the United States.

[Clinical characteristics and prognosis in 84 patients with angioimmunoblastic T-cell lymphoma: a single-center analysis]

目的

对就诊于我院的初治血管免疫母细胞性T细胞淋巴瘤（AITL）患者进行回顾性研究，探讨AITL患者的临床特征及影响预后的因素。

方法

收集2009年7月至2018年9月就诊于福建医科大学附属协和医院，经淋巴结病理及免疫组织化学检查确诊为AITL患者的临床资料，采用Log-rank检验及Cox比例风险回归模型分析影响患者总生存（OS）期和无进展生存（PFS）期的预后因素。

结果

纳入患者84例，中位发病年龄62（39~86）岁，年龄>60岁者44例（52.4%），男60例（71.4%），男女比例2.5∶1，Ann Arbor分期Ⅲ~Ⅳ期者80例（95.2%），伴B症状者53例（63.1%）。国际预后指数（IPI）评分0~2分者25例（29.8%），3~5分者59例（70.2%）。外周T细胞淋巴瘤预后指数（PIT）评分0~1分者42例（50.0%），2~4分者42例（50.0%）。可评估疗效的61例患者中有16例（26.2%）获得完全缓解/不确定的完全缓解，25例（41.0%）获得部分缓解，总体反应率为67.2%，5年OS率和PFS率分别为46.0%和38.3%。单因素分析显示，年龄、IPI评分、PIT评分、HGB水平、是否有浆膜腔积液、是否化疗对AITL的OS有预后意义，而年龄>60岁、HGB<110 g/L及存在浆膜腔积液是影响PFS的不良因素。多因素分析显示，年龄>60岁、有浆膜腔积液是OS的独立不良预后因素。

结论

AITL是一种侵袭性高、进展快、预后差的非霍奇金淋巴瘤，初诊时多为Ⅲ~Ⅳ期。治疗前的年龄、IPI评分、PIT评分、HGB水平及是否有浆膜腔积液可作为评价预后的参考指标。

Delayed diagnosis of Angioimmunoblast T-cell lymphoma presenting with type II Cryoglobulinemia and acute kidney injury: a case report and narrative review of the literature

Background

Angioimmunoblastic T cell lymphoma (AITL) is an infrequent hematological malignancy with variable and often atypical presentations. The presence of dysproteinemia, autoantibodies and systemic involvement in AITL has often led to a delay in diagnosis or even misdiagnosis in practice. We herewith present a case of AITL that primarily presented with acute kidney injury associated with type II Cryoglobulinemia, the underlying cause was only identified 8 months after the emergence of initial symptoms.

Case presentation

A 67-year old woman presented with 2-month history of intermittent joint pain and a 3-day history of bilateral lower limb edema and acute kidney injury. Initial laboratory investigations showed marked hypocomplementemia with positive autoantibodies of ANA, anti-cardiolipin-IgM and direct antiglobulin. The serum and urinary Immunofixation and serum cryoglobulin tests were negative, while the serum free κ to λ light chain ratio was 0.231. A renal biopsy showed a diffuse proliferative glomerulonephritis with intracapillary pseudothrombi formation. There were orderly arranged microtubular structures of 20–35 nm in diameter in the subendothelial and mesangial area on electron microscopy. Shortly afterwards, the patient developed tingling affecting her finger tips and weak hands and legs. A diagnosis of cryoglobulinemia complicated with cryoglobulinemic glomerulonephritis and polyneuropathy was made. She responded well to methylprednisolone, plasma exchange and rituximab. However, 3 months later, she presented with generalized pruritic rash, weight loss, and inguinal lymphadenopathy. A subsequent inguinal excisional lymph node biopsy at month 8 revealed AITL as the underlying disease.

Conclusions

AITL and its associated B cell dysregulation can give rise to autoimmunity and cryoglobulinemia which may conceal itself as the underlying disorder. In various clinical scenarios of auto-immune diseases, it is advisable that the clinicians should take into consideration the multi-faceted lymphoma.

Development of a Novel Clinical Prognostic Model for Patients With Angioimmunoblastic T-Cell Lymphoma

In this study we aimed to identify a set of prognostic factors for angioimmunoblastic T-cell lymphoma (AITL) and establish a novel prognostic model. The clinical data of 64 AITL patients enrolled to the Fourth Hospital of Hebei Medical University (from 2012 Jan to 2017 May) were retrospectively analyzed. The estimated 5-year overall survival and progression-free survival of this cohort of patients were 45.8% and 30.8%, respectively. Univariate analysis showed that age > 60 years, performance status ≥2, Ann Arbor stage III/IV, lactate dehydrogenase > 250 U/L, serum albumin (ALB) < 30 g/l, Coombs test positive, and Ki-67 rate ≥ 70% were significantly associated with poor prognosis. Multivariate analysis demonstrated that age > 60 years, ALB < 30 g/l, Ki-67 rate ≥ 70%, and Coombs test positive were independent prognosis factors for AITL. Here a new prognostic model, named as AITLI, was constructed using the top 5 significant prognostic factors for AITL prognostic prediction. The AITL patients were stratified into 3 risk groups: low, intermediate, and high risk groups. The new prognostic model AITLI showed better performance in predicting prognosis than the International Prognostic Index (IPI) and the prognostic index for PTCL, not otherwise specified (PIT) that were wisely used to predict the outcome for patients with other subtypes of lymphoma.

New preclinical models for angioimmunoblastic T-cell lymphoma: filling the GAP

Mouse models are essential to study and comprehend normal and malignant hematopoiesis. The ideal preclinical model should mimic closely the human malignancy. This means that these mice should recapitulate the clinical behavior of the human diseases such as cancer and therapeutic responses with high reproducibility. In addition, the genetic mutational status, the cell phenotype, the microenvironment of the tumor and the time until tumor development occurs, should be mimicked in a preclinical model. This has been particularly challenging for human angioimmunoblastic lymphoma (AITL), one of the most prominent forms of peripheral T-cell lymphomas. A complex network of interactions between AITL tumor cells and the various cells of the tumor microenvironment has impeded the study of AITL pathogenesis in vitro. Very recently, new mouse models that recapitulate faithfully the major features of human AITL disease have been developed. Here, we provide a summary of the pathology, the transcriptional profile and genetic and immune-phenotypic features of human AITL. In addition, we give an overview of preclinical models that recapitulate more or less faithfully human AITL characteristics and pathology. These recently engineered mouse models were essential in the evaluation of novel therapeutic agents for possible treatment of AITL, a malignancy in urgent need of new treatment options.

Advances in understanding of angioimmunoblastic T-cell lymphoma

It has been nearly half a century since angioimmunoblastic T-cell lymphoma (AITL) was characterized in the early 1970’s. Our understanding of the disease has dramatically changed due to multiple discoveries and insights. One of the key features of AITL is aberrant immune activity. Although AITL is now understood to be a neoplastic disease, pathologists appreciated that it was an inflammatory condition. The more we understand AITL at cellular and genetic levels, the more we view it as both a neoplastic and an inflammatory disease. Here, we review recent progress in our understanding of AITL, focusing on as yet unsolved questions.

The Incremental Prognostic Value of Baseline 18F-FDG PET/CT Imaging in Angioimmunoblastic T-Cell Lymphoma

Methods

From January 2010 to October 2019, a total of 23 patients who pathologically confirmed to have AITL were retrospectively analyzed. All patients underwent whole-body ¹⁸F-FDG PET/CT scan before chemotherapy. The ¹⁸F-FDG PET/CT features, clinical data, laboratory indicators, Ki67 labeling index, and survival status were collected and analyzed.

Results

The median follow-up was 22 months. The expected 1-, 2-, and 3-year survival rate was 72.2%, 49.6%, and 42.5%, respectively. The median overall survival (OS) was 23 months (95% confidence interval (CI): 8.459~37.541). AITL is prone to extranodal infiltration, in addition to nodal infiltration (6 patients had nodal infiltration alone, and 17 patients had both nodal and extranodal infiltration). The SUV_max of nodal lesions were higher than that for the extranodal lesions (10.43 ± 4.45, 6.64 ± 3.51, F = 2.78, t = 4.39, P < 0.01). On multivariate survival analysis, the Eastern Cooperative Oncology Group (ECOG) and SUV_max of extranodal lesions were independent predictors of OS.

Conclusion

Baseline ¹⁸F-FDG PET/CT results and SUV_max of extranodal lesions showed an incremental prognostic value in addition to clinical prognostic factors.

Angioimmunoblastic T-cell lymphoma in Taiwan reveals worse progression-free survival for RHOA G17V mutated subtype

Angioimmunoblastic T-cell lymphoma (AITL) carries genetic mutations of TET2, RHOA, and IDH2, but the prognostic impact of these mutations is not widely investigated. Although one study shows no difference in overall survival between patients with or without RHOA G17V mutation, a poor performance status is associated with RHOA G17V-mutated AITL, which is an independent adverse factor. We retrospectively investigated the prognostic impact of RHOA G17V mutation in AITL patients. A total of 31 cases were enrolled (male-to-female, 2.1; mean age: 62.8 years). RHOA G17V mutation was analyzed by deep sequencing. We found that in contrast to RHOA-wild type, patients with RHOA G17V-mutated AITL more frequently had B symptoms (p = .035), stronger PD1 expression (p = .045), ≥3 TFH markers (p = .011), higher blood vessel density (p<.001), and poorer progression-free survival (p = .046). These results support a role for RHOA genetic testing in AITL patients as ROHA G17V mutation carries a worse prognosis, probably associated with B symptoms and stage IV disease.

EBV status has prognostic implication among young patients with angioimmunoblastic T-cell lymphoma

Epstein‐Barr virus (EBV)‐positive B cells have been detected in 66%‐86% of patients with angioimmunoblastic T‐cell lymphoma (AITL). However, it remains controversial whether EBV status has an impact on the survival of patients with AITL. In this study, we aimed to reevaluate the impact of EBV on the clinicopathological characteristics of AITL. In particular, we focused on the impact of EBV in younger patients with AITL. In total, 270 cases of AITL were studied. Epstein‐Barr virus‐positive B cells were detected in 191 (71%) cases (EBER⁺ group). Among the patients who received anthracycline‐based therapy, the EBER status did not affect the overall survival (OS) or progression‐free survival (PFS). In the younger group of AITL (≤60 years), PFS was significantly worse in the EBER⁻ group compared to the EBER⁺ group (P = .0013). Furthermore, the multivariate analysis identified EBER‐negative status, thrombocytopenia, and elevated serum IgA level as significant adverse prognostic factors for PFS (P < .001, P < .001, and P = .002). Based on these findings, we constructed new prognostic model for the younger group, based on three adverse factors. We classified the patients into two risk groups: low risk (no or 1 adverse factor) and high risk (2 or 3 adverse factors). This new model for younger patients with AITL showed that both OS and PFS were significantly related to the level of risk (P < .0001). In summary, this study showed that, among younger patients with AITL, an EBER⁺ status significantly improved prognosis compared to an EBER⁻ status. Our new prognostic model should be applicable to younger patients with AITL.

Linear IgA dermatosis in association with angioimmunoblastic T-cell lymphoma infiltrating the skin: A case report with literature review

Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive form of peripheral T-cell lymphoma, characterized by systemic symptoms, diffuse lymphadenopathy, hepatosplenomegaly and immunodysregulation. Half of AITL is associated with cutaneous symptoms, but only few cases with bullous eruption have been described. Association with a linear IgA dermatosis is extremely rare. Linear IgA dermatosis can be idiopathic, or linked with drug intake or neoplastic disorders. Some cases of linear IgA dermatosis presenting as toxic epidermal necrolysis (TEN) have been described, most of them being drug induced. We here present the case of a 72-year-old man recently diagnosed with AITL who developed a bullous eruption, presenting as TEN. Histopathology showed deep cutaneous involvement of the lymphoma with a sub-epidermal blistering and direct immunofluorescence revealed a heavy IgA linear deposit on the dermal-epidermal junction. A diagnosis of linear IgA dermatosis associated with cutaneous involvement of an angioimmunoblastic T-cell lymphoma was made. Chemotherapy and corticosteroids allowed cutaneous improvement but the patient died of his lymphoma shortly after.

Angioimmunoblastic T-cell lymphoma mimicking drug fever and infectious etiology after a thyroidectomy: A case report

INTRODUCTION

Angioimmunoblastic T-cell lymphoma (AITL) is a rare subtype of mature peripheral T-cell lymphoma and accounts for approximately 1% to 2% of non-Hodgkin lymphomas. Although the B symptoms with generalized lymphadenopathy are the most frequent manifestations of AITL, its diagnosis remains a challenge as clinical manifestations and pathological features are frequently misleading.

PATIENT CONCERNS

We report herein the case of a 70-year-old man with intermittent fever, pulmonary infection, and skin rash developed for 1 month before admission. Previously, he had undergone thyroidectomy for thyroid papillary carcinoma. Fever occurred on the day of discharge and occurred again during the next month. Symptoms worsened despite treatment with antibiotics and papular rash appeared. The local hospital diagnosed it as drug fever and stopped all antibiotics. Fever and rash were controlled temporarily; however, both relapsed 2 days before admission. On the night of admission, the patient developed fever again. Blood culture showed Staphylococcus epidermidis and Staphylococcus haemolyticus infection.

INTERVENTIONS

Taking into account the recent history of surgery, the patient was diagnosed with septicemia and was treated with anti-infective treatment. On 13th day after admission, the patient developed fever again accompanied by generalized lymphadenopathy. However, multiple blood cultures were negative and bone marrow aspiration cytology, biopsy, immunohistochemistry, and gene rearrangement results were normal.

DIAGNOSIS

The patient was finally subjected to cervical lymph node biopsy and was diagnosed with AITL.

OUTCOMES

The patient was transferred to the Department of Hematology for further treatment.

CONCLUSION

This case highlights the complex diagnostic challenges of AITL. AITL accompanied by thyroid carcinoma may not be a mere coincidence and administration of antibiotics may be a rare cause of AITL.

Methotrexate-associated lymphoproliferative disorders of T-cell phenotype: clinicopathological analysis of 28 cases

Methotrexate-associated lymphoproliferative disorders are categorized as "other immunodeficiency-associated lymphoproliferative disorders in the WHO classification. Methotrexate-associated lymphoproliferative disorder is mainly a B-cell lymphoproliferative disorders or Hodgkin lymphoma type, whereas T-cell lymphoproliferative disorders are relatively rare (4-8%). Only a small number of methotrexate-associated T-cell lymphoproliferative disorders have been detailed thus far. Because of the rarity, methotrexate-associated T-cell lymphoproliferative disorder has not been well studied and its clinicopathological characteristics are unknown. A total of 28 cases of methotrexate-associated T-cell lymphoproliferative disorders were retrospectively analyzed. Histologically and immunohistochemically, they were divided into three main types: angioimmunoblastic T-cell lymphoma (n = 19), peripheral T-cell lymphoma, NOS (n = 6), and CD8⁺ cytotoxic T-cell lymphoma (n = 3). Among the 28 cases, only one CD8⁺ cytotoxic T-cell lymphoma case was Epstein-Barr virus-positive. The other 27 cases were negative for Epstein-Barr virus on tumor cells, but scattered Epstein-Barr virus-infected B-cells were detected in 24 cases (89%), implying the reactivation of Epstein-Barr virus caused by immunodeficient status of the patients. After the diagnosis of methotrexate-associated T-cell lymphoproliferative disorder, methotrexate was immediately withdrawn in 26 cases. Twenty (77%) cases presented with spontaneous regression. Compared to methotrexate-associated B-cell lymphoproliferative disorder, patients with methotrexate-associated T-cell lymphoproliferative disorder had a significantly higher proportion of males (p = 0.035) and presence of B-symptoms (p = 0.036), and lower proportion of Epstein-Barr virus⁺ tumor cells (p < 0.001). Although the difference was not significant, the methotrexate-associated T-cell lymphoproliferative disorder also had more frequent spontaneous regression (p = 0.061). In conclusion, methotrexate-associated T-cell lymphoproliferative disorder was divided into three main types: angioimmunoblastic T-cell lymphoma, peripheral T-cell lymphoma, NOS, and CD8⁺ cytotoxic T-cell lymphoma. Angioimmunoblastic T-cell lymphoma was the most common type. Methotrexate-associated T-cell lymphoproliferative disorder was characterized by a high rate of spontaneous regression after methotrexate cessation. Epstein-Barr virus positivity was relatively rare in methotrexate-associated T-cell lymphoproliferative disorder, significantly less frequent than methotrexate-associated B-cell lymphoproliferative disorder, suggesting different pathogenesis.