Large granular lymphocytic leukemia. Current diagnostic and therapeutic approaches and novel treatment options

T-large Granular Lymphocytic Leukemia: A Rare Diagnosis in a Young Woman With Fever, Necrotic Skin Lesions and Cytopenias

T-large granular lymphocytic leukemia (T-LGLL) is a rare lymphoproliferative disorder. The diagnosis is established by identifying an abnormally high number of clonal granular T lymphocytes in the peripheral blood and eventually in the bone marrow, in cases with medullary infiltration. The majority of patients present with symptoms related to neutropenia and this condition may be associated with autoimmune diseases in up to a third of cases. The authors describe the case of a 26-year-old patient admitted with subacute high fever and bullous dermatitis with necrotic lesions with central bullae. Analytically, she presented anemia and leukopenia with severe neutropenia of 200 cells/L. Skin lesions were compatible with ecthyma and the skin biopsy revealed aspects compatible with leukocytoclastic vasculitis. The myelogram and bone biopsy revealed hypoplasia of the myeloid line and a pathological T population of CD8+, TIA-1+ and granzyme B+, which were associated with compatible flow cytometry (CD3+, T-cell receptor (TCR) Alpha-Beta+, CD5+, CD2+, with loss of CD7 antigen expression) established the diagnosis of T-LGLL. The patient had a favorable evolution, with cytopenias almost returning to normal after two months. She began follow-up at a Hematology Reference Center, remaining asymptomatic without specific treatment considering the indolent course of the disease.

Pathogenesis and Treatment of T-Large Granular Lymphocytic Leukemia (T-LGLL) in the Setting of Rheumatic Disease

A complex relationship exists between rheumatic diseases and cancer. This delicate balance between chronic inflammation and malignant cell transformation in hematologic neoplasms has been observed, but is not well defined. Large Granular Lymphocyte (LGL) leukemia is at the intersection of a clonal lymphoproliferative disease, chronic inflammation, and autoimmunity. The association between rheumatoid arthritis (RA) and the spectrum of Felty’s Syndrome is well-known. Other rheumatic disorders have been reported including systemic lupus erythematosus (SLE), Sjogren’s Syndrome (SS), vasculitis, Behcet’s Disease (BD) and systemic sclerosis. The association between T-LGLL and rheumatic disease pathogenesis has been hypothesized, but has not yet been fully understood. Components of a shared pathogenesis includes chronic antigen stimulation, JAK-STAT pathway activation and overlap of various cytokines. We will summarize current knowledge on the molecular understanding between T-LGLL and rheumatic disease. There are many potential areas of research to help meet this need and lead to development of targeted therapeutic options.

Case Report: First Report of T-Cell Large Granular Lymphocytic Leukemia With NPL-DHX9 Gene Fusion Successfully Treated With Cladribine: Clinical Experience and Literature Review

Background

T-cell large granular lymphocytic leukemia (T-LGLL) is a rare lymphoproliferative disorder that starts in T cells and is usually indolent. Long-term use of immunosuppressants, combined with agranulocytosis, is a double-edged sword, as both can lead to serious infections, especially in patients with combined hematologic malignancies and immune defects.

Case Presentation

A 30-year-old female patient was admitted to the hospital because of agranulocytosis for five years, with chest tightness, fatigue, and fever for two days. Pathology and metagenomic next-generation sequencing (mNGS) detected Aspergillus. Although she received cyclosporine and methylprednisolone, the patient showed drug intolerance and progression with invasive pulmonary fungal infections. After a bone marrow aspiration biopsy and other related examinations, she was diagnosed with T-LGLL and invasive pulmonary aspergillosis (IPA). T-cell immunophenotype was CD45+CD3dim+CD5-CD4-CD8+CD7+CD57p+CD25-CD30-, TCRγδ+, transducer and activator of transcripton-3 (STAT3) Y640F mutation and fusion gene NPL-DHX9 rearrangement were confirmed, which has never been reported in hematological diseases. After voriconazole regimen adjustment during treatment based on therapeutic drug concentration monitoring (TDM) and improvement in lung infection, the patient finally treated with purine nucleoside analogues (PNA) cladribine as a single agent at 0.14 mg/kg/d for 5 days. Complete response was achieved after four-cycles cladribine treatment (WBC 2.1*109/L, HGB 117 g/L, PLT 196*109/L, ANC 1.6*109/L, and ALC 0.2*109/L).

Conclusions

To our knowledge, this is the first case of T-LGLL with a rare γδ type and fusion gene NPL-DHX9 rearrangement. The patient was successfully treated with cladribine, suggesting that this regimen could be a promising therapeutic strategy for patients with aggressive T-LGLL.

Large Granular Lymphocytic Leukemia: Current State of Diagnosis, Pathogenesis and Treatment

PURPOSE OF REVIEW

This manuscript aims at updating the knowledge on the clinico-biological characteristics, pathogenesis, and the diagnostic challenges of T-LGLL and CLPD-NK disorders and reviews the advances in the management and treatment of these patients.

RECENT FINDINGS

It has been shown that clonal large granular lymphocyte (LGL) expansions arise from chronic antigenic stimulation, leading to resistance to apoptosis. All the above findings have facilitated the diagnosis of LGLL and provided insights in the pathogenesis of the disease. At present, there is no standard first-line therapy for the disease. Immunosuppressive agents are the treatment routinely used in clinical practice. However, these agents have a limited capacity to eradicate the LGL clone and induce long-lasting remission. Advances in the knowledge of pathogenesis have made it possible to explore new therapeutic targets with promising results. Since LGLL is a rare disease, international efforts are needed to carry on prospective clinical trials with new potentially active drugs that could include a large number of patients.

[Clinical characteristics of T-cell large granular lymphoblastic leukemia with STAT3 gene mutation]

目的

探讨携带STAT3基因突变的T细胞大颗粒淋巴细胞白血病（T-LGLL）患者的临床特征，为此类患者的临床管理提供参考。

方法

回顾性分析2009至2019年就诊于江苏省人民医院的T-LGLL患者的临床资料，比较STAT3突变患者与未突变患者的基线临床数据、治疗反应及生存结局。

结果

共纳入80例患者，STAT3未突变组66例，STAT3突变组14例（17.5％），其中Y640F突变发生频率最高（42.9％）。STAT3突变组与STAT3未突变组相比，HGB减低（67.5 g/L对82.5 g/L，P＝0.018），中性粒细胞计数减少（0.665×10⁹/L对1.465×10⁹/L，P<0.001），乳酸脱氢酶升高（229 U/L对198 U/L，P＝0.041），铁蛋白升高（402.5 g/L对236.0 g/L，P＝0.029），TCR Vβ亚家族表达率升高（89.2％对65.4％，P＝0.014），具备治疗指征患者比例升高（100％对74％，P＝0.033）。STAT3突变组与未突变组一线免疫抑制治疗的完全缓解率分别为38.5％和32.7％，差异无统计学意义（P＝0.748）。STAT3突变组与未突变组一线免疫抑制治疗的总有效率分别为69.2％和69.4％，差异无统计学意义（P＝1.000）。中位随访63（2～121）个月，两组总生存时间（均未达到）的差异无统计学意义（P＝0.170）。

结论

STAT3基因突变的T-LGLL患者可能有更高的肿瘤负荷和治疗需求，一线应用免疫抑制剂疗效良好。STAT3基因突变对T-LGLL患者预后的意义尚需进一步验证。

Clinicobiological Characteristics and Outcomes of Patients with T-Cell Large Granular Lymphocytic Leukemia and Chronic Lymphoproliferative Disorder of Natural Killer Cells from a Single Institution

T-cell large granular lymphocytic leukemia (T-LGLL) and chronic lymphoproliferative disorder of natural killer (NK) cells are two infrequent diseases characterized by clonal expansions of cytotoxic T lymphocytes and NK cells, respectively. Somatic mutations of STAT3 are involved in the pathogenesis of these entities. We describe the clinicobiological features, mutational status of STAT3/STAT5B, treatment and outcome of 131 patients. Neutropenia was the most frequent finding at diagnosis, followed by anemia. Concurrent hematological disorders were diagnosed in 37% of patients and autoimmune conditions and solid tumors in 17% and 15%, respectively. All patients who needed treatment belonged to the CD8+CD57+ group. Remarkably, patients included in the CD4+ group had a higher association with solid tumors (p = 0.037). STAT3 mutations were found in 17% of patients, mainly Y640F and D661Y mutations. Patients carrying STAT3 mutations more frequently presented with anemia, neutropenia, high LDH, high large granular lymphocyte counts and need for treatment (p = 0.0037). Methotrexate was the most frequently used agent (72% of cases). The overall response rate to all treatments was 50%. The 10-year overall survival of this series was 78%, with no differences according to the mutational status of STAT3. We compared the survival of these patients with the general Spanish population and no differences were found, confirming the indolent nature of these hematological malignancies. Our study further extends findings documented by others on the clinical behavior of the disease and the impact of STAT3, and for the first time analyzes survival compared to a matched general Spanish population.

Large granular lymphocyte leukaemia study at the University Hospital of Donostia

INTRODUCTION

Large granular lymphocyte (LGL) leukaemia is considered a mature T-cell or natural killer (NK) cell neoplasm, characterised by a clonal proliferation of LGL.

AIMS

To analyse the characteristics and to establish (if possible) the prognostic parameters of these patients diagnosed in a single centre: University Hospital of Donostia.

METHODS

We retrospectively studied data about 308 patients with LGL leukaemia diagnosed in our centre.

RESULTS

The frequency of T-LGL leukaemia and chronic lymphoproliferative disorder of NK cells was 89% and 6.8% respectively, and no aggressive NK-LGL leukaemia was seen in our population. The median age at diagnosis was 65.7 years and male-to-female ratio was 1.08. 59% of our patients were asymptomatic at the time of diagnosis. Most patients presented lymphocytosis and 63.6% more than 20% LGLs in the peripheral blood count, but it has to be taken into account that these results may be influenced by the selection bias of our study, as we recognised these patients as 'alarms of the laboratory analysers'. Neutropenia was the most common cytopenia, and autoimmune disorders were described in 16.5% of the patients. Only 12 patients (3.9%) required treatment, a much lower percentage that the one reported in the literature, and this is consistent with the fact that patients were less symptomatic than in other series, as we expected. The 5-year and 15-year overall survival was 92% and 87%, respectively.

CONCLUSIONS

Our patients may represent the even more benign end of the spectrum of clonal T LGL and NK proliferations.

STAT3 and STAT5B Mutations in T/NK-Cell Chronic Lymphoproliferative Disorders of Large Granular Lymphocytes (LGL): Association with Disease Features

Simple Summary

STAT3 and STAT5B mutations have been identified in a subset of T and NK large granular lymphocytic leukemia (T/NK-LGLL). The aim of our study was to evaluate the frequency and type of these mutations in all different subtypes of T/NK-LGL expansions (n = 100 patients), as well as to analyze its association with biological and clinical features of the disease. We show for the first time that STAT3/5B mutations were present in all different T/NK-cell LGLL categories here studied; further, STAT3 mutations were associated with overall reduced counts of almost all normal residual populations of immune cells in blood, together with a shorter time-to-therapy vs. wild type T/NK-LGLL. These findings contribute to support the utility of the STAT3 mutation analysis for diagnostic and prognostic purposes in LGLL.

Abstract

STAT3 and STAT5B (STAT3/STAT5B) mutations are the most common mutations in T-cell large granular lymphocytic leukemia (T-LGLL) and chronic lymphoproliferative disorders of NK cells (CLPD-NK), but their clinical impact remains unknown. We investigated the frequency and type of STAT3/STAT5B mutations in FACS-sorted populations of expanded T/NK-LGL from 100 (82 clonal; 6 oligoclonal; 12 polyclonal) patients, and its relationship with disease features. Seventeen non-LGL T-CLPD patients and 628 age-matched healthy donors were analyzed as controls. STAT3 (n = 30) and STAT5B (n = 1) mutations were detected in 28/82 clonal T/NK-LGLL patients (34%), while absent (0/18, 0%) among oligoclonal/polyclonal LGL-lymphocytosis. Mutations were found across all diagnostic subgroups: TCD8⁺-LGLL, 36%; CLPD-NK, 38%; TCD4⁺-LGLL, 7%; Tαβ⁺DP-LGLL, 100%; Tαβ⁺DN-LGLL, 50%; Tγδ⁺-LGLL, 44%. STAT3-mutated T-LGLL/CLPD-NK showed overall reduced (p < 0.05) blood counts of most normal leukocyte subsets, with a higher rate (vs. nonmutated LGLL) of neutropenia (p = 0.04), severe neutropenia (p = 0.02), and cases requiring treatment (p = 0.0001), together with a shorter time-to-therapy (p = 0.0001), particularly in non-Y640F STAT3-mutated patients. These findings confirm and extend on previous observations about the high prevalence of STAT3 mutations across different subtypes of LGLL, and its association with a more marked decrease of all major blood-cell subsets and a shortened time-to-therapy.

Dysfunction of immune system in the development of large granular lymphocyte leukemia

OBJECTIVES

Large granular lymphocyte (LGL) leukemia is a rare type of lymphoproliferative disease caused by clonal antigenic stimulation of T cells and natural killer (NK) cells.

METHODS

In this review, we focus on the current knowledge of the immunological dysfunctions associated with LGL leukemia and the associated disorders coexistent with this disease. Novel therapeutic options targeting known molecular mechanisms are also discussed.

RESULTS AND DISCUSSION

The pathogenesis of LGL leukemia involves the accumulation of gene mutations, dysregulated signaling pathways and immunological dysfunction. Mounting evidence indicated that dysregulated survival signaling pathways may be responsible for the immunological dysfunction in LGL leukemia including decreased numbers of neutrophils, dysregulated signal transduction of NK cells, abnormal B-cells, aberrant CD8+ T cells, as well as autoimmune and hematological abnormalities.

CONCLUSION

A better understanding of the immune dysregulation triggered by LGL leukemia will be beneficial to explore the pathogenesis and potential therapeutic targets for this disease.

Roles of STAT3 in leukemia (Review)

Leukemia is a type of hematopoietic malignancy, and the incidence rate in the United States and European Union increases by an average of 0.6 to 0.7% annually. The incidence rate in China is approximately 5.17/100,000 individuals, and the mortality rate is 3.94/100,000 individuals. Leukemia is the most common tumor affecting children and adults under 35 years of age, and is one of the major diseases leading to the death of adolescents. Signal transducer and activator of transcription 3 (STAT3) is a vital regulatory factor of signal transduction and transcriptional activation, and once activated, the phosphorylated form of STAT3 (p-STAT3) is transferred into the nucleus to regulate the transcription of target genes, and plays important roles in cell proliferation, differentiation, apoptosis and other physiological processes. An increasing number of studies have confirmed that the abnormal activation of STAT3 is involved in the development of tumors. In this review, the roles of STAT3 in the pathogenesis, diagnosis, treatment and prognosis of leukemia are discussed in the aspects of cell proliferation, differentiation and apoptosis, with the aim to further clarify the roles of STAT3 in leukemia, and shed light into possible novel targets and strategies for clinical diagnosis and treatment.

Mutations in the signal transducer and activator of transcription family of genes in cancer

In recent years, it has become clear that members of the signal transducer and activator of transcription (STAT) family of genes play an important role in cancer. The STAT family consists of seven genes, STAT1‐4,STAT5A, STAT5B and STAT6, that are involved in regulating cellular proliferation, apoptosis, angiogenesis and the immune system response. Constitutive activation of STAT3, via mutational changes, is important in oncogenesis in both solid and hematopoietic cancers. In the case of hematopoietic neoplasms, STAT3 driver mutations have been described in T‐cell large granular lymphocytic (T‐LGL) leukemia and chronic natural killer lymphoproliferative disorders (CLPD‐NK) and are seen in 30%‐40% of T‐LGL leukemia patients. STAT5B is also mutated in T‐LGL leukemia and CLPD‐NK, but in a much smaller proportion. Here we review past and current research on STAT genes in hematopoietic and solid cancers with emphasis on STAT3 and STAT5B and their roles in the pathogenesis of hematopoietic malignancies, particularly T‐LGL leukemia and CLPD‐NK.