Diagnosis and therapy of neutropenia in large granular lymphocyte leukemia:

Context-dependent T-cell Receptor Gene Repertoire Profiles in Proliferations of T Large Granular Lymphocytes

T cell large granular lymphocyte (T-LGL) lymphoproliferations constitute a disease spectrum ranging from poly/oligo to monoclonal. Boundaries within this spectrum of proliferations are not well established. T-LGL lymphoproliferations co-occur with a wide variety of other diseases ranging from autoimmune disorders, solid tumors, hematological malignancies, post solid organ, and hematopoietic stem cell transplantation, and can therefore arise as a consequence of a wide variety of antigenic triggers. Persistence of a dominant malignant T-LGL clone is established through continuous STAT3 activation. Using next-generation sequencing, we profiled a cohort of 27 well-established patients with T-LGL lymphoproliferations, aiming to identify the subclonal architecture of the T-cell receptor beta (TRB) chain gene repertoire. Moreover, we searched for associations between TRB gene repertoire patterns and clinical manifestations, with the ultimate objective of discriminating between T-LGL lymphoproliferations developing in different clinical contexts and/or displaying distinct clinical presentation. Altogether, our data demonstrates that the TRB gene repertoire of patients with T-LGL lymphoproliferations is context-dependent, displaying distinct clonal architectures in different settings. Our results also highlight that there are monoclonal T-LGL cells with or without STAT3 mutations that cause symptoms such as neutropenia on one end of a spectrum and reactive oligoclonal T-LGL lymphoproliferations on the other. Longitudinal analysis revealed temporal clonal dynamics and showed that T-LGL cells might arise as an epiphenomenon when co-occurring with other malignancies, possibly reactive toward tumor antigens.

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.

STAT3 Role in T-Cell Memory Formation

Along with the clinical success of immuno-oncology drugs and cellular therapies, T-cell biology has attracted considerable attention in the immunology community. Long-term immunity, traditionally analyzed in the context of infection, is increasingly studied in cancer. Many signaling pathways, transcription factors, and metabolic regulators have been shown to participate in the formation of memory T cells. There is increasing evidence that the signal transducer and activator of transcription-3 (STAT3) signaling pathway is crucial for the formation of long-term T-cell immunity capable of efficient recall responses. In this review, we summarize what is currently known about STAT3 role in the context of memory T-cell formation and antitumor immunity.

Neutropenia and Large Granular Lymphocyte Leukemia: From Pathogenesis to Therapeutic Options

Large granular lymphocyte leukemia (LGLL) is a rare lymphoproliferative disorder characterized by the clonal expansion of cytotoxic T-LGL or NK cells. Chronic isolated neutropenia represents the clinical hallmark of the disease, being present in up to 80% of cases. New advances were made in the biological characterization of neutropenia in these patients, in particular STAT3 mutations and a discrete immunophenotype are now recognized as relevant features. Nevertheless, the etiology of LGLL-related neutropenia is not completely elucidated and several mechanisms, including humoral abnormalities, bone marrow infiltration/substitution and cell-mediated cytotoxicity might cooperate to its pathogenesis. As a consequence of the multifactorial nature of LGLL-related neutropenia, a targeted therapeutic approach for neutropenic patients has not been developed yet; moreover, specific guidelines based on prospective trials are still lacking, thus making the treatment of this disorder a complex and challenging task. Immunosuppressive therapy represents the current, although poorly effective, therapeutic strategy. The recent identification of a STAT3-mediated miR-146b down-regulation in neutropenic T-LGLL patients emphasized the pathogenetic role of STAT3 activation in neutropenia development. Accordingly, JAK/STAT3 axis inhibition and miR-146b restoration might represent tempting strategies and should be prospectively evaluated for the treatment of neutropenic LGLL patients.

Large Granular Lymphocytic Leukemia: From Immunopathogenesis to Treatment of Refractory Disease

Large Granular Lymphocyte Leukemia (LGLL) is a rare, chronic lymphoproliferative disorder of effector cytotoxic T-cells, and less frequently, natural killer (NK) cells. The disease is characterized by an indolent and often asymptomatic course. However, in roughly 50% of cases, treatment is required due to severe transfusion-dependent anemia, severe neutropenia, or moderate neutropenia with associated recurrent infections. LGLL represents an interesting disease process at the intersection of a physiological immune response, autoimmune disorder, and malignant (clonal) proliferation, resulting from the aberrant activation of cellular pathways promoting survival, proliferation, and evasion of apoptotic signaling. LGLL treatment primarily consists of immunosuppressive agents (methotrexate, cyclosporine, and cyclophosphamide), with a cumulative response rate of about 60% based on longitudinal expertise and retrospective studies. However, refractory cases can result in clinical scenarios characterized by transfusion-dependent anemia and severe neutropenia, which warrant further exploration of other potential targeted treatment modalities. Here, we summarize the current understanding of the immune-genomic profiles of LGLL, its pathogenesis, and current treatment options, and discuss potential novel therapeutic agents, particularly for refractory disease.

Single-Antibody Evaluation of T-Cell Receptor β Constant Chain Monotypia by Flow Cytometry Facilitates the Diagnosis of T-Cell Large Granular Lymphocytic Leukemia

OBJECTIVES

The diagnosis of T-cell large granular lymphocytic leukemia (T-LGLL) is challenging because of overlapping immunophenotypic features with reactive T cells and limitations of T-cell clonality assays. We studied whether adding an antibody against T-cell receptor β constant region 1 (TRBC1) to a comprehensive flow cytometry panel could facilitate the diagnosis of T-LGLL.

METHODS

We added TRBC1 antibody to the standard T-cell and natural killer (NK) cell panel to assess T-cell clonality in 56 T-LGLLs and 34 reactive lymphocytoses. In addition, 20 chronic lymphoproliferative disorder of NK cells (CLPD-NKs) and 10 reactive NK-cell lymphocytoses were analyzed.

RESULTS

Clonal T cells were detected in all available T-LGLLs by monotypic TRBC1 expression and clonal/equivocal T-cell receptor gene rearrangement (TCGR) studies, compared with only 27% of T-LGLLs by killer-cell immunoglobulin-like receptor (KIR) restriction. Overall, 85% of T-LGLLs had a blood tumor burden greater than 500 cells/µL. Thirty-four reactive cases showed polytypic TRBC1 expression, except for 5 that revealed small T-cell clones of uncertain significance. All CLPD-NKs showed expected clonal KIR expression and negative TRBC1 expression.

CONCLUSIONS

Addition of TRBC1 antibody to the routine flow cytometry assay could replace the TCGR molecular study and KIR flow cytometric analysis to assess clonality, simplifying the diagnosis of T-LGLL.

Clonal expansion of large granular lymphocytes in patients with spondyloarthritis and psoriatic arthritis treated with TNFα inhibitors

To determine the prevalence of clonal T-large granular lymphocyte (T-LGL) cells in patients with spondyloarthritis (SpA) and psoriatic arthritis (PsA) and to define possible risk factors for this condition. We present a cross-sectional analysis with retrospective and prospective aspects. 115 SpA patients, 48 PsA patients and 51 controls were recruited between December 28, 2017 and January 23, 2019. Flow cytometry (FACS) was performed to screen for aberrant T-LGL cells. Molecular analysis was then employed to confirm the diagnosis in patients with suggestive FACS findings. Patients with clonal T-LGL populations were followed prospectively by FACS analysis. Electronic patient files were retrospectively analyzed to determine risk factors. Median age was 49 years for SpA, 55.5 years for PsA, and 54 years for controls. Median disease duration of SpA and PsA was 15 years and 11 years, respectively. 79.8% of patients had received biologics at some point, 75.5% had ever received tumor necrosis factor (TNF) inhibitors. 59.5% were treated with TNF inhibitors at the time of study inclusion. We identified clonal T-LGL expansions in 13 individuals equaling a prevalence of 6% (13/214). T-LGL patients were taking TNF inhibitors more frequently at the time of study inclusion (p = 0.022) and were more likely to have ever been treated with TNF inhibition (p = 0.046). Clonal T-LGL expansions can be detected in patients with SpA, PsA and also in healthy controls. Confirming earlier results, exposure to TNFα-blocking agents appears to increase the risk of developing clonal expansions of T-LGL cells.

Clinical outcomes in T-cell large granular lymphocytic leukaemia: prognostic factors and treatment response

T-cell large granular lymphocytic leukaemia (T-LGLL) is an incurable leukaemia characterised by clonal proliferation of abnormal cytotoxic T cells that can result in severe neutropenia, transfusion-dependent anaemia and pancytopenia requiring treatment. The most commonly used agents, methotrexate (MTX), cyclophosphamide (Cy) and cyclosporine primarily produce partial remissions (PRs), with few complete responses (CRs). We evaluated the clinical course and treatment response of 60 consecutive patients with T-LGLL to evaluate clinical outcomes and future potential treatment directions. Impaired overall survival was noted among male patients, patients with elevated lactate dehydrogenase, and those without rheumatoid arthritis. Cy was the most efficacious second-line agent, with a 70% overall response rate (ORR; three CR, four PR). All patients who failed frontline MTX responded to second-line Cy. In the relapsed or Cy-refractory setting, alemtuzumab (n = 4) and pentostatin (n = 3) had an ORR of 50% and 66%, respectively, while duvelisib induced a long-term response in one patient. In this large, retrospective analysis, our results suggest Cy is a highly effective therapy for second-line treatment in T-LGLL and should be considered a strong candidate for up-front therapy in select high-risk patients. Prospective studies evaluating pentostatin, alemtuzumab and novel agents, such as duvelisib, are needed for patients with relapsed/refractory T-LGLL.

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.

Belinostat in Relapsed/Refractory T-Cell Large Granular Lymphocyte Leukemia

T-cell large granular lymphocyte (LGL) leukemia is a rare indolent neoplasm primarily treated with immunosuppression. Few therapies and no consensus exist for the optimal treatment of T-cell LGL leukemia refractory to immunosuppressive therapy. Here, we report a case of relapsed/refractory T-cell LGL treated with belinostat. A 57-year-old male presented with lymphocytosis and anemia and was found to have T-cell LGL, requiring frequent packed red blood cell transfusions. He was initially treated with methotrexate with no response after 7 months. He was then switched to cyclosporine and cyclophosphamide and experienced transfusion independence for 42 months before disease relapse. He was then started on belinostat with noted subsequent transfusion independence for greater than 15 months to date and decreased disease involvement on bone marrow biopsy. To our knowledge, this is the first reported case of belinostat use in relapsed/refractory T-cell LGL leukemia which resulted in a durable clinical and biologic response.

T-cell large granular lymphocyte leukemia in solid organ transplant recipients: case series and review of the literature

T-cell large granular lymphocyte (T-LGL) leukemia is a rare clonal proliferation of cytotoxic lymphocytes rarely described in solid organ transplant (SOT). We reviewed records from 656 kidney transplant recipients in follow-up at our Center from January 1998 to July 2017. In addition, we researched, through PubMed, further reports of T-LGL leukemia in SOT from March 1981 to December 2017. We identified six cases of T-LGL leukemia in our cohort of patients and 10 in the literature. This lymphoproliferative disorder was detected in one combined liver-kidney, one liver and 14-kidney transplant recipients. Median age at presentation was 46.5 years (IQR 39.2-56.9). The disease developed after a median age of 10 years (IQR 4.9-12) from transplantation. Anemia was the most common presentation (62.5%) followed by lymphocytosis (43.7%) and thrombocytopenia (31.2%). Splenomegaly was reported in 43.7% of the patients. Eight patients (50%) who experienced severe symptoms were treated with non-specific immunosuppressive agents. Six of them (75%) had a good outcome, whereas two (25%) remained red blood cell transfusion dependent. No cases progressed to aggressive T-LGL leukemia or died of cancer at the end of follow-up. These results suggest that T-LGL leukemia is a rare but potentially disruptive hematological disorder in the post-transplant period.

Prevalence and Characteristics of Persistent Clonal T Cell Large Granular Lymphocyte Expansions in Rheumatoid Arthritis: A Comprehensive Analysis of 529 Patients

OBJECTIVE

Up to one-third of patients with T cell large granular lymphocyte (T-LGL) leukemia display symptoms of rheumatoid arthritis (RA). In Crohn's disease and psoriasis, treatment with tumor necrosis factor (TNF) inhibitors is associated with hepatosplenic γδ T cell lymphoma and with clonal expansion of γδ T cells, respectively. This study was undertaken to determine the prevalence of clonal T-LGL cells in patients with RA and define risk factors for this rare hematologic malignancy.

METHODS

A total of 529 RA patients were recruited between November 2013 and August 2015. Eight-color flow cytometry (fluorescence-activated cell sorting [FACS]) was performed to screen for aberrant T cell populations of LGLs. Molecular analysis of the T cell receptor was used to confirm the diagnosis in patients with suggestive FACS findings. Electronic patient files were used to determine risk factors. Patients with clonal populations were monitored prospectively for up to 4 years.

RESULTS

The median patient age was 61 years, and 74% were female. The median duration of RA was 12 years. The median Disease Activity Score in 28 joints was 2.8, and 69.9% of patients had ever been treated with biologic disease-modifying antirheumatic drugs. We identified clonal T-LGL expansions in 19 patients, equaling a prevalence of 3.6%. The T-LGL cell clone was constant over time in most patients and was significantly associated with the duration of the exposure to TNF-blocking agents (P = 0.01). No other risk factors could be detected.

CONCLUSION

RA patients with long-term exposure to TNF-blocking agents were at a greater risk of developing clonal expansions of LGLs. This finding may prompt clinicians to refrain from using these substances in RA patients with known T cell aberrations.

T Cell Large Granular Lymphocyte Leukaemia with Cutaneous Infiltration

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LGL leukemia: from pathogenesis to treatment

Large granular lymphocyte (LGL) leukemia has been recognized by the World Health Organization classifications amongst mature T-cell and natural killer (NK) cell neoplasms. There are 3 categories: chronic T-cell leukemia and NK-cell lymphocytosis, which are similarly indolent diseases characterized by cytopenias and autoimmune conditions as opposed to aggressive NK-cell LGL leukemia. Clonal LGL expansion arise from chronic antigenic stimulation, which promotes dysregulation of apoptosis, mainly due to constitutive activation of survival pathways including Jak/Stat, MapK, phosphatidylinositol 3-kinase-Akt, Ras-Raf-1, MEK1/extracellular signal-regulated kinase, sphingolipid, and nuclear factor-κB. Socs3 downregulation may also contribute to Stat3 activation. Interleukin 15 plays a key role in activation of leukemic LGL. Several somatic mutations including Stat3, Stat5b, and tumor necrosis factor alpha-induced protein 3 have been demonstrated recently in LGL leukemia. Because these mutations are present in less than half of the patients, they cannot completely explain LGL leukemogenesis. A better mechanistic understanding of leukemic LGL survival will allow future consideration of a more targeted therapeutic approach than the current practice of immunosuppressive therapy.

Autoimmune and other acquired neutropenias

This educational review addresses the diagnostic evaluation of patients for autoimmune and other forms of acquired neutropenia, including the futility of deconstructing the overlap of chronic "autoimmune," "benign," and "idiopathic" categories. Isolated neutropenias caused by infection, drugs, and immunologic disorders are also addressed. Discussion of management options emphasizes a conservative approach, with largely supportive care for these mostly benign and self-limited disorders.

Single-center Series of Bone Marrow Biopsy-Defined Large Granular Lymphocyte Leukemia: High Rates of Sustained Response to Oral Methotrexate

INTRODUCTION

Large granular lymphocyte (LGL) leukemia is a rare chronic lymphoproliferative disorder, with few large series reported to date. Series using stringent diagnostic criteria incorporating bone marrow biopsy (BMB), immunophenotyping, and T-cell receptor rearrangements are even scarcer.

PATIENTS AND METHODS

The present study was a single-center series of 39 patients with LGL leukemia diagnosed using immunohistochemical analysis of BMB samples and flow cytometric and molecular data.

RESULTS

With a median follow-up of 3.2 years (range, 1.0-15.1 years), 15 patients (38%) never required treatment. Of the remaining 24 patients requiring treatment, 13 were initially treated with prednisolone, for an overall response rate (ORR) of 84.6% and a median duration of response (DOR) of 13.5 months (range, 5.7-70.3 months). Of the 24 patients, 9 received oral low-dose weekly methotrexate as first-line therapy, with 8 (89%) achieving a hematologic response and a median DOR of 132.7 months (range, 6.7-180.5 months). Another 5 patients received methotrexate after prednisolone failure; all 5 responded, with a median DOR of 14 months (range, 4-96 months). Only 2 patients developed progression during methotrexate therapy, and 4 patients experienced responses lasting ≥ 5 years.

CONCLUSION

Single-agent oral methotrexate appears to be highly efficacious, resulting in long response durations and minimal toxicity.

A population-based study of large granular lymphocyte leukemia

Large granular lymphocyte (LGL) leukemia is a lymphoproliferative disorder of cytotoxic cells. T-cell LGL (T-LGL) leukemia is characterized by accumulation of cytotoxic T cells in blood and infiltration of the bone marrow, liver or spleen. Population-based studies have not been reported in LGL leukemia. We present clinical characteristics, natural history and risk factors for poor survival in patients with LGL leukemia using the Surveillance, Epidemiology, and End Results Program (SEER) and the United States National Cancer Data Base (NCDB). LGL leukemia is an extremely rare disease with the incidence of 0.2 cases per 1 000 000 individuals. The median age at diagnosis was 66.5 years with females likely to be diagnosed at 3 years earlier compared with males. Analysis of patient-level data using NCDB (n=978) showed that 45% patients with T-LGL leukemia required some form of systemic treatment at the time of diagnosis. T-LGL leukemia patients have reduced survival compared with general population, with a median overall survival of 9 years. Multivariate analysis showed that age >60 years at the time of diagnosis and the presence of significant comorbidities were independent predictors of poor survival.

[CD4⁺/CD8⁻ T- cell large granular lymphocytic leukemia: one case report and literatures reviews]

目的

提高对CD4⁺/CD8⁻T-大颗粒淋巴细胞白血病的认识。

方法

分析1例因皮疹、白细胞增多就诊的CD4⁺/CD8⁻T-大颗粒淋巴细胞白血病患者的临床资料，并复习相关文献。

结果

患者为老年女性，周身散在片状紫红色斑疹，外周血大颗粒淋巴细胞增多，呈CD3⁺/CD4⁺/CD8⁻免疫表型，PCR检测TCRγ、β基因重排阳性，流式细胞术检测TCRVβ₂亚家族98%。

结论

CD3⁺/CD4⁺/CD8⁻变异型T-大颗粒淋巴细胞白血病少见，临床表现与经典T-大颗粒淋巴细胞白血病有所不同，应谨慎鉴别。

Large granular lymphocytic leukemia presenting late after solid organ transplantation: a case series of four patients and review of the literature

Post-transplantation lymphoproliferative disorder (PTLD) is a significant complication of solid organ transplantation. Most PTLD is of the B-cell subtype, although T-cell subtype PTLD uncommonly occurs. T-cell PTLDs are usually aggressive neoplasms and shorten patient and allograft survivals significantly. We present a single-center case series of 4 patients who developed T-cell large granular lymphocytic (LGL) leukemia, a rare T-cell PTLD characterized by large granular lymphocytes that have characteristic azurophilic granules and a highly variable clinical course.

Uncovering the pathogenesis of large granular lymphocytic leukemia-novel STAT3 and STAT5b mutations

Large granular lymphocytic (LGL) leukemia is an incurable chronic disease, characterized by clonal expansion of cytotoxic T- or NK-cells in blood and bone marrow. Cytopenias (anemia, neutropenia) and autoimmune disorders such as rheumatoid arthritis are the most common clinical manifestations of LGL leukemia. Recently, somatic activating STAT3 gene mutations were shown to be specific for LGL leukemia with a prevalence of up to 70%. Analogous mutations in the STAT5b gene were seen in a smaller proportion of patients. These gain-of-function mutations are located in the SH2 domain of STAT3 and affect the phosphotyrosine-SH2 interaction required for dimerization of STAT3. The mutations increase the phosphorylation of STAT3 and STAT5b and enhance the transcriptional activity of the mutated proteins. STAT3 and STAT5b mutations can be used as molecular markers for LGL leukemia diagnostics, and they present novel therapeutic targets for STAT3 and STAT5b inhibitors, which currently are in development for treatment of cancer and autoimmune disorders.

[Large granular lymphocytic leukemia. A rare disease with personalized treatment options]

INTRODUCTION

Large granular lymphocyte leukemia is rare, mainly chronic disease. The most common complication is neutropenia, but other immune-mediated cytopenia may also occur. There are no unified treatment recommendations and initiation of treatment mainly depends on the severity of the symptoms.

AIM

The aim of the authors was to analyze the main steps of the diagnosis and the necessity and outcome of treatment in their patients diagnosed with large granular lymphocyte leukaemia.

METHOD

The authors retrospectively analyzed the data of 17 large granular lymphocyte leukemia patients.

RESULTS

Of the 17 patients, 7 patients required treatment because of transfusion dependent anemia (4 patients) or neutropenia (3 patients). In 4 patients corticosteroid was given (supplemented with cyclosporine in one patients), while the other patients received anti-CD52 (one patient), low dose methotrexate (one patient) and combined chemotherapy (one patient). Five patients achieved partial response, and two patients died in sepsis.

CONCLUSIONS

In this cohort only a smaller proportion of patients required therapy. Immunosuppression can be successful, but the effect in most cases was temporary. The most serious complication was sepsis, which is associated with a significant risk of mortality in cases with neutropenia.

Evaluation and management of patients with isolated neutropenia

Neutropenia, defined as an absolute neutrophil count (ANC) <1.5 × 10(9)/L, encompasses a wide range of diagnoses, from normal variants to life-threatening acquired and congenital disorders. This review addresses the diagnosis and management of isolated neutropenia, not multiple cytopenias due to splenomegaly, bone marrow replacement, or myelosuppression by chemotherapy or radiation. Laboratory evaluation generally includes repeat complete blood cell counts (CBCs) with differentials and bone marrow examination with cytogenetics. Neutrophil antibody testing may be useful but only in the context of clinical and bone marrow findings. The discovery of genes responsible for congenital neutropenias now permits genetic diagnosis in many cases. Management of severe chronic neutropenia includes commonsense precautions to avoid infection, aggressive treatment of bacterial or fungal infections, and administration of granulocyte colony-stimulating factor (G-CSF). Patients with severe chronic neutropenia, particularly those who respond poorly to G-CSF, have a risk of eventually developing myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML) and require monitoring for this complication, which also can occur without G-CSF therapy. Patients with cyclic, idiopathic, and autoimmune neutropenia have virtually no risk of evolving to MDS or AML. Hematopoietic stem cell transplantation is a curative therapy for congenital neutropenia with MDS/AML or with cytogenetic abnormalities indicating impending conversion.

The pathogenesis and treatment of large granular lymphocyte leukemia

Large granular lymphocyte (LGL) leukemia is a spectrum of rare lymphoproliferative diseases of T lymphocytes and natural killer cells. These diseases frequently present with splenomegaly, neutropenia, and autoimmune diseases like rheumatoid arthritis. LGL leukemia is more commonly of a chronic, indolent nature; however, rarely, they have an aggressive course. LGL leukemia is thought to arise from chronic antigen stimulation, which drives long-term cell survival through the activation of survival signaling pathways and suppression of pro-apoptotic signals. These include Jak-Stat, Mapk, Pi3k-Akt, sphingolipid, and IL-15/Pdgf signaling. Treatment traditionally includes immunosuppression with low dose methotrexate, cyclophosphamide, and other immunosuppressive agents; however, prospective and retrospective studies reveal very limited success. New studies surrounding Jak-Stat signaling suggest this may reveal new avenues for LGL leukemia therapeutics.

Infections in patients with leukemia and lymphoma

Infectious complications remain a significant issue in the care of patients with hematologic malignancies. Inherent immune defects related to the primary disease process are present in patients with disorders such as chronic lymphocytic leukemia, multiple myeloma, hairy cell leukemia, and Hodgkin lymphoma. Therapy-related immunosuppression is also commonplace in these patients. This includes not only treatment-related neutropenia, but also defects in cell-mediated immunity, such as those that occur with purine analog therapy. In this chapter, we will review the pathogenesis of infection in these disorders, as well as the spectrum of infectious complications seen and suggested strategies for the prevention of infection.

Familial CD3+ T large granular lymphocyte leukemia: evidence that genetic predisposition and antigen selection promote clonal cytotoxic T-cell responses

CD3+ T-large granular lymphocyte (T-LGL) proliferations often present with cytopenias and splenomegaly and are linked to autoimmunity, especially rheumatoid arthritis and Felty's syndrome. We report here the intra-family occurrence of T-LGL leukemia in a father and son, both presenting with cytopenias and splenomegaly. Both patients carried the HLA-DRB1*04 allele, strongly associated with rheumatoid arthritis and Felty's syndrome, exhibited distinctive histopathological features suggestive of immune-mediated suppression of hematopoiesis and expressed a remarkably skewed T-cell receptor beta chain gene repertoire with overtime evolution (clonal drift). Immunoinformatics analysis and comparisons with clonotype sequences from various entities revealed (quasi)identities between (i) father and son, and (ii) father or son and patients with autoimmune disorders, T-LGL leukemia or chronic idiopathic neutropenia. Altogether, our results further corroborate antigen selection in the ontogeny of T-LGL leukemia and point to the interplay between genetics and the (micro)environment in shaping the outcome of cytotoxic T cell responses.

Treatment of T-cell large granular lymphocyte leukemia with cyclosporine A: experience in a Chinese single institution

T-cell large granular lymphocyte leukemia (T-LGLL) is a rare chronic lymphoproliferative disorder. Available reported data on the treatment regimens of this disease are variable and limited due to low number of patients. We analyzed the efficiency of cyclosporine A (CsA) in the treatment of 28 patients with T-LGLL. The overall response rate (ORR) was 82.1% with hematologic complete remission (HCR) rate of 57.1%. The median time to response (TTR) was 1.8 months and treatment duration with CsA-based regimens was 34.5 months. CsA shows low and manageable toxicity during treatment. Twenty-one patients survived with a median follow-up time of 42.0 months. Our results indicate that CsA is efficacious and safe in the treatment of T-LGLL.

How to approach neutropenia

Neutropenia is defined as the reduction in the absolute number of neutrophils in the blood circulation. Acute neutropenia is a relatively frequent finding, whereas disorders of production of neutrophils are quite rare. Acute neutropenia is often well tolerated and normalizes rapidly. Neutropenia arising as a result of underlying hematologic disorders is far more significant. Such a patient may be at risk for infectious complications and will likely require a thorough investigation. Acute neutropenia evolves over a few days and occurs when neutrophil use is rapid and production is impaired. Chronic neutropenia may last for 3 months or longer and is a result of reduced production, increased destruction, or excessive splenic sequestration of neutrophils. Neutropenia may be classified by whether it arises secondarily to causes extrinsic to BM myeloid cells, which is common; as an acquired disorder of myeloid progenitor cells, which is less frequent; or as an intrinsic defect arising from impaired proliferation and maturation of myeloid progenitor cells in the BM, which is rare. Severe neutropenia with absolute neutrophil counts below 500/μL increases susceptibility to bacterial or fungal infections. Multiple disorders of severe congenital neutropenia have been found by the discovery of genetic defects affecting differentiation, adhesion, and apoptosis of neutrophil precursors. Elucidation of the multiple genetic defects have provided insight into the biology of the cell involving membrane structures, secretory vesicles, mitochondrial metabolism, ribosome biogenesis, transcriptional regulation, and cytoskeletal dynamics, as well as the risk for myelodysplasia and acute myeloid leukemia.

Large granular lymphocyte leukemia as a complication of rheumatoid arthritis

Large granular lymphocyte leukemia is a rare entity belonging to same spectrum of diseases than Felty's syndrome, which might occur in patients with long-standing rheumatoid arthritis. It is clinically characterized by persistent neutropenia and recurrent bacterial infections associated with the presence in both peripheral blood and bone marrow of clonal expansion of atypic lymphocytes with a cytotoxic T cell phenotype, or less frequently an NK-cell phenotype, as well as splenomegaly. It is more frequently diagnosed in seropositive rheumatoid arthritis, with significant structural damage, extra-articular manifestations and persistently elevated values of ESR, despite them havubg low inflammatory joint activity. We report the case of a 70 year old male with a long-standing rheumatoid arthritis, who developed septic shock secondary to prosthetic hip infection by Salmonella spp. He showed persistent neutropenia, and an aberrant monoclonal T cell population was detected in both peripheral blood and bone marrow, consistent with large granular lymphocyte leukemia.

How I treat LGL leukemia

Large granular lymphocyte (LGL) leukemia is characterized by a clonal expansion of either CD3(+) cytotoxic T or CD3(-) NK cells. Prominent clinical features of T-LGL leukemia include neutropenia, anemia and rheumatoid arthritis (RA). The terminal effector memory phenotype (CD3(+)/CD45RA(+)/CD62L(-)CD57(+)) of T-LGL suggests a pivotal chronic antigen-driven immune response. LGL survival is then promoted by platelet-derived growth factor and interleukin-15, resulting in global dysregulation of apoptosis and resistance to normal pathways of activation-induced cell death. These pathogenic features explain why treatment of T-LGL leukemia is based on immunosuppressive therapy. The majority of these patients eventually need treatment because of severe or symptomatic neutropenia, anemia, or RA. No standard therapy has been established because of the absence of large prospective trials. The authors use low-dose methotrexate initially for T-LGL leukemia patients with neutropenia and/or RA. We recommend either methotrexate or oral cyclophosphamide as initial therapy for anemia. If treatment is not successful, patients are switched to either the other agent or cyclosporine. The majority of patients experience an indolent clinical course. Deaths infrequently occur because of infections related to severe neutropenia. As there are no curative therapeutic modalities for T-LGL leukemia, new treatment options are needed.

Analysis of a French cohort of patients with large granular lymphocyte leukemia: a report on 229 cases

BACKGROUND

Large granular lymphocyte leukemia is a rare lymphoproliferative disorder associated with autoimmune diseases and impaired hematopoiesis. This study describes the clinical and biological characteristics of 229 patients with T-cell or NK-cell large granular lymphocyte leukemia.

DESIGN AND METHODS

The diagnosis was based on a large granular lymphocyte expansion (> 0.5x10(9)/L) lasting more than 6 months. Monoclonal T-cell receptor gamma gene rearrangement was detected in all the cases of T-cell large granular lymphocyte leukemia. Patients with chronic NK-cell lymphocytosis had an indolent disease, while those with multiorgan large granular lymphocyte infiltration and an aggressive clinical disease were considered to have NK-cell large granular lymphocyte leukemia.

RESULTS

The diagnosis of T-cell large granular lymphocyte leukemia was confirmed in 201 cases, chronic NK-cell lymphocytosis in 27 cases and NK-cell large granular lymphocyte leukemia in one case. Associated autoimmune diseases or other neoplasms were present in 74 and 32 cases, respectively. One hundred patients (44%) required treatment, mainly for neutropenia-associated infections (n=45), symptomatic autoimmune diseases (n =24), transfusion-dependant anemia (n=18), and other causes (n=13). Patients were treated with steroids (n= 33), methotrexate (n=62), cytoxan (n=32), or cyclosporine (n=24) either as first-, second-, third- or fourth-line therapy. The overall response rate at 3 months and complete response rate for the various treatments were as follows: steroids (12% and 3%), methotrexate (55% and 21%), cytoxan (66% and 47%), cyclosporine (21% and 4%), respectively. Four out of 13 patients responded to splenectomy. Eleven out of 15 patients responded to cytoxan after methotrexate treatment had failed. The mean number of treatments was 3.4 (range, 1-7). There were 15 large granular lymphocyte leukemia-related deaths.

CONCLUSIONS

Patients with T-cell large granular lymphocyte leukemia and chronic NK-cell lymphocytosis have similar clinical and biological features and responses to treatment. First-line therapy with cytoxan should be tested in a prospective trial.