A lineage-specific STAT5BN642H mouse model to study NK-cell leukemia.

ABSTRACT: Patients with T- and natural killer (NK)-cell neoplasms frequently have somatic STAT5B gain-of-function mutations. The most frequent STAT5B mutation is STAT5BN642H, which is known to drive murine T-cell leukemia, although its role in NK-cell malignancies is unclear. Introduction of the STAT5BN642H mutation into human NK-cell lines enhances their potential to induce leukemia in mice. We have generated a mouse model that enables tissue-specific expression of STAT5BN642H and have selectively expressed the mutated STAT5B in hematopoietic cells (N642Hvav/+) or exclusively in NK cells (N642HNK/NK). All N642Hvav/+ mice rapidly develop an aggressive T/NKT-cell leukemia, whereas N642HNK/NK mice display an indolent NK-large granular lymphocytic leukemia (NK-LGLL) that progresses to an aggressive leukemia with age. Samples from patients with NK-cell leukemia have a distinctive transcriptional signature driven by mutant STAT5B, which overlaps with that of murine leukemic N642HNK/NK NK cells. To our knowledge, we have generated the first reliable STAT5BN642H-driven preclinical mouse model that displays an indolent NK-LGLL progressing to aggressive NK-cell leukemia. This novel in vivo tool will enable us to explore the transition from an indolent to an aggressive disease and will thus permit the study of prevention and treatment options for NK-cell malignancies.

Refractory pure red cell aplasia associated with T-cell large granular lymphocyte leukemia treated by ruxolitinib.

Acquired pure red cell aplasia (PRCA) is a rare syndrome characterized by normocytic normochromic anemia with severe reticulocytopenia and absence of erythroid precursors in the bone marrow. For refractory PRCA patients, the low response rate and high toxicity of alternative therapies pose a great challenge. T-cell large granular lymphocyte (T-LGL) leukemia is one of the most common conditions in secondary PRCA and also the most difficult form to manage with an inferior treatment response to other secondary PRCA forms. T-LGL leukemia exhibits sustained activation of the intracellular JAK-STAT signaling pathway. We herein report a case of PRCA associated with T-LGL leukemia that had been refractory to multiple lines of therapies and was successfully treated by ruxolitinib. The patient achieved complete remission and tolerated ruxolitinib well without occurrence of neutropenia or thrombocytopenia. This preliminary finding favors ruxolitinib as a potential salvage therapy for refractory PRCA associated with T-LGL leukemia.

The complex relationship between large granular lymphocyte leukemia and rheumatic disease.

INTRODUCTION: Large granular lymphocytic (LGL) leukemia is a rare lymphoproliferative disorder characterized by an expansion of clonal T or NK lymphocytes. Neutropenia-related infections represent the main clinical manifestation. Even if the disease follows an indolent course, most patients will ultimately need treatment in their lifetime. Interestingly, LGL leukemia is characterized by a high frequency of autoimmune disorders with rheumatoid arthritis being the most frequent. AREAS COVERED: This review covers the pathophysiology, clinic-biological features and the advances made in the treatment of LGL leukemia. A special focus will be made on the similarities in the pathophysiology of LGL leukemia and the frequently associated rheumatic disorders. EXPERT OPINION: Recent advances in the phenotypic and molecular characterization of LGL clones have uncovered the key role of JAK-STAT signaling in the pathophysiology linking leukemic cells expansion and autoimmunity. The description of the molecular landscape of T- and NK-LGL leukemia and the improved understanding of the associated rheumatic disorders open the way to the development of new targeted therapies effective on both conditions.

The constitutive activation of STAT3 gene and its mutations are at the crossroad between LGL leukemia and autoimmune disorders.

Type T Large Granular Lymphocyte Leukemia (T-LGLL) is a chronic disorder characterized by the abnormal proliferation of clonal cytotoxic T cells. The intriguing association of T-LGLL with autoimmune and inflammatory diseases, the most prominent example being rheumatoid arthritis, raises questions about the underlying pathophysiologic relationships between these disorders which share several biological and clinical features, most notably neutropenia, which is considered as a clinical hallmark. Recent progress in molecular genetics has contributed to a better understanding of pathogenetic mechanisms, thus moving our knowledge in the field of LGL leukemias forward. Focusing on the constitutive activation of STAT3 pathway and the well-established role of STAT3 mutations in T-LGLL, we herein discuss whether the T cell clones occurring in comorbid conditions are the cause or the consequence of the immune-inflammatory associated events. Overall, this review sheds light on the intricate relationships between inflammation and cancer, emphasizing the importance of the STAT3 gene and its activation in the pathophysiology of these conditions. Gaining a deeper understanding of these underlying mechanisms seeks to pave the way for the development of novel targeted therapies for patients affected by inflammation-related cancers.

Group 5 Pulmonary Hypertension Associated With T-Cell Large Granular Lymphocytic Leukemia: Hemodynamics and Treatment.

Group 5 pulmonary hypertension (PH) encompasses diverse diseases, with a few cases linking it to T-cell large granular lymphocytic (LGL) leukemia. We report a case of a 76-year-old woman, diagnosed with LGL leukemia and concomitant PH, treated with oral triple pulmonary arterial hypertension (PAH) therapy. She initially presented with dyspnea on exertion; evaluation revealed severe precapillary PH. Implementing cyclophosphamide for leukemia along with tadalafil and macitentan for PH led to sustained symptomatic and hemodynamic improvement for over 3 years. At that time, deterioration in PH prompted the addition of selexipag, resulting in sustained clinical improvement for an additional 5 years. This case exemplifies the potential for sustained benefits of PAH therapy in leukemia-associated PH and highlights the need for continued research on the mechanistic relationship between LGL leukemia and PH, with the hope of identifying new management strategies.

[Clinical characteristics of myeloid tumors combined with the proliferation of large granular lymphocytes].

Myeloid neoplasms (MNs) belong to a group of hematological malignancies characterized by the abnormal biological functions of hematopoietic stem progenitor cells. The abnormal immune and hematopoietic microenvironment of patients with MN interact with malignant clonal hematopoietic stem cells, promoting the occurrence and development of their diseases. MN large granular lymphocyte proliferation (MN-LGLP) is a special and rare clinical phenomenon in this type of disease. Currently, research on this disease in domestic and international cohorts is limited. This study analyzes the clinical and laboratory characteristics of this type of patient and explores the impact of LGLP on the clinical characteristics and survival of patients with MN. Patients with MN-LGLP are prone to neutropenia and splenomegaly. The presence of LGLP is not a risk factor affecting the survival of patients with MN-LGLP. STAG, ASXL1, and TET2 are the most common accompanying gene mutations in MN-LGLP, and patients with MN-LGLP and STAG2 mutations have poor prognoses.

Clinical features and prognosis of chronic natural killer cell lymphoproliferative disorders.

OBJECTIVE: To analyze the current treatment status and prognostic regression of the chronic NK cell lymphoproliferative disorder (CLPD-NK). METHODS: We retrospectively analyzed the clinical features, treatment and prognosis of 18 patients with CLPD-NK who were treated at our Hospital between September 2016 and September 2022. RESULTS: Eighteen patients were included: three patients were treated with chemotherapy, five patients underwent immune-related therapy, one patient was treated with glucocorticoids alone, five patients were administered granulocyte colony-stimulating factor, blood transfusion therapy, or anti-infection therapy, followed by observation and follow-up, and four patients were observed without treatment. Fifteen patients survived, including two patients who achieved complete remission (CR) and seven patients who achieved partial remission (PR), of whom one patient progressed to Aggressive NK-cell leukemia (ANKL) and sustained remission after multiple lines of treatment; three patients were not reviewed, of which one patient was still in active disease, three patients developed hemophagocytic syndrome during treatment and eventually died, one of them had positive Epstein-Barr virus (EBV) expression. The 5-years overall survival rate was 83%. CONCLUSION: Most patients with CLPD-NK have inert progression and a good prognosis, whereas some patients have a poor prognosis after progressing to ANKL and combined with hemophagocytic syndrome. Abnormal NK cells invading the center suggest a high possibility of ANKL development, and immunosuppressants and hormones are effective treatments for this disease.

Artritis reumatoide y leucemia de linfocitos grandes granulares T. A propósito de un caso / Rheumatoid arthritis and T cell large granular lymphocyte leukaemia: a case report

No disponible

T-cell large granular lymphocytic leukemia: treatment experience with fludarabine

OBJECTIVES: The aim of this retrospective study was to investigate the results of T-cell large granular lymphocytic leukemia treatment with fludarabine by assessing the complete hematologic response, the complete molecular response, progression-free survival, and overall survival. METHODS: We evaluated the records of six patients with T-cell large granular lymphocytic leukemia who were treated with fludarabine as a first-, second-, or third-line therapy, at a dose of 40 mg/m², for three to five days per month and 6 to 8 cycles. RESULTS: Of the six patients investigated with T-cell large granular lymphocytic leukemia who were treated with fludarabine, five (83.3%) were female, and their median age was 36.5 years (range 18 to 73). The median lymphocyte level was 3.4x10(9)/L (0.5 to 8.9). All patients exhibited a monoclonal T-cell receptor gamma gene rearrangement at diagnosis. Two (33.3%) patients received fludarabine as first-line treatment, two (33.3%) for refractory disease, one (16.6%) for relapsed disease after the suspension of methotrexate treatment dueto liver toxicity, and one (16.6%) due to dyspesia. A complete hematologic response was achieved in all cases, and a complete molecular response was achieved in five out six cases (83.3%). During a mean follow-up period of 12 months, both the progression-free survival and overall survival rates were 100%. CONCLUSION: T-cell large granular lymphocytic leukemia demonstrated a high rate of complete hematologic and molecular response to fludarabine, with excellent compliance and tolerability rates. To confirm our results in this rare disease, we believe that fludarabine should be tested in clinical trials as a first-line treatment for T-cell large granular lymphocytic leukemia.

Tumor del estroma gastrointestinal gástrico epitelioide en el curso de una leucemia de linfocitos grandes granulares T / Gastrointestinal stromal tumour coexisting with a T cell large granular lympholcytic leukemia

Los tumores del estroma gastrointestinal (GIST) representan las neoplasias mesenquimales más comunes del tracto gastrointestinal. Estos tumores generalmente muestran expresión inmunohistoquímica de c-KIT y/o DOG-1 y presentan mutaciones en los genes KIT o PDGFRα. La coexistencia de GIST con otras neoplasias ha sido ampliamente documentada en la literatura. Los tumores más comúnmente asociados a GIST son los carcinomas y las patologías hematológicas, sobre todo las leucemias mieloides. Describimos un caso de coexistencia de GIST con leucemia de linfocitos grandes granulares, algo previamente no descrito en la literatura. Se describen las características clinicopatológicas de ambos tumores y se revisa la literatura actualizada sobre el tema (AU)

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract. GISTs usually have c-KIT and/or DOG-1 immunoexpression and are related to mutational activation of KIT or PDGFRα. The coexistence of GISTs with other neoplasms has been frequently reported, the most common secondary neoplasms being carcinomas and hematologic neoplasms, mainly myeloid leukaemia. We describe, to our knowledge for the first time, the coexistence of GIST and T-large granular lymphocytic leukemia (T-LGL). The clinicopathological features of both tumours are discussed and the recent literature is reviewed (AU)

Leucemia de linfocitos grandes granulares como complicación de artritis reumatoide / Large granular lymphocyte leukemia as a complication of rheumatoid arthritis

La leucemia de linfocitos grandes granulares es una entidad poco frecuente, perteneciente al mismo espectro de trastornos que el síndrome de Felty, que puede presentarse en pacientes con artritis reumatoide de larga evolución. Clínicamente se caracteriza por neutropenia persistente e incremento de la susceptibilidad a infecciones bacterianas, asociado a la presencia en sangre periférica y médula ósea de una expansión clonal de linfocitos atípicos con fenotipo de linfocito T citotóxico, o menos frecuentemente de célula NK; y esplenomegalia. Se diagnostica con mayor frecuencia en pacientes con artritis reumatoide seropositiva con importante daño estructural, manifestaciones extraarticulares y valores persistentemente altos de factor reumatoide y VSG, a pesar de poder presentar escasa actividad inflamatoria articular. Presentamos el caso de un varón de 70 años con artritis reumatoide de larga evolución que desarrolló shock séptico secundario a la infección de una prótesis de cadera por Salmonella spp. Presentaba neutropenia persistente, identificándose en sangre periférica y médula ósea una población monoclonal de linfocitos T aberrantes compatibles con leucemia de linfocitos grandes granulares (AU)

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 (AU)

Infiltración cutánea por linfoma-leucemia de células T CD56+ / Cutaneos inflitration by T-cell CD56+ lymphoma-leukemia

Los linfomas de células T periféricos CD56+ son un amplio y heterogéneo grupo de trastornos linfoproliferativos. La molécula de adhesión CD56 se utiliza como marcador de linfocitos T y de un subgrupo celular mal definido, las células natural killer (NK). El linfoma T periférico de células CD56+ es un linfoma no hodgkiniano de localización extranodal, siendo la piel el lugar más frecuente de presentación (62 % casos) y de recidiva. El conocimiento de la sintomatología y las técnicas de inmunohistoquímica, citogenética y estudios moleculares han llevado a una mejor identificación de estos linfomas. Se presenta el caso de un paciente con un linfoma periférico de células CD56+ de tipo nasal con importante afectación cutánea (AU)