Large Granular Lymphocyte Leukemia Research Articles

T-cell LGL leukaemia my mimic felty's syndrome.

T-cell LGL leukaemia my mimic felty's syndrome.

Response to Letter to Editor "T-cell LGL leukaemia may mimic Felty's syndrome".

Response to Letter to Editor "T-cell LGL leukaemia may mimic Felty's syndrome".

Efficacy of ruxolitinib in the treatment of relapsed/refractory large granular lymphocytic leukaemia.

Large granular lymphocytic (LGL) leukaemia is a rare chronic lymphoproliferative disorder characterized by an expansion of cytotoxic T or NK cells. Despite a usually indolent evolution, most patients will require a treatment over the course of the disease because of cytopenia or symptomatic associated autoimmune disorders. First-line treatment is based on immunosuppressive agents, namely cyclophosphamide, methotrexate and ciclosporin. However, relapses are frequent, and there is no consensus on the management of relapsed/refractory patients. The implication of the JAK/STAT pathway in the pathogenesis of this disease has prompted our group to propose treatment with ruxolitinib. A series of 21 patients who received this regimen is reported here. Ten patients (47.6%) were refractory to the three main immunosuppressive drugs at the time of ruxolitinib initiation. Ruxolitinib yielded an overall response rate of 86% (n = 18/21), including 3 complete responses and 15 partial responses. With a median follow-up of 9 months, the median response duration was 4 months. One-year event-free survival and 1-year overall survival were 57% and 83% respectively. Mild side effects were observed. Biological parameters, notably neutropenia and anaemia, improved significantly, and complete molecular responses were evidenced. This study supports ruxolitinib as a valid option for the treatment of relapsed/refractory LGL leukaemia.

Large Granular Lymphocytic Leukemia: Clinical Features, Molecular Pathogenesis, Diagnosis and Treatment.

Large granular lymphocytic (LGL) leukemia is a lymphoproliferative disorder characterized by persistent clonal expansion of mature T- or natural killer cells in the blood via chronic antigenic stimulation. LGL leukemia is associated with specific immunophenotypic and molecular features, particularly STAT3 and STAT5 mutations and activation of the JAK-STAT3, Fas/Fas-L and NF-κB signaling pathways. Disease-related deaths are mainly due to recurrent infections linked to severe neutropenia. The current treatment is based on immunosuppressive therapies, which frequently produce unsatisfactory long-term responses, and for this reason, personalized approaches and targeted therapies are needed. Here, we discuss molecular pathogenesis, clinical presentation, associated autoimmune disorders, and the available treatment options, including emerging therapies.

Roxadustat and transfusional iron overload induced hypothyroidism in a hemodialysis patient: a case report with a literature review

BackgroundAlthough roxadustat has been reported to cause central hypothyroidism, the details of the mechanisms and clinical characteristics of patients who are prone to developing hypothyroidism with roxadustat are uncertain.Case presentationA 53-year-old man with a 3-year history of hemodialysis due to diabetic kidney disease who had been treated with roxadustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor, for 2 years was admitted to the hospital because of worsening gait disturbance and impaired consciousness. He had also acquired pure red cell aplasia associated with T-cell large granular lymphocytic leukemia and received multiple blood transfusions. Because his serum concentration of thyroid hormones was low, we diagnosed him with hypothyroidism, and his consciousness level recovered to normal with thyroid hormone replacement therapy. Computed tomography revealed a high-intensity atrophic thyroid gland, and magnetic resonance imaging showed diffusely reduced T2 and T1 signals of the pituitary anterior gland. These findings confirmed the accumulation of iron in the pituitary and thyroid glands. Combined pituitary stimulation tests with thyrotropin-releasing hormone, luteinizing hormone-releasing hormone, and corticotropin-releasing hormone revealed that the patient had pan-hypopituitarism. After discontinuation of roxadustat, the patient was treated with another hypoxia-inducible factor prolyl hydroxylase inhibitor, vadadustat. One month after switching medication, a stimulation test with thyrotropin-releasing hormone showed normal responses to thyroid-stimulating hormone. The patient was treated with levothyroxine 50 μg daily without any significant symptoms and is currently under follow-up observation as an outpatient.ConclusionsWe encountered a dialysis patient with roxadustat-induced hypothyroidism associated with transfusion iron overload. To our knowledge, this is the first case to clearly show that roxadustat can impair thyroid-stimulating hormone secretion in repeated thyrotropin-releasing hormone stimulation tests. Because the present patient had received roxadustat for more than 2 years before hypothyroidism became apparent, regular monitoring of the thyroid function may be needed in patients with renal anemia who have been treated with roxadustat, especially those at high risk of thyroid dysfunction.

Abstract 3201: Preclinical development of a novel Romidepsin nanoparticle for the treatment of T-Cell lymphoid malignancies

Abstract The histone deacetylase inhibitors (HDACi) have long been regarded as an important class of drugs for treating T-cell lymphoid malignancies (TCL). Romidepsin (Romi), a bicyclic peptide, was approved for patients with relapsed or refractory cutaneous (CTCL) and peripheral T-cell lymphomas (PTCL). Unfortunately, the approval of Romi for relapsed/refractory PTCL was withdrawn due to a negative Phase 4 post-marketing requirement. Given its potent activity against Class I HDACs, Romi is considered one of the most effective HDAC inhibitors studied and used in patients with TCL. Herein, we report on a first-in-class nanoparticle of Romi (NanoRomi) with a superior safety and efficacy profile compared to the free drug in preclinical models of PTCL and large granular lymphocyte leukemia (LGLL). We developed a first-in-class NanoRomi using our proprietary amphiphilic di-block copolymer-based nanochemistry platform. NanoRomi was characterized in cell viability, flow cytometry, and western blotting (WB) assays to determine the concentration-effect relationships with regard to the induction of apoptosis and histone acetylation in cell lines representative of TCL and LGLL, as well as primary LGLL patient PBMC samples. In addition, we performed extensive in vivo modeling using murine xenografts of CTCL, including repeated dose toxicity, biodistribution, efficacy, and survival studies. Cytotoxicity assays demonstrated superior/comparable activity of NanoRomi (IC50: 1.1-2.3 nM) compared to free Romi (IC50: 4.8-10.6 nM) across all PTCL and LGLL cell lines studied, while in primary LGLL samples, NanoRomi exhibited superior cytotoxicity (2-fold) compared to Romi. WB analysis showed that NanoRomi induced apoptosis and increased acetylation of histone H3 and H4 in a time and concentration-dependent manner in cell lines representing CTCL, ALK+-ALCL, and LGLL. Repeat dose toxicity studies in CTCL xenografts confirmed that the overall tolerability of NanoRomi was substantially better than Romi. Tracking studies with a fluorescent dye (DiO) in the NanoRomi demonstrated preferential localization of NanoRomi in tumors of mice compared to the normal organs after 6 hours of drug administration. NanoRomi exhibited superior efficacy in the murine CTCL xenograft models, including a significant improvement in overall survival compared to Romi. Collectively, these data show that NanoRomi exhibits markedly superior pharmacokinetics, tolerability, and efficacy in models of TCL. We anticipate that the improved activity and tolerability of NanoRomi relate to the altered pharmacologic profile and superior bioavailability of the drug, which optimizes the effects of the drug for its influence on epigenetic biology. This unique platform offers the prospect of improving the tolerability and efficacy of epigenetic treatment strategies in these challenging diseases. Citation Format: Ipsita Pal, Anuradha Illendula, Andrea Joyner, Tess M. Deddens, Deepthi P. Damera, Todd E. Fox, Marya E. Dunlap-Brown, Kallesh D. Jayappa, Thomas P. Loughran, David J. Feith, Owen A. O'Connor. Preclinical development of a novel Romidepsin nanoparticle for the treatment of T-Cell lymphoid malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3201.

Abstract 3245: Use of hypomethylating agents to reprogram the epigenome in large granular lymphocyte leukemia

Abstract Large granular lymphocyte (LGL) leukemia is a rare heterogeneous blood cancer that is characterized by the clonal lymphoproliferation of CD8+ T cells (T-LGL leukemia) or, less frequently, natural killer cells (NK-LGL leukemia). These cells evade activation induced cell death, allowing them to accumulate as highly cytotoxic lymphocytes that contribute to autoimmune attacks, neutropenia, and anemia. Frontline treatments are limited to repurposed, nonspecific immunosuppressive agents with limited efficacy and incomplete response rates. As there are no FDA-approved antineoplastic agents for LGL leukemia, our research explores novel therapeutic avenues for this orphan disease. Somatic activating mutations in the transcription factor STAT3 are the most common molecular alteration found in >50% of patients, and STAT3 signaling is dysregulated in almost all LGL leukemia patients. In the largest molecularly profiled LGL leukemia patient cohort to date, we found that STAT3 mutations frequently co-occur with mutations in chromatin and epigenetic modifying genes, suggesting crosstalk and cooperativity between STAT3 activation and epigenetic dysregulation. Moreover, TET2, which promotes DNA demethylation, is frequently inactivated in LGL leukemia via loss-of-function mutations and promoter hypermethylation. As DNA hypermethylation is an emerging hallmark of LGL leukemia, we evaluated the therapeutic potential of two epigenetic agents, azacitidine (AZA) and cladribine (CLAD), that directly and indirectly inhibit DNA hypermethylation, respectively. We hypothesize that AZA and CLAD will 1) exhibit cell intrinsic efficacy, 2) reprogram the epigenome of LGL leukemia through DNA hypomethylation to normalize aberrant gene expression, and 3) induce cytokine-mediated immune responses. AZA and CLAD cytotoxicity was assessed by the Cell Titer Glo viability assay in human LGL leukemia cell lines. Each exhibited potent anti-leukemic effects with IC50 values in the low micromolar and nanomolar ranges. Western blotting analysis demonstrated the decrease in protein expression of DNA methyltransferases and phosphorylated STAT3 levels with treatment in a time- and dose-dependent manner. We also explored the immunomodulatory effects of these hypomethylating agents since LGL leukemia is a pro-inflammatory malignancy with cytotoxic lymphocytes. Preliminary findings using the Isoplexis platform suggest that AZA and CLAD induce production of anti-inflammatory cytokines in LGL leukemia cells. Ongoing studies will identify differential methylation, chromatin accessibility, and gene expression using RRBS, ATAC-seq, and RNA-seq of AZA or CLAD treated samples to define the mechanisms and consequences of DNA demethylation. Uncovering the reprogramming capabilities of AZA and CLAD could allow for the potential repurposing of these inhibitors for treatment of LGL leukemia patients. Citation Format: Ariana Sabzevari, Ipsita Pal, Tess Deddens, Todd Fox, Aakrosh Ratan, David J. Feith, Thomas P. Loughran. Use of hypomethylating agents to reprogram the epigenome in large granular lymphocyte leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3245.

Abstract 5053: Clinicopathologic and molecular genetic features of STAT3-mutated myeloid neoplasms

Abstract STAT3 is a key transcription factor that can mediate cancer progression through phosphorylation or gain-of-function mutations. STAT3 mutations have been mainly associated with large granular lymphocytic T-cell leukemia. Whereas STAT3 activation is common in myeloid neoplasms, it is primarily mediated through STAT3 phosphorylation. STAT3 mutation has only rarely been reported in myeloid neoplasms. We assessed the clinicopathologic and molecular genetic features of 32 STAT3-mutated myeloid neoplasms. Twenty (62.5%) cases were classified as acute myeloid leukemia (AML), 7 (21.9%) as myelodysplastic syndrome (MDS), and 5 (15.6%) as chronic myelomonocytic leukemia (CMML). It is of note that STAT3 mutation was not detected in myeloproliferative neoplasms (MPN). STAT3 mutations were detected at the initial diagnosis in 22 of 25 (88%) cases, suggesting STAT3 mutation is an early event in pathogenesis. However, STAT3 mutations represented the dominant clone in only 6 (18.8%) cases, all classified as AML. Most are missense mutations, located at the SH2 domain. The median variant allele frequencies were 6.8%, 4.6% and 3.1% for AML, MDS and CMML, respectively, and in a case of CMML, the VAF increased from 2.4% to 34.8% upon leukemic transformation. STAT3 mutation was accompanied by co-existing mutations in all cases, with SRSF2 (40.6%), TET2 (40.6%), ASXL1 (37.5%), and SETBP1 (34.4%) being most common. Cases with STAT3 mutations were usually associated with morphologic dysplasia and increased blasts. Monosomy 7/del7q was the most common cytogenetic abnormality, seen in 11 (34.4%) cases. With a median follow-up of 24.5 months, 21 patients died, 6 had persistent disease, and 5 achieved complete remission. We summarize that STAT3 mutation is present in a variety of myeloid neoplasms, but not seen in MPN. It is often an early events and always with concurrent mutations. It may play an important role in the pathogenesis and progression of myeloid neoplasms by activating JAK-STAT pathway, and may serve as a potential therapeutic target. Citation Format: Matthew T. Ye, Zhuang Zuo, Steliana Calin, Fengxi Ye, Hua He, Wataru Kamata, M. James You. Clinicopathologic and molecular genetic features of STAT3-mutated myeloid neoplasms [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5053.

Long-Term Remission After Chemotherapy with Bendamustine in a Patient with Refractory Large Granular Lymphocyte Leukemia

Long-Term Remission After Chemotherapy with Bendamustine in a Patient with Refractory Large Granular Lymphocyte Leukemia

T-Cell Large Granular Lymphocyte Population Involving Chimeric Antigen Receptor-Modified T (CAR T) Cells in Patients with Cytopenia after CD19-Targeted CAR T-Cell Therapy: Case Series

T-Cell Large Granular Lymphocyte Population Involving Chimeric Antigen Receptor-Modified T (CAR T) Cells in Patients with Cytopenia after CD19-Targeted CAR T-Cell Therapy: Case Series

Hepatosplenic T-cell lymphoma displays an original oyster-shell cytological pattern and a distinct genomic profile from that of gamma-delta T-cell large granular lymphocytic leukemia.

Not available.

Flow Cytometry in Mature T- and NK-cell Neoplasms: A Retrospective Descriptive Study from a Tertiary Care Cancer Centre in Kerala, India

Introduction: Mature T- and NK-cell Neoplasms (MTNKN) constitute around 12% of all non-Hodgkin lymphomas. They have a variable clinical course, ranging from indolent to highly aggressive tumours. Flow cytometry immunophenotyping is crucial for the diagnosis, staging, and classification of MTNKN. Aim: To determine the frequency, morphologic, and immunophenotypic profile of various subtypes of MTNKN diagnosed by flow cytometry. Materials and Methods: This was a retrospective descriptive study conducted at the Department of Pathology, Regional Cancer Centre, Thiruvananthapuram, Kerala, India. All cases of MTNKN diagnosed by flow cytometry in peripheral blood, bone marrow aspirates, or body fluids from January 1, 2010 to June 30, 2020 (10.5 years duration) at the cancer centre were studied. The morphology of tumour cells and immunophenotype by flow cytometry were analysed. Clinical parameters (lymphadenopathy, hepatosplenomegaly, skin lesions, effusions, B symptoms) and follow-up details, including Progression-free Survival (PFS) and Overall Survival (OS), were also noted. Descriptive statistics for continuous variables and frequencies and percentages for categorical variables were obtained. The Kaplan-Meier method for survival plots was used. Results: Mature T- and NK-cell neoplasms constituted 83 cases. The median age of patients was 56 years. The majority of patients were males (n=49). Adult T-cell Leukaemia/Lymphoma (ATLL) (n=50) constituted the most common subtype, followed by Mycosis fungoides/Sezary syndrome (MF/SS) (n=14), T-cell Large Granular Lymphocytic Leukaemia (T-LGLL) (n=7), T-cell Prolymphocytic Leukaemia (T-PLL) (n=4), Aggressive NK-cell Leukaemia (ANKL) (n=3), Hepatosplenic T-cell Lymphoma (HSTL) (n=3), and Anaplastic Large Cell Lymphoma (ALCL) (n=2). OS and PFS at three years were 22.3% and 16.6%, respectively. Conclusion: Mature T- and NK-cell neoplasms presenting as leukaemia is rare. ATLL was the most common subtype of MTNKN. Flower cells, Sezary cells, and prolymphocytes are useful morphological clues for diagnosis. Immunophenotyping by flow cytometry, along with clinicopathologic correlation, is crucial for the diagnosis and subclassification of MTNKN. All subtypes except T-LGLL show inferior PFS and OS.

TOX as a new diagnostic marker for T cell large granular lymphocytic leukaemia.

T cell large granular lymphocytic leukaemia (T-LGLL) is a rare disorder that may underlie otherwise unexplained cytopenias. The identification of T-LGLL cells in bone marrow biopsies can be a challenge, because a robust immunohistochemistry marker is lacking. The markers currently in use (granzyme B, TIA-1 and CD8) are difficult to interpret or lack specificity. Therefore, we investigated whether immunohistochemistry for thymocyte selection-associated high-mobility group box (TOX), a transcription factor that associates with chronic T cell stimulation, could be a reliable tool for the identification of T-LGLL cells. In this retrospective study, expression of TOX in CD8+ cells in bone marrow biopsies of T-LGLL patients (n = 38) was investigated and compared to bone marrow of controls with reactive T cell lymphocytosis (n = 10). All biopsies were evaluated for TOX staining within the CD8-positive T cell population. The controls were essentially negative for TOX, whereas all T-LGLL cases were positive (median = 80%, range = 10-100%), even when bone marrow involvement was subtle. TOX is a highly sensitive marker for the neoplastic cells of T-LGLL and we recommend its use, especially in the diagnostic work-up of patients with unexplained cytopenias.

Clinical characteristics and treatment outcomes of Asian patients with T-cell large granular lymphocytic Leukemia: a single-center analysis of 67 cases

Large granular lymphocytic (LGL) leukemia is a clonal lymphoproliferative disorder of LGLs derived from cytotoxic T lymphocytes or natural killer cells. However, the clinical features and treatment responses are still not fully understood because of the rarity of the disease. To describe and assess a cohort of patients with T-cell large granular lymphocytic leukemia (T-LGLL). Single-center, retrospective, observational study. We retrospectively collected the clinical data of patients diagnosed with T-LGLL at Seoul National University Hospital since 2006. We included 67 patients in this study. The median age at diagnosis was 60 years. Additionally, 37 patients (55%) were symptomatic, and 25 (37%) had splenomegaly; 54 patients (81%) required treatment. Cyclophosphamide (n = 35), methotrexate (n = 25), and cyclosporin A (n = 19) were used most frequently for treatment, and their overall response rates were similar: cyclophosphamide (77%), methotrexate (64%), and cyclosporin A (63%). Splenomegaly was associated with an increased response rate to first-line therapy and a decreased complete response rate. Thrombocytopenia was associated with decreased response rates to cyclophosphamide, methotrexate, cyclosporin A, and steroids. In contrast, a high LGL number (> 2000/µL) in the peripheral blood smear was associated with increased response rates to cyclophosphamide, methotrexate, cyclosporin A, and steroids. This study describes the clinical features and treatment outcomes of patients with T-LGLL, providing valuable information for clinical decision-making regarding T-LGLL treatment.

Abstract B041: Understanding T-cell large granular lymphocytic leukemia: Diagnosis and treatment options

Abstract Introduction: T-cell large granular lymphocytic leukemia, or T-LGL leukemia, is rare cancer affecting T-cells and natural killer cells. It is characterized by the abnormal proliferation of mature T-cells expressing specific markers. Standard treatments involve immunosuppressive therapies. Understanding the diagnosis and treatment options is crucial for optimal care. Case Presentation: A 54-year-old male with chronic anemia and iron overload was initially diagnosed with myelodysplastic syndrome (MDS). Vidaza followed treatment with Danazol due to negative MDS and myeloproliferative neoplasm (MPN) results. Concerns of red cell aplasia led to corticosteroid and cyclosporin administration, discontinued during the COVID-19 outbreak. A subsequent biopsy revealed pure red cell aplasia, and the patient was prescribed Cyclosporin and later switched to Danazol. The patient underwent Anti-Thymocyte Globulin (ATG) treatment at a cancer center. A bone marrow biopsy confirmed T-LGL leukemia with abnormal CD8-positive T-cells. PCR analysis confirmed clonal T-cell proliferation. Cytogenetics and mutation analyses were negative. The patient is currently receiving Cyclosporin, prednisone, and Jadenu. Conclusion: This case highlights the challenges in diagnosing and managing T-LGL leukemia, a rare lymphoproliferative disorder. The patient's complex medical history and mimicking of other hematologic disorders underscore the need for a multidisciplinary approach. Individualized therapy based on clinical response is necessary due to limited treatment options. Further research and prospective trials are essential to establish a standard of care. Citation Format: Aliya M. Khan, Kierston R. Patterson, Raj Patel, Sophia Navajas Urisote. Understanding T-cell large granular lymphocytic leukemia: Diagnosis and treatment options [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr B041.

Acquired pure red cell aplasia: unraveling the immune pathogenesis

Acquired pure red cell aplasia (aPRCA) is a rare hematological disorder characterized by normochromic, normocytic anemia, reticulocytopenia, and the absence of erythroblasts. The pathogenesis of aPRCA has remained elusive. This review delves into the intricate web of immune mechanisms underlying the development of this enigmatic condition. By exploring immune responses, cytotoxic effects, and antibody-mediated processes, we dissect the immune-driven assault on erythroid progenitors. The classification of aPRCA, including its primary and secondary forms, is elucidated, with a particular emphasis on etiological factors such as viruses, drugs, thymoma, and large granular lymphocytic leukemia. Furthermore, we discuss the implications of cytogenetic changes in erythroid progenitors and immune cells in the pathophysiology of aPRCA. This comprehensive overview aims to shed light on the complex interplay between immune dysregulation and erythroid failure in aPRCA, offering insights that will be crucial for better understanding and treating this disease.

Epidemiological Insights into Large Granular Lymphocyte Leukemia: A Nationwide SEER Database Study

Background: Large granular lymphocytic (LGL) leukemia is a rare hematological malignancy that arises from cytotoxic T lymphocytes (T-LGL) or natural killer (NK) cells. LGL leukemia accounts for 2% to 5% of chronic lymphoproliferative disorders in the United States of America. LGL leukemia can either present as an indolent type or an aggressive type. Most patients remain asymptomatic and often have associated autoimmune diseases, such as rheumatoid arthritis and hematologic dyscrasias. We analyzed the demographic characteristics of LGL leukemia patients and investigated the influence of social determinants on their survival. Methods: We performed a retrospective cohort study of the Surveillance, Epidemiology, and End Results (SEER) database for patients diagnosed with LGL leukemia between years 2000 and 2020. Patient demographics, year of diagnosis, and timeline of treatment were analyzed by descriptive statistics. Cox proportional hazards regression analysis was performed to identify the factors influencing the survival of these patients. Results: A total of 2589 patients were diagnosed with LGL leukemia. Median age of diagnosis was 67 years. 59.4% were aged more than 65 years of age at the time of diagnosis, 52.7% were males, 81.5% were Caucasians, 64% had an annual income of more than $65,000, and 84.2% lived in metropolitan areas. 91.8% were diagnosed in the past decade after 2010. It is worth noting that 64.5% of the patients received treatment more than six months after diagnosis of LGL leukemia. 81.5% of patients were Caucasians, 9.6% were African Americans, 5.3% were Asians/Pacific Islanders, followed by 2% Hispanics and 1.5% American Indians. At the time of the last follow-up, 65.5% of patients were alive, with an overall median survival of forty months. 70% of patients had LGL leukemia as the only primary malignancy. Age less than 65 years had better outcomes than the older age group (HR 0.32). Female gender was protective (HR 0.69). Poor outcomes were seen in patients with an annual income of less than $65,000 (HR 1.21). The year of diagnosis and residence had no significant effect on survival. Marriage improved the outcomes of patients (HR 0.78) (Table 1). Patients receiving treatment within six months of diagnosis had higher mortality (HR 1.43) than the rest of the population. Caucasians comprised majority of the patient population and had better prognoses (HR 0.11) than Asians/Pacific Islanders (HR 0.49), Hispanics (HR 0.82), and African Americans (HR 0.97) (Figure 1). Conclusion: We present a population-based analysis and the determinants of survival in patients with LGL leukemia, a rare malignancy. The number of cases has increased in the past decade. Significant patient factors influencing survival in LGL leukemia patients include younger age at diagnosis, female gender, marriage and higher annual income.

Incidence, Clinical Features, and Outcomes of Large Granular Lymphocyte Leukemia

Introduction: - Large Granular Lymphocyte (LGL) leukemia is a rare and diverse hematologic disorder characterized by the clonal proliferation of large granular lymphocytes in the peripheral blood and bone marrow. Despite its rarity, population-based studies on LGL leukemia remain limited. This study aims to comprehensively analyze clinical characteristics and outcomes among patients with LGL leukemia. Methods: - We utilized the Surveillance, Epidemiology, and End Results (SEER) database 17 registry to identify patients diagnosed with large granular lymphocytic leukemia between 2000-2020. Data analysis was conducted using SEER*Stat version 8.4.1.2 and STATA. Univariate survival analysis was done using a Kaplan Meir plot with a log-rank test, and the Cox proportion hazard regression model was used for multivariate survival analysis. Results: - We identified a total of 2,589 LGL leukemia cases during the study period. The calculated incidence of LGL leukemia was 0.14 cases per 1,000,000 individuals (range: 0.14 - 0.15). Male patients exhibited a higher incidence rate ratio of 1.19 (95% CI: 1.11 - 1.27, p < 0.01) than females. However, females tended to be diagnosed younger than males (67 vs. 68, p < 0.01). Most cases were observed in the White population (83%) compared to other racial groups. The median age at diagnosis was 67 years (ranging from 7 to 85 years). Patients aged above 70 years showed the highest incidence of LGL leukemia (0.80) in contrast to those aged 45-54 years (0.30) and 55-64 years (0.63). Notably, there was a significant increasing trend in LGL leukemia incidence, with an incidence rate ratio of 13.50 (95% CI: 10.5-17.6, p < 0.001) in the period 2015-2019 compared to 2000-2004. Approximately 32.7% of patients received chemotherapy; the median time from diagnosis to treatment was one month. The survival rates at 12, 36, and 60 months for LGL leukemia patients were 88.9%, 76.5%, and 66.5%, respectively, with a median follow-up of 40 months. Multivariate analysis revealed that females had a more favorable survival outcome than males (HR: 0.78, 95% CI: - 0.64 - 0.97, p: 0.02). Moreover, patients who underwent chemotherapy exhibited better survival than those who did not (HR: 0.72, 95% CI: 0.56 - 0.93, p: 0.01). Elderly patients above 60 years of age had poorer survival rates (HR: 3.1, 95% CI: 2.34 - 4.01, p < 0.01), and no significant difference in outcomes was observed based on the timing of chemotherapy initiation from the time of diagnosis. Conclusion: - This study represents the most extensive and most recent population-based investigation of LGL leukemia. The findings highlight the potential benefits of chemotherapy in improving survival and indicate better outcomes in female patients. Further research is warranted to validate these promising results and gain deeper insights into the management and prognosis of LGL leukemia.

Anti-Inflammatory Response to Anti-Folate and Vitamin D Analog Combination in Large Granular Lymphocyte Leukemia

Large granular lymphocyte (LGL) leukemia is a rare chronic hematological disorder characterized by clonal expansion of circulating cytotoxic T or natural killer (NK) cells. The disease is associated with a number of comorbidities including neutropenia, anemia, and autoimmune diseases. There is no standard of care or curative therapy for LGL leukemia. Instead, it is treated when symptoms arise with a variety of immunosuppressive therapies, chief among them, the anti-folate, methotrexate (MTX). However, a significant proportion of patients remain refractory to treatment, and little characterization has been done regarding MTX's mechanism in vitro. Thus, there is a need to identify new therapeutic approaches such as stronger anti-folates or combination of MTX with existing therapies. Pralatrexate (PDX) is a more potent analog of MTX, not yet utilized in LGL leukemia. It is approved for treatment of relapsed or refractory peripheral T cell lymphomas and may offer a promising new avenue for therapy. Vitamin D is a natural supplement that we have shown to impact key LGL leukemia signaling pathways in vitro by decreasing cytokine levels and STAT1 and STAT3 signaling, all of which are typically elevated in LGL leukemia. Treatment with vitamin D also increases levels of vitamin D receptor (VDR), a known transcriptional controller of reduced folate carrier (RFC), the method of cellular entry for both MTX and PDX. Therefore, we hypothesized that treatment with EB1089, a synthetic vitamin D analog, would sensitize leukemic LGLs to anti-folates, PDX and MTX, by leading to a VDR-mediated increase in RFC thus allowing increased MTX/PDX uptake and therapeutic efficacy. In this study, single MTX treatment of LGL leukemia model cell lines (NKL and TL-1) demonstrated strong decreases in viability at 72h time points (EC50 NKL 10.5nM, TL-1 15.4nM). Single agent PDX effects on viability were even stronger (4-11 fold lower EC50) (Figure A). Key LGL leukemia signaling pathways like STAT phosphorylation were lowered as early as 24h after high dose treatment with MTX (10 µM) in TL-1 cells, and VDR was also lowered by MTX single high dose treatment. When MTX or PDX was given in combination with EB1089, critical inflammatory signaling, such as phosphorylation of STAT1 and STAT3, was attenuated, while VDR was stabilized from anti-folate mediated decrease. Dose dependent changes to STAT3 regulation, RFC, VDR, and PTPN2, a phosphatase specific to STAT1 and STAT3, occurred as early as 6h post combinatorial treatment with a range of MTX dosages (1, 10, 100 nM) in the NK cell line model. A similar anti-inflammatory response in PTPN2, STAT1, and STAT3 levels was observed at 24h following co-treatment in TL-1 cells (Figure B). Additionally, treatment with a combination of EB1089 and PDX (0.1, 1, 10 nM; 10% of the MTX doses) led to anti-inflammatory response with decreases in STAT1 activation and increases in RFC in the TL-1 cell line. In short term assays, there were no measurable changes in anti-folate mediated cell killing when the drugs were combined across cell lines and different dosages of the combination. Taken together, these data suggest a strong single agent potency for PDX and an anti-inflammatory benefit to MTX/PDX and EB1089 combination. Continued mechanistic study of the anti-folate/vitamin D receptor agonist pairing as well as further investigation into PDX's impact on LGLs will be crucial to follow up investigations.

LGL in MGUS or MGUS in LGL? Lessons of Nature and Their Clinical Implications

Associations between seemingly unrelated entities often reveal important lessons of nature, instructive for the understanding of mutual pathogenic roots. While investigating the clinical features of T-cell large granular lymphocytic leukemia (LGL), we noted the frequent presence of plasma cell dyscrasias/monoclonal gammopathies (MGs), chiefly MGUS. There are several potential explanations for this co-occurrence: 1) similar demographics (both conditions mostly presenting in the elderly); 2) the possibility that the two precursors originate from an initial polyclonal immune response to a common target; and 3) as alternative, that monoclonal plasma cells or the Ig product may be the targets of cytotoxic T-LGL cells in a context of tumor surveillance reaction. For instance, clonal TCR may recognize the M protein idiotype or vice versacausing aberrant activations. In addition, while MGUS should not be associated with cytopenias, responses to anti-myeloma therapies have been observed in LGL with MGUS refractory to traditional immunosuppressive therapies. We hypothesized that the study of clinical and epidemiologic features of MGs and LGL may be helpful to elucidate some of these fundamental questions. To address this, a dual approach was applied: 1) MG-forward strategy: screening of LGL in 2348 individuals with documented diagnosis of MGs and available bone marrow exam; 2) LGL-forward strategy: search of MGs in 235 LGL cases with M protein assessment. Overall, among 2348 cases with MGs, we identified 42 cases (1.8%) with concurrent evidence of LGL. We then selected an exploratory cohort of 787 MG patients with clinical annotations for further phenotypic dissection and comparative analyses. Within 533 patients with non-active MGs (i.e., MGUS or smoldering myeloma -SM), 144 (27%) had cytopenias of any type and grade, which could not be attributable to plasma cell infiltration. Screening for comorbid conditions explaining cytopenias left 32 cases (22%) presumed to be idiopathic. LGL was overrepresented in MGUS-SM with cytopenias (6 vs 0.3% in cases without counts alterations, p< .001). This frequency was higher when considering only cases with idiopathic cytopenias (22 vs 1.8% in cases with cytopenias of other causes, p< .001) ( FigA). Reverse analysis of the LGL cohort demonstrated that 71 (30%) LGL cases had M proteins. Overall, the MG/LGL dyad was more frequently associated with concurrent autoimmune conditions (54%), as well as monoclonal B-cell lymphocytosis and other B-cell lymphoid neoplasms (19%). Next, we compared cases with MG/LGL vs those with MGs (N = 775) or LGL (N = 157) exclusively. When compared to the MGs cohort, MG/LGL cases presented a younger age (median 64 vs 70 years, p < .001), had higher frequency of M protein of the IgM type (21 vs 10%, p= .002), and oftentimes exhibited small/transient paraproteinemia (42 vs 2%, p< .001). No specific features were enriched in the MG/LGL cases when compared to the LGL cohort, except for a higher proportion of proliferations of NK-cell subtype (12 vs 4%, p= .02). Finally, to confirm the observed association, we focused on the subgroup of non-active MGs by excluding cases with initial diagnosis of MM or lymphoma. Multivariable analysis (adjusting by sex, age and MG risk) revealed a lower risk of immunoparesis (aOR: 0.4, 95%CI: 0.2 - 0.7, p= .002) in MG/LGL as opposed to MG without LGL, whereas no effect was found in progression to MM/lymphoma (aHR: 0.9, 95%CI: 0.4 - 2.1, p= .81 in a competitive-risk setting). Moreover, when opposed to its MG and LGL counterparts, MG/LGL more frequently presented with severe cytopenias (aOR vsMGs: 28.9, 95%CI: 14.0 - 59.0, p< .001; aOR vsLGL: 2.7, 95%CI: 1.7 - 5.6, p= .008), and with immune-mediated cytopenias (aOR vsMGs: 10.5, 95%CI: 4.9 - 22.2, p< .001; aOR vsLGL: 2.8, 95%CI: 1.0 - 4.8, p= .04) ( FigB). In conclusion, our study reveals that: 1) the association between MGUS and LGL is more than an age-related epidemiological coincidence; 2) distinctive nosologic features for the MG/LGL dyad; and 3) that even “non-active” MGs associated with LGL might be of hematological clinical significance through humoral or cellular immune mechanisms. These findings point towards alternative treatment strategies of cytopenias in MGUS and LGL (immunosuppression vs anti-myeloma therapies, respectively), and provide impetus for the investigation of tumor surveillance in MGUS vs common etiologic factors intertwining these clonopathies.