Chronic neutropenia in LGL leukemia and rheumatoid arthritis

Evidence of membranolytic targeting and intracellular citrullination in neutrophils isolated from patients with rheumatoid arthritis

Anti-citrullinated protein autoantibodies (ACPA) are diagnostic for rheumatoid arthritis (RA). The antigens recognized by these autoantibodies are produced by protein arginine deiminases (PADs), particularly PAD4. However, it remains unknown why and how PAD4 causes this aberrant citrullination in RA. Here, we report that poly-perforin pores are present on freshly isolated neutrophils from RA patients, but not on healthy donor neutrophils. Neutrophils with perforin pores also contained intracellular citrullinated proteins in the region adjacent to the pores. This response was replicated in vitro by treating neutrophils with purified perforin, which generated intense dots of anti-perforin immunofluorescence, calcium influx, and intracellular citrullination. Extensive neutrophil killing in Felty's syndrome, an aggressive form of RA, correlated with particularly high ACPA, and PAD4 autoantibodies. In contrast, other forms of death, including NETosis, apoptosis, and pyroptosis, produced minimal citrullination. We conclude that neutrophil targeting by perforin leading to intracellular citrullination takes place in patients with RA.

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.

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

AIMS

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.

METHODS AND RESULTS

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.

CONCLUSION

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.

Large granular lymphocytic leukemia cured by allogeneic stem cell transplant: a case report

BACKGROUND

Large granular lymphocytic leukemia is a rare lymphocytic neoplasm that can pose a treatment challenge in patients with severe neutropenia in whom conventional therapies fail. We report one of the first cases in which allogeneic stem cell therapy was used as treatment for large granular lymphocytic leukemia. We report and discuss the case of a 42-year-old white Caucasian female who, despite multiple therapies including methotrexate, cyclophosphamide, prednisone, cyclosporine, and pentostatin, continued to show severe neutropenia and recurrent infections. The patient was treated successfully and cured by allogeneic stem cell transplant without any major complications.

CONCLUSIONS

The significant importance of this case report is the introduction of a new treatment algorithm for challenging cases of T-cell large granular lymphocytic leukemia in which standard care fails. We hope that this case report will raise awareness of the potential benefits of allogeneic stem cell transplant in the treatment of aggressive forms of T-cell large granular lymphocytic leukemia.

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.

Intersection Between Large Granular Lymphocyte Leukemia and Rheumatoid Arthritis

Large granular lymphocyte (LGL) leukemia, a rare hematologic malignancy, has long been associated with rheumatoid arthritis (RA), and the diseases share numerous common features. This review aims to outline the parallels and comparisons between the diseases as well as discuss the potential mechanisms for the relationship between LGL leukemia and RA. RA alone and in conjunction with LGL leukemia exhibits cytotoxic T-cell (CTL) expansions, HLA-DR4 enrichment, RA-associated autoantibodies, female bias, and unknown antigen specificity of associated T-cell expansions. Three possible mechanistic links between the pathogenesis of LGL leukemia and RA have been proposed, including LGL leukemia a) as a result of longstanding RA, b) as a consequence of RA treatment, or c) as a driver of RA. Several lines of evidence point towards LGL as a driver of RA. CTL involvement in RA pathogenesis is evidenced by citrullination and granzyme B cleavage that modifies the repertoire of self-protein antigens in target cells, particularly neutrophils, killed by the CTLs. Further investigations of the relationship between LGL leukemia and RA are warranted to better understand causal pathways and target antigens in order to improve the mechanistic understanding and to devise targeted therapeutic approaches for both disorders.

Outcomes for patients with severe chronic neutropenia treated with granulocyte colony-stimulating factor

Severe chronic neutropenia (SCN), defined as blood neutrophils < 0.5 x 109/L for more than 3 months, is an uncommon hematological condition associated with recurrent and severe bacterial infections. After short-term clinical trials showed the benefits of granulocyte colony-stimulating factor (G-CSF) treatment for SCN, the Severe Chronic Neutropenia International Registry (SCNIR) opened to determine the long-term benefits and safety of this treatment. This report summarizes findings from more than 16 000 patient-years of prospective observations for patients with congenital and acquired SCN. We observed that adverse outcomes depend on the underlying etiology. MDS and AML occur infrequently and largely in patients with congenital neutropenias. Having cyclic or chronic autoimmune/idiopathic neutropenia portends a favorable prognosis. A few patients with idiopathic neutropenia evolve to develop lymphoid malignancies, but they do not appear to be at increased risk of myeloid malignancies, even with very long-term G-CSF therapy. Progression to systemic autoimmune diseases, bone marrow failure, aplastic anemia, or non-myeloid malignancies are not expected consequences of SCN or treatment with G-CSF.

Isolated anemia in patients with large granular lymphocytic leukemia (LGLL)

Patients with large granular lymphocytic leukemia (LGLL) frequently present with neutropenia. When present, anemia is usually accompanied by neutropenia and/or thrombocytopenia and isolated anemia is uncommon. We evaluated a cohort of 244 LGLL patients spanning 15 years and herein report the clinicopathologic features of 34 (14%) with isolated anemia. The patients with isolated anemia showed a significantly male predominance (p = 0.001), a lower level of hemoglobulin (p < 0.0001) and higher MCV (p = 0.017) and were less likely to have rheumatoid arthritis (p = 0.023) compared to the remaining 210 patients. Of the 34 LGLL patients with isolated anemia, 13 (38%) presented with pure red cell aplasia (PRCA), markedly decreased reticulocyte count and erythroid precursors, and more transfusion-dependence when compared to non-PRCA patients. There was no other significant clinicopathologic difference between PRCA and non-PRCA patients. 32 patients were followed for a median duration of 51 months (6-199). 24 patients were treated (11/11 PRCA and 13/21 non-PRCA patients, p < 0.02). The overall response rate to first-line therapy was 83% [8/11 (72.7%) for PRCA, 12/13 (92.3%) for non-PRCA], including 14 showing complete response and 6 showing partial response with a median response duration of 48 months (12-129). Half of non-PRCA patients who were observed experienced progressive anemia. During follow-up, no patients developed neutropenia; however, 5/27 (18.5%) patients developed thrombocytopenia. No significant difference in overall survival was noted between PRCA and non-PRCA patients. In summary, this study demonstrates the unique features of LGLL with isolated anemia and underscores the importance of recognizing LGLL as a potential cause of isolated anemia, which may benefit from disease-specific treatment. LGLL patients with PRCA were more likely to require treatment but demonstrated similar clinicopathologic features, therapeutic responses, and overall survival compared to isolated anemia without PRCA, suggesting PRCA and non-PRCA of T-LGLL belong to a common disease spectrum.

Autoimmune polyendocrine syndrome type 1: an Italian survey on 158 patients

BACKGROUND

Autoimmune Polyglandular Syndrome type 1 (APS-1) is a rare recessive inherited disease, caused by AutoImmune Regulator (AIRE) gene mutations and characterized by three major manifestations: chronic mucocutaneous candidiasis (CMC), chronic hypoparathyroidism (CH) and Addison's disease (AD).

METHODS

Autoimmune conditions and associated autoantibodies (Abs) were analyzed in 158 Italian patients (103 females and 55 males; F/M 1.9/1) at the onset and during a follow-up of 23.7 ± 15.1 years. AIRE mutations were determined.

RESULTS

The prevalence of APS-1 was 2.6 cases/million (range 0.5-17 in different regions). At the onset 93% of patients presented with one or more components of the classical triad and 7% with other components. At the end of follow-up, 86.1% had CH, 77.2% AD, 74.7% CMC, 49.5% premature menopause, 29.7% autoimmune intestinal dysfunction, 27.8% autoimmune thyroid diseases, 25.9% autoimmune gastritis/pernicious anemia, 25.3% ectodermal dystrophy, 24% alopecia, 21.5% autoimmune hepatitis, 17% vitiligo, 13.3% cholelithiasis, 5.7% connective diseases, 4.4% asplenia, 2.5% celiac disease and 13.9% cancer. Overall, 991 diseases (6.3 diseases/patient) were found. Interferon-ω Abs (IFNωAbs) were positive in 91.1% of patients. Overall mortality was 14.6%. The AIRE mutation R139X was found in 21.3% of tested alleles, R257X in 11.8%, W78R in 11.4%, C322fsX372 in 8.8%, T16M in 6.2%, R203X in 4%, and A21V in 2.9%. Less frequent mutations were present in 12.9%, very rare in 9.6% while no mutations in 11% of the cases.

CONCLUSIONS

In Italy, APS-1 is a rare disorder presenting with the three major manifestations and associated with different AIRE gene mutations. IFNωAbs are markers of APS-1 and other organ-specific autoantibodies are markers of clinical, subclinical or potential autoimmune conditions.

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.

The Value of Flow Cytometry Clonality in Large Granular Lymphocyte Leukemia

Simple Summary

Large granular lymphocyte (LGL) leukemia, a lymphoproliferative disease, is characterized by an increased frequency of large-sized lymphocytes with typical expression of T-cell receptor (TCR) αβ, CD3, CD8, CD16, CD45RA, and CD57, and with the expansion of one to three subfamilies of the TCR variable β chain reflecting gene rearrangements. Molecular analysis remains the gold standard for confirmation of TCR clonality; however, flow cytometry is time and labor saving, and can be associated with simultaneous investigation of other surface markers. Moreover, Vβ usage by flow cytometry can be employed for monitoring clonal kinetics during treatment and follow-up of LGL leukemia patients.

Abstract

Large granular lymphocyte (LGL) leukemia is a lymphoproliferative disorder of mature T or NK cells frequently associated with autoimmune disorders and other hematological conditions, such as myelodysplastic syndromes. Immunophenotype of LGL cells is similar to that of effector memory CD8⁺ T cells with T-cell receptor (TCR) clonality defined by molecular and/or flow cytometric analysis. Vβ usage by flow cytometry can identify clonal TCR rearrangements at the protein level, and is fast, sensitive, and almost always available in every Hematology Center. Moreover, Vβ usage can be associated with immunophenotypic characterization of LGL clone in a multiparametric staining, and clonal kinetics can be easily monitored during treatment and follow-up. Finally, Vβ usage by flow cytometry might identify LGL clones silently underlying other hematological conditions, and routine characterization of Vβ skewing might identify recurrent TCR rearrangements that might trigger aberrant immune responses during hematological or autoimmune conditions.

Chronic neutropenia: how best to assess severity and approach management?

INTRODUCTION

Neutropenia is a relatively common finding in medical practice and the medical approach requires a gradual and pertinent diagnostic procedure as well as adapted management.

AREAS COVERED

The area of chronic neutropenia remains fragmented between diverse diseases or situations. Here physicians involved in different aspects of chronic neutropenia gather both the data from medical literature till the end of May 2021 and their experience to offer a global approach for the diagnosis of chronic neutropenia as well as their medical care.

EXPERT OPINION

In most cases, the neutropenia is transient, frequently related to a viral infection, and not harmful. However, neutropenia can be chronic (i.e. >3 months) and related to a number of etiologies, some clinically benign, such as so-called 'ethnic' neutropenia. Autoimmune neutropenia is the common form in young children, whereas idiopathic/immune neutropenia is a frequent etiology in young females. Inherited neutropenia (or congenital neutropenia) is exceptional, with approximately 30 new cases per 10⁶ births and 30 known subtypes. Such patients have a high risk of invasive bacterial infections, and oral infections. Supportive therapy, which is primarily based on daily administration of an antibiotic prophylaxis and/or treatment with granulocyte-colony stimulating factor (G-CSF), contributes to avoiding recurrent infections.

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

目的

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

方法

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

结果

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

结论

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

The non-leukemic T cell large granular lymphocytic leukemia variant with marked splenomegaly and neutropenia in the setting of rheumatoid arthritis - Felty syndrome and hepatosplenic T cell lymphoma mask

T cell large granular lymphocytic (T-LGL) leukemia is a rare type of mature T cell neoplasm. The typical features of T-LGL leukemia include an increased number of large granular lymphocytes in the peripheral blood, cytopenia (most commonly neutropenia), and mild-to-moderate splenomegaly. Up to 28% of patients with T-LGL leukemia have rheumatoid arthritis (RA). This study reports ten atypical cases (seven women and three men, median age 60.5 years) of RA-associated T-LGL leukemia presenting with lymphopenia, severe neutropenia, and marked splenomegaly. The weight of the spleens ranged from 892 to 2100 g (median 1100 g). Bone marrow histology and differential counts of bone marrow aspirates revealed no peculiarities in nine of ten cases. The red pulp of the spleen was expanded and showed moderate to strong infiltration by medium-sized slightly pleomorphic lymphocytes in nine cases and subtle infiltration in one. Although lymphocytic infiltration involved both cords and sinusoids, it was more apparent within the splenic cords. The white pulp was preserved and contained prominent germinal centers in eight patients and was atrophic in two patients. Immunohistochemically, malignant lymphocytes were CD3+, CD43+, and CD4- in all cases and TIA-1+ in nine out of ten. TCRαβ positivity and TCRγδ positivity was observed in six and four cases out of ten, respectively. All ten patients had T cell clonality in the spleen tissue, but in three cases it was absent in both blood and bone marrow. STAT3 mutations in the spleen tissue were detected in three of ten cases. In all eight cases studied, neither isochromosome 7q nor trisomy 8 was detected in the spleen tissue. Cases of RA-associated T-LGL leukemia with low LGL count in the peripheral blood, neutropenia, and marked splenomegaly present a diagnostic challenge and can be misdiagnosed as Felty's syndrome or hepatosplenic T cell lymphoma.

Immunodeficiency and bone marrow failure with mosaic and germline TLR8 gain of function

Inborn errors of immunity (IEI) are a genetically heterogeneous group of disorders with a broad clinical spectrum. Identification of molecular and functional bases of these disorders is important for diagnosis, treatment, and an understanding of the human immune response. We identified 6 unrelated males with neutropenia, infections, lymphoproliferation, humoral immune defects, and in some cases bone marrow failure associated with 3 different variants in the X-linked gene TLR8, encoding the endosomal Toll-like receptor 8 (TLR8). Interestingly, 5 patients had somatic variants in TLR8 with <30% mosaicism, suggesting a dominant mechanism responsible for the clinical phenotype. Mosaicism was also detected in skin-derived fibroblasts in 3 patients, demonstrating that mutations were not limited to the hematopoietic compartment. All patients had refractory chronic neutropenia, and 3 patients underwent allogeneic hematopoietic cell transplantation. All variants conferred gain of function to TLR8 protein, and immune phenotyping demonstrated a proinflammatory phenotype with activated T cells and elevated serum cytokines associated with impaired B-cell maturation. Differentiation of myeloid cells from patient-derived induced pluripotent stem cells demonstrated increased responsiveness to TLR8. Together, these findings demonstrate that gain-of-function variants in TLR8 lead to a novel childhood-onset IEI with lymphoproliferation, neutropenia, infectious susceptibility, B- and T-cell defects, and in some cases, bone marrow failure. Somatic mosaicism is a prominent molecular mechanism of this new disease.

A case of LGL leukemia with paucity of erythropoiesis

The differential diagnosis for neutropenia is large and includes, drug effect, viral infections, sepsis, immune, hypersplenism, and bone marrow disorder. The presence of an autoimmune disorder and large granular lymphocytosis should prompt assessment for immunophenotyping and in select cases a bone marrow biopsy to rule out LGL-leukemia.

Successful abatacept treatment for Felty's syndrome in a patient with rheumatoid arthritis

We report the case of a 69-year-old man with a 38-year history of rheumatoid arthritis (RA), who developed Felty's syndrome, successful treatment with abatacept (ABT). He was treated with etanercept 50 mg/w and methotrexate 8 mg/w for the past 5 years. He was suffered from febrile neutropenia 6 months ago. Etanercept and methotrexate was discontinued 3 months ago, however, neutrophil count was not changed. Abdominal ultrasound showed splenomegaly, the diagnosis of Felty's syndrome was made. Granulocyte colony-stimulating factor therapy showed no effect on neutropenia, he was treated with ABT. After ABT therapy, absolute neutrophil count was elevated 234/μL to 1840/μL.

Large granular lymphocyte leukemia serum and corresponding hematological parameters reveal unique cytokine and sphingolipid biomarkers and associations with STAT3 mutations

Large granular lymphocyte (LGL) leukemia is a rare hematological disorder with expansion of the T-cell or natural killer (NK) cell lineage. Signal transducer and activator of transcription 3 (STAT3) exhibits somatic activating mutations in 30%-40% of LGL leukemia cases. Transcriptional targets of STAT3 include inflammatory cytokines, thus previous studies have measured cytokine levels of LGL leukemia patients compared to normal donors. Sphingolipid metabolism is a growing area of cancer research, with efforts focused on drug discovery. To date, no studies have examined serum sphingolipids in LGL leukemia patients, and only one study compared a subset of cytokines between the T-LGL and NK-LGL subtypes. Therefore, here, we included both LGL leukemia subtypes with the goals of (a) measuring serum sphingolipids for the first time, (b) measuring cytokines to find distinctions between the subtypes, and (c) establishing relationships with STAT3 mutations and clinical data. The serum analyses identified cytokines (EGF, IP-10, G-CSF) and sphingolipids (SMC22, SMC24, SMC20, LysoSM) significantly different in the LGL leukemia group compared to normal donors. In a mixed STAT3 mutation group, D661Y samples exhibited the highest mean corpuscular volume (MCV) values. We explored this further by expanding the cohort to include larger groups of single STAT3 mutations. Male D661Y STAT3 samples had lower Hgb and higher MCV compared to wild type (WT) or Y640F counterparts. This is the first report examining large groups of individual STAT3 mutations. Overall, our results revealed novel serum biomarkers and evidence that D661Y mutation may show different clinical manifestation compared to WT or Y640F STAT3.

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.

Genomics of LGL leukemia and select other rare leukemia/lymphomas

Genomic analysis of cancer offers the hope of identifying new treatments or aiding in the selection of existing treatments. Rare leukemias pose additional challenges in this regard as samples may be hard to acquire and when found the underlying pathway may not be attractive to drug development since so few individuals are affected. In this case, it can be useful to identify common mutational overlap among subsets of rare leukemias to increase the number of individuals that may benefit from a targeted therapy. This chapter examines the current mutational landscape of large granular lymphocyte (LGL) leukemia with a focus on STAT3 mutations, the most common mutation in LGL leukemia to date. We examined the linkage between these mutations and autoimmune symptoms and disorders, in cases of obvious and suspected LGL leukemia. We then summarized and compared mutations in a set of other rare leukemias that also have JAK/STAT signaling pathway activation brought about by genomic changes. These include T-cell acute lymphoblastic leukemia (T-ALL), T-cell prolymphocytic leukemia (T-PLL), cutaneous T-cell lymphoma (CTCL), select peripheral T-cell lymphoma (PTCL), and adult T-cell leukemia/lymphoma (ATLL). Though STAT3 activation is common in these leukemias, the way in which it is achieved, such as the activating cytokine pathway and/or the co-mutational background, is quite diverse.

Autoimmune disease in patients with diffuse large B-cell lymphoma: occurrence and impact on outcome

Background: Patients with certain autoimmune diseases (AID) have an increased risk of developing diffuse large B-cell lymphoma (DLBCL). However, the occurrence of AID in patients with DLBCL as well as the impact of AID on outcome has not been extensively studied. The main purpose of this study was to establish the occurrence of AIDs in a population-based cohort of DLBCL patients and to compare outcomes in patients with or without AID treated with rituximab(R)-CHOP/CHOP-like treatment. We also aimed to analyse gender differences and the potential role of different AIDs on outcome and the frequency of treatment-associated neutropenic fever. Patients and methods: All adult patients treated 2000-2013 with R-CHOP/CHOP-like treatment for DLBCL in four counties of Sweden were included (n = 612). Lymphoma characteristics, outcome and the presence of AID were obtained through medical records. Results: The number of patients with AID was 106 (17.3%). Thyroid disease dominated (n = 33, 31.1%) followed by rheumatoid arthritis (RA) (n = 24, 22.6%). The proportion of AID was significantly higher in females (59/254, 23.2%) vs. in males (47/358, 13.1%) (p = .001). In the whole cohort there was no difference in event free survival (EFS) or overall survival (OS) between patients with or without AID. However, patients with an AID primarily mediated by B-cell responses (thyroid disorders excluded) had a worse OS (p = .037), which seemed to affect only women. The AID group more often had neutropenic fever after first treatment (16.0% vs 8.7%, p = .034) and those with neutropenic fever had a worse OS (p = .026) in Kaplan-Meier analyses. Conclusion: There is a high prevalence of AID among patients with DLBCL. AIDs categorized as primarily B-cell mediated (in this study mainly RA, systemic lupus erythematosus and Sjögren's syndrome) may be associated with inferior OS. AID patients may be more prone to neutropenic fever compared to patients without concomitant AID.