Analysis of Cytotoxic Granules and Constitutively Produced Extracellular Vesicles from Large Granular Lymphocytic Leukemia Cell Lines.

BACKGROUND: Large granular lymphocyte leukemias (LGLLs) are rare lymphoproliferative malignancies caused by clonal expansion of granular lymphocytes. T-cell LGLL and natural killer (NK) cell LGLL are defined based on their cellular origin. Their clinical manifestation and pathophysiology vary depending on the subtype and include, e.g., neutropenia, anemia, recurrent infections, and autoimmunity. A limited number of available patient-derived cell lines are considered valuable tools to study the biology of these malignancies. They differ in the expression of lineage-specific surface markers, but generally contain cytotoxic effector molecules in characteristic granules. METHODS: We investigated the presence and release of lysosome-associated effector proteins in patient-derived LGLL cell lines by flow and imaging cytometry, by Western blotting and by bottom-up proteomics profiling. RESULTS: The tested cell lines did not express FasL (CD178), but did express CD26/DPP4+. Intracellularly, we detected major differences in the abundance and subcellular distribution of granzymes, perforin, and granulysin. Similar differences were seen in enriched lysosome-related effector vesicles (LREVs). The proteomics profiling of enriched EVs from an NK-LGLL line (NKL) and a T-LGLL line (MOTN-1), confirmed individual profiles of effector molecules. CONCLUSION: Our analyses underscore the individual distribution of effector proteins but also open new routes to define the role of intra- and extracellular granules in the disease manifestation or pathology of LGLLs.

Aleukemic variant of T-cell large granular lymphocyte leukemia in patients with rheumatoid arthritis - diagnostically challenging subtype.

INTRODUCTION: The typical clinical manifestations of T-cell large granular lymphocyte (T-LGL) leukemia are an increase in the number of large granular lymphocytes (LGLs) in the blood > 2000 cells/µL, neutropenia, and splenomegaly. In rare cases of so-called 'aleukemic' T-LGL leukemia, the number of LGLs is <400-500 cells/µL. In patients with rheumatoid arthritis (RA), distinguishing T-LGL leukemia with low tumor burden in the blood and bone marrow from Felty syndrome (FS) poses diagnostic challenges. AREAS COVERED: This review aimed to describe the basic characteristics and variants of aleukemic T-LGL leukemia, with a special focus on aleukemic T-LGL leukemia with massive splenomegaly (splenic variant of T-LGL leukemia) and differential diagnosis of such cases with hepatosplenic T-cell lymphoma. The significance of mutations in the signal transducer and activator of transcription 3 (STAT3) gene for distinguishing aleukemic RA-associated T-LGL leukemia from FS is discussed, along with the evolution of the T-LGL leukemia diagnostic criteria. PubMed database was used to search for the most relevant literature. EXPERT OPINION: Evaluation of STAT3 mutations in the blood and bone marrow using next-generation sequencing, as well as a comprehensive spleen study, may be necessary to establish a diagnosis of aleukemic RA-associated T-LGL leukemia.

T-Cell Lymphoproliferative Disorders Following Allogeneic Bone Marrow Transplant: A Report of Two Cases and a Literature Review.

Post-transplantation lymphoproliferative disorders (PTLD) are a commonly occurring condition following solid organ transplantation (SOT) and, rarely, hematopoietic stem cell transplantation (HSCT). As the name suggests, a PTLD is a condition where there is a clonal proliferation of lymphoid cells that occurs as a complication after transplantation. Though the clonal origin cell is primarily associated with the B-cell lineage, there are existing cases in the literature describing PTLD from the T-cell lineage. Large granulocytic leukemia (LGL) is one rare T-cell lineage subtype that typically progresses with a passive clinical course and is discovered with leukocytosis and peripheral blood smears demonstrating large granules in lymphocytes. In this study, we describe two patients initially diagnosed with acute myeloid leukemia (AML) who were both found to have T-cell PTLD after undergoing allogeneic hematopoietic stem cell transplant. One was found with a clonal expansion of T-cells on flow cytometry and the other with LGL on peripheral blood and flow cytometry. This discovery was made at 16 and 20 months after their transplant respectively. Distinguishing factors for these two patients are demonstrated by the derivation of lymphoproliferative disorder from graft vs. host disease (GVHD) or viral etiology, which is significant as both of which have been shown to be associated with PTLD. Epstein-Barr virus (EBV) and cytomegalovirus (CMV) positivity have been shown to be associated with PTLD, and both our patients were EBV-negative but had harbored prior CMV infections. Additionally, they had a benign course with no development of cytopenias or symptoms since the time of diagnosis. These two cases add to the growing literature that is working to better characterize the rare development of LGL and, in general, T-cell PTLD following allogeneic bone marrow transplantation.

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.

A case report of T-LGL leukemia-associated pure red cell aplasia harboring STAT3, TNFAIP3, and KMT2D mutation.

Background: T-large granular lymphocyte (T-LGL) leukemia is a rare clonal lymphoproliferative disorder, which has a favorable prognosis. There are different complications between Asian and Western patients diagnosed with LGL leukemia. In Asians, pure red cell aplasia (PRCA) is the most common hematological compatible clinical feature of LGL leukemia, whereas in Western patients, rheumatoid arthritis and neutropenia are more commonly seen. Herein, a rare case of T-LGL leukemia associated PRCA was reported. Case Description: A 72-year-old man, presenting with anemia and leukopenia, was admitted to hospital. The bone marrow (BM) smear revealed that erythroid series were suppressed with only 4%, mature lymphocytes constituting up to 23% of the marrow cells. The results of T-cell receptor (TCR) arrangement revealed mutations in the TCR-ß and TCR-γ genes. Further, STAT3 mutation (p. [D661Y; N664T] and p.N647I), TNFAIP3 mutation (p.L48fs), and KMT2D mutation (p.E5291K) were confirmed. The patient was diagnosed with CD8+ TCRαß T-LGL leukemia-associated PRCA, harboring STAT3, TNFAIP3 and KMT2D mutation. The BM smear, immunophenotype, gene rearrangement and karyotype were consistent with those of the first diagnosis. Cyclosporine A (CyA) based regimens were effective, even in a cessation of discontinued treatment. The patient refused BM-related examinations and has remained in hematological complete remission (CR) until the time of writing (at least 3 years). Conclusions: The administration of CyA yielded a CR in this case. However, the standard therapy for T-LGL leukemia-associated PRCA is not clear, and more prospective studies are needed to ascertain the underlying mechanism of pathogenesis.

T-large granular lymphocytic leukemia.

T-cell large granular lymphocyte (T-LGL) leukemia is characterized by clonal expansion of cytotoxic T cells resulting in cytopenia. The proliferation of clonal LGLs is caused by prolonged antigenic stimulation, which leads to apoptotic dysregulation owing mainly to the constitutive activation of survival pathways, notably the JAK/STAT pathway. Understanding how leukemic T-LGL persists can aid in the development of future immunosuppressive therapies. In this review, we summarize the diagnosis and current standard of therapy for T-LGL leukemia, as well as recent advances in clinical trials.

BLNK mutation associated with T-cell LGL leukemia and autoimmune diseases: Case report in hematology.

We present the case of a female patient with a heterozygous somatic BLNK mutation, a T-cell LGL (large granular lymphocyte) leukemia, and multiple autoimmune diseases. Although this mutation seems uncommon especially in this kind of clinical observation, it could represent a new mechanism for autoimmune diseases associated with LGL leukemia. The patient developed several autoimmune diseases: pure red blood cell apalsia, thyroiditis, oophoritis, and alopecia areata. She also presented a T-cell LGL leukemia which required treatment with corticosteroids and cyclophosphamide, with good efficacy. Interestingly, she had no notable infectious history. The erythroblastopenia also resolved, the alopecia evolves by flare-ups, and the patient is still under hormonal supplementation for thyroiditis and oophoritis. We wanted to try to understand the unusual clinical picture presented by this patient. We therefore performed whole-genome sequencing, identifying a heterozygous somatic BLNK mutation. Her total gamma globulin level was slightly decreased. Regarding the lymphocyte subpopulations, she presented a B-cell deficiency with increased autoreactive B-cells and a CD4+ and Treg deficiency. This B-cell deficiency persisted after complete remission of erythroblastopenia and LGL leukemia. We propose that the persistent B-cell deficiency linked to the BLNK mutation can explain her clinical phenotype.

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

Background: T-cell large granular lymphocytic leukemia (T-LGLL) is a rare lymphoproliferative disorder that starts in T cells and is usually indolent. Long-term use of immunosuppressants, combined with agranulocytosis, is a double-edged sword, as both can lead to serious infections, especially in patients with combined hematologic malignancies and immune defects. Case Presentation: A 30-year-old female patient was admitted to the hospital because of agranulocytosis for five years, with chest tightness, fatigue, and fever for two days. Pathology and metagenomic next-generation sequencing (mNGS) detected Aspergillus. Although she received cyclosporine and methylprednisolone, the patient showed drug intolerance and progression with invasive pulmonary fungal infections. After a bone marrow aspiration biopsy and other related examinations, she was diagnosed with T-LGLL and invasive pulmonary aspergillosis (IPA). T-cell immunophenotype was CD45+CD3dim+CD5-CD4-CD8+CD7+CD57p+CD25-CD30-, TCRγδ+, transducer and activator of transcripton-3 (STAT3) Y640F mutation and fusion gene NPL-DHX9 rearrangement were confirmed, which has never been reported in hematological diseases. After voriconazole regimen adjustment during treatment based on therapeutic drug concentration monitoring (TDM) and improvement in lung infection, the patient finally treated with purine nucleoside analogues (PNA) cladribine as a single agent at 0.14 mg/kg/d for 5 days. Complete response was achieved after four-cycles cladribine treatment (WBC 2.1*109/L, HGB 117 g/L, PLT 196*109/L, ANC 1.6*109/L, and ALC 0.2*109/L). Conclusions: To our knowledge, this is the first case of T-LGLL with a rare γδ type and fusion gene NPL-DHX9 rearrangement. The patient was successfully treated with cladribine, suggesting that this regimen could be a promising therapeutic strategy for patients with aggressive T-LGLL.

[The efficacy of alemtuzumab for pure red cell aplasia associated with autoimmune polyendocrine syndrome type 1].

We present a case of a 41-year-old woman who was diagnosed with autoimmune polyendocrine syndrome type 1 (APS-1) at the age of 2. She developed severe anemia and was diagnosed with pure red cell aplasia (PRCA) and T-cell large granular lymphocyte leukemia at the age of 34. The pathogenesis of APS-1 is based on the presence of an inactive mutation in the autoimmune regulator gene on thymic medullary epithelial cells. It is thought that the autoimmune T cells generated by impaired negative selection in the thymus induce PRCA. The patient was treated with immunosuppressive therapy (ciclosporin, antithymocyte globulin, prednisolone, and cyclophosphamide) for a long time by her previous doctor. After a long period of remission and exacerbation, she became dependent on blood transfusion approximately at the age of 40 and was transferred to our hospital. At our hospital, alemtuzumab treatment resulted in the disappearance of large granular lymphocytes and improvement of anemia. We report this case as a valuable demonstration of the efficacy of alemtuzumab for treating PRCA associated with APS-1.

Persistent Large Granular Lymphocyte Clonal Expansions: "The Root of Many Evils"-And of Some Goodness.

Large granular lymphocyte leukemia (LGLL) is a chronic disease of either mature phenotype cytotoxic CD3+ T lymphocytes or CD3- NK cells. LGLL diagnosis is hampered by the fact that reactive persistent clonal LGL expansions may fulfill the current criteria for LGLL diagnoses. In addition to the presence of characteristic clinical and hematological signs such as anemia or neutropenia, LGLL/LGL clonal expansions have been associated with an array of conditions/disorders. We review here the presence of these persistent clonal expansions in autoimmune, hematological disorders and solid neoplasms and after hematopoietic stem cell transplantation. These associations are a unique translational research framework to discern whether these persistently expanded LGL clones are causes or consequences of the concomitant clinical settings and, more importantly, when they should be targeted.

[Investigation of large granular lymphocytic leukemias: data from the laboratory of hematology at Nancy University Hospital, France]. / Investigation des leucémies à grands lymphocytes à grains : expérience d'un laboratoire d'hématologie.

Large granular lymphocytic leukemia (LGLL) is a rare clonal lymphoproliferative disorder from T or NK origin. PURPOSE: to report on the diagnostic and therapeutic management of LGLL investigated in the university hospital at Nancy, France. METHODS: retrospective (7 years) collection of clinical and biological data and patients' cohort analysis. RESULTS: Eight out of fifteen patients presented with neutropenia, including five profound neutropenia (neutrophils < 500 × 109/L). Four patients had an infection. Two patients have rheumatoid arthritis and an associated Felty's syndrome, one a Sweet syndrome. Two also suffered from chronic Lymphocytic Leukemia, and one from a diffuse large B-cell lymphoma. Twelve patients had LGLL-T and 3 had a chronic LGLL-NK. Eleven out of twelve patients had a clonal LGLL-T when polymerase chain reaction assessed. No KIR clonality was sought among the 3 LGL-NK patients. Five patients out of fifteen received immunosuppressive treatment. CONCLUSION: Although using simple and robust investigations, our series demonstrates a high heterogeneity in LGLL detection and assessment.

Toward a Better Classification System for NK-LGL Disorders.

Large granular lymphocytic leukemia is a rare lymphoproliferative disorder characterized by a clonal expansion of T-lineage lymphocyte or natural killer (NK) cells in 85 and 15% of cases respectively. T and NK large granular leukemia share common pathophysiology, clinical and biological presentation. The disease is characterized by cytopenia and a frequent association with autoimmune manifestations. Despite an indolent course allowing a watch and wait attitude in the majority of patients at diagnosis, two third of the patient will eventually need a treatment during the course of the disease. Unlike T lymphocyte, NK cells do not express T cell receptor making the proof of clonality difficult. Indeed, the distinction between clonal and reactive NK-cell expansion observed in several situations such as autoimmune diseases and viral infections is challenging. Advances in our understanding of the pathogenesis with the recent identification of recurrent mutations provide new tools to prove the clonality. In this review, we will discuss the pathophysiology of NK large granular leukemia, the recent advances in the diagnosis and therapeutic strategies.

[Large granular lymphocyte CD3+CD56+ Leukemia revealed by ocular tumor]. / Leucémie à grands lymphocytes granuleux CD3+ CD56+ révélée par une tumeur oculaire.

Large granular lymphocyte leukemia (LGL) constitutes a heterogeneous entity with very different immunophenotypic, clonal and evolutionary characteristics. The most common LGL-T are CD3 +, CD8 +, CD16 +, CD57 +, CD56-. The majority of patients have a chronic disease, systemic signs are rare, and symptoms mainly result from neutropenia or associated autoimmune diseases. We report here a very special case of a 44-year-old woman patient diagnosed with aggressive LGL-T variant also expressing CD56.

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. TCRαß 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.

Concurrence of Myelodysplastic syndromes and large granular lymphocyte leukemia: clinicopathological features, mutational profile and gene ontology analysis in a single center.

The concurrence of Myelodysplastic syndromes (MDS) and large granular lymphocyte leukemia (LGLL) has been reported in a small group of patients and might suggest an etiologic relationship rather than a simple coincidence. In this present study, clinicopathological features were detailed in ten cases of MDS concurrent with LGLL (MDS-LGLL). These cases included seven patients with T-LGLL, two with mixed-phenotype LGLL, and one with CLPD-NK. Subsequently, gene mutation screening for commonly myeloid-related or lymphoid-related genes was performed in MDS-LGLL patients by using next generation sequencing (NGS). The genes with the highest frequency of mutations were ASXL1 (3/10, 30%) and STAG2 (3/10, 30%) among a panel of 114 genes. LGLL-associated mutations of STAT3 (2/10, 20%) and STAT5b (1/10, 10%) were also detected. Moreover, whole-exome sequencing (WES) and gene ontology (GO) analysis for one patient in his different phases revealed increased enrichment of histone H3 lysine 4 (H3K4) mono-methylation (GO:0097692) pathway and decreased enrichment of translocation of ZAP-70 to immunological synapse (R-HAS-202430) pathway upon progression from MDS to MDS-LGLL.

Linking the KIR phenotype with STAT3 and TET2 mutations to identify chronic lymphoproliferative disorders of NK cells.

Distinguishing chronic lymphoproliferative disorders of NK cells (CLPD-NK) from reactive NK-cell expansion is challenging. We assessed the value of killer immunoglobulin-like receptor(KIR) phenotyping and targeted high-throughput sequencing in a cohort of 114 consecutive patients with NK cell proliferation, retrospectively assigned to a CLPD-NK group (n = 46) and a reactive NK group (n = 68). We then developed an NK-cell clonality score combining flow cytometry and molecular profiling with a positive predictive value of 93%. STAT3 and TET2 mutations were respectively identified in 27% and 34% of the patients with CLPD-NK, constituting a new diagnostic hallmark for this disease. TET2-mutated CLPD-NK preferentially exhibited a CD16low phenotype, more frequently displayed a lower platelet count, and was associated with other hematologic malignancies such as myelodysplasia. To explore the mutational clonal hierarchy of CLPD-NK, we performed whole-exome sequencing of sorted, myeloid, T, and NK cells and found that TET2 mutations were shared by myeloid and NK cells in 3 of 4 cases. Thus, we hypothesized that TET2 alterations occur in early hematopoietic progenitors which could explain a potential link between CLPD-NK and myeloid malignancies. Finally, we analyzed the transcriptome by RNA sequencing of 7 CLPD-NK and evidenced 2 groups of patients. The first group displayed STAT3 mutations or SOCS3 methylation and overexpressed STAT3 target genes. The second group, including 2 TET2-mutated cases, significantly underexpressed genes known to be downregulated in angioimmunoblastic T-cell lymphoma. Our results provide new insights into the pathogenesis of NK-cell proliferative disorders and, potentially, new therapeutic opportunities.

CD8-positive cutaneous lymphoproliferation associated with large granular lymphocyte leukemia in a patient with X-linked agammaglobulinemia.

Patients with primary immunodeficiency are at increased risk for malignancy, especially hematologic neoplasms. This paper reports a unique case of a 47-year-old man with X-linked agammaglobulinemia who presented with progressive asymptomatic violaceous papules and plaques on his face, hands, and trunk for 1 year. Skin biopsies revealed deep, nodular infiltrates of histiocytes and CD8-positive lymphocytes, with a CD4:CD8 ratio of 1:10. Laboratory studies showed cytopenias. Flow cytometry in the skin, blood, and bone marrow (BM) showed a CD3+/CD8+/CD57+ large granular lymphocyte population. BM biopsy showed 30% involvement with these atypical T-cells. T-cell gene rearrangement studies of skin, blood, and BM revealed identical T-cell clones. He was diagnosed with T-large granular lymphocyte leukemia (T-LGLL) with an associated CD8+ cutaneous lymphoproliferation. Skin involvement was suspected to represent infiltration by T-LGLL. However, co-existence of two lymphoproliferative disorders (LPDs), T-LGLL and CD8+ granulomatous LPD, remains a possibility. In general, cutaneous infiltrates associated with LGLL are rare and poorly understood. It has been suggested that they are markers of poor prognosis. Our case report describes skin, blood, and BM findings in an immunosuppressed patient with T-LGLL in detail. These findings have not yet been reported and their significance requires further investigation.

Analysis of a single-institution cohort of patients with Felty's syndrome and T-cell large granular lymphocytic leukemia in the setting of rheumatoid arthritis.

T-cell large granular lymphocytic leukemia (T-LGLL) is a lymphoproliferative disorder characterized by a persistent increase in the number of large granular lymphocytes (LGLs), neutropenia, and splenomegaly. Clinical manifestations of T-LGLL in the setting of rheumatoid arthritis (RA) are often identical to those in which one would suspect Felty's syndrome (FS). These disorders are distinguished by the presence of T-cell clonality, which is present in T-LGLL but not in FS. Mutations in the signal transducer and activator of transcription 3 (STAT3) and 5b (STAT5b) genes can be used as molecular markers of T-LGLL, but their prevalence in FS is unknown.Eighty-one patients with RA and unexplained neutropenia or/and an increase in the number of LGLs above 2 × 109/L were stratified into RA-associated T-LGLL (N = 56) or FS (N = 25) groups based on the presence or absence of T-cell clonality. STAT3 and STAT5b gene mutations were assessed in each group by means of allele-specific polymerase chain reaction assays. Clinical, immunological, laboratory data and the results of immunophenotyping of blood and bone marrow lymphocytes were also evaluated.Mutations of the STAT3 gene and an increase in the number of LGLs above 2 × 109/L were detected in RA-associated T-LGLL, but not in FS (39% vs 0% and 21% vs 0%, respectively). Mutations in the STAT5b gene were not observed in either group. Expression of CD57, CD16, and CD5-/dim on CD3+CD8+ T-lymphocytes was observed in both RA-associated T-LGLL and FS.STAT3 gene mutations or LGL counts over 2 × 109/L in RA patients are indicative of T-LGLL.

Simultaneous Presentation of Leukemic Non-Nodal Mantle Cell Lymphoma and Gamma-Delta T-Large Granular Lymphocytic Leukemia in a Patient with Rheumatoid Arthritis.

The peculiar features of T-cell large granular lymphocytic leukemia (T-LGLL) are its association with autoimmune disorders (particularly with rheumatoid arthritis (RA)) and a broad spectrum of B-cell lymphoproliferative disorders. However, association of T-LGLL with mantle cell lymphoma (MCL) is extremely rare. Here, we describe a case of an 80-year-old man admitted with suspected Felty's syndrome. The blood count showed white blood cells at 2.2×109/L, with 3% neutrophils, 88% lymphocytes, and at 0.66×109/L LGLs. The spleen had been removed 43 months prior to the admission due to suspected B-cell splenic lymphoma. Re-examination of the spleen revealed cyclin D1+ and SOX11- lymphocytes in the inner part of the unexpanded mantle zones of the white pulp follicles, thus displaying a so-called in situ histologic pattern of MCL, and in small clusters in the red pulp. The splenic cords were moderately expanded by lymphocytes expressing CD3, TIA1, and granzyme B but not CD4 and CD8. Monoclonal rearrangements of the immunoglobulin heavy chain gene and the T-cell receptor (TCR) gamma and delta chain genes, polyclonal rearrangements of the TCR beta chain gene, mutation of the signal transducer and activator of transctiption 3  gene (c.1940A>T; p.N647I), and t(11;14)(q13;q32) translocation were identified in the spleen sample. Flow cytometry of bone marrow revealed a population of TCR γδ+, CD3+, CD4-, CD5-, CD7+, CD8-, CD16-, CD56-, and CD57- lymphocytes. Fragment analysis demonstrated identical TCR gene clonal rearrangement patterns in the spleen and bone marrow samples. In this study, we describe the first case of simultaneous presentation of γδ T-LGLL and leukemic non-nodal MCL (L-NN-MCL) in a patient with RA and present morphological findings of L-NN-MCL in the spleen.

Rituximab for rheumatoid arthritis-associated large granular lymphocytic leukemia, a retrospective case series.

OBJECTIVES: To assess the efficacy and tolerance profile of rituximab in rheumatoid arthritis (RA)-associated large granular lymphocyte leukemia (LGLL). METHODS: Multicenter retrospective case series. Inclusion criteria were RA defined by the ACR/EULAR 2010 criteria and LGLL defined by absolute LGL count ≥ 0.3 × 109/L with evidence of an expanded clonal LGL population (flow cytometry, TCR-γ polymerase chain reaction, or Stat3 mutation). RESULTS: Fourteen patients (10 women, mean age 55.2 ± 14.2 years) included; 13 were seropositive for anti-cyclic citrullinated peptides (n = 11) or rheumatoid factor (n = 10). LGLL diagnosis was made 9.5 [IQR: 3.25;15.5] years after RA diagnosis. Thirteen patients had T-LGLL. Rituximab was the first-line therapy for LGLL for 4 patients. Previous treatment lines included methotrexate (n = 7), cyclophosphamide (n = 2), cyclosporin A (n = 1), or granulocyte colony-stimulating factor (n = 4). Rituximab was used in monotherapy (n = 8) or associated to methotrexate (n = 3), granulocyte colony-stimulating factor (n = 2), or alkylating agents (n = 1). The number of rituximab cycles ranged from 1 to 11 (median 6), with high heterogeneity in dosing regimens. Median duration response after rituximab initiation was 35 [IQR: 23.5;41] months. The overall response rate was 100%: 8 patients experienced complete response (normalization of blood count and LGL ≤ 0.3 × 109/L) and 6 experienced partial responses (improvement in blood counts without complete normalization). The tolerance profile was good, with no infectious complications. CONCLUSION: rituximab appears as a valuable therapeutic option for RA-associated LGLL.