Prevalence of STAT3 mutations in patients with rheumatoid arthritis-associated T-cell large granular lymphocytic leukaemia and Felty syndrome.

OBJECTIVES: Neutropenia is a key presentation of Felty syndrome (FS) and rheumatoid arthritis (RA)-associated T-cell large granular lymphocytic (T-LGL) leukaemia. Clonal rearrangement of T-cell receptor (TCR) gene supports the diagnosis of T-LGL leukaemia but not FS. Mutations in the signal transducer and activator of transcription 3 (STAT3) gene are highly specific for T-LGL leukaemia, but their prevalence in FS remains poorly clarified. METHODS: The study included 100 patients with RA and unexplained neutropenia. TCR rearrangements were examined in blood (100 cases), bone marrow (47 cases), and spleen (12 cases) using the BIOMED-2 protocol. Patients were stratified into RA-associated T-LGL leukaemia cohort if a clonal TCR rearrangement was identified in any of the tested patient samples, and into FS cohort in other cases. Mutations in the STAT3 were examined using next-generation sequencing (NGS) technology in blood (100 cases), bone marrow (37 cases), and spleen (7 cases). RESULTS: STAT3 mutations were identified in 71% (49/69) patients with RA-associated T-LGL leukaemia and in 10% (3/31) patients with FS (p=4.7×10-8). Three samples from the RA-associated T-LGL leukaemia cohort and 5 samples from the FS cohort had STAT3 mutations in the absence of clonal TCR rearrangement. CONCLUSIONS: The results suggest that STAT3 mutations are significantly less common in FS than in RA-associated T-LGL leukaemia. Moreover, NGS can detect clones undetectable by fragment analysis. We speculate that in patients with RA and neutropenia, the detection of STAT3 mutations can point to T-LGL leukaemia even in the absence of clonal TCR rearrangement.

Severe alveolar bone resorption in Felty syndrome: a case report.

BACKGROUND: Felty syndrome is defined by three conditions: neutropenia, rheumatoid arthritis, and splenomegaly. Neutropenia associated with pancytopenia may further affect the dental condition of a patient. Periodontal treatment and surgery in patients with Felty syndrome necessitates cooperation with a hematologist. Here we present a case of a patient with Felty syndrome who was initially referred to the oral surgery hospital attached to the School of Dentistry for extensive periodontitis. She was effectively treated in collaboration with the hematology department. CASE PRESENTATION: A 55-year-old Asian woman visited our department with concerns of worsening tooth mobility, discomfort, and spontaneous gingival bleeding. Initial periodontal examination revealed generalized severe periodontitis (Stage IV Grade C) resulting from leukopenia/neutropenia and poor oral hygiene. A thorough treatment strategy involving comprehensive dental procedures, such as multiple extractions and extensive prosthetic treatment, was implemented. Following the diagnosis of Felty syndrome, the patient was started on treatment with oral prednisolone 40 mg/day, which effectively controlled the disease. Furthermore, there was no recurrence of severe periodontitis after the periodontal treatment. CONCLUSIONS: Dentists and physicians should be aware that immunocompromised individuals with pancytopenia and poor oral hygiene are at risk of developing extensive periodontitis. If their susceptibility to infection and pancytopenia-related bleeding can be managed, such patients can still receive comprehensive dental treatment, including teeth extractions and periodontal therapy. Cooperation among the dentist, hematologist, and patient is necessary to improve treatment outcomes and the patient's quality of life.

[Visceral leishmaniasis mimicking Felty's syndrome in rheumatoid arthritis treated with methotrexate and etanercept]. / Imitation eines Felty-Syndroms durch eine viszerale Leishmaniasis bei rheumatoider Arthritis unter Therapie mit Methotrexat und Etanercept.

Visceral leishmaniasis (VL) is a chronic parasitic disease caused by pathogens of the genus Leishmania, which can mimic numerous diseases. The leading symptoms of VL (splenomegaly, pancytopenia, fever) can be misinterpreted, especially if autoantibodies are detected, and lead to the misdiagnosis of an underlying rheumatic disease (e.g. systemic lupus erythematosus, Felty's syndrome). Proinflammatory cytokines such as tumour necrosis factor alpha (TNF-α) play an important role in infection control. In this context, there are increasing reports of VL as an opportunistic infection during treatment with anti-TNF­α agents. A case of VL mimicking Felty's syndrome in a patient with rheumatoid arthritis treated with methotrexate and etanercept is presented.

Felty syndrome: a case report.

BACKGROUND: Felty syndrome is a rare manifestation of chronic rheumatoid arthritis in which patients develop extraarticular features of hepatosplenomegaly and neutropenia. The typical presentation of Felty syndrome is in Caucasians, females, and patients with long-standing rheumatoid arthritis of 10 or more years. This case report presents a patient with an early-onset and atypical demographic for Felty syndrome. CASE PRESENTATION: Our patient is a 28-year-old African American woman with past medical history of rheumatoid arthritis diagnosed in 2017, asthma, pneumonia, anemia, and mild intellectual disability who was admitted to inpatient care with fever, chills, and right ear pain for 7 days. The patient's mother, also her caregiver, brought the patient to the hospital after symptoms of fever and ear pain failed to improve. Our patient was diagnosed with sepsis secondary to pneumonia and urinary tract infection. She had been admitted twice in the past year, both times with a diagnosis of pneumonia. During this visit in September 2019, it was discovered that the patient had leukopenia and neutropenia. Bone marrow biopsy revealed increased immature mononuclear cells with left shift and rare mature neutrophils. During the hospital course, the patient was provisionally diagnosed with Felty syndrome and treated with adalimumab and hydroxychloroquine for her rheumatoid arthritis. Her sepsis secondary to pneumonia and urinary tract infection was treated with ceftriaxone and doxycycline, which was later switched to cefepime because of positive blood and urine cultures for Pseudomonas aeruginosa. She was discharged with stable vital signs and is continuing to control her rheumatoid arthritis with adalimumab. CONCLUSION: This case report details the clinical course of sepsis secondary to pneumonia and urinary tract infection in the setting of Felty syndrome. Our patient does not fit the conventional profile for presentation given her race, age, and the length of time following diagnosis of rheumatoid arthritis.

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.

Rheumatoid arthritis patients with peripheral blood cell reduction should be evaluated for latent Felty syndrome: A case report.

RATIONALE: Felty syndrome is a rare and life-threatening type of rheumatoid arthritis (RA). PATIENT CONCERNS: A patient with RA had skin rash and subcutaneous hemorrhage, with a significant decrease in blood hemoglobin (Hb), white blood cell count (WBC), and blood platelet count (BPC). DIAGNOSES: The patient had a history of RA, splenomegaly, decreased Hb, WBC, BPC, and normal immunological indexes, combined with a series of bone marrow related tests and genetic tests. INTERVENTIONS: She was given high-doses of glucocorticoids intravenously, followed by oral prednisone and cyclosporine maintenance therapy. OUTCOMES: Her symptoms were resolved within 2 weeks after the start of immunosuppression. After 2 weeks of discharge, the Hb, WBC, BPC basically returned to normal, and prednisone gradually decreased. LESSONS: Felty syndrome is a rare complication of RA. Reductions in Hb, WBC, BPC, and subcutaneous hemorrhage should be considered strongly as the possibility of Felty syndrome. Multi-disciplinary diagnosis and related tests of bone marrow and genes are helpful for diagnosis and correct treatment.

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.

Phenotypic variability in a child with Felty's syndrome: a case report.

BACKGROUND: Felty's syndrome (FS) is characterized by the triad of rheumatoid arthritis (RA), splenomegaly and neutropenia. The arthritis is typically severe and virtually always associated with high-titer rheumatoid factor. The presence of persistent neutropenia is generally required to make the diagnosis. Most patients diagnosed with FS are aged 50-70 years and have had RA for more than 10 years. It is rarely seen in patients with juvenile idiopathic arthritis (JIA), with only five cases having been reported throughout the world. CASE PRESENTATION: The present study describes the case of a 14-year-old female with a seven-year history of polyarticular JIA, presenting with splenomegaly, hepatomegaly, cholestasis and thrombocytopenia. However, she occasionally developed neutropenia. Titers of rheumatoid factor and anti-CCP were persistently high, and the antinuclear antibody titer was 1:320, while the antibody results for anti-dsDNA and anti-Sm were negative. Serum levels of IgA, IgG, IgM and IgE were all persistently elevated, and the ratio of CD19+ lymphocytes in the subgroups of lymphocytes was persistently high. The level of complements was normal. No STAT3 and STAT5B mutations were found by next-generation sequencing. The patient did not respond to methotrexate, prednisolone, hydroxychloroquine (HCQ), sulfasalazine and etanercept but was responsive to rituximab. CONCLUSIONS: JIA, thrombocytopenia and splenomegaly are the most common and important features in six children with FS, while persistent neutropenia is not seen in all these patients. No complement deficiency has been found in children with FS so far. Manifestations of FS without neutropenia may be extremely rare. There are differences between adults and children in the clinical and laboratory features of FS.

Neutropaenia and splenomegaly without arthritis: think rheumatoid arthritis.

Felty syndrome(FS) is an uncommon, but severe, extra-articular manifestation of rheumatoid arthritis (RA). It occurs in patients with longstanding RA. It is extremely rare for RA to present as FS or develop after initially presenting as neutropaenia and splenomegaly. We describe a case of 47-year-old woman who was diagnosed simultaneously with FS and possible RA after testing positive for anticyclic citrullinated peptide antibody, but a negative rheumatoid factor. She had an excellent response to methotrexate. We review the existing literature of such cases and emphasise the importance of serological testing for RA in patients presenting with neutropaenia and splenomegaly, even in the absence of joint symptoms or prior diagnosis of RA.

Somatic STAT3 mutations in Felty syndrome: an implication for a common pathogenesis with large granular lymphocyte leukemia.

Felty syndrome is a rare disease defined by neutropenia, splenomegaly, and rheumatoid arthritis. Sometimes the differential diagnosis between Felty syndrome and large granular lymphocyte leukemia is problematic. Recently, somatic STAT3 and STAT5B mutations were discovered in 30-40% of patients with large granular lymphocyte leukemia. Herein, we aimed to study whether these mutations can also be detected in Felty syndrome, which would imply the existence of a common pathogenic mechanism between these two disease entities. We collected samples and clinical information from 14 Felty syndrome patients who were monitored at the rheumatology outpatient clinic for Felty syndrome. Somatic STAT3 mutations were discovered in 43% (6/14) of Felty syndrome patients with deep amplicon sequencing targeting all STAT3 exons. Mutations were located in the SH2 domain of STAT3, which is a known mutational hotspot. No STAT5B mutations were found. In blood smears, overrepresentation of large granular lymphocytes was observed, and in the majority of cases the CD8+ T-cell receptor repertoire was skewed when analyzed by flow cytometry. In bone marrow biopsies, an increased amount of phospho-STAT3 positive cells was discovered. Plasma cytokine profiling showed that ten of the 92 assayed cytokines were elevated both in Felty syndrome and large granular lymphocyte leukemia, and three of these cytokines were also increased in patients with uncomplicated rheumatoid arthritis. In conclusion, somatic STAT3 mutations and STAT3 activation are as frequent in Felty syndrome as they are in large granular lymphocyte leukemia. Considering that the symptoms and treatment modalities are also similar, a unified reclassification of these two syndromes is warranted.

Zytopenien : Anämie, Leukopenie und Thrombopenie.

Hematological alterations can often be observed during rheumatic diseases. The effects can be clinically severe, ranging from anemia of different grades of severity, through increased risk of hemorrhage due to thrombocytopenia up to severe infections as a result of high-grade leukocytopenia. The clinical sequelae for patients are predominantly determined by the extent of cytopenia. The underlying disease itself can initially be considered as the cause. Examples are anemia as a result of chronic inflammation, antibody-mediated thrombocytopenia as in systemic lupus erythematosus (SLE) or granulocytopenia within the framework of Felty's syndrome. Immunosuppressive treatment also often leads to alterations in the blood constituents. Although some substances, such as cyclophosphamide can suppress all three cell types, there are also selective effects, such as isolated thrombocytopenia under treatment with tocilizumab and JAK inhibitors. The differential diagnostic clarification of cytopenia can be difficult and necessitates a systematic work-up of the course of the disease and the subsequent treatment. The reviews of anemia, leukocytopenia and thrombocytopenia presented here summarize the most important components of the differentiation of hematological alterations in patients with rheumatic diseases.

Felty's Syndrome: A Qualitative Case Study.

Felty's syndrome is a triad of rheumatoid arthritis, splenomegaly, and neutropenia. This rare disorder is difficult to diagnose and produces many complications. The purpose of this descriptive qualitative case study was to provide a comprehensive, context-bound understanding of one patient's struggle with the condition.