title: Felty's Syndrome, Insights and Updates.
abstract: Felty's syndrome (FS) is characterized by the triad of seropositive rheumatoid arthritis (RA) with destructive joint involvement, splenomegaly and neutropenia. Current data shows that 1-3 % of RA patients are complicated with FS with an estimated prevalence of 10 per 100,000 populations. The complete triad is not an absolute requirement, but persistent neutropenia with an absolute neutrophil count (ANC) generally less than 1500/mm3 is necessary for establishing the diagnosis. Felty's syndrome may be asymptomatic but serious local or systemic infections may be the first clue to the diagnosis. FS is easily overlooked by parallel diagnoses of Sjӧgren syndrome or systemic lupus erythematosus or lymphohematopoietic malignancies. The role of genetic (HLA DR4) is more prominent in FS in comparison to classic rheumatoid arthritis. There is large body of evidence that in FS patients, both cellular and humoral immune systems participate in neutrophil activation, and apoptosis and its adherence to endothelial cells in the spleen. It has been demonstrated that proinflammatory cytokines may have inhibitory effects on bone marrow granulopoiesis. Binding of IgGs to neutrophil extracellular chromatin traps (NET) leading to neutrophil death plays a crucial role in its pathophysiology. In turn, "Netting" neutrophils may activate auto-reactive B cells leading to further antibody and immune complex formation. In this review we discuss on basic pathophysiology, epidemiology, genetics, clinical, laboratory and treatment updates of Felty's syndrome.
authors.affiliation: Department of Internal Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Mohammad Bagher
authors.initials: MB
authors.lastname: Owlia
authors.affiliation: Rheumatology Program, National Institute of Arthritis, Musculoskeletal, and Skin Disease (NIAMS), National Institutes of Health, 10 Center Drive, Room 6N216, Bethesda, MD 20892-1616, USA.
authors.forename: Kam
authors.initials: K
authors.lastname: Newman
authors.affiliation: Jane Anne Nohl Division of Hematology and Center for the Study of Blood Diseases, University of Southern California (USC)/Norris Cancer Center, USC University Hospital, 1441 Eastlake Avenue, Norris Topping Tower 3463, MC 9172, Los Angeles, CA 90033-9172, USA.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Akhtari
keywords: Cytopenia; Felty’s syndrome; LGL syndrome; neutropenia; rheumatoid arthritis; splenomegaly; treatment.