Felty syndrome is a rare autoimmune disorder that is associated with a triad of rheumatoid arthritis, splenomegaly, and neutropenia.
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Epidemiology
It is thought to occur in ~ 1% of patients with rheumatoid arthritis 2. It is more common in women, and it is most commonly diagnosed in people above the age of 50.
Clinical presentation
Felty syndrome comprises of the triad of:
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typically with severe articular and extra-articular disease
Additionally, patients may have bicytopaenia or pancytopaenia, recurrent bacterial infections, and non-cirrhotic portal hypertension.
Pathology
Serological markers
rheumatoid factor (RF): >95% of patients are positive 5
antinuclear antibody (ANA): 47-100% are positive 5
HLA-DR4*0401 antigen: 78% of patients have the antigen 5
large granular lymphocyte (LGL) expansion: ~ 30% of patients may have it 5
Radiographic Features
Plain radiograph
X-rays may show signs of joint destruction, osteoporosis, joint space narrowing, erosions, and deformities.
Ultrasound
Ultrasound of the joints may show synovial thickening and fluid accumulation within the joints, which are features typical of rheumatoid arthritis.
CT
CT of the chest may demonstrate bronchiectasis, pleural effusions, and pulmonary nodules.
Treatment and prognosis
Treatment is through immunosuppression such as methotrexate and rituximab 6. If frequent severe bacterial infections are encounted, G-CSF may be administered 6.
History and etymology
It is named after Augustus Roi Felty (1895 -1964), an American physician 1.