From the Guidelines
Felty syndrome should be treated with disease-modifying antirheumatic drugs (DMARDs), particularly methotrexate, as the first-line treatment, with a focus on controlling the underlying rheumatoid arthritis, as recommended by the 2015 American College of Rheumatology guideline for the treatment of rheumatoid arthritis 1. The treatment approach for Felty syndrome involves a combination of medications and lifestyle modifications to manage the symptoms and prevent complications. The primary goal is to control the underlying rheumatoid arthritis, which can help alleviate the associated neutropenia and splenomegaly.
- Methotrexate is often the first-line treatment, with doses ranging from 15-25 mg weekly, as it has been shown to be effective in managing rheumatoid arthritis and its associated conditions 1.
- For patients with severe neutropenia or recurrent infections, granulocyte colony-stimulating factor (G-CSF) may be administered to increase neutrophil counts.
- Rituximab has also been shown to be effective in refractory cases, with a typical dose of 1000 mg IV on days 1 and 15.
- Splenectomy is reserved for patients with severe, persistent neutropenia unresponsive to medical therapy. The syndrome increases infection risk due to neutropenia, so patients should receive appropriate vaccinations (pneumococcal, influenza, Haemophilus influenzae) and promptly report fever or signs of infection.
- Regular blood count monitoring is essential, typically every 1-3 months, to track the patient's neutrophil count and adjust treatment as needed. The pathophysiology of Felty syndrome involves abnormal immune system activity, where antibodies target neutrophils, leading to their destruction in the enlarged spleen.
- The 2015 American College of Rheumatology guideline for the treatment of rheumatoid arthritis provides a comprehensive approach to managing rheumatoid arthritis and its associated conditions, including Felty syndrome 1.
From the Research
Definition and Characteristics of Felty Syndrome
- Felty syndrome is characterized by a triad of rheumatoid arthritis, neutropenia, and splenomegaly that typically occurs in patients with seropositive rheumatoid arthritis 2.
- It is a rare manifestation of severe rheumatoid arthritis, occurring in less than 1% of RA patients 3.
- Clinically, it is characterized by severe joint destruction contrasting with moderate or absent joint inflammation and severe extra-articular disease 3.
Treatment Options for Felty Syndrome
- Disease-modifying anti-rheumatic drugs (DMARDs) such as methotrexate can be effective in treating neutropenia in Felty syndrome 3.
- Other treatment options include leflunomide 4, abatacept 2, rituximab 5, 6, and granulocyte colony-stimulating factor (G-CSF) 3.
- Splenectomy can also result in immediate improvement of neutropenia in 80% of patients, but the rate of infection decreases to a lesser degree 3.
Response to Treatment
- Treatment with abatacept has been shown to improve hemoglobin, leukocyte, and platelet counts and absolute neutrophil counts in a patient with Felty syndrome 2.
- Leflunomide has been reported to dramatically improve leukopenia and neutropenia as well as control arthritis in a patient with Felty syndrome 4.
- Rituximab has been shown to lead to a sustained neutrophil response and marked symptomatic improvement in patients with Felty syndrome 5, 6.