Felty Syndrome Treatment & Management

The best treatment for Felty syndrome is to control the underlying rheumatoid arthritis (RA). Immunosuppressive therapy for RA often improves granulocytopenia and splenomegaly; this finding reflects the fact that Felty syndrome is an immune-mediated disease. Most of the traditional medications used to treat RA have been used in the treatment of Felty syndrome. No well-conducted, randomized, controlled trials support the use of any single agent. Most reports on treatment regimens involve small numbers of patients.

• Historically, most patients were once treated with gold salts, reflective of their long history of use in RA prior to the advent of methotrexate; however, the response of the condition is slow. Older studies report a response rate of 60-80%. Intramuscular aurothioglucose (Solganal) was the agent most commonly used, but it is now used very infrequently.
• Methotrexate acts faster than gold and is the preferred agent of rheumatologists for treating RA. As experience using methotrexate in Felty syndrome increases, this drug is likely to become the agent of choice for therapy. If urgent correction of neutropenia is unnecessary, most practicing rheumatologists use this drug first when treating Felty syndrome. It is usually combined with folic acid to minimize adverse effects. Note that the beneficial effects of methotrexate may not be evident for 4-8 weeks.
• The potential for leukopenia limits the use of cyclophosphamide, although it may have a role in some cases. A recent report described 2 patients with refractory Felty syndrome who responded to high-dose cyclophosphamide; however, physicians have had far more experience using cyclophosphamide for rheumatoid vasculitis and other serious RA extra-articular manifestations than for Felty syndrome. For this reason, it is not an initial choice of therapy.
• Penicillamine is being used less frequently for RA because of its adverse effect profile. Penicillamine is never a first-choice therapy for patients with Felty syndrome.
• Etanercept, adalimumab, and infliximab are all newer agents prescribed for RA. These agents act by blocking the effects of tumor necrosis factor-α (TNF-α). These drugs are very effective in the treatment and control of RA, although the experience of using them for Felty syndrome is limited.^[4]
• Intravenous immunoglobulin (IVIG) does not show reproducibly demonstrable success.
• Recombinant granulopoietic growth factors, such as G-CSF and granulocyte-monocyte colony-stimulating factor (GM-CSF), effectively and quickly raise the granulocyte count, which is important in patients with life-threatening infections. Initial treatment of patients with Felty syndrome and life-threatening infections should include the administration of a growth factor. Long-term use of G-CSF appears to be well tolerated, although hypersensitivity vasculitis and flare-ups of the underlying RA in these patients have been reported.
• At high doses, corticosteroids can increase the granulocyte count, partly through demargination. This effect does not persist when tapering the patient to a typical low dose (< 10 mg/d) used for RA articular disease. Empiric administration of high-dose intravenous methylprednisolone is often prescribed for Felty syndrome, but the effect is time limited. Long-term use of high-dose corticosteroids further increases the risk for infection. Corticosteroids should probably be viewed as a second-line treatment modality.
• Case reports in the past few years have noted a lack of response to leflunomide (Arava),^{[5, 6]} and a response to salazosulfapyridine.^[7] These were all single-patient reports.
• Encouraging reports of a positive response to rituximab (Rituxan) in treating Felty syndrome have emerged,^{[8, 9]} despite initial negative reports.^[10]

Splenectomy is recommended only in patients with severe intractable disease who exhibit no improvement with medical therapy and experience recurrent or serious infection. Less commonly, extrinsic hemolysis or recurrent cutaneous ulcers may indicate a need for splenectomy. Granulocytopenia recurs in approximately 25% of patients who have undergone splenectomy.

• Rheumatologist
• Hematologist
• Infectious diseases specialist

Dictate patient activity according to infection risk and spleen size. Recommend that the patient avoid any activity that could result in blunt trauma to the left upper quadrant.