Felty syndrome is a condition that includes rheumatoid arthritis, splenomegaly (enlargement of the spleen) and granulocytopenia (decreased level of the certain type of white blood cells). In Felty syndrome, rheumatoid arthritis is seropositive, which means that rheumatoid factor can be found in the blood. This syndrome is sometimes seen as a complication of rheumatoid arthritis
This syndrome usually includes:
- Leukopenia, a low overall white blood cell count
- Neutropenia, a low number of neutrophils (a type of white blood cells)
- Splenomegaly, an enlarged spleen
- Occasionally, a swollen liver
The condition was named after its founder Augustus Roi Felty, after the doctor reportedly saw patients in 1924 with a combination of conditions never before documented. The presence of chronic arthritis, splenomegaly, and leucopenia in all 5 patients prompted him to use his name to define the unknown syndrome.
Epidemiology of Felty Syndrome
More than one percent of individuals with rheumatoid arthritis suffer from Felty’s syndrome. Felty’s syndrome is more frequent in individuals suffering from rheumatoid arthritis for about 10 years of duration. In the course of rheumatoid arthritis, is men get affected with Felty’s syndrome earlier when compared to women. Women are three times more prone to Felty’s syndrome when compared to men. Whites more commonly get affected with Felty’s syndrome than blacks. Presently, a decline is seen in the incidence of Felty’s syndrome with the evolution of better and more effective treatment for rheumatoid arthritis.
Some of the risk factors of FS include
- Having a positive test result for the HLA-DR4 gene
- Having inflammation of tissues lining the joints
- Testing positive for rheumatoid factor, which is an antibody used to diagnose RA
- Having RA symptoms outside of the joints
- Being Caucasian
- Being older than age 50
Causes of Felty Syndrome
There is currently no evidence for the exact cause of FS.
- However, both genetics and immunosuppressive drugs, used to treat previous aggressive and seropositive RA, tend to play a large role in its etiology.
- It is thought that genetics and the use of immunosuppressive drugs weaken the immune system, lowering the body’s natural defences and allowing for an increased risk of infection.
- Research shows that about 86% of those who have FS are positive for HLA-DR4, which is a cell surface receptor antigen.
- More specifically, literature illustrates that the presence of two HLA-DRB1*04 alleles increases the susceptibility for extra-articular manifestations of RA and increases the chance of getting FS.
- Unfortunately, those who have the RA with extra-articular manifestations component of FS tend to have a worse prognosis and a higher risk for mortality.
Some of the symptoms are as follows:
- Loss of appetite.
- Weight loss.
- Feeling discomfort or malaise.
- Joint pain.
- Stiffness in the joints.
- Pale colored skin.
- Joint swelling.
- Eye burning and discharge.
- Joint deformity.
- Repeated infections.
Complications of Felty Syndrome
In some cases, Felty syndrome can cause severe and life threatening conditions like:
- Rupture of the spleen
- Life-threatening infection
- Toxic reaction to drug therapy, that can cause conditions like Steven-Johnson syndrome
- Portal hypertension
- Gastrointestinal bleeding
Diagnosis and test
There is no specific diagnostic criterion for Felty’s syndrome. It is a clinical diagnosis in patients with RA with unexplained neutropenia and splenomegaly.
Relevant investigations may include:
- FBC – for neutropenia ± anaemia of chronic disease.
- Autoantibodies – rheumatoid factor and anti-CCP antibody.
- Inflammatory markers (ESR and CRP) may be elevated.
- LFTs – may be raised if there is liver involvement (see ‘Complications’, below).
- Ultrasound or CT scan to evaluate splenomegaly.
X-Ray of patient hand with the felty syndrome
Bone marrow biopsy:
- May be required to differentiate Felty’s syndrome from haematological malignancies – eg, non-Hodgkin’s lymphoma.
The best way of treating Felty syndrome (FS) is to control the underlying rheumatoid arthritis (RA). Immunosuppressive therapy for RA often improves granulocytopenia and splenomegaly; this finding reflects the immune-mediated nature of FS. Most of the traditional medications used to treat RA have been used in the treatment of FS. No well-conducted, randomized, controlled trials support the use of any single agent. Most reports on treatment regimens involve small numbers of patients.
Splenectomy is sometimes performed in some patients who:
- Have a severe condition
- Do not respond to pharmacological treatment
- Experience constant, serious infections
- Have hemolysis or recurrent skin ulcers
- Methotrexateis usually the first choice
- Leflunomide± methotrexate,
- Rituximab± methotrexate,
- Splenectomy: Generally reserved for those not responding to medical treatment. Splenectomy improves neutropenia in most patients (80%).
- Immunisationagainst influenza and pneumococcus
Prevention of Felty Syndrome
No. There is no prevention for Felty’s syndrome. But the prompt treatment of RA with currently available medicines markedly decreases the risk of developing Felty syndrome.