Felty syndrome
Seropositive rheumatoid arthritis (RA); Felty's syndromeFelty syndrome is a disorder that includes rheumatoid arthritis, a swollen spleen, decreased white blood cell count, and repeated infections. It is rare.
Rheumatoid arthritis
Rheumatoid arthritis (RA) is a disease that leads to inflammation of the joints and surrounding tissues. It is a long-term disease. It can also aff...
White blood cell count
A WBC count is a blood test to measure the number of white blood cells (WBCs) in the blood. It is a part of a complete blood count (CBC). WBCs are a...
Causes
The cause of Felty syndrome is unknown. It is more common in people who have had rheumatoid arthritis (RA) for a long time. People with this syndrome are at risk for infection because they have a low white blood cell count.
Symptoms
Symptoms include:
- General feeling of discomfort (malaise)
Malaise
Malaise is a general feeling of discomfort, illness, or lack of well-being.
Read Article Now Book Mark Article - Fatigue
- Weakness in leg or arm
- Loss of appetite
- Unintentional weight loss
- Ulcers in the skin
- Joint swelling, stiffness, pain, and deformity
Joint swelling
Joint swelling is the buildup of fluid in the soft tissue surrounding the joint or the joint itself.
ImageRead Article Now Book Mark Article - Recurrent infections
- Red eye with burning or discharge
Exams and Tests
A physical exam will show:
Physical exam
During a physical examination, a health care provider checks your body to determine if you do or do not have a physical problem. A physical examinati...
Read Article Now Book Mark Article- Swollen spleen
- Joints that show signs of RA
- Possibly swollen liver and lymph nodes
A complete blood count (CBC) with differential will show a low number of white blood cells called neutrophils. Nearly all people with Felty syndrome have a positive test for rheumatoid factor.
CBC
A complete blood count (CBC) test measures the following:The number of white blood cells (WBC count)The number of red blood cells (RBC count)The numb...
An abdominal ultrasound may confirm a swollen spleen.
Abdominal ultrasound
Abdominal ultrasound is a type of imaging test. It is used to look at organs in the abdomen, including the liver, gallbladder, spleen, pancreas, and...
Treatment
In most cases, people who have this syndrome are not getting recommended treatment for RA. They may need other medicines to suppress their immune system and reduce the activity of their RA.
Methotrexate may improve the low neutrophil count. The drug rituximab has been successful in people who do not respond to methotrexate.
Granulocyte-colony stimulating factor (G-CSF) may raise the neutrophil count.
Some people benefit from removal of the spleen (splenectomy).
Splenectomy
Spleen removal is surgery to remove a diseased or damaged spleen. This surgery is called splenectomy. The spleen is in the upper part of the belly, ...
Outlook (Prognosis)
Without treatment, infections may continue to occur.
RA is likely to get worse.
Treating the RA, however, should improve Felty syndrome.
Possible Complications
You may have infections that keep coming back.
Some people with Felty syndrome have increased numbers of large granular lymphocytes, also called LGL leukemia. This will be treated with methotrexate in many cases.
When to Contact a Medical Professional
Contact your health care provider if you develop symptoms of this disorder.
Prevention
Prompt treatment of RA with currently recommended medicines markedly decreases the risk of developing Felty syndrome.
References
Cameron J. Spleen. In: Cameron J, ed. Current Surgical Therapy. 14th ed. Philadelphia, PA: Elsevier; 2023:chap 10.
England BR, Mikuls TR. Clinical features of rheumatoid arthritis. In: Firestein GS, Budd RC, Gabriel SE, Koretzky GA, McInnes IB, O'Dell JR, eds. Firestein & Kelley's Textbook of Rheumatology. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 76.
Gazitt T, Loughran TP Jr. Chronic neutropenia in LGL leukemia and rheumatoid arthritis. Hematology Am Soc Hematol Educ Program. 2017;2017(1):181-186. PMID: 29222254 pubmed.ncbi.nlm.nih.gov/29222254/.
Myasoedova E, Matteson EL. Extraarticular features of rheumatoid arthritis. In: Hochberg MC, Gravallese EM, Smolen JS, van der Heijde D, Weinblatt ME, Weisman MH, eds. Rheumatology. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 91.
Savola P, Brück O, Olson T, et al. Somatic STAT3 mutations in Felty syndrome: an implication for a common pathogenesis with large granular lymphocyte leukemia. Haematologica. 2018;103(2):304-312. PMID: 29217783 pubmed.ncbi.nlm.nih.gov/29217783/.
Wang CR, Chiu YC, Chen YC. Successful treatment of refractory neutropenia in Felty's syndrome with rituximab. Scand J Rheumatol. 2018;47(4):340-341. PMID: 28753121 pubmed.ncbi.nlm.nih.gov/28753121/.
Antibodies - illustration
Antigens are large molecules (usually proteins) on the surface of cells, viruses, fungi, bacteria, and some non-living substances such as toxins, chemicals, drugs, and foreign particles. The immune system recognizes antigens and produces antibodies that destroy substances containing antigens.
Antibodies
illustration
Antibodies - illustration
Antigens are large molecules (usually proteins) on the surface of cells, viruses, fungi, bacteria, and some non-living substances such as toxins, chemicals, drugs, and foreign particles. The immune system recognizes antigens and produces antibodies that destroy substances containing antigens.
Antibodies
illustration
Review Date: 4/30/2023
Reviewed By: Neil J. Gonter, MD, Assistant Professor of Medicine, Columbia University, New York, NY, and private practice specializing in Rheumatology at Rheumatology Associates of North Jersey, Teaneck, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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