Health Topics

Skip navigation

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( Lock Locked padlock icon ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

You Are Here:
Home →
Felty syndrome
URL of this page: //medlineplus.gov/ency/article/000445.htm

Felty syndrome

Felty syndrome is a disorder that includes rheumatoid arthritis (RA), a swollen spleen, decreased white blood cell count, and repeated infections. It is rare.

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:

Exams and Tests

A physical exam will show:

  • 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.

An abdominal ultrasound may confirm a swollen spleen.

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 their spleen (splenectomy).

Outlook (Prognosis)

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.

Alternative Names

Seropositive rheumatoid arthritis (RA); Felty's syndrome

Images

References

Johnson TM, Mikuls TR, England BR. Clinical features of rheumatoid arthritis. In: Firestein GS, McInnes IB, Koretzky GA, Mikuls TR, Tuhina N, O'Dell JR, eds. Firestein & Kelley's Textbook of Rheumatology. 12th ed. Philadelphia, PA: Elsevier; 2025:chap 72.

McInnes IB. Rheumatoid arthritis. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 243.

Savola P, Bhattacharya D, Huuhtanen J. The spectrum of somatic mutations in large granular lymphocyte leukemia, rheumatoid arthritis, and Felty's syndrome. Semin Hematol. 2022;59(3):123-130. PMID: 36115688 pubmed.ncbi.nlm.nih.gov/36115688/.

Review Date 4/1/2025

Updated by: Diane M. Horowitz, MD, Rheumatology and Internal Medicine, Northwell Health, Great Neck, NY. 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.

Related MedlinePlus Health Topics

A.D.A.M., Inc. is accredited by URAC, for Health Content Provider (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process, and privacy policy.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language.
© 1997- 2026 A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
All content on this site including text, images, graphics, audio, video, data, metadata, and compilations is protected by copyright and other intellectual property laws. You may view the content for personal, noncommercial use. Any other use requires prior written consent from Ebix. You may not copy, reproduce, distribute, transmit, display, publish, reverse-engineer, adapt, modify, store beyond ordinary browser caching, index, mine, scrape, or create derivative works from this content. You may not use automated tools to access or extract content, including to create embeddings, vectors, datasets, or indexes for retrieval systems. Use of any content for training, fine-tuning, calibrating, testing, evaluating, or improving AI systems of any kind is prohibited without express written consent. This includes large language models, machine learning models, neural networks, generative systems, retrieval-augmented systems, and any software that ingests content to produce outputs. Any unauthorized use of the content including AI-related use is a violation of our rights and may result in legal action, damages, and statutory penalties to the fullest extent permitted by law. Ebix reserves the right to enforce its rights through legal, technological, and contractual measures.