In the first place, Felty syndrome consists of a combination of RA , enlarged spleen and bone marrow suppression (with low white blood cell counts). It leads to serious infections because of a weakness in the immune system and vasculitis. This is coupled with leg ulcers and nerve damage (mononeuritis). By the same token there are findings of low platelets leading to prolonged bleeding and anemia. In addition, there can be swelling of lymph glands. At the same time this needs to be separated from lymphomas and leukemias.
Nerve entrapments are common such as carpal tunnel syndrome and ulnar neuropathy affecting sensitivity and strength in the hands and wrists, tarsal tunnel syndrome in the ankles/feet and other more rare signs. Nerve root compressions can be present, more commonly in the cervical spine, but sometimes also in the lumbar spine from subluxations and compression fractures of end stage RA of facet joints and osteoporosis. There is a great danger to the spinal cord when the bony spinal support structure has been eroded.
There are a number of immunological abnormalities that are found in patients with RA. The most well known is the already mentioned rheumatoid factor (RF), which is an abnormal antibody directed against the altered immunoglobulins IgG and IgM.
The higher the titer, the more likely that there is an antibody/antigen reaction and immune complexes form. These in turn will cause vasculitis, glomerulonephritis (a kidney disease) and neuropathies. About 80% of patients have seropositive RA, where the RF is present. On the other hand 20% have seronegative arthritis and they have all the clinical signs of RA. Other parts of the immune system are also affected: The synovial membranes are infiltrated by T helper lymphocytes that help the plasma cells to produce RF. Macrophages that process the synovial membrane antigen are also present in the joint effusions of RA patients. The immune complexes lead to release of prostaglandins and enzymes in the joints that destroy cartilage, ligaments and tendons.
1. ABC of rheumatology, second edition, edited by Michael L. Snaith , M.D., BMJ Books, 1999. Chapter 10.
2. The Merck Manual, 7th edition, by M. H. Beers et al., Whitehouse Station, N.J., 1999. Chapter 50.
3. J O’Dell J Rheumatol Suppl 2001 Jun;62:21-26.
4. ET Koh Ann Acad Med Singapore 2001 Mar;30(2):170-173.
5. AJ Ostor et al. Aust Fam Physician 2001 Apr;30(4):314-320.
6. C Richard-Miceli et al. BioDrugs 2001;15(4):251-259.
7. B. Sears: “The age-free zone”.Regan Books, Harper Collins, 2000.
8. B. Sears: “Zone perfect meals in minutes”. Regan Books, Harper Collins, 1997.
9. Ferri: Ferri’s Clinical Advisor: Instant Diagnosis and Treatment, 2004 ed., Copyright © 2004 Mosby, Inc.
10. Rakel: Conn’s Current Therapy 2004, 56th ed., Copyright © 2004 Elsevier