It is associated to a late immunologic complication of seropositive (rheumatic factor-positive) rheumatoid arthritis (RA) and is characterized by splenomegaly and granulocytopenia.
Immunologic disorder complicating RA first described in 1924 by Augustus Roi Felty, an American physician.
Only three reported cases of Felty Syndrome complicating juvenile RA versus an incidence of approximately 1% in adults with RA. There is a predominance in whites people (rare in the black population) and is known to be predominantly in observed in females when compared to males (3:1).
The human leukocyte antigen DR4 (HLA-DR4) genotype is strongly associated with Felty Syndrome.
Laboratory studies show a lower granulocyte count in the splenic vein compared to the splenic artery, the presence of immune complexes coating the granulocytes, low granulocyte growth factor levels, and numerous circulating autoantibodies (especially those against granulocyte surface antigens).
Development of splenomegaly and granulocytopenia (<2000/mm3) in patients with severe RA; confirmed by immunologic studies. Cryoglobulins may be present.
Felty Syndrome usually develops after many years of destructive RA with extraarticular manifestations (rheumatoid nodules, vasculitis, pleuropericarditis, peripheral neuropathy, ocular complications, Sjögren Syndrome, adenopathy, skin ulcers). Affected individuals present frequently bacterial infections (possibly life-threatening) and severe pain in the upper quadrant of the abdomen (splenic infarct, capsular distention). Immunosuppressive therapy for RA often improves granulocytopenia and splenomegaly, confirming the immune-mediated nature of the disease. Recombinant granulopoietic growth factors quickly raise the granulocyte count and improve the physical condition of the patient in case of life-threatening infections. Splenectomy is only a last-chance therapy; granulocytopenia recurs in approximately 25% of splenectomized patients.
Precautions before anesthesia
In presence of severe RA, complete evaluation of cardiac and renal function is highly recommended. Chronic corticosteroid therapy and potential side effects must be evaluated. Use of gold salt must be confirmed and their effect on the kidneys assessed. Obtain a complete blood count (CBC). Obtain full history (infection, Sjögren Syndrome).
Patients are more prone to infection, so intravenous access or invasive monitoring should be done under sterile conditions. Regional technique should be avoided in the presence of a thrombocytopenic patient. Other considerations are those related to RA, such as joint stiffness and deformations and temporomandibular involvement, which can complicate tracheal intubation.
Methotrexate can induce hepatorenal dysfunction; if it is a concern, appropriate blood tests and management are warranted. Patients receiving gold salt medication must be carefully assessed for renal dysfunction. If so, anesthetic medications must be selected appropriately. Consider these patients to be immunodeficient.