Study Examines Food Allergy, Rheumatoid Arthritis Link
Hypersensitivity reactions may heighten autoimmune response
TUESDAY, Sept. 12 (HealthDay News) -- The intestinal fluid of rheumatoid arthritis patients contains higher levels of cross reactive antibodies to food-related proteins than that of people without rheumatoid arthritis, according to a report in the Sept. 8 issue of Gut.
Mette Hvatum, of the University of Oslo in Oslo, Norway, and colleagues analyzed the IgG, IgA and IgM antibodies from antigens (cow's milk, cereals, hen's egg, cod fish and pork meat) in serum and jejunum perfusion samples of 14 patients with rheumatoid arthritis and 20 controls to measure systemic and mucosal immune responses.
Although all three immunoglobulin classes were elevated in many rheumatoid arthritis patients, only IgM in the jejunal fluid was significantly increased (unrelated to total IgM levels), while IgA and secretory IgA trended toward increases. Intestinal IgA activity was lower than IgM, and significant cross reactivity of IgM and IgA antibodies was also measured. Intestinal IgG activity to food was low in rheumatoid arthritis patients, but still significantly increased against many antigens compared to controls.
Rheumatoid arthritis patients' "food related problems may reflect the additive effect of multiple modest hypersensitivity reactions mediated, for instance, by immune complexes which could predispose the joints for autoimmune tissue destructive reactions," the authors concluded.