The Pathogenesis of Rheumatoid Arthritis is Associated with Milk or Egg Allergy.

Rheumatoid arthritis (RA) is a very complicated autoimmune disease with apparent synovial hyperplasia and cartilage and bone destruction.In the present study, we aimed to determine whether the pathogenesis of RA correlates with food allergy and which allergen(s) are relevant.We used type-II collagen (CII) to induce arthritis (collagen-induced arthritis, CIA) model in Wistar rats, and the development of arthritis was evaluated accordingly by scoring system. Proinflammatory cytokine levels in plasma were measured by enzyme-linked immunosorbent assay (ELISA), and concentrations of circulating immune complexes (CICs) were analyzed by C1q solid phase method. Furthermore, food-specific immunoglobulin G (IgG) and immunoglobulin E (IgE) levels were determined in the CIA model.In the CIA model, we found that levels of tumor necrosis factor-alpha (TNF-a), interleukin (IL)-1, IL-6, and IL-17, as well as CICs, were elevated significantly. Moreover, concentrations of milk- or egg-specific IgG and IgE were enhanced strikingly in CIA rats.The results suggest that pathogenesis of RA correlates closely to increased egg- or milk-specific antibodies.