IGHE and arthritic joint disease: Pro-inflammatory cytokines (tumor necrosis factor-alpha [TNF-α], interleukin [IL]-6, IL-1β), antibodies (immunoglobulin [Ig]G, IgE), cyclooxygenase-2 (COX-2) enzyme activity, paw edema, and arthritis indices were measured using enzyme-linked immunosorbent assay and standard methods.