The role of chicken IL-1β, IL-6 and TNF-α in the occurrence of amyloid arthropathy

In this study, the roles of IL-1 beta, IL-6 and TNF-alpha in amyloid arthropathic chickens with variable amounts (severe, moderate and mild) of amyloid accumulation were investigated. The presence and the levels of cytokines were evaluated in serum and in joint tissues by using ELISA and immunohistochemistry, respectively. One hundred brown layer chicks were allocated into four groups and intra-articular injections of Freund's adjuvant were used to induce amyloid arthropathy in Groups II, III and IV. Vitamin A in group II, and methylprednisolone in Group IV were added to enhance and to reduce the severity of amyloidosis, respectively. At the end of the study, a positive correlation was observed among the incidence and severity of amyloidosis, the serum amyloid A levels and the IL-1 beta values both in the serum and tissues. Elevation in the tissue TNF-alpha levels in parallel with the severity of amyloidosis has also been noted. As a conclusion, IL-1 beta appears to play an important role in avian AA amyloidosis either alone or in combination with TNF-alpha. Further investigation is needed for understanding the role of the pro-inflammatory cytokines in avian AA amyloidosis.