Therapeutic Efficacy of Anakinra against Rheumatoid Arthritis-Induced Splenitis in Rats: A Biochemical and Histopathological Study

Rheumatoid arthritis (RA) is characterized by server inflammation of bones, cartilage, and synovial joints. Like many autoimmune diseases, RA is associated with many systemic disorders. Oxidative stress, inflammatory cytokines and immunoglobulins have been implicated in the pathogenesis of RA. The objective of this study is to assess the efficacy of interleukin-1 receptor antagonist (IL-1RA), refers to anakinra, as a treating agent in splenic abnormalities associated with RA in rats. Complete Freund's adjuvant (CFA) was used to induce RA. After one and four weeks of CFA induction, the morphological characteristics of the hind leg paws such as swelling, atrophy, and skin inflammation were evaluated. Notable alteration in spleen weight (+114.28%), glutathione (GSH) (-43.62%), malondialdehyde (MDA) (+123.90%), superoxide dismutase (SOD) (-66.27%), tumor necrosis factor-alpha (TNF-α) (+188.13%), immunoglobulins G and M (IgG, IgM) (-41.94 and -39.61%, respectively) were recorded after one week of RA induction to rats. Treatment of one-week arthritic rats with IL-1RA and indomethacin recorded amelioration with variable degrees and the histopathological architectures of spleen tissue. Untreated arthritic rats for 4 weeks showed the inability of splenic tissue to self-heal or self-repair. In conclusion, IL-1RA could treat spleen disorders associated with RA more efficiently than indomethacin. It may be considered as a promising candidate against splenitis symptoms secondary to RA disease.