Background: Toxoplasmosis is a zoonotic disease caused by the parasite Toxoplasma gondii, a cosmopolitan intracellular parasite. It can be a risk factor for autoimmune diseases, including rheumatoid arthritis (RA). This study was designed to investigate the possible association between serological history of T. gondii infection and defined clinical manifestation of RA in Northeast of Iran.Methods: Overall, serum samples were collected from 50 RA patients and 40 healthy controls, from Qaem Hospital in Mashhad City, northeastern Iran in 2018. Seroprevalence of T. gondii infection was determined by ELISA.Results: The prevalence of anti -T. gondii IgG in RA patients 48% (24.50) was significantly higher than the control group 10% (4.40) (P < 0.001). Erythrocyte sedimentation rate (ESR), anti-cyclic citrullinated peptide (anti-CCP) and (rheumatoid factor) RF levels between the RA and control groups (P < 0.01). Control group were matched with patients for age, gender and living area.Conclusion: Given that a high correlation has been demonstrated between positivity rate of anti-T. gondii IgG and RA in Northeastern Iran, further studies will be necessary to clarify the pathogenesis of T. gondii among these patients.
