Toxocariasis seroprevalence in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease for which immunogenetic susceptibility factors have been defined. The aim of this study was to investigate seroprevalence of Toxocara canis (T. canis) in patients with RA. Forty-five patients with RA who were all diagnosed according to the ACR criteria and 48 health controls were included in this study. The mean age of patients with RA and of controls was 50+/-14 and 49+/-13, respectively. In both groups T. canis IgG antibodies were investigated with ELISA. Toxocara canis seroprevalence in patients with RA (35.6%) was significantly higher than that in the control group (8.3%) (p=0.001). There was no significant difference between patients with RA and control group in terms of behavioral factors (except in frequency of hand washing), demographic and socio-economic factors, while there was a difference in terms of owning dogs and cats or in the duration of ownership. When the patients with RA were divided into seropositive and seronegative, there were no significant differences between both groups in terms of demographic factors, socio-economic factors, behavioral factors, owning dogs and cats or duration of ownership and active or remission state of the illness, duration of disease and disability level in patients with RA (p > 0.05). In view of the present results, it is suggested that Toxocara infection was acquired before RA had developed and that high seroprevalence may result from exposure to pets and soil. It seems that this subject requires further investigations with larger numbers of samples in order to fully evaluate the causes of high seropositivity.