Toxoplasma gondii infection in patients with malignant and benign bone tumours

Abstract

Toxoplasma gondii (T. gondii) is an intracellular parasite that infects humans, and seroprevalence of its infection varies from about 10 to 80 percent in different countries with a higher prevalence in warmer and humid regions. In this study, the rate of acute and chronic toxoplasmosis in patients with benign or malignant bone tumours was investigated. Fifty-three patients who suffered from various bone tumours, as well as sixty-five healthy controls with an unknown sero-logical profile for anti-Toxoplasma antibodies, were enrolled in this cross-sectional study. Anti-Toxoplasma antibodies were detected in serum samples using enzyme-linked immunosorbent assay (ELISA) and blood samples of them were used for real-time PCR. Thirty-two (60.32%) and twenty-one (39.63%) of patients had malignant tumours and benign tumours, respectively. The results showed a higher and significant seropositivity rate of IgM antibodies in primary bone tumour patients compared to the control group and Toxoplasma DNA became positive in 18.86% of patients with primary bone tumours and 6.15% of controls. Surprisingly, the high presence of parasite DNA was detected in patients with malignant tumours. The seroprevalence of T. gondii IgM antibodies and DNA positivity among the cancer patients were significantly higher than healthy individuals. Also, chronic toxoplasmosis (it was shown with IgG positive) appears to be more common in people with benign cancers than malignancies. The study showed a relatively high seroprevalence of anti-T. gondii antibodies in patients with primary bone cancer. However, the considerable rate of positive blood samples for the presence of parasite’s DNA should not be ignored. A key to the effective management of diseases in immunosuppressed individuals is prompt and accurate diagnosis of toxoplasmosis. Moreover, it seems that PCR tests may be more reliable than serological methods and it could be considered as a precise method for diagnosis of acute toxoplasmosis.