Introduction: Latent toxoplasmosis, a zoonosis caused by protozoan Toxoplasma gondii, is the most widespread human parasitosis in developed countries (prevalence 2080%). Upon infection, T. gondii stays in human organism lifelong. It has been linked to several autoimmune diseases, including autoimmune thyroid disease (AITD). The aim of our study was to assess the impact of latent T. gondii infection on the prevalence of AITD in pregnancy with regard to the pregnancy outcome.
Methods: We assessed the presence of latent toxoplasmosis by using complement-fixation reaction and ELISA-measurement of IgG and IgM antibodies in serum of 1247 consecutive pregnant women in 9th11th gestational weeks. Two women suspected from acute toxoplasmosis were excluded from the study. We determined serum levels of autoantibodies against thyroid peroxidase (TPOAb) (upper cut-off limit for the first trimester of pregnancy was 143 kU/l) and TSH in the same serum sample. In 592 women, data on pregnancy outcome were available (after exclusion of twin-pregnancies).
Results: The overall prevalence of latent toxoplasmosis among was 22.6%. Women with high elevation of TPOAb (>500 kU/l) suffered from latent toxoplasmosis more frequently than women with TPOAb <500 kU/l (36.8 vs 21.8%, P=0.007). This effect wasnt present when the cut-off 143 kU/l was used. Serum levels of TPOAb correlated with the toxoplasma IgG-index of positivity (P=0.009, r=−0.077). We didnt find any effect of latent toxoplasmosis on TSH in TPOAb-positive women. However, among the TPOAb-negative ones, those positive for T. gondii had significantly lower TSH values (1.051 vs 1.240 mU/l, P=0.017). Women with latent toxoplasmosis didnt have an increased prevalence of complications during pregnancy or adverse pregnancy outcomes.
Conclusions: Latent toxoplasmosis is frequent in pregnancy and it may increase the risk of AITD. However, it is not linked to adverse pregnancy outcomes.
27 Apr - 01 May 2013
European Society of Endocrinology