Effects of latent toxoplasmosis on autoimmune thyroid diseases in pregnancy
Kanková, S., Procházková, L., Flegr, J., Calda, P., Springer, D., Potluková, E.
PLoS ONE, 9(10): e110878, 2014
Click for abstract
Background:
Toxoplasmosis, one of the most common zoonotic diseases worldwide, can induce various hormonal and
behavioural alterations in infected hosts, and its most common form, latent toxoplasmosis, influences the course of
pregnancy. Autoimmune thyroid diseases (AITD) belong to the well-defined risk factors for adverse pregnancy outcomes.
The aim of this study was to investigate whether there is a link between latent toxoplasmosis and maternal AITD in
pregnancy.
Methods:
Cross-sectional study in 1248 consecutive pregnant women in the 9–12
th
gestational weeks. Serum thyroid-
stimulating hormone (TSH), thyroperoxidase antibodies (TPOAb), and free thyroxine (FT4) were assessed by
chemiluminescence; the
Toxoplasma
status was detected by the complement fixation test (CFT) and anti-
Toxoplasma
IgG enzyme-linked immunosorbent assay (ELISA).
Results:
Overall, 22.5% of the women were positive for latent toxoplasmosis and 14.7% were screened positive for AITD.
Women with latent toxoplasmosis had more often highly elevated TPOAb than the
Toxoplasma
-negative ones (
p
= 0.004),
and latent toxoplasmosis was associated with decrease in serum TSH levels (
p
= 0.049). Moreover, we found a positive
correlation between FT4 and the index of positivity for anti-
Toxoplasm
a IgG antibodies (
p
= 0.033), which was even stronger
in the TPOAb-positive
Toxoplasma
-positive women, (
p
= 0.014), as well as a positive correlation between FT4 and log
2
CFT
(
p
= 0.009).
Conclusions:
Latent toxoplasmosis was associated with a mild increase in thyroid hormone production in pregnancy. The
observed
Toxoplasma
-associated changes in the parameters of AITD are mild and do not seem to be clinically relevant;
however, they could provide new clues to the complex pathogenesis of autoimmune thyroid diseases