Endocrine Abstracts

Some authors observed lower thyroid antibodies titers (AbT) in children than in the adult population. The aim of this work was to consider the prevalence of positive results in AbT and elevated TSH levels. We have considered AbT and TSH measurements in a large population. We divided samples in 7 age groups 0–18, 18–20, 20–40, 40–50, 50–60, 60–70 and >70 years old. Cut-off positivity for AbTg and AbTPO was 50 and for TSH was 10 mUI/ml.

The concordance of altered AbT and TSH was calculated and expressed as prevalence in the population. For both the tested antibodies and elevated TSH (AbTg and AbTPO) a prevalence remarkably lower (0.4%) was observed in the pediatric population (0–18 years old) compared to all the other age groups.

A linear increasing prevalence trend could be seen from pediatric population to the older age group, altered TSH and positive AbTg reached prevalence of 1,0% in the adulthood (40–50 years old) and a peak of 1.5% in the elderly (>70 years old).

Autoimmunity is correlated to different players, in particular in two orders of factors belonged to humoral immunity on one hand and cellular-mediated immunity on the other, strictly related. The first one is expressed as antibodies production, the second is mainly related to immune-competent cells. The damage is perhaps correlated to the second process rather than to the antibodies production, often epiphenomena of autoimmunity. Finally the elevation of TSH represents the actual damage consequent to thyroid autoimmunity.

Our results demonstrated that in the pediatric population there is a lower AbT positivity in conjunction with altered TSH. Probably because cell-mediated immunity more than humoral immunity plays the more relevant role and humoral autoimmunity remain ad epiphenomenon.

It could be assumed that in the natural history of thyroid autoimmunity the cell-mediated anticipates the expression of humoral immunity.