Immunological Characteristics of Children with Hashimoto's Autoimmune Thyroiditis.

ABSTRACT

The main cause of autoimmune thyroiditis of Hashimoto's type (HT) is a pathological immune response to thyroid antigens. The aim of the study was to present clinical characteristics and immune profile of children with HT. Ninety five children were examined 45 with HT (age 8-18 years) and 50 healthy age-matched controls. The peripheral blood mononuclear cells' (PBMC) phenotype was evaluated using a Beckman Coulter flow cytometer with the following monoclonal antibodies CD4-FITC, CD28-PC5, CD152-PE and CD8-FITC, CD28-PC5, CD152-PE. The thyroid stimulating hormone, thyroid hormones, and antibodies against thyroid peroxidase (TPO) and thyroglobulin (TG) were evaluated by a microparticle enzyme immunoassay. We found that goiter was present in 53% of children, the thyroid had an increased density in palpation in 98%, and hypothyroidism was diagnosed in 11% of HT patients. The number of CD152+ was lower in HT than in healthy children (p<0.05). CD4+ and CD8+ PBMC subsets did not differ between the groups at baseline. After stimulation with phytohemagglutinine (PHA), CD4+ cells decreased in healthy controls and remained constant in HT children. Anti-TPO and anti-TG antibodies were higher in children with a lower percentage of CD152+. No other markers correlated with the immunological profile of PBMC. The percentages of CD4+ and CD152+ negatively correlated with the anti-TG concentration. We conclude that children with HT have a different PBMC profile than healthy children and show a different pattern of response to stimulation.