Endocrine Abstracts

The mechanism of autoimmune destruction of thyrocytes in pathogenesis of Hashimoto thyroiditis remain unclear. It has been showed that the HT patients produce antibodies to DNA, which are directed against various structures of the nucleus and probably may be involved in process of apoptosis.

In order to show that the increased production of anti-DNA antibodies is intrinsic property of HT, but not of another non-autoimmune thyroid diseases, we have measured the levels of antibodies to single-stranded (ssDNA) and double-stranded DNA (dsDNA) in the sera from eu-, hypo- and hyperthyroid patients with HT (30 subjects in each group), 30 patients with euthyroid endemic goiter (EEG) and 30 healthy donors. The diagnosis was confirmed according to the standard criteria. The concentrations of free thyroid hormones, TSH, antibodies to thyroglobulin (TG), thyroid peroxidase (TPO) and levels of anti-ssDNA and anti-dsDNA antibodies were measured by immunometric enzyme immunoassay (ELISA).

All patients with HT are characterized by reliable (P<0.01) elevation of all types of anti-DNA antibodies in comparison to donors and patients with EEG. It was strong positive correlation between concentrations of anti-DNA antibodies and levels of anti-TG and anti- TPO antibodies in HT, especially in patients with thyroid dysfunction. The elevation of antibodies to dsDNA (17.9±0.35 IU/ml) in HT patients was reliably (P<0.01) more significant than antibodies to ssDNA (10.6±0.23 IU/ml).

Additionaly anti-dsDNA antibodies were tested by piezoelectric quartz immunosensor (PQIS) in the same groups and in 10 patients with systemic lupus erytrematodes (SLE). PQIS demonstrated reliable (P<0.01) increasion of anti-dsDNA antibodies in HT (124.5±3.1 Hz) and SLE (144±2 Hz) patients in comparison to donors (74±2.5 Hz). Since the PQIS proved to be more sensitive in detection of anti-DNA antibodies in HT patients than ELISA, it can be proposed as additive diagnostic method.