SERUM THYROTROPHIN AND CIRCULATING THYROGLOBULIN AND THYROID MICROSOMAL ANTIBODIES IN A FINNISH POPULATION

Abstract

Circulating thyroglobulin antibodies (TgA) were detected in 7.9% and thyroid microsomal antibodies (MsA) in 25.8% of a sample of 507 subjects in the adult population of southern Finland when titers as low as 1/5 for TgA and 1/10 for MsA were included. Both antibodies were measured by passive hemagglutination techniques. The prevalence of high titers was 0.6% for TgA (.gtoreq. 1/25,000) and 4.2% for MsA (.gtoreq. 1/100,000). Of the TgA positive subjects 88% also had MsA. The MsA titers were usually makedly higher than those of TgA in the same subjects. Serum thyrotropin (TSH), cholesterol and triglycerides were measured in 123 euthyroid subjects with thyroid antibodies and no history of thyroid diseases, and in controls matched for age and sex. Serum TSH was elevated in 31% of the TgA positive subjects and the mean TSH concentration was significantly above that of the controls. All 3 subjects with high TgA titers also had elevated TSH levels. Serum TSH concentration was increased also in 25% of those with MsA and the mean TSH value was significantly above the control level. High MsA titers were found in 19 subjects and the serum TSH was elevated in 10 of them (53%). The prevalence of symptomless autoimmune thyroiditis (SAT) was 2 and 5% of the population when high titers of TgA or MsA were used as criteria. Elevation of serum TSH was also used as a criterion. Previous observations were supported. There was no difference in serum cholesterol or triglycerides in the TgA or MsA positive subjects or in the corresponding matched controls.