Anticardiolipin antibodies in autoimmune thyroid disease.

IgG and IgM anticardiolipin antibodies were assayed by an ELISA technique in 69 patients with autoimmune thyroid disease (ATD) and compared with 43 patients with thyroid disease of no autoimmune aetiology (non-ATD) and 72 healthy controls. IgG anticardiolipin antibodies were detectable in 3 of 41 patients with Graves' disease, in 4 of 28 patients with Hashimoto's thyroiditis, in 5 of 43 non-ATD patients and in 3 of 72 normal subjects (differences not significant). IgM antibodies were measurable in 3 patients with Graves' disease, in 1 patient with Hashimoto's thyroiditis, in 1 non-ATD patient and in 2 normal subjects (differences not significant). Patients with anticardiolipin antibodies did not exhibit a higher titre of thyroglobulin or thyroid microsomal antibodies than patients without anticardiolipin antibodies. There was no relation between IgG or IgM anticardiolipin antibody levels and the thyroid function status, the serum concentration of thyroid hormones or thyrotrophin levels. Neither was there any correlation between anticardiolipin antibody levels and age, sex, previous treatments or time of disease progress. Our results suggest that there is no association between anticardiolipin antibodies and ATD.