Antithyroid antibodies in antiphospholipid syndrome: prevalence and clinical associations.

Autoimmune thyroid disease has been associated with several systemic autoimmune disorders. However, limited data are available regarding the prevalence and clinical associations of thyroid autoimmunity in antiphospholipid syndrome (APS). Seventy-five patients with APS, 75 patients with systemic lupus erythematosus (SLE) and 75 healthy controls were tested for the presence of antithyroid antibodies (ATAs) (anti-thyroglobulin and anti-thyroid peroxidase [anti-TPO]) using commercial ELISA. Clinical data were also recorded. Although no significant differences in the prevalence of ATAs were detected among APS, SLE patient groups and healthy controls, a significant increase of anti-TPO antibodies in patients with APS-SLE was found. An increased prevalence of ATAs in APS population with ischemic central nervous system (CNS) clinical manifestations was also detected. We present novel associations between thyroid autoimmunity and ischemic CNS clinical manifestations in the setting of APS.