Prevalence of non-thyroid autoantibodies in autoimmune dysthyroidies

Organ- and non organ-specific autoantibodies can be detected in patients with AITD but large comparative studies have seldom been performed. This study evaluated the prevalence of anti-thyroid, -smooth muscle, -mitochondria, -parietal gastric cells, -salivary duct, -nuclear and -ds DNA autoantibodies assayed by indirect immunofluorescence in 224 patients with Graves' disease or Hashimoto's thyroiditis. Results evidenced a high prevalence of antinuclear antibodies, mostly of non homogenous fluorescence in Graves' (63.1%) and Hashimoto's patients (65.5%), as well as for antisalivary duct antibodies (55.2 and 75%). No positive anti-ds DNA were noticed. No correlation was found between antithyroid antibodies and the others. Different hypothesis could explain this observation which favours a general dysregulation of the autoimmune system.