Pendrin and NIS antibodies are absent in healthy individuals and are rare in autoimmune thyroid disease: evidence from a Danish twin study

Objective Antibodies against thyroglobulin, thyroid peroxidase and the TSH receptor are accepted as pathophysiological and diagnostic biomarkers in autoimmune thyroid disease (AITD). In contrast, the prevalence, aetiology and clinical relevance of autoantibodies against the human sodium‐iodine symporter (NISAb) and pendrin (PenAb) remain unclear. The objectives of the study were to investigate the presence of NISAb and PenAb in Danish twins, with and without AITD, to study whether the published variations in NISAb and PenAb frequencies were related to differences in methodology or study populations, and to evaluate whether the presence of NISAb or PenAb most likely results from genetic or nongenetic factors. Methods Sera from 93 patients with AITD and 230 healthy controls were evaluated for NISAb and PenAb using radioligand binding assays (RBA). Results Patients with AITD had a higher prevalence than the controls: NISAb: 17% vs 0% (P