The prevalence of thyroid nodular disease in patients with increased titers of anti-thyroidal peroxidase antibodies.

OBJECTIVES: The aim of our study was to evaluate the possible association between autoimmunity and thyroid nodular disease (TND).

DESIGN AND SETTING: We conducted a study on 58 patients who were treated in outpatient setting at the Department of Endocrinology, Metabolism and Internal Medicine. Serum samples were analyzed for TSH concentration and anti-TPO antibodies titers. Thyroid ultrasonography was performed in each subject in order to evaluate volume of the gland, and the number and size of nodules.

RESULTS: TND occurred in 70% of anti-TPO positive subjects and in 57.9% of anti-TPO negative subjects, but statistical analysis did not demonstrate a significant concordance between the presence of anti-TPO antibodies and prevalence of TND (p>0.05). We showed that the mean (0.82 vs 0.75; p=0.49), minimal (0.2 vs 0.3; p=0.89) and maximal (2.7 vs 2.4; p=0.49) diameters of a nodule were similar in both groups. Solely in anti-TPO positive patients, anti-TPO titers positively correlated with the number of nodules (p=0.04).

CONCLUSION: Our results favor the role of autoimmunity in TND development although associations between thyroid nodules and thyroid autoimmunity are complicated and may be the subject of much controversy. Increased anti-TPO may influence the number of nodules rather than the presence of TND itself.