Objectives The aim of this study is to assess thyroid dysfunction and the presence of anti-thyroid antibodies in patients with systemic lupus erythematosus (SLE), and its association with disease characteristics and activity.
Methods 167 patients with SLE underwent laboratory evaluation for serum free T3, free T4, TSH (Thyroid-Stimulating Hormone). SLE patients with abnormal thyroid function test (TFT) and/or positive history of thyroid disease were further tested for antithyroglobulin antibody (Ab TG) and antithyroid peroxidase antibody (AbTPO). Patients who were tested negative for both of these autoantibodies were further tested for thyrotropin receptor antibody.
Results 119 patients were euthyroid, 11 patients had subclinical hyperthyroidism, 6 – hyperthyroidism, 19 - subclinical hypothyroidism, and 12 - overt hypothyroidism. The SLE patients with hypothyroidism had statistically significant higher Ab TG, SLEDAI and SLAM score than the euthyroid and patients with subclinical hyperthyroidism, but no statistically significant difference between all groups as regard Ab TPO. There was a positive correlation between Ab TG levels and disease activity. The proportion of SLE patients with antithyroglobulin antibodies were found in higher frequency among the hypothyroid subgroup as compared to the hyperthyroid subgroup. Among the patients in the hyperthyroid subgroup, one patient had antithyroglobulin antibody, one patient had TSH receptor antibody and manifested signs characteristic of Grave's disease.
Conclusions The thyroid dysfunction is frequent in SLE patients. Hypothyroidism were more likely to occur in SLE patients. There are a positive correlation between Ab TG levels and disease activity and negative correlation with free T3 and free T4. It is prudent to screen all SLE patients for thyroid dysfunction.
Disclosure of Interest None declared