Background The relationship between autoimmune thyroid disease and systemic lupus erythematosus (SLE) has been revealed but the prevalence of thyroid disease in lupus patients is controversial.
Objectives The aim of this study is to assess thyroid dysfunction and the presence of anti-thyroid antibodies in patients with SLE, and its association with disease characteristics and disease activity.
Methods Sixty patients with SLE ≥18 years who satisfied the American College of Rheumatology (ACR) criteria and thirty age and sex matched normal volunteers were included, all underwent laboratory evaluation for serum free T3, free T4, TSH, Antithyroglobulin antibody (Ab TG) and Antithyroid peroxidase antibody (Ab TPO). Clinical and serological characteristics and disease activity of SLE were assessed; correlation with thyroid dysfunction was studied.
Results 2 patients (3.33%) had subclinical hyperthyroidism, 24 patients (40%) were euthyroid, 12 patients (21.67%) had subclinical hypothyroidism and 22 patients (35%) had overt hypothyroidism. All subjects of the control group were euthyroid. Patients with thyroid dysfunction had more arthralgias, arthritis, changes of voice, bowel habits and weight, irregular menstruation, sleep disturbance, nervousness and tremors than the euthyroid lupus patients (p<0.05). The lupus patients with subclinical and overt hypothyroidism had statistically significant higher (Ab TG) than the euthyroid patients and patients with subclinical hyperthyroidism and control group (p<0.05) but no statistically significant difference between all groups as regard (Ab TPO). SLE patients with subclinical and overt hypothyroidism had statistically significant higher ESR and SLAM score than the euthyroid patients and patients with subclinical hyperthyroidism (p<0.05). There was a positive correlation between (Ab TG) levels and body mass index BMI, ESR and disease activity measures by SLAM score (p<0.05).
Conclusions The thyroid dysfunction is more frequent in SLE patients than control group. Subclinical and overt hypothyroidism are 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 & free T4.
Zakeri Z. & Sandooghi M. Thyroid Disorder in Systemic Lupus Erythematosus Patients in Southeast Iran. Shiraz E Medical Journal.2010; 11: 34-8.
Scofield RH. Autoimmune thyroid disease in systemic lupus erythematosus and Sjögren's syndrome. Clin Exp Rheumatol 1996; 14: 321-30.
Boey ML., Fong PH., Lee JSC., Ng WY. & Thai AC. Autoimmune thyroid disease in SLE in Singapore. Lupus 1993; 2: 51-4.
Magaro M., Zoli A., Altomonte L., Mirone L., La Sala L., Barini A. & Scuderi F. The association of silent thyroiditis with active systemic lupus erythematosus. Clin Exp Rheumatol.1992;10:67.
Disclosure of Interest None declared