Thyroid Dysfunction Andthyroid Autoantibodies in Egyptian Patients with Systemic Lupus Erythematosus (SLE)

Background: Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with many clinical manifestations and immunological abnormalities. SLE and autoimmune thyroid disease are at the two endpoints of a shared immunogenetic mechanism. Aim of the study: To evaluate the link between SLE and thyroid disorders. Patients and Methods: Thirtypatients known to have SLE were recruited in this study, with ageranged from 17 to 35 years. All patients were submitted to history taking, clinical examination, and relevant laboratory investigation. Results: Thyroid disorderswere common (33.3%) in lupus patients. Hypothyroidism was the commonest (16.6%) abnormality in SLE patients then euthyroid (10.0%), and lastly hyperthyroidism (6.6%). The mean age of SLE patients was 26.1+1.5 year. Eighty percent ofthe patientswere females. The most common SLEcharacteristics were malar flush (90.0%), photosenstivity (80.0%), fever (70.0%), and arthritis (50.0%). Mean Hb level was 9.2±0.59 g/dL. While, mean values of acute phase reactants were erythrocyte sedmentaion rate (ESR) at 1st and 2nd hour (74.3±6.6 and 121.4±5.26 mm/h, respectively) and C-reactive protein (20±6.7 mg/L). The meansof FT3, FT4, TSH, TG Ab, and anti thyroperoxidase (TPO) Abin SLE patiets were 136.6±14.1 ng/dL, 8.83±1.2 ng/dL, 4.15±1.27ng/dL, 15.12±11.15ng/dL, and 121±65.4 IU/mL, respectively. Meanwhile, 30.0% and 76.7% of SLE patients were +ve for rheumatoid factor (RF) and antineuclearAb, respectively. There were 6.7% and 16.7% of the patients +ve for thyroglobulin Ab and anti TPO Ab, respectively. The statistically significant differences parameters in SLE patients with normal and abnormal thyroid function were ESR at 1 & 2 hours, RF, and antiTPO Ab (P=0.00, 0.00, 0.03, and 0.03, respectively). The statistically significant differences parameters of demographic, clinical, and laboratory data in SLE patients with normal and subgroups of abnormal thyroid function were age, SLE duration, Hb level, RBC, WBC, PLT, and ESR at 1 & 2 hours (P=0.00, 0.00, 0.00, 0.001, 0.0001, 0.00, 0.00, and 0.00, respectively). Conclusion and Recommendation: Thyroid disordersare common in SLE patients. The most common form is hypothyrodism. Patients with SLE should be evaluated for thyroid disorders by testing FT3, FT4, TSH, TG Ab, and anti PO Abfor early detection of thyroid abnormalities. Further studies are needed to support and clarify the association between SLE and thyroid disorders.