A study of treatment-naive patients with systemic lupus erythematosus: focus on the status of thyroid profile across a real-life clinical setting

Background: Systemic Lupus Erythematosus (SLE) is potentially associated with thyroid disturbances, which might remain underdiagnosed. The objective was to analyse the thyroid profile in adults newly diagnosed with SLE. Methods: In this observational, real-life, cross-sectional study, treatment-naïve SLE subjects were compared to (SLE-free) controls in terms of thyroid profile and clinical, hematologic, electrophoretic, immunologic, and metabolic parameters. Individuals with a prior history of autoimmune diseases, thyroidectomy, and thyroid ailments were excluded. The statistical significance cut-off was p < 0.05. Results: SLE patients (N=22) versus age- and gender-matched controls (N=50) had a higher prevalence of thyroid dysfunction (22.7% versus 2%, p=0.001), mostly subclinical hypothyroidism, with similar TSH (thyroid-stimulating hormone), free thyroxine, and anti-thyroperoxidase (TPO) antibody levels. The prevalence of autoimmune thyroiditis (as defined by positive TPO) in the SLE group (27.3%) versus controls (14%) was not statistically significant (p=0.236). Thyroid ultrasound findings, namely, the highest size-based nodules category rates, displayed no between-group differences. Additional parameters (25-hydroxyvitamin D and glucose status) showed a similar profile. SELENA-SLEDAI score correlated with gamma-globulins (rho=0.55, p=0.008) and glycated haemoglobin A1c (rho=0.50, p=0.017), but not with thyroid function or TPO. Conclusion: Commonalities in the fields of thyroid and SLE should be taken into account from SLE onset, especially thyroid function. Indirect interplay might involve the glucose profile and vitamin D status.