Evaluation of thyroid dysfunction in childhood-onset systemic lupus erythematosus: Risk factors for Hashimoto's thyroiditis.

Objective: Increased frequency of autoimmune thyroid disease, particularly Hashimoto's thyroiditis (HT) was reported several studies in the literature, in individuals with childhood-onset systemic lupus erythematosus (cSLE). Our study aimed to investigate the prevalence and contributing factors of thyroid dysfunction and HT among cSLE patients.

Methods: Thyroid function tests were obtained cross-sectionally from cSLE patients. Demographic, clinical, and laboratory characteristics and activity scores were collected from medical records. Patients diagnosed with cSLE were compared to the healthy control group for the frequency of thyroid dysfunction. The Mann-Whitney U, independent samples t test, and the Chi-square or Fisher's exact test were used to compare study groups. A p-value below 0.05 was considered statistically significant.

Results: Out of 73 cSLE patients, 14 (19.1%) had subclinical hypothyroidism, 9 (12.3%) had clinical hypothyroidism, 12 (16.4%) were diagnosed with HT, and 12 (16.4%) had a family history of HT. Thyroid USG was performed in 5 euthyroid patients and 1 borderline subclinical hypothyroid patient with positive thyroid autoantibody and reported as diffuse heterogeneous echogenicity enlargement in the thyroid gland. There were no significant differences in clinical and laboratory data or medication used between the groups with and without HT; however, patients with HT had a higher frequency of clinical hypothyroidism and family history of HT. Cumulative prednisolone dose was significantly lower in patients diagnosed with HT. The frequency of HT was considerably higher in patients with cSLE compared to the healthy control group.

Conclusion: The results demonstrate an increased incidence of HT in cSLE patients, even if they are euthyroid, and recommend that cSLE patients be screened more frequently.