Thyroid auto-antibodies in newly diagnosed multiple sclerosis patients: A cross sectional study.

Introduction: Multiple sclerosis (MS) is a chronic inflammatory disease in which the immune system attacks the myelin sheath of the central nervous system (CNS). It has been proposed that autoimmune conditions may occur together and an individual's immune system may attack more than one system. Autoimmune thyroid disease is one of the most common comorbidities along with MS. Since thyroid hormones are crucial for normal brain function and remyelination, we aimed to determine the prevalence of thyroid dysfunction in a group of MS patients compared with healthy controls.

Methods: This cross-sectional study was conducted in medical clinics affiliated to Shiraz University of Medical Sciences, South of Iran. To prevent the effects of MS modifying drugs on thyroid function, we examined 73 newly diagnosed MS patients, which had not been treated yet, compared to 72 healthy individuals.

Results: After measurement of the serum level of TSH, Anti TPO-Ab, and Anti TG-Ab, we found a significantly higher prevalence rate of abnormal TSH levels (high or low) in the MS group ( = 0.02). We also found a higher frequency of thyroid dysfunction in the female MS group ( = 0.01). However, there was no significant difference in the two other anti-thyroid antibodies among the groups. Our results demonstrate a significant and positive linear relationship between age and TSH levels ( = 0.402;  < 0.001) and also age and Anti TPO-Ab levels ( = 0.397;  < 0.001) among the MS population.

Conclusion: We found a higher prevalence of TSH alteration among the MS population. Anti TPO-Ab and Anti TG-Ab levels did not differ among groups. These findings suggest that MS patients might be at an increased risk for thyroid dysfunction. However, further studies are required to determine the underlying cause. The linear relationship between age and TSH and Anti TPO-Ab levels in MS patients suggest that there is an association between TSH dysfunction and age.