Early synthesis and correlation of serum anti-thyroid antibodies with clinical parameters in multiple sclerosis.
A high frequency of anti-thyroid antibodies has been demonstrated in multiple sclerosis (MS), but there is a lack of data on the possible association of thyroid autoimmunity with disease activity. To assess whether anti-thyroid antibodies are synthesized early in MS or are induced over the course of the disease and whether or not they are correlated with clinical findings, we assayed serum anti-peroxidase and anti-thyroglobulin antibodies in 129 relapsing-remitting MS patients at the time of diagnosis and prior to any immunosuppressive or immunomodulatory treatment. Anti-peroxidase antibodies were detected in 28/129 (21.7%) MS patients, compared to 12/130 (9.2%) neurological controls (P=0.006) and 8/152 (5.3%) normal healthy subjects (P<0.0001). High titres of anti-thyroglobulin antibodies were detected in 11/129 (8.5%) MS patients compared to 6/130 (4.6%) patients with other neurological diseases (P=0.22) and 5/152 (3.3%) normal healthy subjects (P=0.07). Anti-peroxidase antibodies were associated with initial relapse in 14 of 28 (50%) of the patients compared to 18/101 (18%) without antibodies (P=0.001). Similarly, anti-thyroglobulin antibodies were associated with first relapse in 8/11 (73%) of the patients compared to 11/118 (9.3%) of those without (P<0.0001). However, there was no correlation between anti-thyroid antibody titres and disease duration or CSF IgG index values. By contrast, a significant inverse correlation was found between anti-thyroglobulin antibody titres and EDSS score (r(s)=-0. 75; P=0.008). Our findings demonstrate that anti-peroxidase and anti-thyroglobulin antibodies are synthesized early in relapsing-remitting MS and are associated with early clinical disease activity. Furthermore, high titres of anti-thyroglobulin antibodies are associated with low disability scores, suggesting a possible protective role of these antibodies that deserves further investigation.