Correlation between serum thyroxine and complements in patients with multiple sclerosis and neuromyelitis optica

The aim of this study is to assess serum levels of thyroid hormones (TH) and complement C3, C4, CH50 in patients with multiple sclerosis (MS) and neuromyelitis optica (NMO), and investigate whether there is a correlation between serum TH and complement factors in these patients.

One hundred and eighty-eight MS patients and sixty-five NMO patients were included in this study. The levels of serum TH were measured by magnetic antibody enzyme linking immunoassay and complement C3, C4 and CH50 were determined by immunoturbidimetry.

The levels of TT4, complement C4 and CH50 in the serum were significantly higher in NMO patients than that in the MS. There were no significant differences in serum TT3, FT3, FT4 concentrations between NMO and MS patient. In MS patients, significant correlations between mean EDSS levels and serum C3 (r=0.223, p=0.014), and serum C4 (r=0.216, p=0.017) were found, and serum TT3 was positively correlated with serum CH50 (r=0.342, p=0.01). In NMO patients, the positive association between serum FT4 and C4 (r=0.533, p=0.006) were also found.

These results indicate that NMO patients has different serum TH and complement C3, C4 and CH50 levels from MS patients, and that serum TH levels is correlated with CH50 and C4 in these patients, suggesting TH may play a different role in modulating the complement activation in MS and NMO.