J Interferon Cytokine Res 2002 Jul;22(7):773-81
Monzani F, Meucci G, Caraccio N, Saviozzi M, Casolaro A, Moscato G, Lombardo F, Mosti S, Scagnolari C, Bruschi F, Antonelli G, Ferrannini E, Murri L.
Department of Internal Medicine, University of Pisa, Pisa, Italy.
Interferon-beta1b (IFN-beta1b) therapy is associated with a relatively high risk of developing thyroid disease.
IFN-beta1a is regarded as less immunogenic than IFN-beta1b because of its structural homology to natural IFN-beta.
We assessed the effect of 1 year of IFN-beta1a treatment on thyroid function and autoimmunity in 14 multiple sclerosis (MS) patients.
The results were compared with those obtained in a series of 31 MS patients treated with IFN-beta1b.
The prevalence of positive binding antibody (BAb) titer and neutralizing (NAb) anti-IFN antibody titer in the two groups was also assessed.
The BAb and NAb positivity rate in IFN-beta1a-treated patients was significantly lower than in the group submitted to IFN-beta1b therapy (7% vs. 84% and 0% vs. 30%, respectively).
Although the incidence of thyroid dysfunction was slightly higher in IFN-beta1b-treated patients than in those undergoing IFN-beta1a treatment (33% vs. 23%, respectively), it did not reach statistical significance.
Thyroid disease was unrelated to the presence of positive serum BAb or NAb titer in both the group undergoing IFN-beta1a therapy and in that treated with IFN-beta1b.
In both groups, thyroid disease developed mostly in women (71%) against a background of preexisting thyroiditis and a diffuse hypoechoic ultrasound thyroid pattern (80%).
IFN-beta1a treatment was associated with a significantly lower prevalence of both BAb and NAb-positive titers than was IFN-beta1b.
Conversely, thyroid disease was similar and unrelated to the presence of positive anti-IFN-beta antibody titer.
Therefore, routine thyroid assessment may be advised during IFN-beta1a treatment, especially in patients with preexisting thyroiditis.