F. Monzani et al., Effect of 1-year treatment with interferon-beta 1b on thyroid function andautoimmunity in patients with multiple sclerosis, EUR J ENDOC, 141(4), 1999, pp. 325-331
Objective: Interferon-beta (IFN-beta) is a widely used therapy for multiple
sclerosis (MS), a demyelinating disease of the central nervous system. Thi
s study has evaluated the effect on thyroid function and autoimmunity of a
I-year treatment with IFN-beta 1b in patients with MS.
Patients: We studied 31 patients (age 34 +/- 7 years, 21 women) with relaps
ing-remitting MS during IFN-beta 1b treatment of I year duration, Systemati
c thyroid assessment and measurements of serum interleukin-6 (IL-6) levels
were performed at baseline and every 3 months during treatment.
Results: Sixteen percent of the patients had autoimmune thyroiditis before
IFN-beta 1b, all positive for anti-peroxidase antibodies. The overall incid
ence of thyroid dysfunction was 33% over 1 year (10% hyperthyroidism, 23% h
ypothyroidism). Thyroid autoimmunity developed in 5/26 patients (19%), in o
ne case without dysfunction. In addition to autoantibody positivity at base
line, female gender and the presence of an ultrasound thyroid pattern sugge
stive of thyroiditis were identified by multiple logistic regression as add
itional risk predictors for the development of thyroid dysfunction. During
IFN-beta 1b treatment, serum IL-6 levels rose in a consistent biphasic patt
ern: there was, however, no difference between patients with or without inc
ident thyroid abnormalities.
Conclusions:We conclude that IFN-beta 1b therapy can induce multiple altera
tions in thyroid function, some of which are unrelated to thyroid autoimmun
ity. IL-6 measurement is not useful to identify patients prone to develop t
hyroid abnormalities. Though thyroid dysfunction is generally subclinical a
nd often transient, systematic thyroid assessment should be performed durin
g IFN-beta 1b treatment.