RESUMO
BACKGROUND: The aim of the present study was to determine whether the adverse effects (AE) of interferon beta 1b (IFNb-1b) are related to patient weight, height and body surface area. Moreover, whether the basal incapacity and/or some of these AE may be related to the evolutive prognosis were also studied. METHODS: Twenty-nine females and 14 males with remittent-recurrent multiple sclerosis treated with IFNb-1b were studied. The clinical data and the AE, were compared with the number of outbreaks and the progression of incapacity over the first year of treatment in patients with high weight, height and body surface area with respect to those under the mean. RESULTS: Although the presence of fever was similar in the two groups during the first month (8/19 in the high weight patients and 11/24 in the low weight group), in the following months, overall, the low weight patients continued to present fever. Fever during the first month was associated with a lower number of outbreaks at one year of evolution (0.04 +/- 0.1, n = 19 vs 0.30 +/- 0.5, n = 24; p = 0.04). Furthermore, the patients with lesser incapacity presented a better evolution than those with more incapacity, particularly at 2 years (0.21 +/- 1.3 vs 1.36 +/- 0.9; p = 0.05). CONCLUSIONS: During the first month of treatment fever is very frequent in all the patients regardless of weight and fever was correlated with a lower number of outbreaks at one year of evolution. From the third month fever was less frequent in the lower weight patients group.
