MAGNETIC-RESONANCE-IMAGING CHANGES WITH RECOMBINANT HUMAN INTERFERON-BETA-1A - A SHORT-TERM STUDY IN RELAPSING-REMITTING MULTIPLE-SCLEROSIS

Objective-To evaluate whether recombinant human interferon-beta-1a sig nificantly affects disease activity as measured by a reduction in the number and volume of Gd enhancing lesions on monthly MRI. The study al so evaluated the effect on six-monthly T2 weighted abnormality and rel apse frequency. Methods-After a baseline scan and a six month pretreat ment period, 68 patients were randomly assigned to receive either 3 MI U or 9 MIU of interferon-beta-1a by subcutaneous injection three times a week for six months. All patients were examined by Gd enhanced MRI every month in both pretreatment and treatment periods. The evaluation of Gd enhancing lesions was performed blind at the end of the study. Results-The mean number of Gd enhancing lesions was higher during the pretreatment period than during treatment. This difference was statist ically significant for the two different dose subgroups (3.5 v 1.8, P < 0.001 for the 3 MIU group and 2.4 v 0.9, P < 0.001 for the 9 MIU gro up, corresponding to a reduction of 49% and 64% respectively). The mea n volume of Gd enhancing lesions also significantly decreased by 61% ( 3 MIU group) and 73% (9 MIU group). These reductions were evident only after the first month of treatment. The six-monthly rate of new lesio ns as seen in T2 weighted images showed a similar trend of reduction w ith treatment (65% and 70% respectively). Lesion volume on T2 scans si gnificantly increased during the pretreatment period whereas it remain ed almost stable during the treatment period in both groups. Clinical relapse rate was significantly reduced by treatment (53% for the 3 MIU group, P < 0.001; 69% for the 9 MIU group, P < 0.001). Conclusion-Int erferon-beta-1a seemed effective in reducing disease activity in relap sing-remitting multiple sclerosis at both the doses used.