Objective: To correlate changes in serum levels of intercellular adhesion molecule-1 (sICAM-1) and matrix metalloproteinases (MMP) with clinical and MRI evidence of disease activity in MS patients receiving treatment with interferon-beta (rIFNbeta)-1b.
Background: rIFNbeta reduces the frequency of gadolinium-enhancing (Gd+) MRI in relapsing-remitting MS (RRMS). Its mechanism of action on improving the integrity of the blood-brain barrier remains unclear.
Methods: sICAM-1 and MMP-9 and MMP-2 serum levels were longitudinally (24 months) investigated (ELISA; zymography) in correlation with the modifications of the integrated area under the curve of Expanded Disability Status Scale scores normalized to entry baseline (deltaEDSS AUC) and of GD+ MRI scans, and with neutralizing antibodies (NAB) to rIFNbeta-1b production (MxA) in 36 RRMS patients.
Results: During the first 12 months of treatment, levels of sICAM-1 increased and MMP-9 decreased significantly. After 12 months, levels returned toward baseline. Levels of sICAM-1 and MMP-9 were significantly negatively correlated. MMP-2 levels did not change significantly during the same period. During the second semester of the study, deltaEDSS AUC was significantly reduced. The percentage of patients with Gd+ MRI decreased significantly in the first (33%), second (29%), third (20%), and fourth (28%) semesters of treatment compared to baseline (62%). The NAB+ patients (14%) tended to have lower sICAM-1 levels at the ninth month; a higher MMP-9 activity at the sixth, 12th, and 18th months; and a greater deltaEDSS AUC in the third semester of treatment in comparison with the NAB- patients.
Conclusions: These results show that rIFNbeta-1b therapy increases sICAM-1 serum levels and reduces serum MMP-9 activity.