Increased percentage of IL-12+ monocytes in the blood correlates with the presence of active MRI lesions in MS.

Interleukin (IL)-12 is a cytokine thought to play a major role in the pathogenesis of multiple sclerosis (MS). We have previously shown that patients with progressive MS have a high percentage of IL-12-producing monocytes in the blood compared to normal individuals. We analyzed 269 blood samples from 189 MS patients for the percentage of IL-12-producing monocytes. We found that the increased IL-12 expression correlates with disability, as measured by the Expanded Disability Status Scale (EDSS), and with disease activity, measured by the presence of gadolinium-enhancing magnetic resonance imaging (MRI) lesions.