Predictive cytokine biomarkers of clinical response to glatiramer acetate therapy in multiple sclerosis.

A prospective study of 62 patients with relapsing-remitting multiple sclerosis (RRMS) treated with Glatiramer acetate (GA) was conducted to evaluate the value of baseline and treatment-modulated cytokines in predicting the clinical response to the drug after 2years of therapy. There were 32 responders and 30 non-responders. GA upregulated Th2/regulatory cytokines and inhibited Th1 cytokines in sera or PBMC supernatants 3 and 6months into treatment. We found two prognostic models with clinical utility. A model based on IL-18 at baseline, the change in TNFa from baseline to 3months, the change in IL-4 from baseline to 6months, and the change in the log of the ratio of TNFa/IL-4 from baseline to 6months had an area under the curve (AUC) of 0.80. A high IL-18 level at baseline and a reduction of TNF-alpha over time are associated with a response to GA. Although the study identified predictive biomarkers of clinical response to GA, the results will need to be validated in other data sets.