Analysis of Proinflammatory and Anti-Inflammatory Cytokine Serum Concentrations in Patients With Multiple Sclerosis by Using a Multiplexed Immunoassay

We examined cytokines and other inflammatory markers in serum samples from 833 patients with multiple sclerosis and 117 healthy control subjects. A multiplexed immunoassay was used to assess the concentrations of 13 cytokines/inflammatory markers: interferon (IFN)-γ; interleukins (ILs)-1β, 2, 4, 5, 6, 8, 10, 12, and 13; tumor necrosis factor (TNF)-α; IL-2 receptor; and soluble CD40 ligand. Significant increases between patients and control subjects were found for IFN-γ (mean, 7.5 vs 0.4 pg/mL; P = .0002), IL-2 (mean 5.7 vs 1.0 pg/mL; P =.0002), IL-1β (mean, 23.0 vs 11.3 pg/mL; P ≤ .0001), TNF-α (mean, 4.1 vs 1.2 pg/mL; P = .01), IL-4 (mean, 1.4 vs 0.1 pg/mL; P ≤ .0001), IL-10 (mean, 16.8 vs 7.5 pg/mL; P = .03), and IL-13 (mean, 4.5 vs 0.8 pg/mL; P ≤ .0001). Profiling cytokines in multiple sclerosis may help to identify mechanisms involved in the pathogenesis of the disease, aid in monitoring the disease course and in evaluating responses to specific therapies, and, potentially, lead to new therapies directed at cytokines or their receptors. Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system. In addition, there is also axonal injury that may contribute to disease progression. Clinically, the disease is characterized by abnormal sensation, weakness, paralysis, incoordination, and ocular symptoms associated with relapses and remissions. MS has been further classified into several subtypes based on the course of the disease, including relapsing remitting, secondary progressive, primary progressive, and progressive relapsing. 1 Subtype classification can be useful in determining the prognosis of the disease and in making therapeutic decisions. The pathology of MS suggests an autoimmune cause involving cellular and humoral components of the immune system. Active MS lesions are characterized by T-cell and macrophage infiltration and the presence of immune mediators, including adhesion molecules, chemokines, and cytokines. The hallmark relapsing-remitting characteristic of MS gives reason to believe that proinflammatory and anti-inflammatory effects are occurring over time in the progression of the disease. In this study, we measured the levels of cytokines and other markers in 833 patients with confirmed MS and 117 healthy control subjects. Proinflammatory and anti-inflammatory cytokines were analyzed to assess differences in cytokine profiles between healthy subjects and patients with MS and among patients with the different subtypes of MS. A multiplexed fluorescent microsphere immunoassay system was developed and used in this study to simultaneously assess the concentrations of 11 cytokines, including interferon (IFN)γ; interleukins (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12 p70, and IL-13; tumor necrosis factor (TNF-α); a cytokine receptor, IL-2r; and soluble CD40 ligand (sCD40L) in only 75 μL of serum sample. 2,3 This report presents data