Increased neutralization capacity of TNF-α in sera of relapsing remitting multiple sclerosis patients is not related to soluble TNF-a receptors or anti-TNF-α autoantibody levels

The increased TNF-alpha levels in active lesions and CSF of multiple sclerosis (MS) patients and the beneficial effect of TNF-alpha blockade in animal models of MS led to the therapeutic usage of TNF-alpha antagonists. However, systemic TNF-alpha blockade exacerbated MS activity and was associated with new-onset MS when implemented for treating other autoimmune disorders. We employed a TNF-alpha neutralization bioassay and demonstrated that the capacity of sera from untreated and IFN-beta-treated relapsing remitting MS patients to neutralize TNF-alpha is significantly higher than that of matched healthy controls. This finding was not related to sTNFRI, sTNFRII, or anti-TNF-alpha Abs levels. (C) 2015 Elsevier B.V. All rights reserved.