Thrombotic Processes in Multiple Sclerosis as Manifestation of Innate Immune Activation

INTRODUCTION Multiple sclerosis (MS) is a chronic demyelinating inflammatory disease of the central nervous system (CNS) affecting prevalently young adults (1, 2). The pathogenesis of MS has long been attributed to self-reactive T cells but recently the relevant role of B cells has also been recognized (2, 3). Furthermore, it has been demonstrated that innate immunity has a pivotal role in the beginning and in advanced stages of MS (4–6). Innate immunity represents the immediate non-specific defense against infections and dangerous agents acting through its essential arms such as inflammation and blood coagulation (7–10). The coagulant processes are normally balanced by the natural anti-coagulant system needed to limit the host damage, and their imbalance leads to venous thrombosis (7, 8). Many evidences reported below support a significant presence of local and systemic thrombotic events in MS confirming the global over-stimulation of innate immunity for both its inflammatory and coagulant components.