Glatiramer Acetate for Multiple Sclerosis With Autoimmune Comorbidities

Multiple Sclerosis (MS) is an auto-immune neurodegenerative disease that affects more than 400,000 individuals in the United States, and 2.5 million worldwide (www.nationalmssociety.org). The main pathogenic mechanism in MS involves an inflammatory condition that damages the myelin of the central nervous system (CNS), resulting in axonal damage and neurological impairment, often leading to severe disability. MS is one of the most common causes of neurological disability in young and middle-aged adult individuals, and as such has a tremendous physical, psychological and social impact on patients' lives. MS is a complex disease diagnosed by McDonald criteria with different clinical and pathological phenotypes. Several forms of MS have been described: Relapsing-Remitting (RRMS), Secondary-Progressive MS (SPMS), Progressive-Relapsing MS (PRMS), and Primary-Progressive MS (PPMS). Glatiramer Acetate (GA) and Beta-Interferons (β-IFNs) are well established first-line immunomodulating treatment options for relapsing remitting multiple sclerosis (RRMS) with excellent safety profiles. The mechanisms of action of GA and IFNs are different. It is well known that in general Disease-Modifying Treatments (DMTs) reduce relapse rate in more than half of the multiple sclerosis (MS) patients who receive DMT, while having little if any effect on the rest. It has been speculated that the response to beta-interferons or GA may have genetic basis. As Axtell RC et al. indicated the experimental autoimmune encephalomyeilits (EAE) in mouse caused by TH1 cells generally respond well to interferon-beta, while EAE caused by TH17 cells get worse with interferon-beta. Autoimmune disease is an extreme situation where the autoimmune response overshoots and goes out of control. The other extreme is a degenerative disorder, where the autoimmune response is not strong enough for effective protection, and degeneration therefore continues. GA being an immunomodulator may provide both properly regulated immune suppression (in the case of autoimmune disease) and properly regulated immune activation (in the case of the neurodegenerative disease). Autoimmune conditions cluster in families with high risk for multiple sclerosis than in general population which suggests that the disease might arise on a background of a generalized susceptibility to autoimmunity. Occurrence of psoriasis, autoimmune thyroiditis, vasculitis, rheumatoid arthritis, scleroderma, lupus are seen more commonly in MS patients. Many of these patients initially get started on beta-IFNs, and usually do not do well on them. According to Investigator's and the USC MS Comprehensive Care Center experience, autoimmune co-morbidity associated with MS can serve as a biological marker predicting good response to GA and unfavorable response to the IFNs.