Multiple sclerosis (MS) is a chronic and often a disabling disease of the central nervous system. It is one of the most common neurological illnesses in Europe and North America, and it was considered to be a rare disease in Iraq. However, and for unknown reason, the last few years witnessed a significant increase of newly diagnosed patients. Despite the numerous etiological factors that have been assumed to be responsible for the development of the disease like the involvement of certain viruses, toxins, and autoimmunity, the real cause is yet to be discovered. Whatever the initiator of the disease was, myelin loss, death of oligodendrocytes, along with axonal injury can occur through the disease process. This may be accompanied with an inflammatory immune response in which infiltration of mononuclear cells take place, and eventually uptake and digestion of myelin by macrophages. Esterases, being suggested to'have a role on phagocytic capacity and migratory potential was evaluated in peripheral blood monocytes. The presence of oligoclonal bands in cerebrospinal fluid of MS patients is regarded as one of the most important immunological abnormalities which aids in the diagnosis of the disease. It was found that such bands are also present in tear samples of the patients. In this study, the validity of tears as a possible biological marker for MS patients was explored. Myelin basic protein, which is supposed to be targeted by the immune system, was purified to be used in further studies. Lack of knowledge of what might be the cause of the disease make it impossible to find a cure for MS. However, immunomodulatory treatments, like beta interferon, seemed to be beneficial for the patients at least for a certain period of time. Still, the precise action of beta interferon is unknown. We have found that beta interferon had significantly increased the level of esterases in peripheral blood monocytes. We also found that beta interferon had reduced oligoclonal bands to a diminished level.