Introduction:
Multiple sclerosis is a severe form of nerve disease. It causes autoimmune destruction of nerve fibers and nerve cells. It is also associated with severe disabilities. Symptoms include loss of neuro-muscular coordination and difficulties in talking, smiling, and eating food. Gradually this causes a loss of cognitive functions and loss of other essential functions. This is also associated with repeated cases of relapse. Though, several treatment options are employed to treat this disorder. It is difficult to cure completely.
What Is Multiple Sclerosis?
Multiple sclerosis is one of the most common chronic autoimmune disorders that primarily target the central nervous system. It has a global prevalence of nearly 2.5 million individuals and is one of the most frequently encountered inflammatory conditions affecting the central nervous system. The activation and infiltration of T-lymphocytes and macrophages due to autoimmune activity triggers the inflammatory response within the nerves. This leads to the damage of nerve cells and the destruction of the protective myelin sheath.
Pathophysiology:
T helper (Th) cells or CD4+ T-cells, become activated as a result of the immune-inflammatory pathway. This process involves two immune pathways: the adaptive pathway and the innate pathway. In the adaptive pathway, the presence of specific antigens in T lymphocytes triggers the activation of both Th1 and Th17 T-cells. These activated cells contribute to the focal injury of the blood-brain barrier, leading to its disruption. Inflammatory cells target the endothelial cells of the central nervous system and release various inflammatory mediators. These mediators further promote the aggregation of inflammatory mediators, such as B-lymphocytes. The involvement of B-lymphocytes is particularly observed in multiple sclerosis and is associated with infectious conditions like the Epstein-Barr virus (EBV). On the other hand, the innate immune response is initiated by microbial products, which trigger the immune reaction. The inflammatory cells and mediators produced during this process cause damage to nerve cells. This damage is characterized by demyelination of the nerve fibers, loss of nerve cells, and the proliferation of fibrous cells like glial cells.
Treatment Options:
The traditional treatment option involved in multiple sclerosis is known as disease-modifying therapy. The goal of this therapy is to reduce inflammatory response. The drugs used for this purpose are interferon beta, glatiramer acetate, and Fingolimod. Interferon beta is a type of protein used to boost the immunity of the human body. It is given as a subcutaneous or intravenous injection. Glatiramer acetate is composed of a large number of peptides and is given subcutaneously. Fingolimod is a sphingosine-1 phosphate (S1P) receptor modulator and acts as an oral drug. This drug has neuroprotective effects.
What Is Infusion Treatment for Multiple Sclerosis?
Infusion therapy includes administration of the drugs into the systemic circulation via intravenous route. In this method, different disease-modifying drugs are administered. Infusion is mostly a type of immunoglobulin therapy used to treat multiple sclerosis. This is a pooled antibody and is used as a biological agent. The drugs used in infusion therapy are,
Alemtuzumab:
This is a monoclonal antibody that binds to the CD52, which are glycoprotein present on the surface of various inflammatory cells like lymphocytes and monocytes. Also, it is present on the surface of the dendritic cells. Binding to this antigen causes the destruction of the immune cells. This is responsible for autoimmune lysis of the T and B lymphocytes. An intravenous infusion of 12 to 24 milligrams of this drug is given for five days. After the application of the initial dose, the second dose is to be given in the twelfth month. At this phase, 12 to 24 milligrams of the drug are given for three days. This drug is helpful in preventing relapse up to 74 percent of cases. Some of the main adverse events associated with this are rash, headache, fever, and urinary tract infection. According to some researchers, it is associated with increased cancer risk and organ toxicity. It is also associated with thyroid disorders, platelet disorders, and Goodpasture’s syndrome (a disorder of the lungs and kidneys).
Natalizumab:
As already discussed, the adhesion of leukocytes to the endothelial cells of the central nervous system is important for the inflammatory reaction of multiple sclerosis. This process is mediated by the adhesion of the inflammatory cells and is aided by the action of cells-like molecules like vascular cell adhesion molecule 1 (VCAM-1). This molecule is responsible for crossing the blood-brain barrier. Natalizumab is a monoclonal antibody that prevents the binding of the endothelial cells. This drug blocks the functioning of the VCAM-1 molecule.
Additionally, this drug prevents the activation of the lymphocytes and their migration. 300 milligrams of this drug is given intravenously for 28 days intravenously. Sometimes, it is combined with interferon therapy. This combination therapy helps prevent disease progression, relapse, and disability progression. The side effects of this drug are progressive multifocal leukoencephalopathy (viral infection of the white matter of the brain), urinary tract infection, pneumonia, and skin rashes.
Mitoxantrone:
This is one of the most commonly used FDA-approved drugs used as an infusion medication in multiple sclerosis. At first, it was developed as an anti-cancer drug for leukemia and prostate cancer. It acts as an immunosuppressive agent and can be useful in treating secondary progressive multiple sclerosis and relapsing-remitting multiple sclerosis (a type of multiple sclerosis where symptoms get worse). This drug is administered as 12 milligrams per square meter of body surface area for over 30 minutes every three months. The cumulative dose must not cross 140 milligrams per square meter of body surface area. The common side effects associated with this drug are loss of hair, infection, vomiting, and nausea.
What Is the Need for Infusion Therapy?
Infusion therapy is one of the emerging therapies prescribed to patients suffering from multiple sclerosis. This is helpful in faster recovery and prevents relapsing. Also, it can be useful in preventing disability associated with multiple sclerosis. Also, it is associated with faster recovery.
Conclusion:
The goal of any therapy in multiple sclerosis is to reduce the amount of inflammation present in the central nervous system. The traditional treatment options cannot prevent relapse of the disease. Also, the onset of action of these drugs is slower. Infusion therapy is an emerging therapy that prevents relapse of multiple sclerosis. However, side effects associated with these drugs are severe.
