Immunoglobulins, also known as antibodies, work in conjunction with other components of the immune system to defend our bodies against infections. These immunoglobulin (Ig) normally circulate in the liquid part of our blood, called the plasma, and if they detect something foreign in our body, flags are set off with cascading effects to help remove what is found from our system.
There are multiple types of immunoglobulins in the blood plasma. They are named IgG, IgM, IgA, IgD and IgE. The particular immunoglobulin found to provide therapeutic benefit is IgG. Commercial preparations of immunoglobulin therapy focus on securing purified IgG preparations containing relatively little amounts of the other immunoglobulins.
Although there are many uses for immunoglobulin therapy, it is primarily used to treat immunodeficiencies and autoimmune disorders.
Use of immunoglobulin therapy for immune deficiency:
Patients may suffer from a part of their immune system not functioning properly or being absent, which results in having an immune deficiency disease. These immunodeficient patients are more prone to repeated infections, severe infections, and/or infections that are unusually hard to cure and require hospitalization.
The causes of immune deficiency disease can be genetic or acquired. In either case, patients benefit from receiving immunoglobulin replacement therapy, also known as IVIG (intravenous immunoglobulin) or SCIG (subcutaneous immunoglobulin).
Immunoglobulin therapy is given as a temporary replacement for the deficient levels of antibodies in the blood to help strengthen the immune system and reduce the risk of recurrent bacterial infections. Over time, as the infusions are given continuously, the level of functioning IgG antibodies can be maintained in a sufficient amount to mimic the part of the immune system that did not work as intended. Primary immunodeficient patients will require this replacement therapy for life.
Researchers have found more than 150 types of immunodeficiency diseases, but those commonly treated with immunoglobulin therapy include:
- CVID (Common Variable Immune Deficiency)
- XLA (X-Linked Agammaglobulinemia)
- Hyper-IgM syndromes
- Wiskott-Aldrich syndrome
- SCID (Severe Combined Immunodeficiency)
Use of immunoglobulin therapy for autoimmune diseases:
Autoimmune disorders occur when the body mistakenly produces an antibody response against components of itself, such as its own particular cells, tissues or organs. In these situations, a patient does not have an immune deficiency, but more of a hyperactive response to its own body by creating auto-antibodies. What triggers an autoimmune response is not well understood, but there may be a genetic predisposition for these disorders, or they may be caused by a virus, bacterial infection or drug reaction.
For autoimmune diseases, the treatment goal is to suppress the auto-antibody response and prevent any further deterioration by saturating the body with IgG immunoglobulins.
Neurologists found that they could weaken the autoimmune response in patients with particular disorders, often affecting the neurological system, by administering extemporaneous IgG. The following disorders are treated with immunoglobulin therapy, although in many cases, this is not the first-line therapy and may be preceded by other treatments, including immunosuppressants such as corticosteroids or plasmapheresis. Peripheral neuropathies, conditions caused by damage to the peripheral nervous system, are commonly treated with IgG.
- Chronic inflammatory demyelinating polyneuropathy (CIDP)
- Guillain-Barré syndrome (GBS)
- Multifocal motor neuropathy (MMN)
- Myasthenia gravis (MG)
- Relapsing-remitting multiple sclerosis (MS)
- Stiff-person syndrome
The length of immunoglobulin therapy for autoimmune disorders varies from a one-time infusion, to monthly, or multi-year treatment plans, depending on the patient’s condition and response to treatment.
Prescribers may also utilize immunoglobulin therapy for autoimmune conditions affecting other systems in the body: