Immunomodulatory therapy consists of a series of three types of treatments for diseases that plague the human immune system, and it is more often referred to as just immunotherapy. The three types of immunomodulatory therapy strategies involve the use of immunosuppressant drugs to scale back the natural action of the immune system or the use of immunostimulant drugs to enhance its response, and the use of tolerogens which condition the immune system to tolerate tissue such as that of transplanted organs. Each class of treatments is designated for specific immune system problems. Immunosuppressant drugs and tolerogens are used together to treat autoimmune diseases like multiple sclerosis (MS) and organ transplants where the body is attacking its own tissue. Immunostimulant drugs are given to enhance the immune system in cases where it is weakened, such as with cancer, AIDS, and other life-threatening infections.
In cases where immunomodulatory therapy is used in an immunosuppressant role, the therapy itself can operate somewhat in the dark. With multiple sclerosis, little is still understood of the pathogenesis or inception and development of the disease over time. The role of immunomodulatory therapy itself in alleviating some of the suffering from such a condition is also poorly understood, but the treatment has been the only available method in existence to help patients with MS as of 2004. Because of the benefits that it offers to chronically ill patients, immunomodulatory therapy consisting of four immunomodulatory medications and one immunosuppressive medication have been given to patients in the US since 1993. The treatments are approved by the US Food and Drug Administration (FDA), though a complete understanding of how they work is unclear.
With both immunostimulant and immunosuppressive treatments, the premise is that broad effects on the immune system overall will have a generally helpful result in treating whatever condition is present. The idea is that such immunomodulatory therapy drugs nonspecifically stimulate action by the human immune system even though doctors and researchers have been unable to trace direct cause-and-effect results from the treatments as of 2011. The support for continuing such treatments to date has been entirely based on empirical evidence, or evidence of experience and observation in the field by medical professionals without thorough scientific data and theories to back up their assumptions.
Due to this empirical approach with immunomodulatory therapy, there has been some controversy in the medical field as to whether such approaches are truly warranted. This is especially true in the case of treatment of infections with companion animals, such as recurrent skin diseases, where immunostimulant drugs are prescribed. Such conditions may have underlying causes that are not based on a malfunctioning immune system. If the treatment is suspended, the condition may return, therefore, and the cycle will have to be continued again, as it was not caused by an immunodeficiency in the first place.