Immune Therapy: Cytokines

Immune chemicals may hold hope for new treatments in HIV

January 2005     View PDF     En español

Cytokines: the past or the future?

One of the great clichés of popular writings about medicine is the claim that some products “boost the immune system”. This is far easier said than done, nor is it always clear that the goal, even in HIV disease, should be to “boost” any aspect of the system. Just as often, the real goal may be to suppress or modulate some aspect of the immune response.

Therapies designed to influence the immune system are called immune-based therapies (IBTs). The field IBTs is still in its infancy, but not so new that the reality of IBTs is outside the grasp of day-to-day use in the practice of medicine. There are currently approved and proven cytokine therapies that are routinely used by people living with HIV. These include cytokines like interferon-alpha, granulocyte colony stimulating factor and erythropoietin-alpha.

Interferon-alpha
Interferon-alpha (Infergen, Roferon, Intron-A, Peg-Intron) is a cytokine with broad antiviral properties. It has been researched and proven useful in treating viral hepatitis. It is also used in treating an AIDS-related cancer, Kaposi’s Sarcoma (KS), which is triggered by human herpes virus 8 (HHV-8), also called KS Herpes Virus (KSHV).

Interferon-alpha is most known in the setting of HIV as a broad spectrum antiviral. While test tube studies show some anti-HIV activity of interferon-alpha, studies in people have been conflicting. Other facets of its impact on immune functions are also being explored. For example, studies are underway to see if its use can prevent diabetes. It has also been proven to be useful in treating non-viral cancers, such as malignant melanoma. It is available in standard and “PEG” (pegylated) forms. These forms combine it with PolyEthylene Glycol, which stabilizes the interferon and keeps it in the bloodstream longer, thus improving its effectiveness.

Granulocyte colony stimulating factor
Granulocyte colony stimulating factor (G-CSF, neupogen, Filgrastim) is used by people with low neutrophil cell counts (neutropenia). Neutrophils are important in fighting bacterial infections. When these counts are very low (below 750), people are at increased risk for severe and potentially life-threatening bacterial infections. Drugs to treat HIV and related conditions, particularly anti-CMV drugs, can cause neutropenia. It has also been associated with HIV disease progression. G-CSF mobilizes neutrophil cells and causes them to reproduce.

Erythropoetin-alpha (epoetin-alpha, Epogen)
Erythropoetin-alpha (epoetin-alpha, Epogen) is used for treating mild-to-moderate AZT-associated anemia. Anemia is a decrease in red blood cell counts. Red blood cells carry oxygen throughout the body. Severe anemia is treated with blood transfusion. Symptoms of anemia may include fatigue, dizziness, difficulty concentrating, menstrual abnormalities and/or decreased sex drive. Anemia can be caused by HIV, HIV-related conditions and/or by drugs used to treat HIV.

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