Your immune system protects you from illness and foreign substances that can harm you. Scientists have found a way to use the body's immune system to help treat or prevent many health problems. This treatment is known as biological therapy, also called immunotherapy, biological response modifier therapy, or biotherapy.
Uses of Immunotherapy
Immunotherapy may be used to:
- Treat or manage cancer. Immunotherapy may be used with other treatments to help them work better. Immunotherapy works best to treat early-stage cancers.
- Prevent cancer. Cancer vaccines help protect against viruses that can cause some cancers. One example is the vaccine for human papillomavirus, or HPV. This virus causes cervical cancer, as well as other cancers.
- Control asthma and allergy symptoms. Immunotherapy or allergy shots are often given to people with severe allergies or asthma. A series of allergy shots over time may be part of your allergy treatment plan and may help reduce your allergy symptoms. The shots start with a small amount of allergen. This helps the immune system build up a tolerance to that allergen. The person is then less sensitive to the allergen and has fewer symptoms.
What is Immunotherapy / Biological Therapy?
Immunotherapy uses the body's immune system to fight cancer. The cells, antibodies, and organs of the immune system work to protect and defend the body against foreign invaders, such as bacteria or viruses. Healthcare providers and researchers have found that the immune system might also be able to both determine the difference between healthy cells and cancer cells in the body, and to eliminate the cancer cells. (By itself, the immune system is not always good at destroying cancer cells.)
Biological therapies are designed to boost the immune system, either directly or indirectly. They assist in the following:
- Stop, control, or suppress the processes that allow cancers to grow
- Making cancer cells more recognizable by the immune system, and therefore more capable of being destroyed by the immune system
- Boosting the killing power of immune system cells
- Changing the way cancer cells grow, so that they act more like healthy cells
- Stopping the process that changes a normal cell into a cancerous cell
- Enhancing the body's ability to repair or replace normal cells damaged or destroyed by other forms of cancer treatment, such as chemotherapy or radiation
- Preventing cancer cells from spreading to other parts of the body
Biological therapies can be used alone to treat cancer. They can also be combined with other treatments, such as chemotherapy and radiation therapy.
How Can the Immune System Fight Cancer?
The immune system includes different types of white blood cells, each with a different way to fight against foreign or diseased cells, including cancer:
- Lymphocytes. These are white blood cells, including B cells, T cells, and NK cells:
- B cells. Cells that make antibodies that attack other cells.
- T cells. Cells that directly attack cancer cells themselves and signal other immune system cells to defend the body.
- Natural killer cells (NK cells). Cells that make chemicals that bind to and kill foreign invaders in the body.
- Monocytes. These are white blood cells that swallow and digest foreign particles.
- Dendritic cells. Cells that present the foreign cells to the immune system.
These types of white blood cells—B cells, T cells, natural killer cells, and monocytes—are in the blood and circulate to every part of the body, providing protection from cancer and other diseases. White blood cells secrete many types of substances, including antibodies and cytokines. Antibodies respond to harmful substances that they recognize, called antigens. Specific (helpful) antibodies match specific (foreign) antigens by locking together. Cytokines are proteins made by some immune system cells that attract other immune system cells or that may directly attack cancer cells. Cytokines are also messengers that communicate with other cells.
Are There Side Effects of Biological Therapies?
As each person's medical profile and diagnosis is different, so is his or her reaction to treatment. Side effects may be severe, mild, or absent. Be sure to discuss with your cancer care team any or all possible side effects of treatment before the treatment begins.
Side effects of biological therapy vary according to the type of therapy given. They may include the following:
- Loss of appetite
Specifically, interleukins and interferons often cause flulike symptoms. These include fever, chills, aches, and fatigue. Other side effects may include a rash or swelling at the injection site. Interleukins can be associated with low blood pressure and generally need close monitoring in the hospital during infusion. Monoclonal antibodies sometimes cause allergic reactions during the treatment or infusion.