BACKGROUND: A new form of immunotherapy combines a vaccine with an infusion of a person's own T-cells that have been given a "jump start" and then are grown in the laboratory. The new approach helps to restore cancer patients' ability to fight off infection after high-dose chemotherapy. It could also one day be used to treat others with compromised immune systems, such as those with HIV and the elderly.
THE STUDY: Patients with advanced myeloma, a cancer of the plasma cells in the bone marrow, received high-dose chemotherapy and a bone marrow transplant. They received a series of vaccinations against a common bacterial form of pneumonia as well as an injection of their own lab-enhanced immune cells. Researchers found the therapy was most effective when patients received vaccinations before the bone marrow transplant to jump-start their immune system, and then collected the "vaccine-primed" T cells, activated them in the lab, and gave them back to the patients 12 days after the transplant. Within one month, those patients showed significant improvement in their immune response. The researchers will next combine this T-cell therapy with a cancer vaccine that would target tumor cells, hopefully to one day enhance the body's immune response to cancer.
WHAT IS IMMUNOTHERAPY? A slow or non-functioning immune system is a serious problem for cancer patients, especially those who receive intensive chemotherapy prior to bone marrow transplants. Patients are at high risk of developing infections and recurrence of their cancer. Immunotherapy stimulates a patient's own immune system to work harder. It's often used in conjunction with other forms of therapy -- in the case of cancer, it is combined with surgery, radiation therapy, or chemotherapy. In general, immunotherapy is most likely to be effective when treating small cancers and is less effective for advanced stages of the disease.
WHAT ARE T-CELLS? T-cells are a type of white blood cell called lymphocytes, and help the immune system fight off diseases. There are two kinds of T-cells. T4 cells are "helper" cells that lead the attack against infections. T8 cells are "suppressor cells" that end the immune response, although they can also kill cancer cells and cells infected with a virus. Scientists tell T4 and T8 cells apart by the different proteins attached to the outside of each cell. The number of T4 cells in your blood tells you how healthy your immune system is. A person with a healthy immune system has an average T-cell percentage of more than 30 percent.
ABOUT CHEMOTHERAPY: Chemotherapy is a treatment for cancer, in which certain drugs (poisonous to cancer cells) are injected into the blood to kill cancer cells or to stop them from spreading. They can travel around the body and attack cancer cells wherever they find them, so chemotherapy is used when cancers have spread beyond one region of the body.