| Active immunotherapy | |
|---|---|
| Specialty | Immunology |
Active immunotherapy is a type of immunotherapy that aims to stimulate the host's immune system or a specific immune response to a disease or pathogen and is most commonly used in cancer treatments. [1] [2] Active immunotherapy is also used for treatment of neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, prion disease, and multiple sclerosis. [3] Active immunotherapies induce an immune response through direct immune system stimulation, while immunotherapies that administer antibodies directly to the system are classified as passive immunotherapies. [4] Active immunotherapies can elicit generic and specific immune responses depending on the goal of the treatment. [5] The categories of active immunotherapy divide into:
Active immunotherapies fall under the category of activation immunotherapies, which is a subset of immunotherapies that activate the immune system as opposed immunotherapies that suppress the immune system.
Non-specific active immunotherapy is administered with the overall goal of generally eliminating malignant pathogens or cells from the host system. [5] This treatment stimulates the immune system in a general sense, rather than specifically targeting a cell type e.g. cancer cells. Non-specific approaches aim to create a robust immune response that would lead to the eventual killing of malignant cells through immunomodulators such as cytokines. [6]
Immunomodulating agents regulate the immune system's response and are produced by various immune cells. These agents include the following agents and markers:
| Class | Examples |
|---|---|
| Cytokines | Ig, Interferons, TNF |
| Chemokines | CXC, CC, CX3C, XC |
| Interleukins | IL-2, IL-7, 1L-10, 1L-12 |
The BCG vaccine has been used against tuberculosis, mycobacteria, and various cancers in the form of vaccination as an initial immune system stimulant. [7] In cancer, the anti-tumor immunological effects are elicited by the host's immune response and the BCG infection against the tumor cells, most commonly in bladder cancer. [7] The immune activation allows for further recognition and elimination of malignant tumor cells. [7]
Specific active immunotherapy administers a specific antigen as the therapy. The therapy allows the host to create an antigen-specific response with the development of antibodies, proliferation of cytotoxic T lymphocyte responses, or both, directed at the desired pathogen or malignant tumor cell in the case of cancer therapy. [5]
Vaccine therapies are a type of specific active immunotherapy. Vaccine therapies deliver various agents that will lead to a specific immune response e.g. antibody development or CTL response. [5] Tumor antigens have been a main target in specific active immunotherapy by way of vaccination. Tumor antigens are antigens produced by tumor cells and can be common among patients with the same cancer-type, or unique to a particular patient. Their specificity to malignant tumor cells makes tumor antigens ideal candidates for vaccination. [2]