Basic components of the immune system part 132

Monoclonal antibodies can also be used as antitumor agents. Specific targeting and killing of tumour cells can be enhanced by linking tumor-antigen specific monoclonal antibodies to agents as follows:

• A cytotoxic drugs such as methotrexate
• A radioisotope such as iodine-131 or ytrium-90
• A toxin such as ricin

Monoclonal antibodies are now approved for the treatment of non-Hodgkin's lymphoma, myeloid and lymphocytic leukemia, breast cancer and colorectal cancer.