Trastuzumab (Herceptin) is a monoclonal antibody that can be used to treat some type of breast cancers and stomach cancers. Monoclonal antibodies are man-made complexes that resemble antibodies an act in the same manner as an antibody produced by the body. They are made to react to a specific antigen in order to alert the immune system of the invader to destroy it. They can also be used to neutralize the ability of the pathogen to continue to negatively affect the body. Monoclonal antibodies can be made in four different ways: murine, chimeric, humanized, and human, and are named based on what they are made of. Trastuzumab is a humanized antibody, meaning that it is made from a human protein that has been attached to a smaller portion of a mouse protein. It is also considered a naked monoclonal antibody.
Trastuzumab is a monoclonal antibody that recognizes the HER2 protein that is present on many breast and stomach cancer cells. By attaching, it tags these cancerous cells for the immune system to then kill and destroy. It is considered a naked monoclonal antibody because it does not have any type of radioactive material or drug attached to it. It works by attaching itself to the antigen that it recognizes (the HER2 transmembrane protein) on HER2 positive cells. Because the presence of HER2 on the cell works to increase the growth of that cell, by attaching itself to the HER2 protein, the HER2 protein does not become activated and the cell does not grow. It is important that the cancerous cells are tested for the presence of the HER2 transmembrane protein before treatment begins. It works as a mediator of antibody-dependent cellular cytotoxity, meaning that it recognizes the antigen and then Natural Killer cells are able to attack and destroy the infected cell. Some of the possible side effects of taking Trastuzumab are:
- Heart problems
- Fever and chills
- Nausea
- Vomiting
- Pain (sometimes at the site of the tumor)
- Headache
- Dizziness
- Shortness of breath
- Severe shortness of breath
- Fluid in or around the lungs
- Weakening of the valve between the heart and the lungs
- Not enough oxygen to the body
- Swelling of the lungs
- Scaring of the lungs
- Low white and red blood cell count
- Muscle pain
- Infusion reactions
- Increased cough
- Rash
Taking Trastuzumab has been linked with neutropenia and when taking in conjunction with chemotherapy (as it is usually recommended when treating breast cancer) can cause large negative impacts on the immune system. This can affect the way that the body is able to amount an immune response to other disease causing pathogens. It is important that anyone taking Trastuzumab takes careful precautions to avoid any sick individuals and is considered immunocompromised. Because the drug helps to activate ADCC, it is helping to activate the innate immune system through the Natural Killer cell assistance. The Natural Killer cells are able to recognize the Trastuzumab that has recognized and linked to the HER2 transmembrane protein. Then the Natural Killer cell can release perforins and granzymes in order to induce apoptosis in the cancerous cell. The results of treatment with Trastuzumab have been very positive, and I believe that this is the future of treating cancers. To be able to specifically engineer an antibody that recognizes the cancerous cells in the body and directs the immune system to attack just these is the most effective way to eliminate cancerous cells while keeping normal cells alive. I believe that soon chemotherapy will be less popular and monoclonal antibodies such as Trastuzumab will be the more common course of treatment with overall better outcomes.
Thoughts about Small Things 