Monoclonal Antibody Drugs. How do they work?

I have chosen to write about the monoclonal antibody drug adalimumab (Humira) this week. I chose this specific drug because it is used to treat Rheumatoid arthritis which my stepdad suffers from. According to Mednet, a monoclonal antibody is a manufactured antibody that is made in order to attack human antibodies that are not working properly. If someone has an autoimmune disorder, like Rheumatoid arthritis, their antibodies are mistaking self cells for pathogens and trying to destroy them. Scientists can take those antibodies that don’t work and place them in an animal reservoir like a mouse and then retrieve the antibodies the mouse produces against them. They now have monoclonal antibodies programmed to attack the antibodies that are attacking self cells. 

The purpose of Humira for someone with Rheumatoid arthritis is to “prevent further damage to your bones and joints and help your ability to perform daily activities”. The target of Humira is a protein called TNF-alpha. In a person with a normal functioning immune system, TNF-alpha is supposed to control the amount of inflammation in the body. In Rheumatoid arthritis, the body produces TNF-alpha in excess which leads to lots of joint inflammation and pain. Humira works to lessen this inflammation by binding to TNF-alpha and blocking it from causing further inflammation. The side effects of Humira are:

• Serious infections like Tuberculosis
• Hepatitis B in carriers
• Allergic reactions
• Nervous system problems
• Blood problems
• Heart failure
• Immune reactions such as chest pain and rashes
• Liver problems
• Psoriasis

I think that these side effects all sound very serious and are something that a person would have to consider when deciding if they want to take the medication. Personally, it would depend on how much pain I was in. If my pain was very severe I would probably risk these side effects in order to get relief. Another thing to consider would be if you have latent TB or Hep B. If you had these latent infections it would not be a good idea to take Humira because they have a higher chance of being reactivated. I looked at a paper from the American Society for Microbiology in order to understand the reason that Humira increases the risk of TB since I couldn’t find an exact explanation on the Humira website. The reason is that Humira is a TNF-alpha blocker, and one function of TNF-alpha is to control granulomas/tubercles. So in patients taking Humira, they would not be able to fight off new TB infections or latent TB infections as well.  This is an example of how the drug suppresses both innate and acquired immunity.