A chelator is an agent that binds to metal in the tissues and draws it out through the urine. There is also IV chelation, which is a bit different. We use oral chelation. Except to say that I also have heavy metal toxicity. Lead, aluminum and copper.
Heavy metals can definately affect the immune system.
All of us have food allergies, chronic ear and throat infections etc. I also have endometriosis. It is run by Stephen B. Edelson, M.D. and is called Environmental and Preventative Health Center of Atlanta. To let you know just how metal can affest the brain, my youngest son at almost 5 had no speech. He could not ask a question or answer one, even What is your name.