Alright I just want to briefly go over autoimmune reactions or autoimmune diseases here. Excuse me. So obviously the issue with an autoimmune disease is not that you have a strong or weak immune system. It's that it's lost it's tolerance. So because of a process called thymic selection your T cells that were part of you are supposed to be eliminated when you're young but something happens in autoimmune disease where you lose what's called self-tolerance and you create autoantibodies or you have sensitized T cells attacking your own tissue. Basically your immune system is plenty powerful it's just attacking the wrong target. The different types I don't have any images here but the first type of autoimmune reaction is going to be cytotoxic. Let me just get this right out here. All right so cytotoxic autoimmune reactions are going to involve the antibodies are going to react to your cell surface antigen. So now the cell isn't actually destroyed though but what it can do Like a good example of this would be the most common autoimmune hyper-thyroidism condition that would be Graves Disease. So in Graves Disease the antibodies actually mimic thyroid stimulating hormones. So even though there's plenty of thyroid hormone being produced the thyroid gland's continually told there's not feedback inhibition because this is not a hormone this is an autoantibody so that the thyroid gland continues to make thyroid stimulating hormone the pituitary does Or no. The pituitary gland doesn't make this TSH I'm sorry. The thyroid gland continues to receive the message from thyroid stimulating hormone thinking that it's coming from the pituitary gland but it's actually it actually is an autoantibody. So this person's going to develop the bulging eyes high metabolism really hot racing heart that kind of stuff. That's probably the best example of a cytotoxic autoimmune reaction. Next we have what are called immune complex. Let me get this. Immune complex autoimmune reactions and these are going to be Lupus rheumatoid arthritis would be really good examples here of a immune complex reaction. And what's going to happen here is you actually get an immune complex reaction which is what happens when it's affecting your own tissues. So your body produces antibodies directed at your own cells. Could be any part of the cell. The problem with this is these complexes can form and do lots of damage. Like I have a lot of family members who have rheumatoid arthritis and what actually happens is these immune complexes deposit in the joints and basically eats up the joints. Like my grandmother's joints are just wore away. Her hands especially. So that's going to be So basically this chronic inflammation caused by these immune complexes sitting in your joints are what cause the bone cartilage to basically wear away. So that would be an example of immune complex autoimmune reactions. Actually these complexes of antibodies that form the inflammatory reaction caused by them that does all the damage. The last type we'll talk about on autoimmune reaction (phone beeps) is cell-mediated. Let me go ahead and get my phone quick here. Okay sorry about that. So we're talking about cell-mediated autoimmune reactions. You've definitely heard of some of these. Type Diabetes psoriasis MS these are examples of cell-mediated reaction. So something happens either a TH or TH it just means that one part of your immune system gets too dominant and that's why you don't want to stimulate or suppress the immune system. I mean in a perfect situation you would modulate it. And we can talk in class about some ways to do that. But most of the treatments that are used now for autoimmune diseases actually suppress the immune system. So yes they calm down the autoimmune reaction but they also increase your risk of cancer and do other things to weaken your immune system as well. So for example with like people think that MS is linked with some sort of virus same thing probably with Type Diabetes something happens where T cells start to attach the pancreatic islets or the islets of the Langerhans the endocrine portion of the pancreas that definitely appears to be T cell related. Psoriasis is the same type of thing. T cells target a chemical called Tumor Necrosis Factor Alpha. It leads to more skin to be produced which is what which is too bad but the main issue is that a large chunk of people with psoriasis develop a form of arthritis called psoriatic arthritis which can be as bad as RA as rheumatoid arthritis. All right so those are your three examples of autoimmune diseases. Just remember that they lose their tolerance and they produce what are called autoantibodies.