I copied this from Wellspere about cytokines. I have taken this off topic but I still need more information about BLO herx.
It's like this. In the presence of toxins, pro-inflammatory immune system proteins, called cytokines, are sent out to areas of infection. Problem is, they tend to be battalion-happy and, when it comes to Lyme disease, they are fond of flooding the body with their presence. Don't get me wrong; cytokines play a vital role in the immune system. They mobilize white blood cells for the purpose of destroying pathogens, recognize antigens (invaders) and have a number of vital functions besides. Problem is, and especially in the presence of Lyme biotoxins, their overwhelming presence causes a person to suffer.
How? Well...where do I start? First, inflammation blocks oxygen flow to cells by suppressing VEGF-vascular endothelial growth factor, which is responsible for blood vessel dilation and growth. Without proper dilation and growth, red blood cells can't get through the capillaries in order to make it to the tissues! As a result, cells don't get the nutrients they need, which has a multitude of negative implications for the body. It's why you feel tired; it's why your gut and your brain don't function right. Cells need oxygen and nutrients, in order to function!
Also, cytokines cause the release of an enzyme called MMP9, which allows inflammatory compounds to move from the bloodstream into the tissues and organs. MMP9 makes you feel absolutely horrible. Measuring MMP9 levels, by the way, can help you to discern whether you have an explosion of inflammatory cytokines in the body.
Further, it is thought that inflammation can initiate auto-immune processes, causing the body to produce different types of antibodies, which in turn exacerbates the inflammation!
The process can become out of control. But that's not the worst of it. The initiation of auto-immune processes brings more trouble to the body. For instance, in people with high levels of biotoxins, inflammation is thought to induce the production of anticardiolipins, which contribute to abnormal blood clotting processes. As another example, it can initiate the destruction of myelin shealth, the protective covering of nerve fibers.