A contact activation product refers to a substance or material that triggers a cascade of biochemical reactions known as the contact system when it comes into contact with blood or biological fluids. The contact system is an integral part of the body's immune response and plays a crucial role in maintaining the integrity of blood vessels, regulating inflammation, and initiating the coagulation process.
When a contact activation product interacts with blood, it stimulates the sequential activation of various proteins, notably factor XII (FXII), prekallikrein (PK), and high-molecular-weight kininogen (HMWK). This activation releases active enzymes, such as kallikrein, which further converts more PK and HMWK into their active forms. These activated enzymes and proteins have diverse roles in clotting, inflammation, and vascular permeability.
The contact activation product is commonly found in medical devices used in surgeries, such as cardiopulmonary bypass circuits, hemodialysis machines, and catheters. It can also be found in certain biomaterials utilized for tissue engineering, drug delivery systems, and diagnostic assays.
Understanding the impact of contact activation products is crucial in clinical settings as they may lead to adverse reactions, including blood clot formation, inflammatory responses, or hypersensitivity reactions. Researchers and clinicians are continuously exploring strategies to minimize the activation of the contact system during medical interventions to improve patient outcomes and device compatibility.
In summary, a contact activation product is a substance that activates the contact system when in contact with blood, initiating a sequence of biochemical reactions essential for coagulation, inflammation, and vascular integrity.
