What is Blood-Brain Barrier Integrity IgG?
The blood-brain barrier is a specialised endothelial interface between the systemic circulation and the central nervous system parenchyma, formed by tight junctions between capillary endothelial cells and supported by astrocyte endfeet, pericytes, and a basement membrane. It selectively restricts the passage of macromolecules and immune cells into brain tissue. In some neuroinflammatory and systemic autoimmune conditions, barrier integrity may be compromised, and immune reactivity to barrier proteins has been hypothesised as a marker of that compromise.