A fibroblast growth factor binding protein in human cerebral spinal fluid.

A soluble protein which binds basic fibroblast growth factor (FGF-2) has been detected in cerebral spinal fluid from normal individuals and patients with Alzheimer's disease and Parkinson's disease. This 70-85 kDa protein is recognized by an antibody to the extracellular domain of the high affinity FGF receptor and is not detected by an antibody to the intracellular domain of the FGF receptor, suggesting that it consists of a truncated portion of the extracellular domain of the high affinity FGF receptor. This FGF-BP appears to be identical to the two IgG-like loop form of FGFR-1 identified and purified from human and bovine blood. The possibility that this FGF-BP may play a role in transporting, sequestering, or even delivering the FGFs to target cells in the CNS is discussed.