Pregnancy-specific beta 1-glycoprotein-like material in human cerebrospinal fluid

Human cerebrospinal fluid (CSF) from 34 unselected neurological patients was studied for pregnancy-specific beta 1-glycoprotein (SP1) activity because of the recent finding of SP1 production by cultured glial cells. An organic central nervous system lesion was diagnosed in 9 patients, but not in the other 25. Low levels of SP1 immunoreactivity were found in CSF by RIA, and the adsorption of anti-SP1 antiserum with concentrated CSF abolished the positive immunohistochemical staining of placental tissue obtained with the unadsorbed antiserum. By means of immunoadsorption using monoclonal anti-SP1 antibodies, it was possible to isolate SP1 immunoreactive material from CSF and to demonstrate that it had the same electrophoretic mobility in sodium dodecyl sulfate-polyacrylamide gel electrophoresis as purified placental SP1. These results show that CSF contains SP1-like material that is closely related, if not identical, to placental SP1. The amount of SP1 in CSF has no direct correlation to an organic central nervous system lesion or to abnormality of the CSF.