Cellular distribution of beta trace protein in CNS and brain tumours

Abstract

Beta trace protein constitutes about 7% of the total cerebrospinal fluid (CSF) protein content, whereas the serum concentration is only one seventh of that in CSF. The highest amounts of beta trace protein are found within white CNS matter; but also grey CNS matter and some genital organs, especially epididymis, contain rather high amounts of the protein. In the present investigation, beta trace protein was found in a concentration three times higher in fractions enriched in human glial cells than in fractions enriched in neuronal cells. By means of immunofluorescence on normal squirrel monkey brain, specific fluorescence was seen in glial cells, particularly in those resembling astrocytes and oligodendrocytes. In pathological human brain tissue consisting of different brain tumours, beta trace protein was found in significantly higher concentrations in tumours derived from glial cells than in tumours of other origin, e.g., meningiomas and metastatic tumours. These findings are not reflected in CSF. The present investigations of normal human and monkey brains, as well as pathological human brain tissues, show that beta trace protein is predominantly of glial cells origin, although, to some extent, it is also present in neuronal tissue. The high concentrations in glial cell tumours may be of diagnostic value.