IMMUNOLOGICAL HETEROGENEITY OF FOLATE BINDING PROTEIN IN HUMAN CEREBROSPINAL FLUID

We determined the concentration of high-affinity folate binding protein in individual specimens of human cerebrospinal fluid by two methods, radioligand binding and immunoassay (ELISA with antibodies against human milk folate binding protein). The immunoreactivity or cross-reactivity showed great interindividual variations. Thus one specimen with high radioligand binding showed virtually no immunoreactivity, while two specimens with low radioligand binding were highly immunoreactive. The immunological heterogeneity of the folate binding protein in cerebrospinal fluid is consistent with the presence of different isoforms of the protein. Future studies should focus on a possible association between the occurrence of different isoforms of folate binding protein in cerebrospinal fluid and certain neurological diseases. (C) 1998 Chapman & Hall Ltd.