Abstract
INTRODUCTION: There is a need for a biomarker with high sensitivity and specificity to aid glioma diagnosis. Current methods of diagnosis are invasive with the diagnostic test requiring hospitalisation. A rapid diagnostic based upon blood serum and CSF samples would allow for a relatively non-invasive test and open up the possibility of screening for glioma as well as effective treatment monotoring and prediction of tumour recurrance. Analysis of the source of the proteins may reveal information regarding the mechanism of immunosuppression in these tumours. MATERIALS AND METHODS: Serum from 110 high grade and 44 low grade glioma patients, were analysed along with 33 control sera from non-cancerous patients. CSF was also analysed from 8 high grade glioma patients taken with lumbar puncture. The analysis was performed using a luminex immunoassay measuring 36 cancer-associated analytes simultaneously. Immunohistochemistry was also performed on tumour tissue from the same patients. RESULTS: There were significant differences in several analytes between sera and CSF of glioma patients of low and high grade and non-cancerous control patients. These were Angiopoietin, Follistatin, FGF, G-CSF, sHER2neu, HGF, sIL-6R, Leptin, PDGF-BB, PECAM-1, Prolactin and sVEGFR-1. CSF level differences confirmed and correlated with serum level differences in the majority of cases. Tumour tissue also revealed increased expression of several of the proteins. CONCLUSIONS: These results suggest that specific protein levels in different media can be used to detect and confirm a glioma diagnosis as well as to distinguish between low and high grade gliomas. These results may also be used to predict tumour recurrance and transformation between low and high grade gliomas. There was an interesting up-regulation of several receptor analytes that may have masked the presence of their associated ligand indicating that some potential biomarkers may be obscured. Modification of the capture antibody could reveal more potential biomarkers with greater clinical usefulness.