In vitro, high‐resolution 1H and 31P NMR based analysis of the lipid components in the tissue, serum, and CSF of the patients with primary brain tumors: one possible diagnostic view

Abstract

In vitro, high-resolution (1)H and (31)P NMR based qualitative and quantitative analyses of the lipid components of the tissue, serum, and CSF of patients with primary brain tumors were performed. Proton NMR spectra of the lipid extract of serum (blood specimen collected before the surgical procedure) and surgically discarded tissue showed that the total cholesterol (T.CHOL) and choline containing phospholipids (PL) were significantly higher in quantity in medulloblastoma and glioblastoma multiforme as compared to normal subjects. Serum lipid extracts of grade II/ III gliomas showed a higher quantity of PL than normal subjects. Cholesterol esters (CHOLest) were detectable in the tissue lipid extract of the patients with tumors and absent in normal tissue. There was a reduction in the quantity of CHOLest in the serum lipid extract of the tumor patients as compared to normal subjects. Ratio of PL to T.CHOL in serum lipid extract showed a significant difference between different grades of tumors versus normal subjects, while, a significant difference was observed only in medulloblastoma versus normal subjects in tissue lipid extract. Ratio of CHOL to CHOLest distinguishes the different grades of tumors versus normal subjects as well as between different grades of tumors (except medulloblastoma versus glioblastoma). The ratio of the Ph (total phospholipids except phosphatidylcholine) to PC (phosphatidylcholine) in (31)P NMR based study showed a significant difference in all grades of tumors (except medulloblastoma) in normal subjects in tissue lipid extract as well as between different grades of tumors. Medulloblastoma could be differentiated from glioblastoma as well as from normal subjects in serum lipid extract by the ratio of the Ph to PC. Proton NMR spectra of the lipid extract of CSF showed that the CHOL, CHOLest, and PL were present in the patients with tumors, although these were absent in the patients with meningitis, motor neuron disease, and mitochondrial myopathies as well as in normal subjects. PL and T.CHOL provided discrimination between different grades of tumors (except glioblastoma versus medulloblastoma) in the lipid extract of the CSF. This study suggests the role of lipid estimation in CSF and serum as a complementary diagnostic tool for the evaluation of brain tumors preoperatively. NMR-based lipid estimation of post-surgical tumor tissue may also contribute to differentiating the tumor types.