Quantitative Proteomic Profiling of Cerebrospinal Fluid to Identify Candidate Biomarkers for Alzheimer's Disease.

PURPOSE: The aim of this study is to identify the potential cerebrospinal fluid (CSF) biomarkers for Alzheimer's disease and to evaluate these markers on independent CSF samples using parallel reaction monitoring (PRM) assays. EXPERIMENTAL DESIGN: High-Resolution mass spectrometry and tandem mass tag (TMT) multiplexing technology are employed to identify potential biomarkers for Alzheimer's disease. Some of the identified potential biomarkers are validated using PRM assays. RESULTS: A total of 2327 proteins are identified in the CSF of which 139 are observed to be significantly altered in the CSF of AD patients. The proteins altered in AD includes a number of known AD marker such as MAPT, NPTX2, VGF, GFAP, and NCAM1 as well as novel biomarkers such as PKM and YWHAG. These findings are validated in a separate set of CSF specimens from AD dementia patients and controls. NPTX2, in combination with PKM or YWHAG, leads to the best results with AUCs of 0.935 and 0.933, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: The proteins that are found to be altered in the CSF of patients with AD could be used for monitoring disease progression and therapeutic response and perhaps also for early detection once they are validated in larger studies.

Levels of enolase and other enzymes in the cerebrospinal fluid as indices of pathological change.

The activities of enolase, aldolase, pyruvate kinase, lactate dehydrogenase and creatine phosphokinase were measured in cerebrospinal fluid of 121 patients presenting with a range of disorders of the central nervous system. The results from 41 patients undergoing myelography were used as controls. An assessment was made of the relative merits of these five enzymes as markers of brain damage with special reference to brain tumours. Enolase was the most sensitive marker of pathological change and was the only enzyme raised in the CSF of patients with low grade astrocytomas.

Some glycolytic enzymes in normal cerebrospinal fluid, brain tissue and blood plasma of infants.

The activities of several glycolytic enzymes (hexokinase, phosphofructokinase, pyruvate kinase, lactate dehydrogenase) as well as glycerol-1-phosphate dehydrogenase and (Mg2+)ATPase in normal cerebrospinal fluid (CSF) and blood plasma samples, from 12 healthy infants, aged 2-18 months, and in supernatants from brain tissue slices, taken during neurosurgical operations from infants of the same range of age were estimated. The values obtained confirm the high activity of the above enzymes found in animal brains, and indicate an independence of these activities in blood plasma and CSF. The origin of the activities of the investigated enzymes in CSF seems to be mainly, if not, exclusively, from brain tissue. This might be useful for detection of brain tissue damage as was earlier proven with LDH activity in CSF.