👤 Eleftherios P Diamandis

Alzheimer's disease (AD) biomarkers in plasma and cerebrospinal fluid (CSF) are useful for disease diagnosis, prognosis, risk assessment and monitoring therapy response, as well as for uncovering altered disease pathways. Previously, we and others cloned a novel gene, KLK6, which encodes a serine protease of the kallikrein family. The protein (hK6) is highly expressed in the brain, spinal cord and cerebellum. To examine the correlation of hK6 concentration in CSF with various clinicopathological variables in AD, we used a quantitative ELISA system. The variables examined included patient age, sex, MMSE score, APOE status, amyloid β 1-42 (Αβ1-42), phosphorylated Tau 181 (p-Tau181), total Tau (t-Tau). Previously, using a cohort of Swedish and Norwegian patients, we established a positive correlation between CSF hK6 and age as well as the levels of core AD biomarkers in four groups of patients (cognitively normal, MCI without progression to AD, MCI with progression to AD within 2 years and AD dementia). In this investigation, our goal was to validate these previous data with a large and independent patient cohort from Spain. We found that CSF hK6 is minimally or not affected by patient age and sex, but it significantly correlates with MMSE score and CSF Aβ1-42, p-Tau1811 and t-Tau. We conclude that these correlations further support our previous findings and suggest that hK6 may be an additional biomarker for AD and may play some role in the pathogenesis of AD. Show less

Multiple sclerosis (MS) is a clinically and biologically heterogenous disease with currently unpredictable progression and relapse. After the development and success of neurofilament as a cerebrospinal fluid (CSF) biomarker, there is reinvigorated interest in identifying other markers of or contributors to disease. The objective of this study is to probe the predictive potential of a panel of brain-enriched proteins on MS disease progression and subtype. This study includes 40 individuals with MS and 14 headache controls. The MS cohort consists of 20 relapsing remitting (RR) and 20 primary progressive (PP) patients. The CSF of all individuals was analyzed for 63 brain enriched proteins using a method of liquid-chromatography tandem mass spectrometry. Wilcoxon rank sum test, Kruskal-Wallis one-way ANOVA, logistic regression, and Pearson correlation were used to refine the list of candidates by comparing relative protein concentrations as well as relation to known imaging and molecular biomarkers. We report 30 proteins with some relevance to disease, clinical subtype, or severity. Strikingly, we observed widespread protein depletion in the disease CSF as compared to control. We identified numerous markers of relapsing disease, including KLK6 (kallikrein 6, OR = 0.367, p < 0.05), which may be driven by active disease as defined by MRI enhancing lesions. Other oligodendrocyte-enriched proteins also appeared at reduced levels in relapsing disease, namely CNDP1 (carnosine dipeptidase 1), LINGO1 (leucine rich repeat and Immunoglobin-like domain-containing protein 1), MAG (myelin associated glycoprotein), and MOG (myelin oligodendrocyte glycoprotein). Finally, we identified three proteins-CNDP1, APLP1 (amyloid beta precursor like protein 1), and OLFM1 (olfactomedin 1)-that were statistically different in relapsing vs. progressive disease raising the potential for use as an early biomarker to discriminate clinical subtype. We illustrate the utility of targeted mass spectrometry in generating potential targets for future biomarker studies and highlight reductions in brain-enriched proteins as markers of the relapsing remitting disease stage. Show less