Alzheimer’s disease, biomarkers and the role of the inflammatory profile in the cerebrospinal fluid

Introduction: Amyloid plaques and neurofibrillary tangles are associated with neuronal injury in Alzheimer's disease (AD). Objective: To investigate the relationship between biomarkers of neurodegeneration and the inflammatory profile in the cerebrospinal fluid (CSF) of patients with AD and mild cognitive impairment (MCI). Methods: A cross-sectional study including data on biochemical markers and clinical characteristics related to CSF biomarkers (p-tau, t-tau, and Aβ1-42) of 51 patients with MCI or AD was performed. Results:  A positive correlation between lactate dehydrogenase (LDH) and both p-tau (r=0.548; p<0.001) and t-tau (r=0.757; p<0.001), a negative correlation between lactate and p-tau (r=0.399; p<0.005), and a positive correlation between aspartate aminotransferase and p-tau (r=0.489; p<0.001) were found. Discussion: The positive correlation between LDH and tau protein points to a role for oxidative stress in AD. The negative correlation between lactate and p-tau suggests a detrimental effect of tau protein on cell metabolism. Conclusions: Inflammatory biomarkers might aid in AD workup. Technical simplicity and their potential association with tau protein warrant further research into LDH and lactate in AD.