Age-related changes in cerebrospinal fluid protein concentrations

Area of Science:

• Neuroscience
• Gerontology
• Biochemistry

Background:

• The blood-brain barrier (BBB) is crucial for maintaining cerebrospinal fluid (CSF) homeostasis and normal neuronal function.
• Aging may compromise BBB integrity, increasing brain vulnerability, but this is under-investigated in healthy elderly individuals.
• Measuring CSF/serum protein quotients is a common method to assess BBB function.

Purpose of the Study:

• To investigate age-related changes in the CSF/serum quotients of specific proteins in adults without neurological deficits.
• To identify sensitive biomarkers for BBB function changes in aging populations.

Main Methods:

• A prospective study involving 107 subjects aged 18-89 years undergoing spinal anesthesia or myelography.
• Measurement of CSF/serum quotients for prealbumin, albumin, immunoglobulin G, and alpha 2-macroglobulin.
• Correlation analysis between protein quotients and participant age.

Main Results:

• A weak positive correlation was observed between age and CSF/serum quotients for all proteins studied.
• Except for alpha 2-macroglobulin, these changes likely reflect age-related decreases in serum protein concentrations.
• Alpha 2-macroglobulin emerged as a sensitive indicator of BBB function, suggesting a subtle decline with age.

Conclusions:

• A subtle decline in blood-brain barrier integrity may occur with increasing age, as indicated by alpha 2-macroglobulin.
• This age-related change could be a true physiological alteration or reflect increased subclinical disease in older populations.
• Alpha 2-macroglobulin is a promising biomarker for monitoring BBB integrity in large-scale aging studies.