Validated age-specific reference values for CSF total protein levels in children.

Area of Science:

• Pediatric Neurology
• Clinical Biochemistry

Background:

• Cerebrospinal fluid (CSF) total protein levels are crucial biomarkers in pediatric neurological disorders.
• Existing reference values for CSF total protein in children lack age specificity, potentially impacting diagnostic accuracy.

Purpose of the Study:

• To establish age-specific reference values for CSF total protein in pediatric populations.
• To validate these new reference values in children diagnosed with Guillain-Barré syndrome (GBS), acute disseminated encephalomyelitis (ADEM), and multiple sclerosis (MS).

Main Methods:

• Analysis of 6145 diagnostic CSF samples from 3623 children (<18 years) to define reference ranges.
• Confirmation of reference values using a subgroup of 378 children with conditions unrelated to elevated CSF protein.
• Validation of reference values in pediatric cohorts diagnosed with GBS, ADEM, and MS.

Main Results:

• Established age-specific upper limits of normal for CSF total protein: 0.25 g/L (6 months-6 years), 0.28 g/L (6-12 years), and 0.34 g/L (12-18 years).
• CSF protein levels in infants (<6 months) were highly variable (median 0.47 g/L).
• The new values identified elevated CSF protein in 85% of GBS, 66% of ADEM, and 23% of MS cases, showing higher sensitivity.

Conclusions:

• Accurate, age-specific reference values for pediatric CSF total protein have been determined.
• The newly defined reference values demonstrate increased sensitivity for diagnosing GBS and ADEM in children compared to existing standards.