Cerebrospinal Fluid Protein Concentrations in Children: Age-related Values in Patients without Disorders of the Central Nervous System

Abstract

The published reference values for cerebrospinal fluid (CSF) total protein concentrations in children suffer from two major drawbacks: (a) the age-related range often is too broad when applied to the steeply falling concentrations in early infancy; and (b) no values have been published for widely used dry chemistry methods. We conducted a 2-year retrospective survey of CSF results obtained in a children's hospital with a dry chemistry-based method set up on the Vitros 700 analyzer. The data related to ambulatory children up to 16 years of age and term neonates with no clinical or biological signs of brain disease (n = 1074). Seven age groups with significantly different CSF protein values were identified, and their age-related percentiles (5th, 50th, and 95th) were determined. On the basis of the upper 95th percentile, from age 0 to 6 months the CSF protein concentrations fell rapidly from 1.08 to 0.40 g/L. A plateau (0.32 g/L) was reached from age 6 months to 10 years, followed by a slight increase (0.41 g/L) in the 10-16 years age range. These results imply that CSF total protein concentrations in the pediatric setting, particularly in infants, must always be interpreted with regard to narrow age-related reference values to avoid false-positive results.