We agree strongly with the comment of Wong et al1 that cerebrospinal fluid (CSF) protein concentration is age dependent and that neonates have higher CSF protein values than older children. In an analogous study we examined CSF obtained by nontraumatic lumbar puncture from 63 full-term neonates (aged 0-4 weeks) who were evaluated for sepsis or meningitis.2 Of them, 38 with no sepsis or meningitis (bacterial or aseptic) and an uneventful clinical course were considered "healthy." The mean (range) CSF protein concentration in these healthy neonates was 0.49 g/L (0.25-0.82 g/L), similar to the concentration reported by Wong et al.
Anagnostakis D, Mandyla H, Damianos D. Cerebrospinal Fluid Protein Concentration in Full-Term Neonates. Arch Pediatr Adolesc Med. 2001;155(5):618-619. doi:10.1001/archpedi.155.5.618