Cerebrospinal fluid IgG in childhood: the establishment of reference values.

A retrospective analysis of quantitative and qualitative immunoglobulin G (IgG) results from 253 children who were either medically and neurologically normal or highly unlikely to have abnormalities of CSF IgG is reported. Normal values in this reference population vary with age for CSF/albumin IgG ratio and CSF/serum IgG index and are significantly different from the adult reference values. The rate of false positivity is lower for quantitative values than for qualitative IgG determinations (oligoclonal bands).