title: Pyridoxal 5'-phosphate values in cerebrospinal fluid: reference values and diagnosis of PNPO deficiency in paediatric patients.
abstract: Our aim was to establish reference values for cerebrospinal fluid (CSF) pyridoxal 5'-phosphate (PLP) in a paediatric population for the diagnosis of pyridox(am)ine 5'-phosphate oxidase (PNPO) deficiency. For reference values, CSF samples from 113 paediatric controls (age range: 1 day-18 years) from Barcelona and London were analysed. Cerebrospinal fluid PLP and biogenic amine concentrations were analysed by HPLC with fluorescence and electrochemical detection. Pyridoxal 5'-phosphate concentrations in 4 patients with PNPO deficiency were determined. A negative correlation between CSF PLP values and age of controls was observed in both populations (r=-0.503; p<0.0001 and r=-0.542; p=0.002). Reference values were stratified into 4 (Barcelona) and 3 age groups (London). For the newborn period, CSF PLP reference intervals were 32-78 and 44-89 nmol/L for the Barcelona and London centers, respectively). No correlation was observed in the different age groups between PLP values and biogenic amines metabolites. PLP values in neonates with PNPO deficiency were clearly decreased (PLP=3.6, 12.0, 14.0 and 18.0 nmol/L) compared with our reference ranges. In conclusion, reference values for CSF PLP should be stratified according to age. No association was observed between PLP values and biogenic amines metabolites. In our 4 cases with PNPO deficiency, CSF PLP values were clearly below the reference values.
authors.affiliation: Departments of Clinical Biochemistry and Neurology, Hospital Sant Joan de Déu and Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Passeig Sant Joan de Déu 2, 08950, Esplugues, Barcelona, Spain.
authors.forename: Aida
authors.initials: A
authors.lastname: Ormazabal
authors.forename: Marcus
authors.initials: M
authors.lastname: Oppenheim
authors.forename: Mercedes
authors.initials: M
authors.lastname: Serrano
authors.forename: Angels
authors.initials: A
authors.lastname: García-Cazorla
authors.forename: Jaume
authors.initials: J
authors.lastname: Campistol
authors.forename: Antonia
authors.initials: A
authors.lastname: Ribes
authors.forename: Angeles
authors.initials: A
authors.lastname: Ruiz
authors.forename: Juan
authors.initials: J
authors.lastname: Moreno
authors.forename: Keith
authors.initials: K
authors.lastname: Hyland
authors.forename: Peter
authors.initials: P
authors.lastname: Clayton
authors.forename: Simon
authors.initials: S
authors.lastname: Heales
authors.forename: Rafael
authors.initials: R
authors.lastname: Artuch
mesh_terms: D000293:Adolescent; D001679:Biogenic Amines / Q000134:cerebrospinal fluid; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D003677:Deficiency Diseases / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000201:enzymology* / Q000235:genetics; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011732:Pyridoxal Phosphate / Q000134:cerebrospinal fluid*; D011734:Pyridoxaminephosphate Oxidase / Q000134:cerebrospinal fluid* / Q000172:deficiency*; D012016:Reference Values; D013030:Spain; D006113:United Kingdom
chemical_list: D001679:Biogenic Amines; D011732:Pyridoxal Phosphate; D011734:Pyridoxaminephosphate Oxidase