Establishment of a paediatric age-related reference interval for the measurement of urinary total fractionated metanephrines.

Abstract

Normetanephrine and metanephrine are intermediate metabolites of noradrenaline and adrenaline metabolism. To assess whether normetanephrine and metanephrine analysis may aid in the diagnosis of Neuroblastoma, a reference interval for these metabolites must first be established.

The overall aim of this study was to establish a paediatric age-related reference interval for the measurement of total fractionated metanephrines.

A total of 267 urine samples were analysed following acid hydrolysis. This releases the metanephrines from their sulphate-bound metabolites. The samples were analysed using reverse phase high-performance liquid chromatography with electro-chemical detection on a Gilson automated sequential trace enrichment of dialysate sample system.

Data were analysed using Minitab Release version 14. Outliers were removed using the Dixon/Reed one-third rule. Partitioning of the age groups was achieved using Harris and Boyd's standard normal deviate test. Non-parametric analysis of the data was performed, followed by the establishment of the 2.5th and the 97.5th reference limits.

The established reference intervals are described in Table 2.