Reference Values for Urinary HMMA, HVA, Noradrenaline, Adrenaline, and Dopamine Excretion in Children Using Random Urine Samples and HPLC with Electrochemical Detection

Abstract

SUMMARY. Random urine samples were collected from 305 children aged from birth to 14 years and the values of hydroxymethoxymandelic acid, homovanillic acid, noradrenaline, adrenaline, and dopamine were measured by high-performance liquid chromatography with electrochemical detection. The results were reported relative to the urinary creatinine concentration and the values declined progressively with increasing age for each analyte with the exception of adrenaline. The results for each age group were not normally distributed and all values except outliers were retained in determining the upper reference limits. Additional key phrases: catecholamines; vanillylmandelic acidIn children, the urinary excretion of biogenic amines and their metabolites increases with agel but when these values are related to the urinary creatinine excretion the relative values decrease.P Changing reference values are particularly important in the diagnosis of tumours such as neuroblastoma, 750/0 of which occur before the age of 4 years. The validity and convenience of random urine samples for these analytes has been accepted.v? Relating excretion to urinary creatinine which is produced at a constant rate minimizes the differences in children of similar ages due to size or sex," although this is controversial." Taking daytime samples minimizes the influence of diurnal variation. 1In neuroectodermal tumours, the pattern of urinary excretion of amines and their metabolites varies widely and dopamine as well as the adrenaline and noradrenaline pathways should be assessed to maximize the sensitivity of the biochemical test. 8.9 Recently reported data from the European Neuroblastoma Study Group concluded that the screening of infants using urinary hydroxymethoxymandelic acid (HMMA) and homovanillic acid (HV A) The widely differing published reference values for the excretion of catecholamines and their metabolites reflect the diversity of analytical methods and data manipulations used. Reports from the United Kingdom External Quality Assessment Scheme (UKEQAS) for urinary catecholamines confirm the continuing large variation in laboratory analytical performance. With increasing interest in screening programmes aimed at improving the detection rate of neuroblastoma, and hopefully the prognosis, the importance of establishing detailed reference ranges cannot be overstated. Thus we report our age and creatinine related upper reference limits for urinary adrenaline, noradrenaline, dopamine, HMMA, and HVA using high-performance liquid chromatography (HPLC) with electrochemical (EC) detection. MATERIALS AND METHODSRandom urine samples were collected from 305 well children. These included 198 attending orthopaedic outpatient clinics, 44 from a general practice age register, 33 from neonatal and 6 week post partum routine hospital baby checks and 30 from a daycare nursery. All specimens were collected during the normal working day.

Age-related medical decision limits for urinary free (unconjugated) metadrenalines, catecholamines and metabolites in random urine specimens from children

“…Validation of medical decision limits was achieved by comparison of the observed ranges with our pre-existing limits for NA, AD, DA, VMA and HVA, which were based on the work of Dr Fitzgibbon and her colleagues 14,22 using random urine specimens collected from 305 well children divided into the same age ranges. Furthermore, for all the analytes, comparisons were made with the results from: (a) 55 patients harbouring neuroblastic tumours (neuroblastoma, ganglioneuroblastoma, ganglioneuroma) on specimens obtained at time of diagnosis; and (b) with the results from 11 patients presenting in childhood with phaeochromocytoma or paraganglioma again on specimens obtained at time of diagnosis.…”

Reference intervals for urinary catecholamines and metabolites from birth to adulthood

“…Most of them have been determined decades ago with out-dated analytical methods and therefore may not be appropriate for the interpretation of results obtained from current clinical laboratory instrumentation [4,5,[10][11][12]. Today, high performance liquid chromatography with electrochemical detection (HPLC-EC) represents the gold method for the determination of free catecholamines, total metanephrines, vanillylmandelic (VMA) and homovanillic (HVA) acids [2,[6][7][8][9]13]. More recently, commercial kits have been developed to improve the standardization between laboratories of the extraction and chromatographic steps, but without up-dating paediatric normal values.…”

Laboratory Evaluation of Pheochromocytoma and Paraganglioma

“…Due to difficulties in obtaining complete 24-h collections, urine samples from children are most commonly collected as spot urines with outputs of metanephrines normalized to creatinine. In contrast to 24-h samples, which show age-dependent increases in outputs of metanephrines (39 ), when samples are normalized to creatinine the reverse is observed (40 -42 ). This appears to reflect dependence of creatinine on total muscle mass, which is also higher in males than females, so that sex differences in 24-h urine outputs can disappear or even be reversed when normalized to creatinine.…”