Reference interval for urinary catecholamines and methylated catecholamines analysed using HPLC
Catecholamines are stress hormones that are produced and released by a rare tumor called pheochromocytoma. This tumor can cause hypertension which if undiagnosed and untreated leads to death. Since good therapy is available, it is important to find the tumor in time. The most common way to diagnose the tumor is measurement of the biochemical markers; catecholamines and their metabolites, methylated catecholamines.After observation that almost all normetanephrine results for women were higher than the upper reference limit and therefore pathological, the accuracy of the present reference intervals was questioned. Therefore new reference intervals for both urinary catecholamines and methylated catecholamines were developed by analysis of 46 samples using HPLC. Creatinine was analysed in acidified urine in order to see if the results became the same as when analysed in non-acidified urine.Urinary catecholamines and methylated catecholamines were analysed using HPLC. Comparison between measurement of creatinine in acidified urine and non-acidified urine with an enzymatic method was performed using Architect ci 8200, Abbott.As suspected, there was a difference between the present and new intervals. Therefore the new intervals will be used for future diagnosis. There was no difference between the two treatments of creatinine samples wherefore it can be measured in both.In conclusion reference intervals determind in this study will be used and it was shown that creatinine can be measured in acidified urine.