Clinical Significance:
The ISI plasma 5-HIAA assay correlates well with the 24-hour urinary 5-HIAA assays. This test has been clinically validated for NETS patients who previously relied on the 24-hour urinary 5-HIAA. The plasma 5-HIAA saves time, alleviates the need to collect urine in a container for 24 hours, and provides equivalent clinical information.
Reference Range:
Up to 22 ng/mL
Procedure:
5-HIAA plasma is measured by GC-MS/MS.
Patient Preparation:
Patient should fast overnight prior to collection of specimen.
Specimen Collection:
Collect 10mL blood directly into ISI’s Z-tubeTM Preservative and separate as soon as possible. Freeze plasma immediately after separation. Special Z-tubeTM Preservatives are available from ISI. Minimum specimen size is 1mL. Note: one Z-tubeTM may be shared for up to three tests. After centrifuging tube, aliqout 1mL per test in separate vials, mark with name of test and freeze.
Important Precaution:
Specimens for this assay must be collected using ISI’s Z-tubeTM. Specimens must be shipped frozen; specimens are not stable refrigerated or ambient. No substitute preservatives are acceptable.
Special Specimens:
*Frozen Z-tubeTM plasma is the only acceptable sample type for this assay.
Shipping Instructions:
Ship specimens frozen in dry ice.
References:
1. Tellez MR, Mamikunian G, O’Dorisio TM et al. A single fasting plasma 5-HIAA value correlates with 24-hour urinary 5-HIAA values and other biomarkers in midgut neuroendocrine tumors (NETs). Pancreas. 2013:42(3): 405-410.
2. Cai H-L, Zhu R-H, Li H-D, et al. MultiSimplex optimization of chromatographic separation and dansyl derivatization conditions in the ultra performance liquid chromatography-tandem mass spectrometry analysis of neurotransmitters in human urine. J Chromato B 2011;879:1993-1999.
3. Gonzalez RR, Fernandez RF, Vidal JLM et al. Development and validation of an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous determination of neurotransmitters in rat brain samples. J Neuro Meth 2011;198: 187-194.
4. Stephanson N, Helander A, Beck O. Alcohol biomarker analysis: simultaneous determination of 5-hydroxytryptophol glucuronide and 5-hydroxyindoleacetic acid by direct injection of urine using ultra-performance liquid chromatographytandem mass spectrometry. J Mass Spect 2007;42: 940-949.