We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
LGC Clinical Diagnostics

Download Mobile App




Events

09 Apr 2024 - 12 Apr 2024
15 Apr 2024 - 17 Apr 2024
23 Apr 2024 - 26 Apr 2024

Chromaffin Cell Tumors Diagnosed by Plasma Panel

By LabMedica International staff writers
Posted on 19 Nov 2018
Print article
Image: The AB Sciex QTRAP 5500 triple quadrupole mass spectrometer (Photo courtesy of Sciex).
Image: The AB Sciex QTRAP 5500 triple quadrupole mass spectrometer (Photo courtesy of Sciex).
Pheochromocytomas and paragangliomas include adrenal and extraadrenal chromaffin cell tumors as well as head and neck paragangliomas and measurements of plasma or urinary metanephrines are recommended for diagnosis of pheochromocytoma and paraganglioma (PPGL).

Current clinical practice guidelines stipulate with a high level of evidence that biochemical screening for PPGLs should include measurements of plasma free or urinary fractionated metanephrines that is normetanephrine and metanephrine, with no recommendation concerning preference of either test.

An international team of scientists led by those at Technische Universität Dresden (Dresden, Germany) screened a study population included 2,056 patients (1,011 male) with a median age of 53 years (range, 10–93 years) for PPGLs. A reference population of 351 normotensive (132 male) and 239 hypertensive (129 male) volunteers with a median age of 42 years (range, 18–82 years) was also included for establishing reference intervals.

Blood samples collected into heparinized tubes were placed on ice or cool pads at 4 °C before centrifugation to separate plasma. On the final day of collection, 24-hour urine specimens were returned to study centers. Urine volumes were then determined and samples aliquoted. Measurements of plasma and urinary metanephrines (normetanephrine, metanephrine) and methoxytyramine were performed at a single laboratory using liquid chromatography tandem mass spectrometry (LC-MS/MS), with a AB Sciex QTRAP 5500 triple quadrupole mass spectrometer.

The scientists reported that measurements of plasma free metabolites offered higher diagnostic sensitivity (97.9%) than urinary free (93.4%) and deconjugated (92.9%) metabolites at identical specificities for plasma and urinary free metabolites (94.2%) but at a lower specificity for deconjugated metabolites (92.1%). The addition of methoxytyramine offered little value for urinary panels, but provided higher diagnostic performance for plasma measurements than either urinary panel according to areas under ROC curves. Diagnostic performance of urinary and plasma tests was similar for patients at low risk of disease, whereas plasma measurements were superior to both urinary panels for high-risk patients.

The authors concluded that the diagnosis of PPGLs using plasma or urinary free metabolites provides advantages of fewer false-positive results compared with commonly measured deconjugated metabolites. The plasma panel offers better diagnostic performance than either urinary panel for patients at high risk of disease and, with appropriate preanalytics, provides the test of choice. Measurements of methoxytyramine in urine show limited diagnostic utility compared with plasma. The study was published in the October 2018 issue of the journal Clinical Chemistry.

Related Links:
Technische Universität Dresden

Platinum Member
COVID-19 Rapid Test
OSOM COVID-19 Antigen Rapid Test
HLX
POCT Fluorescent Immunoassay Analyzer
FIA Go
New
Gold Member
Plasma Control
Plasma Control Level 1

Print article

Channels

Molecular Diagnostics

view channel
Image: MOF materials efficiently enrich cfDNA and cfRNA in blood through simple operational process (Photo courtesy of Science China Press)

Blood Circulating Nucleic Acid Enrichment Technique Enables Non-Invasive Liver Cancer Diagnosis

The ability to diagnose diseases early can significantly enhance the effectiveness of clinical treatments and improve survival rates. One promising approach for non-invasive early diagnosis is the use... Read more

Hematology

view channel
Image: The low-cost portable device rapidly identifies chemotherapy patients at risk of sepsis (Photo courtesy of 52North Health)

POC Finger-Prick Blood Test Determines Risk of Neutropenic Sepsis in Patients Undergoing Chemotherapy

Neutropenia, a decrease in neutrophils (a type of white blood cell crucial for fighting infections), is a frequent side effect of certain cancer treatments. This condition elevates the risk of infections,... Read more

Pathology

view channel
Image: The OvaCis Rapid Test discriminates benign from malignant epithelial ovarian cysts (Photo courtesy of INEX)

Intra-Operative POC Device Distinguishes Between Benign and Malignant Ovarian Cysts within 15 Minutes

Ovarian cysts represent a significant health issue for women globally, with up to 10% experiencing this condition at some point in their lives. These cysts form when fluid collects within a thin membrane... Read more
Copyright © 2000-2024 Globetech Media. All rights reserved.