scholarly journals In Matrix Derivatization Combined with LC-MS/MS Results in Ultrasensitive Quantification of Plasma Free Metanephrines and Catecholamines

2020 ◽  
Vol 92 (13) ◽  
pp. 9072-9078 ◽  
Author(s):  
Martijn van Faassen ◽  
Rainer Bischoff ◽  
Karin Eijkelenkamp ◽  
Wilhelmina H. A. de Jong ◽  
Claude P. van der Ley ◽  
...  
2020 ◽  
Vol 4 (3) ◽  
Author(s):  
Laura Maria Roose ◽  
Niels J Rupp ◽  
Christof Röösli ◽  
Nadejda Valcheva ◽  
Achim Weber ◽  
...  

Abstract It is estimated that up to 40% of all head and neck paragangliomas (HNPGL) have a hereditary background with the most common mutations being found in the succinate dehydrogenase (SDH) genes. SDHAF2 mutation leads to the rare paraganglioma syndrome 2. The authors present the case of a 15-year-old male patient with 2, non-secretory HNPGLs, presenting with left-sided, pulsatile tinnitus, and hearing loss. Imaging led to the suspicion of a jugulotympanic paraganglioma on the left, as well as a carotid body tumor on the right. After resection of the jugulotympanic tumor, histology confirmed the presence of a paraganglioma; immunohistochemistry furthermore suggested a loss of SDHB expression. Genetic testing revealed a rare germline, loss-of-function mutation in the SDHAF2 gene, previously described to cause hereditary paraganglioma syndrome 2. Twenty months after the first operation, the patient underwent a resection of the right carotid body paraganglioma. Plasma-free metanephrines/catecholamines always remained within the reference range; the patient is under regular follow-up, and his relatives will be screened. Our findings emphasize the relevance of genetic testing in patients with HNPGL, also with negative family history, especially when the patients present at a young age and with multiple lesions.


Author(s):  
R Casey ◽  
TP Griffin ◽  
D Wall ◽  
MC Dennedy ◽  
M Bell ◽  
...  

Background The Endocrine Society Clinical Practice Guideline on Phaeochomocytoma and Paraganglioma recommends phlebotomy for plasma-free metanephrines with patients fasted and supine using appropriately defined reference intervals. Studies have shown higher diagnostic sensitivities using these criteria. Further, with seated-sampling protocols, for result interpretation, reference intervals that do not compromise diagnostic sensitivity should be employed. Objective To determine the impact on diagnostic performance and financial cost of using supine reference intervals for result interpretation with our current plasma-free metanephrines fasted/seated-sampling protocol. Methods We conducted a retrospective cohort study of patients who underwent screening for PPGL using plasma-free metanephrines from 2009 to 2014 at Galway University Hospitals. Plasma-free metanephrines were measured using liquid chromatography-tandem mass spectrometry. Supine thresholds for plasma normetanephrine and metanephrine set at 610 pmol/L and 310 pmol/L, respectively, were used. Results A total of 183 patients were evaluated. Mean age of participants was 53.4 (±16.3) years. Five of 183 (2.7%) patients had histologically confirmed PPGL (males, n=4). Using seated reference intervals for plasma-free metanephrines, diagnostic sensitivity and specificity were 100% and 98.9%, respectively, with two false-positive cases. Application of reference intervals established in subjects supine and fasted to this cohort gave diagnostic sensitivity of 100% with specificity of 74.7%. Financial analysis of each pretesting strategy demonstrated cost-equivalence (€147.27/patient). Conclusion Our cost analysis, together with the evidence that fasted/supine-sampling for plasma-free metanephrines, offers more reliable exclusion of PPGL mandates changing our current practice. This study highlights the important advantages of standardized diagnostic protocols for plasma-free metanephrines to ensure the highest diagnostic accuracy for investigation of PPGL.


2002 ◽  
Vol 87 (5) ◽  
pp. 1955-1960 ◽  
Author(s):  
Martina Weise ◽  
Deborah P. Merke ◽  
Karel Pacak ◽  
McClellan M. Walther ◽  
Graeme Eisenhofer

2015 ◽  
Vol 62 (3) ◽  
pp. 243-250 ◽  
Author(s):  
Hye Jeong Kim ◽  
Ji In Lee ◽  
Yoon Young Cho ◽  
Soo Youn Lee ◽  
Jung Han Kim ◽  
...  

Pathology ◽  
2009 ◽  
Vol 41 (2) ◽  
pp. 173-177 ◽  
Author(s):  
Peter E. Hickman ◽  
Michelle Leong ◽  
Julia Chang ◽  
Susan R. Wilson ◽  
Brett McWhinney

2020 ◽  
Vol 30 (2) ◽  
pp. 325-330
Author(s):  
Caroline M Joyce ◽  
Audrey Melvin ◽  
Paula M O’Shea ◽  
Seán J Costelloe ◽  
Domhnall J O’Halloran

Plasma free metanephrines or urinary fractionated metanephrines are the biochemical tests of choice for the diagnosis of pheochromocytoma as they have greater sensitivity and specificity than catecholamines for pheochromocytoma detection. This case highlights the preanalytical factors which can influence metanephrine measurement and cause a false positive result. It describes a patient with a high pre-test probability of pheochromocytoma due to hypertension and a past medical history of adrenalectomy for a purported pheochromocytoma in her home country. When biochemical screening revealed grossly elevated urine normetanephrine in the presence of a previously identified right adrenal lesion, there was high clinical suspicion of a pheochromocytoma. However, functional imaging did not support this view which prompted additional testing with plasma metanephrines. Results for plasma and urine metanephrines were discordant and preanalytical drug interference was suspected. Patient medications were reviewed and sulfasalazine, an anti-inflammatory drug was identified as the most likely analytical interferent. Urinary fractionated metanephrines were re-analysed using liquid chromatography tandem mass spectrometry (LC-MS/MS) and all metanephrines were within their reference intervals. This case illustrates how method-specific analytical drug interference prompted unnecessary expensive imaging, heightened patient anxiety and resulted in lengthy investigations for what turned out to be a phantom pheochromocytoma.


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