October - December 2011, Volume 7, Issue 4

Stefanescu AM, Schipor S, Paun D, Dumitrache C, Badiu CV

Salivary Free Catecholamines Metabolites as Possbile Biochemical Markers in Pheochromocytoma Diagnosis

Acta Endo (Buc) 2011, 7 (4): 431-439
doi: 10.4183/aeb.2011.431

Background: Salivary monitoring of hormone levels has many advantages over the more conventional serum/plasma analysis. Salivary free metanephrines (MN) and normetanephrines (NMN) could precise biochemical diagnosis of pheochromocytoma (PHEO) as an alternative to plasma metabolites.\r\nSubjects and methods: The prospective case-control study included a group of 30 patients confirmed with PHEO an age-matched control group of 70 normotensive subjects. The PHEO diagnosis was suspected on clinical ground and confirmed by imaging studies and classical neuroendocrine markers. Free plasma and salivary NMN and MN were assayed using enzyme immunoassay for both metabolites.\r\nResults: In tumor cases all metabolites were increased. As expected, values for all 4 parameters (mean?SEM) differed significantly in tumor group vs. normal group: free plasma\r\nnormetanephrines (NMNp): 1514.16 ? 282.97 pg/mL vs 47.82?2.52 pg/mL; free salivary normetanephrines (NMNs):\r\n663.63?168.47 pg/mL vs 44.98? 2.47 pg/mL; free plasma metanephrines (MNp): 445.20 ? 99.92 pg/mL vs 18.87?1.03\r\npg/mL; free salivary metanephrines (MNs):206.60?91.48 pg/mL vs 14.47?0.72 pg/mL with significant correlations in all\r\n100 subjects. Passing & Bablok regression showed no significant deviation from linearity in Elisa assay of NMNs vs NMNp; a significant deviation from linearity existed\r\nin Elisa assay of MNs vs MNp. Cut-off values, sensitivity and specificity for all 4 parameters were calculated by ROC\r\nanalysis. Plasma and salivary normetanephrines proved similar sensitivity (100%) and specificity (100%). Pairwise\r\ncomparison of ROC curves areas showed no significant differences between NMNp vs NMNs and MNp vs MNs. Ten cases were investigated post-surgery. All 4 parameters\r\nshowed no significant differences vs. control group.\r\nConclusions: Salivary free normetanephrines could be used as a nonstressful marker for diagnosis purpose in pheochromocytoma proving similar sensitivity and specificity as plasma free normetanephrines.

Keywords: pheochromocytoma, free normetanephrines, free metanephrines,\r\nELISA, salivary hormones

Correspondence: Ana-Maria Stefanescu PhD, “C.I.Parhon” National Institute of Endocrinology, 34-36 Aviatorilor Blvd., 011863, Bucharest, Romania, Tel:+40213172041 ext 170, Fax: +4021- 3170607 ; E-mail: stefanescuam@yahoo.com