Abstract. Background: Simultaneously determined plasma chromogranin A (CgA) and free metanephrines can substantially enrich laboratory diagnosis of.
General Endocrinology doi: 10.4183/aeb.2011.153
PLASMA VERSUS SALIVARY CHROMOGRANIN A AS SELECTIVE MARKERS IN PHEOCHROMOCYTOMA DIAGNOSIS A. M. Stefanescu1*, S. Schipor1, D. Paun1,2, C. Dumitrache1,2, C. Badiu1,2 1
Department of Endocrinology, “Carol Davila” University of Medicine and Pharmacy, Department of Endocrinology of “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania Abstract Background: Simultaneously determined plasma chromogranin A (CgA) and free metanephrines can substantially enrich laboratory diagnosis of pheochromocytoma (PHEO). CgA-like immunoreactivity was discovered in saliva. Salivary CgA (CgA-LIS) could precise PHEO diagnosis in a non-aggressive manner for the patient using saliva instead of plasma samples. Subjects and methods: A group of 10 PHEO patients: 7 women (22 to 72 years ) and 3 men (42 to 59 years) and a control group of 10 subjects were included in this retrospective study. Plasma free metanephrines and CgA were assayed by Elisa kits. Salivary CgA was assayed by an EIA kit. Both analytical and diagnosis performance of the CgA-LIS vs. CgA were compared using Passing& Bablok regression and Receiver Operating Curves (ROC analysis). Results: In tumor group, mean values for all 4 assayed parameters were significantly increased in comparison with the same parameters in normal group as expected: free plasma normetanephrines (NMNp) was: 2773 ± 704.57pg/mL versus
48.51 ± 9.87 pg/mL in controls; free plasma metanephrines (MNp) was: 864.4 ± 330.75 pg/mL versus 19.18 ± 3.69 pg/mL in normals; CgA was: 695.10±235.22 ng/mL versus 74.4±5.37 ng/mL in controls; CgALIS was: 17.62±6.79 pmol/L versus 0.94 ± 0.20 pmol/L in normals. Passing & Bablok regression equation for CgA-LIS versus CgA was: Y=0.0181 + 0.0146X. Cusum test for linearity revealed no significant deviation from linearity (P>0.10). A significant correlation between NMNp and CgA-LIS was established in all 20 subjects: r=0.82, P
