April - June 2011, Volume 7, Issue 2

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

Plasma versus Salivary Chromogranin A as Selective Markers in Pheochromocytoma Diagnosis

Acta Endo (Buc) 2011, 7 (2): 153-161
doi: 10.4183/aeb.2011.153

Background: Simultaneously determined plasma chromogranin A (CgA) and free metanephrines can substantially enrich laboratory diagnosis of pheochromocytoma (PHEO). CgA-like\r\nimmunoreactivity was discovered in saliva. Salivary CgA (CgA-LIS) could precise PHEO diagnosis in a non-aggressive\r\nmanner for the patient using saliva instead of plasma samples.\r\nSubjects and methods: A group of 10 PHEO patients: 7 women (22 to 72 years ) and 3 men (42 to 59 years) and a control\r\ngroup of 10 subjects were included in this retrospective study. Plasma free metanephrines and CgA were assayed by\r\nElisa 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).\r\nResults: In tumor group, mean values for all 4 assayed parameters were significantly increased in comparison with\r\nthe 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 ?\r\n0.20 pmol/L in normals. Passing & Bablok regression equation for CgA-LIS versus CgA was: Y=0.0181 + 0.0146X. Cusum test\r\nfor 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<0.0001. Pairwise comparison of ROC curves for both markers showed no significant difference between areas. Salivary CgA could be successfully used instead of plasma CgA in biochemical diagnosis of pheochromocytoma.\r\nConclusions: We can conclude that salivary CgA could be used as a nonstressfull marker for diagnosis purpose in pheochromocytoma.

Keywords: chromogranin A, free plasma normetanephrines, free plasma\r\nmetanephrines

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