Serum chromogranin-alpha immunoradiometric assay in the diagnosis of pheochromocytoma.
BACKGROUND
The diagnosis of pheochromocytoma is based on laboratory tests that demonstrate an increase in urinary excretion of catecholamines or their metabolites. Chromogranin A (CgA) is a member of the granin family and is widely distributed in neuroendocrine cells and particularly in chromaffin adrenal cells. Consequently, serum CgA increases in patients affected by pheochromocytoma and other diseases of the chromaffin system.


OBJECTIVE
This study investigated the performance of serum CgA assay in the diagnosis of pheochromocytoma and compared serum CgA with 24-hour urinary epinephrine (E), norepinephrine (NE), vanillylmandelic acid (VMA) and metanephrines (MNs).


METHODS
We enrolled 15 patients with histologically proven pheochromocytoma; 100 healthy blood donors and 148 patients with essential hypertension were enrolled as controls. Serum CgA was assayed by a specific immunoradiometric method (IRMA). Urinary tests were done with high performance liquid chromatography (HPLC).


RESULTS
Circulating CgA showed a higher sensitivity (1.00), specificity (0.96) and accuracy (0.96) than all other tests. Serum levels of CgA clearly increased from blood donors and patients with essential hypertension to patients with pheochromocytoma (p<0.0001). Furthermore, a strong relationship between serum CgA and tumor mass was found (p<0.0001). In conclusion, our data suggest that the CgA assay might be used as a single test for the diagnosis of pheochromocytoma.
Department of Nuclear Medicine, University Hospital Ospedale di Circolo e Fondazione Macchi, Varese, Italy. lucamednuc@libero.it
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Giovanella
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Ceriani
D000310:Adrenal Gland Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000652:urine; D000328:Adult; D000368:Aged; D053379:Chromogranin A; D002864:Chromogranins / Q000097:blood*; D005260:Female; D006801:Humans; D015592:Immunoradiometric Assay; D008297:Male; D008676:Metanephrine / Q000652:urine; D008875:Middle Aged; D009638:Norepinephrine / Q000652:urine; D010673:Pheochromocytoma / Q000097:blood / Q000175:diagnosis* / Q000652:urine; D014642:Vanilmandelic Acid / Q000652:urine
D053379:Chromogranin A; D002864:Chromogranins; D008676:Metanephrine; D014642:Vanilmandelic Acid; D009638:Norepinephrine