Diagnostic value of free plasma metanephrines for pheochromocytoma / 中华检验医学杂志

ABSTRACT

Objective To investigate the application value of free plasma metanephrines metanephrine(MN) and normetanephrine (NM) measured with enzyme immunoassay (EIA), NM in diagnosis of pheochromocytoma. Methods Histologically confirmed pheochromocytomas (n=30) and control patients with hypertension (n=51) were enrolled in the study. Blood tests for free plasma metanephrines(MN and NM) were performed with a commercially available EIA kit and the results were compared with [3] I-metaiedobenzyl guanidine (MIBG) whole body scan findings. Results The whole body scan was positive in all pheochromocytoma patients and negative in 15 control patients with 100% accuracy. The median values in the 2 groups were 59.3 ng/L and 33.7 ng/L (Z=-2. 440, P<0.05) for MN, 652.0 ng/L and 36. 3 ng/L (Z=-6.699, P<0.001) for NM, with 96. 7% (29/30) sensitivity, 86. 3% (44/51)specificity and 90.1% (73/81) accuracy for their combination ( either or both positive). There was no significantly statistical difference when compared with 13I-MIBG whole body scan findings (100. 0% ,P >0. 05). Conclusion The results show that the EIA method may be eligible as an alternative to HPLC for plasma metanephrines determination in the identification of pheochromocytoma.