Radioimmunoassay of chromogranin A and free metanephrines in diagnosis of pheochromocytoma.

摘要

This work discusses the clinical performance of chromogranin A,free metanephrine and normetanephrine determination in plasmausing a radioimmunoanalytical methods for the diagnosisof pheochromocytoma and paraganglioma. Blood sampleswere collected from 55 patients (46 pheochromocytomas,9 paragangliomas). A sampling of biological materials wasperformed preoperatively and about one week, six months andone year after adrenal gland surgery. The comparative groupwithout a diagnosis of pheochromocytoma/paragangliomaconsisted of 36 pheochromocytoma/paraganglioma patients morethan 4 months after adrenal gland surgery, and of 87 patients,16 of them with multiple endocrine neoplasia, 9 with medullaryand 5 with parafolicullar carcinoma of the thyroid gland. Therest were patients with various adrenal gland disorders.Chromogranin A, metanephrine and normetanephrine weredetermined in the EDTA-plasma using a radioimmunoassay kitsCisbio Bioassays, France and IBL International GmbH, Germany.Clinical sensitivity was 96 % for the combination of metanephrineand normetanephrine, and 93 % for chromogranin A. Clinicalspecificity was 100 % for the combination metanephrine andnormetanephrine, and 96 % for chromogranin A. Falsely elevatedlevels of chromogranin A were observed in 1 patient with chronicrenal insufficiency and 9 analyses were influenced by theadministration of proton pump inhibitors. These results wereexcluded of CGA specificity. Both the combination of plasmafree metanephrine, normetanephrine and chromogranin A asdetermined by radioimmunoassays, which are simple without thenecessity of special laboratory material, are effective markers ofpheochromocytoma or paraganglioma. Chromogranin A exertsassociation to malignity and all markers are associated withtumor mass.