W. Raber et al., Diagnostic efficacy of unconjugated plasma metanephrines for the detectionof pheochromocytoma, ARCH IN MED, 160(19), 2000, pp. 2957-2963
Citations number
18
Categorie Soggetti
General & Internal Medicine","Medical Research General Topics
Background: Recently, measurement of plasma metanephrines was suggested to
improve the detection of pheochromocytoma compared with the other common bi
ochemical tests.
Objective: To examine the diagnostic precision of measurements of plasma me
tanephrines, plasma catecholamines, and urinary catecholamines and to asses
s their variability.
Methods: Plasma metanephrine as well as plasma and urinary catecholamine co
ncentrations were measured by high-performance liquid chromatography with e
lectrochemical detection. Before surgery, responses of plasma metanephrines
and catecholamines to change of posture were determined. Intraoperatively,
metanephrines and catecholamines were measured before skin incision, durin
g maximal mechanical tumor manipulation, and repetitively after the tumor w
as separated from the circulation. Patients were reexamined 1 months after
surgery. Patients with pheochromocytoma (n=17) and with histologically prov
ed other adrenal tumors (n=14) were studied before, during, and after surge
ry.
Results: Measurement of plasma metanephrines and plasma and urinary catecho
lamines provided 100% and 82% sensitivity, respectively, for the detection
of pheochromocytoma (P<.001). Levels of plasma catecholamines but not metan
ephrines increased in response to change of posture (norepinephrine, P=.03;
epinephrine, P=.07) and intraoperative stress (norepinephrine, P=.002; epi
nephrine, P=.009).
Conclusions: Plasma metanephrines offer improved efficacy for the diagnosis
of pheochromocytoma. Less variability in response to external factors may
favor plasma metanephrines in the screening for this disease.