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Timo Deutschbein, Nicole Unger, Jakob Hinrichs, Martin K Walz, Klaus Mann and Stephan Petersenn

Objective

In patients with adrenal incidentalomas, hormonally active masses need to be considered, particularly cortisol-producing adenomas (CPA), aldosterone-producing adenomas, and pheochromocytomas. The screening for hypercortisolism relies on confirming excess cortisol secretion and insufficient suppression after dexamethasone. Because of its high correlation with free cortisol and its stress-free collection, salivary cortisol (SaC) may offer advantages over serum cortisol (SeC). We evaluated the value of SaC and SeC for the diagnosis of CPA.

Design

Comparative study between 2001 and 2006.

Methods

Thirty-eight patients with confirmed CPA were compared with 18 healthy subjects as well as 48 control patients suffering from aldosterone-producing adenomas (n=13), pheochromocytomas (n=16), or nonfunctioning adenomas (n=19). Sampling of saliva and serum was performed at 2300 and at 0800 h following low-dose dexamethasone suppression. Receiver operating characteristics analysis was used to calculate thresholds with at least 95% sensitivity for CPA.

Results

Regarding the cutoffs for late-night cortisol, SaC (4.8 nmol/l, sensitivity 97%, specificity 69%) was slightly more specific than SeC (115 nmol/l, sensitivity 97%, specificity 63%). In contrast, the cutoff for dexamethasone-suppressed SaC (3.7 nmol/l, sensitivity 97%, specificity 83%) was slightly less specific than SeC (94 nmol/l, sensitivity 97%, specificity 88%). However, the latter cutoffs demonstrated greater specificity when compared with the cutoffs for late-night cortisol.

Conclusion

The diagnostic accuracy of SaC is as good as SeC. Owing to its higher specificity, dexamethasone-suppressed cortisol is preferable to late-night cortisol when screening for Cushing's syndrome in patients with adrenal incidentalomas.

Free access

Timo Deutschbein, Martina Broecker-Preuss, Jörg Flitsch, Andrea Jaeger, Ricarda Althoff, Martin K Walz, Klaus Mann and Stephan Petersenn

Background

Salivary cortisol is increasingly used to assess patients with suspected hypo- and hypercortisolism. This study established disease-specific reference ranges for an automated electrochemiluminescence immunoassay (ECLIA).

Methods

Unstimulated saliva from 62 patients with hypothalamic–pituitary disease was collected at 0800 h. A peak serum cortisol level below 500 nmol/l during the insulin tolerance test (ITT) was used to identify hypocortisolism. Receiver-operating characteristic (ROC) analysis allowed establishment of lower and upper cutoffs with at least 95% specificity for adrenal insufficiency and adrenal sufficiency. Saliva from 40 patients with confirmed hypercortisolism, 45 patients with various adrenal masses, and 115 healthy subjects was sampled at 2300 h and after low-dose dexamethasone suppression at 0800 h. ROC analysis was used to calculate thresholds with at least 95% sensitivity for hypercortisolism. Salivary cortisol was measured with an automated ECLIA.

Results

When screening for secondary adrenal insufficiency, a lower cutoff of 3.2 nmol/l and an upper cutoff of 13.2 nmol/l for unstimulated salivary cortisol allowed a highly specific diagnosis (i.e. similar to the ITT result) in 26% of patients. For identification of hypercortisolism, cutoffs of 6.1 nmol/l (sensitivity 95%, specificity 91%, area under the curve (AUC) 0.97) and 2.0 nmol/l (sensitivity 97%, specificity 86%, AUC 0.97) were established for salivary cortisol at 2300 h and for dexamethasone-suppressed salivary cortisol at 0800 h.

Conclusions

The newly established thresholds facilitated initial screening for secondary adrenal insufficiency and allowed excellent identification of hypercortisolism. Measurement by an automated immunoassay will allow broader use of salivary cortisol as a diagnostic tool.

Free access

Nicole Unger, Christian Pitt, Ingo Lopez Schmidt, Martin K Walz, Kurt W Schmid, Thomas Philipp, Klaus Mann and Stephan Petersenn

Objective: Pheochromocytomas are neoplasms generally characterized by the autonomous production of catecholamines. This study compared various biochemical parameters for the diagnosis of adrenal pheochromocytoma in patients with adrenal mass.

Design: One hundred and fifty subjects were studied, including 24 histologically proven pheochromocytomas, 17 aldosterone-secreting and 21 cortisol-secreting adrenal adenomas and 30 nonfunctioning adrenal masses, 16 patients with essential hypertension and 42 healthy normotensive volunteers. Spontaneous blood samples and 24-h urine samples were collected prospectively.

Methods: Plasma and urinary epinephrine and norepinephrine levels were measured by high performance liquid chromatography, whereas plasma and urinary metanephrine and normetanephrine levels were determined by radioimmunoassay (RIA). Putative ratio thresholds were calculated by receiver operating characteristic (ROC) analysis to balance between sensitivity and specificity.

Results: Plasma normetanephrine was found to be the best single parameter with the highest sensitivity (91.7%) and specificity (95.6%) using a threshold of 126 pg/ml. In combination, plasma normetanephrine and metanephrine had a higher sensitivity of 95.8% with lower specificity (79.4%). All other combinations of plasma and/or urinary parameters demonstrated a lower accuracy.

Conclusion: Plasma metanephrines measured by RIA are reliable screening parameters for the diagnosis of pheochromocytoma.

Restricted access

Ravi Kumar Dutta, Thomas Arnesen, Anette Heie, Martin Walz, Piero Alesina, Peter Söderkvist and Oliver Gimm

Objective

To screen for CLCN2 mutations in apparently sporadic cases of aldosterone-producing adenomas (APAs).

Description

Recently, CLCN2, encoding for the voltage-gated chloride channel protein 2 (ClC-2), was identified to be mutated in familial hyperaldosteronism II (FH II). So far, somatic mutations in CLCN2 have not been reported in sporadic cases of APAs. We screened 80 apparently sporadic APAs for mutations in CLCN2. One somatic mutation was identified at p.Gly24Asp in CLCN2. The male patient had a small adenoma in size but high aldosterone levels preoperatively. Postoperatively, the patient had normal aldosterone levels and was clinically cured.

Conclusion

In this study, we identified a CLCN2 mutation in a sporadic APA comprising about 1% of all APAs investigated. This mutation was complementary to mutations in other susceptibility genes for sporadic APAs and may thus be a driving mutation in APA formation.