Impairment of 11 beta-hydroxylase but not 21-hydroxylase in adrenal 'incidentalomas'

Decreased steroidogenic enzyme activity in benign adrenocortical tumors is more pronounced in bilateral lesions as determined by steroid profiling in LC-MS/MS during ACTH stimulation test

Objective

Large response of steroid precursors, including 17-hydroxyprogesterone, to adrenocorticotropic hormone (ACTH) has been described in adrenocortical tumors, suggesting the existence of intra-tumoral enzymatic deficiencies. This study aimed to compare steroidogenesis enzymes activity in unilateral and bilateral benign tumors using serum steroid profiling in liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) in the basal state and after ACTH 1-24 stimulation.

Design and methods

A serum profile of seven consecutive adrenal steroids was determined in LC-MS/MS in the basal state (T0) and after ACTH 1-24 stimulation (T60) in 35 patients with bilateral adrenocortical tumors (BL), 38 patients with unilateral tumors (UL) and 37 control subjects (CT). Response amplitude of each individual steroid was evaluated by T60/T0 ratio, whereas enzymatic activity was assessed by the downstream/upstream steroid ratio. Adrenal volume was quantified by a semi-automatic segmentation method.

Results

For the seven steroids assayed, the amplitude of response to ACTH was higher in BL than in UL and in CT. The difference between BL and UL persisted even after matching patients on adrenal volume. On glucocorticoids pathway, enzymatic activity of CYP11B1 was significantly decreased in BL (78.3 (43.1-199.4)) in comparison to both UL (122.7 (13.8-228.4), P = 0.0002) and CT (186.8 (42.1-1236.3), P < 0.0001). On mineralocorticoids and androgens pathways, the enzymatic activity of CYP11B2 and CYP17A1-17,20 lyase was also lower in BL than UL and CT.

Conclusions

Decreased activity of distal steroidogenesis enzymes CYP11B1, CYP11B2 and CYP17A1-17,20 lyase, responsible for an explosive response to ACTH of upstream precursors in bilateral tumors, limits the synthesis of bioactive steroids, in particular cortisol, despite the increase in adrenal mass.

Significance statement

Activity of distal steroidogenesis enzymes (CYP11B1, CYP11B2 and CYP17A1 on glucocorticoids, mineralocorticoids and androgens pathways, respectively) is decreased in adrenocortical benign tumors. This decrease is more pronounced in bilateral lesions and seems to depend more on the nature of the lesion than on the increase in adrenal volume. It is responsible for the explosive response to ACTH of steroid precursors located upstream of these enzymes. It probably allows bioactive steroids, particularly cortisol, to stay in the normal range for a long time despite the increase in adrenal mass.

Steroidogenesis in patients with adrenal incidentalomas: Extended steroid profile measured by liquid chromatography-mass spectrometry after ACTH stimulation and dexamethasone suppression

OBJECTIVE

Describe the secretion and profile of adrenal steroids in patients with adrenal incidentalomas compared to control subjects.

DESIGN, SETTING AND PARTICIPANTS

A prospective study, 73 patients with adrenal incidentalomas, 21 bilateral and 52 unilateral and 34 matched controls in University Hospital.

METHODS

Collect fasting blood sample before and 60 min after ACTH test (250 µg IV). One week later, perform overnight 1 mg dexamethasone test. The following steroids were measured by liquid chromatography-mass spectrometry (LC-MS): pregnenolone, 17-OH pregnenolone, 17-OH progesterone, 11-deoxycorticosterone, 11-deoxyortisol, 21-deoxycortisol, corticosterone, cortisol, androstenedione and aldosterone.

RESULTS

Mean baseline serum cortisol was higher in incidentalomas, bilateral 361 ± 124, (range 143-665) nmol/L,(p < .0001), unilateral 268 ± 89 3.2 (range 98-507) nmol/L (p < .019) compared to controls 207 ± 100 (range 72-502) nmol/L. ACTH stimulation showed significantly higher levels in bilateral and unilateral cases compared to controls. After dexamethasone, mean serum cortisol levels suppressed in bilaterals 89 ± 69 (range 30-3) nmol/L (p < .0001), 58 ± 52 (range 16-323) nmol/L in unilateral (p < .01) compared to 26 ± 9 (range 7-46) nmol/L in controls. Mean baseline serum corticosterone was higher in bilateral 9.3 ± 4.8 (range 2.4-18.4) nmol/L (p < .005) and unilateral 7.3 ± 5.7 (range 0.1-30.3) nmol/L (p < .01) compared to controls 4.2 ± 2.4 (range 1.1-10.2) nmol/L, after ACTH stimulation significantly increased to higher levels in bilateral (p < .0002) and unilateral cases (p < .044) compared to controls. After dexamethasone, mean levels were 2.5 ± 2.6 (range 0.5-12.5) nmol/L in bilateral (p < .0006), 1.5 ± 1.6 (range 0.3-9.3) nmol/L in unilateral (p < .09) and 0.75 ± 0.46 (range 0.1-2.1) nmol/L in controls. Mean baseline serum 11-deoxycorticosterone (DOC) was higher in bilaterals 0.32 ± 0.23 (range 0.08-1.1) nmol/L (p < .03) compared to controls 0.15 ± 0.21 (range 0.08-1.1) nmol/L. ACTH stimulation increased levels to 3.27 ± 1.72 (range 0.5-7.4) nmol/L in bilateral cases compared to controls 1.369 ± 1.53 (range 0.1-7.1) nmol/L (p < .0001). Dexamethasone decreased levels to baseline (p ns). There were significant differences in serum 21-deoxycortisol (p < .0002) and serum pregnenolone (p < .004) only after ACTH stimulation.

CONCLUSIONS

There is increased activity in several steroid biosynthesis pathways and higher steroid levels in bilateral compared to unilateral cases and evidence of hypercortisolism in 30% unilateral and 62% of bilateral incidentalomas.

Cardiovascular complications of mild autonomous cortisol secretion

Adrenal incidentalomas (AI) may be associated with a mild autonomous cortisol secretion (MACS) in up to one third of cases. There is growing evidence that MACS patients actually present increased risk of cardiovascular disease and higher mortality rate, driven by increased prevalence of known cardiovascular risk factors, as well as accelerated cardiovascular remodelling. Adrenalectomy seems to have cardiometabolic beneficial effects in MACS patients but their management is still a debated topic due to the lack of high-quality studies. Several studies suggested that so called "non-functioning" AI may be actually "functioning" with an associated increased cardiovascular risk. Although the individual cortisol sensitivity and peripheral activation have been recently suggested to play a role in influencing the cardiovascular risk even in apparently eucortisolemic patients, to date the degree of cortisol secretion, as mirrored by the cortisol levels after dexamethasone suppression test remains the best predictor of an increased cardiovascular risk in AI patients. However, whether or not the currently used cut-off set at 50 nmol/L for cortisol levels after dexamethasone suppression could be considered completely reliable in ruling out hypercortisolism remains unclear.

Defining Nonfunctioning Adrenal Adenomas on the Basis of the Occurrence of Hypocortisolism after Adrenalectomy

Background

In patients with adrenal incidentalomas (AIs), there is uncertainty on how to rule out hypercortisolism. The occurrence of postsurgical (unilateral adrenalectomy) hypocortisolism (PSH) has been proposed as a proof of the presence of presurgical hypercortisolism in AI patients. The aim of this study was to define the thresholds of cortisol level after the 1 mg overnight dexamethasone suppression test (F-1mgDST), urinary free cortisol (UFC), midnight serum cortisol (MSC), and adrenocorticotropin (ACTH) to predict the absence of PSH in AI patients undergoing surgery.

Methods

In 60 patients who underwent AI excision, cortisol secretion was assessed by a low-dose corticotropin stimulation test or insulin tolerance test when needed. We searched for the lowest presurgical value of F-1mgDST, UFC, and MSC and the highest value for ACTH in AI patients with PSH as indexes of normal cortisol secretion.

Results

The lowest values of F-1mgDST, UFC, and MSC and the highest value for ACTH in PSH patients were 1.2 µg/dL (33 nmol/L), 10.4 µg/24 hours (29 nmol/24 hours), 1.2 µg/dL (33 nmol/L), and 26.9 pg/mL (6 pmol/L), respectively, but only F-1mgDST <1.2 µg/dL (33 nmol/L) was able to predict the absence of PSH. Among AI patients with F-1mgDST <1.2 µg/dL (33 nmol/L) no subjects had diabetes mellitus and/or metabolic syndrome, and these subjects tended to have a better metabolic profile than those with F-1mgDST ≥1.2 µg/dL (33 nmol/L).

Conclusion

In AI patients a F-1mgDST <1.2 µg/dL (33 nmol/L) rules out PSH and could be used to exclude hypercortisolism in AI patients.

Adrenal Tumor Mimicking Non-Classic Congenital Adrenal Hyperplasia

Elevated 17-hydroxyprogesterone may be caused by congenital adrenal hyperplasia, ovarian or adrenal tumors. A positive cosyntropin stimulation test result for 17-hydroxyprogesterone may be found in functional or non-functional tumors and be related to tumor size. Here, we present a case of a 36-year-old woman with a 4-year history of infertility. Laboratory test results revealed elevated progesterone and 17-hydroxyprogesterone, with normal luteinizing hormone, follicle-stimulating hormone, estrogen, testosterone, and anti-Mullerian hormone levels. The 250-μg cosyntropin stimulation test revealed a 17-hydroxyprogesterone level of 11.3 ng/ml (34.3 nmol/L) and 31.8 ng/ml (96.2 nmol/L) at 0 and 60 min, respectively. Non-classic congenital adrenal hyperplasia was diagnosed initially; however, genetic testing revealed no 21-hydroxylase deficiency. She received dexamethasone but progesterone and 17-hydroxyprogesterone levels remained high. Abdominal computed tomography found a 4.5 × 4.8-cm left adrenal tumor. Subsequent pathological report was compatible with an adrenal cortical adenoma. Progesterone and 17-hydroxyprogesterone levels returned to the normal range postoperatively and the 250-μg cosyntropin stimulation test of 17-hydroxyprogesterone showed a normal response. When biochemically diagnosed NCCAH demonstrate no typical features and show poor response to steroid, the patient should undergo gene mutation analysis and receive adrenal or ovarian imaging. For women suffering from infertility, adrenalectomy of 17-OHP secreting adrenal tumor may improve fertility outcome.

Novel GC-MS/MS Technique Reveals a Complex Steroid Fingerprint of Subclinical Hypercortisolism in Adrenal Incidentalomas

CONTEXT

Improvement of imaging methods has led to more incidental adrenal tumor findings, especially adenomas. Routine hormonal evaluation uses only a few steroids to evaluate possible hormonal hypersecretion of these adenomas, but a wide spectrum of serum steroid hormone changes has not been published.

OBJECTIVE

To measure the serum levels of 83 steroids from patients with unilateral and bilateral adrenal incidentalomas to uncover full steroid profile changes in patients with subclinical hypercortisolism (SH).

DESIGN

Cross-sectional study.

SETTING

The study was conducted at a tertiary inpatient clinic.

PATIENTS

Fifty-two patients with adrenal incidentalomas (unilateral, n = 29; bilateral, n = 23), including nonfunctioning (n = 11) vs SH (n = 41), and 26 age- and sex-matched controls from the general population were included.

MAIN OUTCOME MEASURES

Eighty-three serum steroids were measured by gas chromatography-tandem mass spectrometry (GC-MS/MS) before and after 1 mg dexamethasone, ACTH, midnight serum cortisol, and urinary free cortisol/24 hour.

RESULTS

Of 83 measured steroids, 10 were significantly decreased in patients with SH, including dehydroepiandrosterone sulfate (DHEAS), androsterone sulfate, epiandrosterone sulfate, androstenediol sulfate, conjugated 5α-androstane-3β,17β-diol, and conjugated 5α-androstane-3α,17β-diol. This finding was observed even when unilateral, bilateral, male, and female subgroups were analyzed separately. When we compared routine clinical methods and GC-MS/MS‒measured steroids, the most discriminatory was DHEAS followed by midnight serum cortisol, epiandrosterone sulfate, androsterone sulfate, ACTH, and 16α-hydroxypregnenolone.

CONCLUSIONS

SH was associated with decreased levels of adrenal androgens, their metabolites, and pregnenolone metabolite. GC-MS/MS is a powerful tool for measuring serum levels of these undescribed changes in steroid metabolism, which are characteristic of SH in adrenal incidentalomas.

Metabolomic Biomarkers in Urine of Cushing's Syndrome Patients

Cushing’s syndrome (CS) is a disease which results from excessive levels of cortisol in the human body. The disorder is associated with various signs and symptoms which are also common for the general population not suffering from compound hypersecretion. Thus, more sensitive and selective methods are required for the diagnosis of CS. This follow-up study was conducted to determine which steroid metabolites could serve as potential indicators of CS and possible subclinical hypercortisolism in patients diagnosed with so called non-functioning adrenal incidentalomas (AIs). Urine samples from negative controls (n = 37), patients with CS characterized by hypercortisolism and excluding iatrogenic CS (n = 16), and patients with non-functioning AIs with possible subclinical Cushing’s syndrome (n = 25) were analyzed using gas chromatography-mass spectrometry (GC/MS) and gas chromatograph equipped with flame ionization detector (GC/FID). Statistical and multivariate methods were applied to investigate the profile differences between examined individuals. The analyses revealed hormonal differences between patients with CS and the rest of examined individuals. The concentrations of selected metabolites of cortisol, androgens, and pregnenetriol were elevated whereas the levels of tetrahydrocortisone were decreased for CS when opposed to the rest of the study population. Moreover, after analysis of potential confounding factors, it was also possible to distinguish six steroid hormones which discriminated CS patients from other study subjects. The obtained discriminant functions enabled classification of CS patients and AI group characterized by mild hypersecretion of cortisol metabolites. It can be concluded that steroid hormones selected by applying urinary profiling may serve the role of potential biomarkers of CS and can aid in its early diagnosis.

Clinical perspectives in congenital adrenal hyperplasia due to 11β-hydroxylase deficiency

Congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency is a rare autosomal recessive genetic disorder. It is caused by reduced or absent activity of 11β-hydroxylase (CYP11B1) enzyme and the resultant defects in adrenal steroidogenesis. The most common clinical features of 11 beta-hydroxylase deficiency are ambiguous genitalia, accelerated skeletal maturation and resultant short stature, peripheral precocious puberty and hyporeninemic hypokalemic hypertension. The biochemical diagnosis is based on raised serum 11-deoxycortisol and 11-deoxycorticosterone levels together with increased adrenal androgens. More than 100 mutations in CYP11B1 gene have been reported to date. The level of in-vivo activity of CYP11B1 relates to the degree of severity of 11 beta-hydroxylase deficiency. Clinical management of 11 beta-hydroxylase deficiency can pose a challenge to maintain adequate glucocorticoid dosing to suppress adrenal androgen excess while avoiding glucocorticoid-induced side effects. The long-term outcomes of clinical and surgical management are not well studied. This review article aims to collate the current available data about 11 beta-hydroxylase deficiency and its management.

Adrenal adenomas, subclinical hypercortisolism, and cardiovascular outcomes

PURPOSE OF REVIEW

Recent evidence has highlighted the link between cardiovascular outcomes and incidentally discovered adrenal masses. The purpose of this review is to summarize the most recent findings on the cardiovascular profile of patients with nonfunctional adrenal adenomas.

RECENT FINDINGS

Nonsecreting adrenal tumors, defined mostly by cortisol levels after dexamethasone suppression test below 1.8 μg/dl, are associated with impairment of markers of subclinical atherosclerosis such as intima-media thickness and flow-mediated vasodilation. The presence of impaired indices of insulin resistance could represent an additional factor that contributes to the worsening of the cardiovascular profile of those patients. No evidence of increased cardiovascular outcomes was found in this group of patients. On the contrary, according to the findings of recent long-term retrospective studies, patients with subclinical hypercortisolism have an increased incidence of cardiovascular outcomes and related mortality with respect to nonsecreting adrenal masses and to the general population.

SUMMARY

An impaired cardiovascular profile is a common finding in patients with apparently nonfunctional adrenal masses. However, the incidence of cardiovascular outcomes and related mortality seems to be increased only in patients with mild cortisol hypersecretion.

Non-functioning adrenal incidentalomas caused by 21-hydroxylase deficiency or carrier status?

Adrenal incidentalomas (AI) are an escalating clinical issue due to the increasing use of imaging techniques. Occasional patients with AIs have been reported who have subsequently been diagnosed with congenital adrenal hyperplasia (CAH) due to CYP21A2 mutations (21-hydroxylase deficiency) or carrier status. The objective of this investigation was to describe a larger cohort of patients with AI suspected to be caused by 21-hydroxylase deficiency or carrier status. All patients with AI and suspected CYP21A2 mutations during the last decade at a single center in Stockholm, Sweden, were included. Nine patients were identified (54 ± 19-year-old at presentation). Two-thirds were females and two-thirds were from Sweden, while one-third was from the Middle East. Almost all (8/9) had children, but two had experienced fertility problems. Four of six women had symptoms of hyperandrogenism, and three had previously been diagnosed with polycystic ovary syndrome. The majority (7/9) had multiple AIs. In two cases, the initial suspicion had been adrenal cortical cancer, but increased urinary pregnanetriol had lead to the diagnosis of CAH. Basal serum 17-hydroxyprogesterone was 10 (1.75-338) nmol/L. Seven was diagnosed with CAH (six non-classic, one simple virilizing). Two patients were considered to be carriers. However, in four patients, no CYP21A2 mutation was found and thus no confirmation of the diagnosis could be achieved. Patient presented with multiple AIs with hyperandrogenism or a Middle East origin screening for CAH or carrier status may be indicated.

Simultaneous quantitation of seven endogenous C-21 adrenal steroids by liquid chromatography tandem mass spectrometry in human serum

Quantitation of endogenous steroids is important in the diagnosis of several endocrine disorders. In this study we present a new method for simultaneous quantitation of cortisol, cortisone, 11-desoxycortisol, 21-desoxycortisol, corticosterone, 17-hydroxyprogesterone and 11-desoxycorticosterone in human serum by on-line extraction and LC-MS/MS. Analytes extraction was performed on-line using a 2-position and 6-port valve equipped with a monolithic silica cartridge. After chromatographic separation of all analytes, detection was performed in the multiple reaction monitoring mode using positive atmospheric pressure chemical ionization mode. Total imprecision of the assay ranged from 5.5 to 15.5%. Comparison with immunoassays yielded coefficients of 0.893 for cortisol, 0.848 for 11-desoxycortisol and 0.924 for 17-hydroxyprogesterone. The sensitivity of this method provides meaningful data for patients within normal and elevated range and it may be useful for the diagnosis of a variety of adrenal dysfunctions.

The role of 21-hydroxylase in the pathogenesis of adrenal masses: review of the literature and focus on our own experience

An exaggerated response of 17- hydroxyprogesterone (17-OHP) to exogenous ACTH stimulation has been found in 30 to 70% of patients with incidentally discovered adrenal tumors, supporting the concept that congenital 21- hydroxylase deficiency may be a predisposing factor for adrenocortical tumorigenesis. Decreased expression of 21-hydroxylase gene has been observed in sporadic non-functioning adrenocortical adenomas and adrenocortical carcinomas, in agreement with the reduced steroidogenic activity found in these types of tumors. Screening studies for the presence of mutations in CYP21A2 gene, encoding 21-hydroxylase, in patients with sporadic adrenocortical tumors yielded discordant results. Overall, a higher frequency of germline 21-hydroxylase mutation carriers has been found among patients with adrenal tumors, including incidentalomas, than in the general population. However, the presence of mutations did not correlate with endocrine test results and tumor mass features, suggesting that 21-hydroxylase deficiency does not represent a relevant mechanism in adrenal tumorigenesis. Mechanisms leading to reduced 21-hydroxylase expression and activity are still unknown.

Decreased response of plasma cortisol to intravenous metyrapone in ocular hypertension and primary open-angle glaucoma

PURPOSE

To determine if there is a difference in response to metyrapone, which blocks the conversion of 11-deoxycortisol to cortisol in the adrenal gland between normals and ocular hypertensives (OH) plus primary open-angle glaucomas (POAG) without pigmented angles.

METHODS

Intravenous metyrapone was given to 20 normals and 15 ocular hypertensives plus primary open-angle glaucomas without pigmented angles. Blood samples were obtained at 4, 6, and 8 hours after administration of intravenous metyrapone for analyses of 11-deoxycortisol and cortisol.

RESULTS

The ocular hypertensives plus primary open-angle glaucoma group showed significantly lower cortisol values compared with the normal group at 6 hours (P = 0.002) but not at 4 or 8 hours. There were no significant differences between the two groups for 11-deoxycortisol values at 4, 6, or 8 hours. The percent decrease of plasma cortisol from baseline was significantly greater for the ocular hypertensives plus open-angle glaucoma group compared with the normals at 4 hours (P = 0.010) and 6 hours (P = 0.0004). Significant negative correlations were observed for the total group of subjects between levels of plasma cortisol at 6 hours and intraocular pressure, worse eye (P = 0.029), percent area of cupping, worse eye (P = 0.045), pallor, worse eye (P = 0.001), and visual field loss, worse eye (P = 0.048), so that the less the plasma cortisol, the greater the abnormality of the glaucomatous parameters. Multivariate analyses with the 6-hour plasma cortisol level as the dependent variable showed that the only significant (P = 0.0004) independent variable was the percent area of pallor, worse eye, associated with a smaller level of plasma cortisol at 6 hours. Similarly, the multiple regression models using the percent change from baseline of the 6-hour plasma cortisol value showed a significant association of larger percent decreases of plasma cortisol in the ocular hypertensives plus open-angle glaucoma compared with the normals.

CONCLUSIONS

The ocular hypertensives plus primary open-angle glaucoma subjects show greater adrenal inhibition to metyrapone in the synthesis of cortisol from 11-deoxycortisol compared with normals. This observation suggests an adrenal abnormality in the ocular hypertensive plus primary open-angle glaucoma subjects.

Functional and nonfunctional adrenocortical tumors demonstrate a high responsiveness to low-dose adrenocorticotropin

Aldosterone-producing adenomas (APAs) demonstrate exquisite sensitivity to endogenous ACTH. We previously showed an ACTH receptor overexpression in APAs compared with the other adrenal tumors. To evaluate the meaning of such findings, we investigated the response of aldosterone, cortisol, and 17OH progesterone (17OHP) to 1 microg ACTH in 42 patients with adrenocortical tumors (23 NHAs, 9 APAs, and 10 CPAs) and 10 normal subjects (C). All 52 subjects were responsive to ACTH, and hormone peak levels were reached at 30 min. The aldosterone peak level was significantly higher in APAs [mean +/- SEM: 84.3 +/- 13.1 ng/dl (2335.1 +/- 362.9 pmol/liter)] than in other tumors and control (C). Cortisol peak levels was higher in CPAs [37.1 +/- 3.9 microg/dl (1023.9 +/- 107.6 nmol/liter)] than in NHAs (P < 0.01), in C (P < 0.01) and in APAs (P = n.s.). 17OHP peak levels were significantly higher in patients with adrenocortical tumors toward C. In summary: 1) low-dose ACTH induces an important stimulation in all tumors, suggesting preservation of high responsiveness to ACTH; 2) this is especially true for aldosterone in APA and could be of primary importance when performing diagnostic tests for hyperaldosteronism; and 3) 17OHP-hyperresponsiveness to low-dose ACTH is the most common alteration both in functional and nonfunctional tumors.

Twenty-four hour 17-hydroxyprogesterone response to adrenocorticotropine in adrenal incidentalomas: augmented response after adrenalectomy in two patients

The current study aimed to investigate the midterm (24 hour) response of 17-hydroxyprogesterone (17-OHP) and dehydroepiandrosterone sulphate (DHEA-S) to synthetic high-dose adrenocorticotropin (ACTH) in adrenal incidentalomas (Al). Seventeen patients with Al and 40 age- and sex-matched controls received synthetic ACTH (tetracosactide, 1000 microg, IM). Plasma, 17-OHP and DHEA-S were collected in basal conditions and after 1, 4, 6, 8 and 24 hours. (HPA) axis was also evaluated using circadian serum cortisol, urinary free cortisol and over-night 2 mg dexamethasone suppression. Basal plasma 17-OHP levels did not differ among the groups. However, the increment in plasma 17-OHP in patients both in terms of peak [13.76 +/- 2.52, 4.77 +/- 0.30ng/ml, mean +/- S.E.M, p < 0.001] and area under the curve [190 +/- 46, 96.75 +/- 32 ng/ml/h, p < 0.001] were significantly higher than that of the controls. Stimulated 17OH-P levels never reached 9.1 ng/ml in controls. Sixty-five (11/17) % of the patients were found to have exaggerated response. Three of the patients were found to have subclinical Cushing's syndrome and interestingly, two augmented their 17-OHP response to ACTH after unilateral adrenalectomy and normalisation of their HPA axis. Basal DHEA-S levels of the patients were significantly lower [99.21 +/- 45, 230.18 +/- 34 microg/dl, p < 0.01] and stayed persistently lower than that of the controls. Evidence of a heterozygous 21 hydroxylase deficiency, as indicated by the exaggerated 17-OHP response to ACTH, has been widely reported in Al patients. However, to our knowledge to date there is no report on augmented 17-OHP response to ACTH after adrenalectomy. Possible reasons for the augmentation were discussed.

A new specific and sensitive time resolved-fluoroimmunoassay of 11-deoxycortisol in serum

A biotinylated 11-deoxycortisol tracer was synthesized from 11-deoxycortisol-3-carboxymethyloxime and the conjugate obtained by acylation of biotinylaminopropylammonium trifluoroacetate. This biotinylated tracer was used to develop an 11-deoxycortisol time-resolved-fluoroimmunoassay (TR-FIA). The tracer was quantified after adding streptavidine-Europium. A TR-FIA sensitive standard curve, with displacement of 20, 50, and 80% of tracer was obtained with 12.4, 70.7, and 512.8 pg of 11-deoxycortisol, respectively. After extraction followed by Celite chromatography, purified serum samples were simultaneously assayed by RIA and TR-FIA. The results obtained by the two methods were practically identical, however, this new specific, non-isotopic 11-deoxycortisol assay has the advantage of being more sensitive than RIA, thus well-suited to accurate measurement in endocrinological studies, particularly when serum 11-deoxycortisol levels in patients are just above the highest normal values. Moreover, this non-isotopic assay is cheaper than RIA.

Comparative analysis of plasma 17-hydroxyprogesterone and cortisol responses to ACTH in patients with various adrenal tumors before and after unilateral adrenalectomy

Patients with non-hyperfunctioning adrenal adenomas often have an increased plasma 17-hydroxyprogesterone response to ACTH stimulation. The effects of adrenal surgery on this abnormality have rarely been investigated. One hundred and sixty-one patients with unilateral adrenal tumors (non-hyperfunctioning adenomas, 78; cortisol-producing adenomas, 8; aldosterone-producing adenomas, 37; adrenal cysts, 12; pheochromocytomas, 26) were studied. Patients before and after adrenal surgery as well as 60 healthy subjects underwent an ACTH stimulation test using 2 mg synthetic ACTH(1-24) (Cortrosyn Depot, Organon). Basal and ACTH-stimulated plasma 17-hydroxyprogesterone and cortisol concentrations are reported. Before adrenal surgery, the basal plasma 17-hydroxyprogesterone concentrations were normal in patients with all types of tumors. However, the ACTH-stimulated plasma 17-hydroxyprogesterone levels were abnormally increased in 53% and 31% of patients with non-hyperfunctioning adenomas and aldosterone-producing adenomas, respectively. In addition, a few patients with adrenal cysts and pheochromocytomas also showed an increased ACTH-stimulated 17-hydroxyprogesterone response. After unilateral adrenalectomy, this hormonal abnormality disappeared in most, although not all patients with adrenal tumors. In patients with non-hyperfunctioning adrenal tumors, ACTH-stimulated plasma 17-hydroxyprogesterone and cortisol concentrations significantly correlated with the size of the tumors. These results firmly indicate that the tumoral mass itself may be responsible for the increased plasma 17-hydroxyprogesterone and cortisol responses after ACTH stimulation in patients with non-hyperfunctioning and hyperfunctioning adrenal adenomas.

Steroid 21-hydroxylase mutations and 21-hydroxylase messenger ribonucleic acid expression in human adrenocortical tumors

Twenty-one hydroxylase (P450c21) is a key enzyme essential for normal zona glomerulosa and fasciculata function. Recently, 21-hydroxylase deficiency has been implicated in the pathogenesis of adrenocortical tumors. Therefore, we investigated the mutational spectrum of the CYP21B gene and the messenger RNA expression of P450c21 in six aldosterone-producing adenomas, seven cortisol-producing adenomas, two nonfunctional incidentally detected adenomas, and four adrenal carcinomas. DNA from leukocytes and tumors was amplified by PCR using primers specific for the CYP21B gene. The 10 exons, intron 2, intron 7, all other exon/intron junctions, and 380 bp of the promoter region of CYP21B were automatically sequenced. Poly(A) RNA was extracted from tumor tissue, dot blotted on a nylon membrane, and hybridized with 32P-labeled P450 side-chain cleavage, P450 17-alpha-hydroxylase, and P450c21 complementary DNA probes. We detected heterozygous germline mutations (exon 7, Val 281Leu) in two patients, one with a cortisol-producing adenoma and the other with an androgen-secreting adrenocortical carcinoma. A somatic, heterozygous microdeletion was found in exon 3 of one aldosterone-producing adenoma. The P450c21 gene expression correlated with the clinical phenotype of the tumor, with low P450c21 messenger RNA expression in nonfunctional adenomas (18.8%, 1.5%) compared with high P450c21 expression in aldosterone- and cortisol-producing adenomas (84 +/- 8% and 101 +/- 4%, respectively, vs. normal adrenals, 100 +/- 10%). In conclusion, the prevalence of heterozygous germline mutations in the CYP21B gene was higher in patients with adrenocortical tumors (11%; 95% confidence interval, 1-34%) than in the general European population (2%; 95% confidence interval, 1.93-2.06%), but this difference is questionable because of the low number of subjects in our series. The pathophysiological significance of this finding in the presence of one normal CYP21B gene seems to be low, suggesting that 21-hydroxylase deficiency is not a major predisposing factor for adrenal tumor formation.