Steroid biomarkers in human adrenal disease.

Adrenal steroidogenesis is a robust process, involving a series of enzymatic reactions that facilitate conversion of cholesterol into biologically active steroid hormones under the stimulation of angiotensin II, adrenocorticotropic hormone and other regulators. The biosynthesis of mineralocorticoids, glucocorticoids, and adrenal-derived androgens occur in separate adrenocortical zones as a result of the segregated expression of steroidogenic enzymes and cofactors. This mini review provides the principles of adrenal steroidogenesis, including the classic and under-appreciated 11-oxygenated androgen pathways. Several adrenal diseases result from dysregulated adrenal steroid synthesis. Herein, we review growing evidence that adrenal diseases exhibit characteristic modifications from normal adrenal steroid pathways that provide opportunities for the discovery of biomarker steroids that would improve diagnosis and monitoring of adrenal disorders.

Using Machine Learning to Aid the Interpretation of Urine Steroid Profiles.

BACKGROUND: Urine steroid profiles are used in clinical practice for the diagnosis and monitoring of disorders of steroidogenesis and adrenal pathologies. Machine learning (ML) algorithms are powerful computational tools used extensively for the recognition of patterns in large data sets. Here, we investigated the utility of various ML algorithms for the automated biochemical interpretation of urine steroid profiles to support current clinical practices. METHODS: Data from 4619 urine steroid profiles processed between June 2012 and October 2016 were retrospectively collected. Of these, 1314 profiles were used to train and test various ML classifiers' abilities to differentiate between "No significant abnormality" and "?Abnormal" profiles. Further classifiers were trained and tested for their ability to predict the specific biochemical interpretation of the profiles. RESULTS: The best performing binary classifier could predict the interpretation of No significant abnormality and ?Abnormal profiles with a mean area under the ROC curve of 0.955 (95% CI, 0.949-0.961). In addition, the best performing multiclass classifier could predict the individual abnormal profile interpretation with a mean balanced accuracy of 0.873 (0.865-0.880). CONCLUSIONS: Here we have described the application of ML algorithms to the automated interpretation of urine steroid profiles. This provides a proof-of-concept application of ML algorithms to complex clinical laboratory data that has the potential to improve laboratory efficiency in a setting of limited staff resources.

Associations among systemic blood pressure, microalbuminuria and albuminuria in dogs affected with pituitary- and adrenal-dependent hyperadrenocorticism.

BACKGROUND: Hypertension and proteinuria are medical complications associated with the multisystemic effects of long-term hypercortisolism in dogs with hyperadrenocorticism (HAC). METHODS: This study investigated the relationships among adrenocorticotropic hormone (ACTH)-stimulation test results, systemic blood pressure, and microalbuminuria in clinically-healthy dogs (n = 100), in dogs affected with naturally occurring pituitary-dependent (PDH; n = 40), or adrenal-dependent hyperadrenocorticism (ADH; n = 30). RESULTS: Mean systemic blood pressure was similar between clinically healthy dogs and dogs with HAC (p = 0.803). However the incidence of hypertension was highest in dogs with ADH (p = 0.017), followed by dogs with PDH, with the lowest levels in clinically healthy dogs (p = 0.019). Presence of microalbuminuria and albuminuria in clinically healthy dogs and dogs affected with HAC was significantly different (p < 0.001); incidences of albuminuria followed the same pattern of hypertension; highest incidence in dogs with ADH, and lowest level in clinically healthy dogs; but microalbuminuria showed a different pattern: clinically healthy dogs had highest incidences and dogs with ADH had lowest incidence. The presence of albuminuria was not associated with blood pressure values, regardless of whether dogs were clinically healthy or affected with ADH or PDH (p = 0.306). CONCLUSIONS: Higher incidence of hypertension and albuminuria, not microalbuminuria was seen in dogs affected with HAC compared to clinically healthy dogs; incidence of hypertension and albuminuria was significantly higher in dogs affected with ADH compared to PDH. However, presence of albuminuria was not correlated with systemic blood pressure.

Aberrant cortisol regulations in bilateral macronodular adrenal hyperplasia: a frequent finding in a prospective study of 32 patients with overt or subclinical Cushing's syndrome.

CONTEXT: ACTH-independent macronodular adrenal hyperplasia (AIMAH) is a rare and heterogeneous condition characterized by abnormal steroid production. Cortisol secretion can be regulated by aberrant hormone receptors. OBJECTIVE: A large series of patients with AIMAH were evaluated to provide information on the prevalence and profile of aberrant regulations, in relation with the functional status. DESIGN AND PATIENTS: Thirty-two consecutive patients with AIMAH were prospectively studied: 10 had a Cushing's syndrome (CS), and 22 had a subclinical CS (SCS). METHODS: A baseline endocrine evaluation was followed by an in vivo protocol in search of aberrant cortisol responses (seven provocative tests). An acute inhibition test with the somatostatin analog octreotide was also performed. RESULTS: At least one aberrant cortisol response was identified in 28 of 32 (87%) patients. The overall prevalence of aberrant responses was independent of the functional status. Responses to the upright posture and to metoclopramide were frequently observed (67 and 56% respectively). A glucagon response was frequently observed in the SCS group (58%). A cortisol inhibition by octreotide was specifically found in the three CS patients who positively responded to the mixed meal, and was observed also in 12 of 13 (92%) patients with SCS. CONCLUSIONS: Cortisol responses indicative of aberrant receptor expression were highly prevalent in AIMAH. Thorough phenotyping of AIMAH may help uncover the underlying pathophysiology.

Elevated urinary catecholamines and adrenal haemorrhage mimicking phaeochromocytoma.

A 51-year-old woman was admitted with left-sided flank pain initially thought to be renal colic. However, a CT urogram was normal. During the course of the admission the pain persisted and she developed severe sustained hypertension. A repeat CT scan of the abdomen revealed a 5×3 cm left adrenal abnormality consistent with haemorrhage, not seen on the original scan. Further assessment revealed elevated urine catecholamines and a short synacthen test showed a suboptimal cortisol response. The diagnosis was initially considered as a phaeochromocytoma, she received phenoxybenzamine with good resolution of hypertension and was referred for surgical opinion. However, serial urinary catecholamine concentrations returned to within the normal range and the diagnosis was revised to adrenal infarction and haemorrhage due to antiphospholipid syndrome. This case illustrates the importance of recognising adrenal infarction as a potential cause of 'pseudophaeochromocytoma'.

Development of a highly sensitive ELISA for aldosterone in mouse urine: validation in physiological and pathophysiological states of aldosterone excess and depletion.

BACKGROUND: Clinical studies have established aldosterone as a critical physiological and pathophysiological factor in salt and water homeostasis, blood pressure control and in heart failure. Genetic and physiological studies of mice are used to model these processes. A sensitive and specific assay for aldosterone is therefore needed to monitor adrenocortical activity in murine studies of renal function and cardiovascular diseases. METHODS: Antibodies against aldosterone were raised in sheep as previously described. HRP-Donkey-anti-sheep IgG enzyme tracer was produced in our laboratory using the Lightning-Link HRP technique. Aldosterone ELISA protocol was validated and optimised to achieve the best sensitivity. The assay was validated by analysing the urine of mice collected under various experimental conditions designed to stimulate or suppress aldosterone in the presence of other potentially interfering steroid hormones. RESULTS: Cross-reactivity with the steroids most likely to interfere was minimal: corticosterone=0.0028%, cortisol=0.0006%, DOC=0.0048% except for 5alpha-dihydro-aldosterone=1.65%. Minimum detection limit of this ELISA was 5.2 pmole/L (1.5 pg/mL). The validity of urinary aldosterone ELISA was confirmed by the excellent correlation between results obtained before and after solvent extraction and HPLC separation step (Y=1.092X+0.03, R(2)=0.995, n=54). Accuracy studies, parallelism and imprecision data were determined and all found to be satisfactory. Using this assay, mean urinary aldosterone levels were (i) approximately 60-fold higher in females than males mice; (ii) increased 6-fold by dietary sodium restriction; (iii) increased 10-fold by ACTH infusion and (iv) reduced by >60% in Cyp11b1 null mice. CONCLUSION: We describe an ELISA for urinary aldosterone that is suitable for repeated non-invasive measurements in mice. Female aldosterone levels are higher than males. Unlike humans, most aldosterone in mouse urine is not conjugated. Increased levels were noted in response to dietary sodium restriction and ACTH treatment. The sensitivity of the assay is sufficient to detect suppressed levels in mouse models of congenital adrenal hyperplasia.

Urinary steroid profile analysis.

BACKGROUND: A detailed analysis (profile) of the steroid metabolites in urine is useful for diagnosis of adrenal problems. Hospitals from many of UK health regions and around the world use the specialist assay and advisory service at UCLH. According to the total workload, samples are from patients with precocious puberty/premature adrenarche (21%), ambiguous genitalia (17%), Cushing's syndrome (13%), tumors (11%), polycystic ovaries (9%), hypertension (6%), problems of growth and development (5%), salt-loss (3%) and male pseudohermaphroditism (3%). Sixty percent of samples are from children and comprehensive reference data for steroid excretion rates in childhood unique to this laboratory were essential for interpretation of the results. CONCLUSION: The recognition and high excretion rates of certain steroids not easily measured in blood or urine by any other assays was particularly in cases of hypertension and tumors. The assay is cost effective by comparison with the combined costs of several individual hormone measurements but that cost may delay early referral to a specialist centre and that is not in the best interests of the families involved.

Glucocorticoid replacement therapy: are patients over treated and does it matter?

BACKGROUND AND OBJECTIVES: Adequate assessment of patients on glucocorticoid replacement therapy is of great importance to avoid the consequences of under or over treatment, but no simple test is available for this. The aims of this study were (1) to assess adequacy of glucocorticoid replacement in hypoadrenal patients, (2) to correlate serum cortisol levels (cortisol day curve) with 24-hour urine free cortisol excretion and (3) to assess the impact of glucocorticoid dose optimization on markers of bone formation and bone resorption. DESIGN: Cross-sectional study of current replacement therapy and a prospective study of the effect of dose alteration on bone turnover markers. PATIENTS: Thirty-two consecutive patients on replacement glucocorticoid therapy (12 Addison's disease, 20 hypopituitarism) from a University teaching hospital out-patient department. MEASUREMENTS: Serum and urinary cortisol, osteocalcin, N-telopeptide of type I collagen (NTX) and bone mineral density. RESULTS: 28/32 (88%) patients required a change of therapy; 24/32 (75%) a total reduction in dose, 18/32 (56%) a change in replacement therapy regimen or drug and 14/32 (44%) both changes. The mean daily dose of hydrocortisone was reduced from 29.5 +/- 1.2 to 20.8 +/- 1.0 mg. A significant correlation was found between peak cortisol and 24-hour urine free cortisol/ creatinine (Spearman correlation r = 0.60, P < 0.0001; n = 51). Following hydrocortisone dose reduction, median osteocalcin increased from 16.7 micrograms/l (range 8.2-65.7) to 19.9 micrograms/l (8.2-56.3); P < 0.01, with no change in the NTX/creatinine ratio. CONCLUSIONS: A high proportion of patients on conventional corticosteroid replacement therapy are over treated or on inappropriate replacement regimens. To reduce the long term risk of osteoporosis, corticosteroid replacement therapy should be individually assessed and over replacement avoided.

An assessment of optimal hydrocortisone replacement therapy.

OBJECTIVE: To assess the management of hydrocortisone replacement therapy in one institution, and derive recommendations for optimum starting and maintenance replacement therapy with hydrocortisone. DESIGN: Retrospective survey of clinical management using a clinical information system and the patient case notes. PATIENTS: Using the department's clinical information system, 210 patients were identified who had been treated with hydrocortisone. Case notes were reviewed and 130 patients were identified whose records contained the results of at least one valid hydrocortisone day curve. Data on 174 day curves performed on these patients (65 on twice daily and 109 on thrice daily hydrocortisone regimes) formed the basis of this analysis. METHODS: Hydrocortisone day curves had been performed as part of routine clinical management: patients collected a 24 h urine for free cortisol on the day prior to the test and took their morning hydrocortisone at the normal time, at home, on wakening. During a day-case attendance serum cortisol was then measured at 0900 h, 1230 h (prior to any lunchtime dose) and 1730 h (prior to the evening dose). 'Optimal replacement' was arbitrarily defined as that dose which achieved a UFC and 09:00 h cortisol within the reference range for the normal population (to avoid over-replacement) combined with 1230 h and 1730 h cortisol above 50 nmol/l, and ideally above 100 nmol/l (to avoid under-replacement). Raw data from all hydrocortisone day curves was analysed in an Excel spreadsheet to determine the effect of different dose regimens on the percentage of patients achieving each and all of these 4 criteria, and on an overall 'quality score' (comprising 1 point for each of the 4 criteria attained). RESULTS: Patients on twice daily hydrocortisone regimes achieved optimal replacement in 15% of cases compared to 60% on thrice daily regimes (P < 0.001 by chi 2); mean overall 'quality scores' for these regimens were 2.72 and 3.49 respectively (P < 0.001 by t-test). Of individual dose regimens with sufficient cases for valid comparison, a dose of 10 mg/5 mg/5 mg (rising/lunch/evening) achieved optimal replacement in 66% and mean 'quality score' of 3.62 (n = 53), compared to 50% and 3.32 for 10 mg/ 10 mg/5 mg (n = 28) and 10% and 2.48 for 20 mg/-/10 mg (n = 29). CONCLUSIONS: The use of arbitrary, but logical, criteria to assess the quality of hydrocortisone replacement regimens indicates that optimal replacement is achieved with thrice daily hydrocortisone regimens, and that the traditional twice daily regime results in a 0900 h cortisol above normal in one-third, and late afternoon cortisol below 50 nmol/l in one-half of patients thus treated. An appropriate starting dose of hydrocortisone of 10 mg/5 mg/5 mg (rising/lunch/evening) is suggested, with subsequent individual adjustment based on simple hydrocortisone day curves.

The regularity of intersteroidal relations in urine as related to the law of mass action.

The relation between 14 urinary steroid excretions was investigated by intersteroidal regression analysis with urine from 59 follicular stage women, 135 luteal stage women and 5 female patients with adrenal disorders. The regularity of intersteroidal relation in urine, as detected for all steroid pairs of all groups studied, was explained in terms of the law of mass action, and a chemical equilibrium point was located with a high degree of reproducibility for each steroid and for each group. The theoretical and practical usefulness of urinary steroid regression analysis is emphasized in relation to the possible impact of multihormonal information on endocrinology.

Gas chromatography of C19 and 17-oxogenic steroids in urine.

17-oxogenic steroids have been analysed by gas chromatography (GC) with capillary column and flame ionization detector. The best separation of steroid products was gained after ethyloxime-trimethylsilyl ether formation. The value of the GC method as a screening procedure for patients with suspected adrenal disease is illustrated in selected cases where the diagnosis was equivocal from data derived by RIA analysis of plasma steroids.

Urinary excretion of aldosterone metabolite Kelly-M1 in patients with adrenal dysfunction.

Using tetrahydroaldosterone antibody a radioimmunoassay was developed to measure substance Kelly-M1 (K-M1) in human urine. The normal values were lower than observed by Kelly et al. who discovered the catabolite after giving large doses of exogenous aldosterone. While in essential hypertension the excretion of K-M1 was predominantly within the normal range, elevated values were found in most cases of 21-hydroxylase deficiency, both the simple virilizing and salt losing form, primary aldosteronism, renal hypertension and cystinosis. Our findings suggest that K-M1 may be formed from 21-deoxyaldosterone and/or by microbial intervention from aldosterone or its metabolites.

Mass spectrometric identification of 2-hydroxy-sebacic acid in the urines of patients with neonatal adrenoleukodystrophy and Zellweger syndrome.

The urines of children with neonatal adrenoleukodystrophy and Zellweger syndrome contained an excess of unusual even- and odd-numbered dicarboxylic acids with a chain length of from 5 to 15 carbon atoms, as well as 2-hydroxy-compounds, including 2-hydroxy-isocaproate, 2-hydroxy-glutarate and 2-hydroxy-sebacate. The latter product, not previously found in metabolic diseases, appears as an additional useful marker of these peroxisomal disorders.

A fluorometric determination of urinary 17-hydroxycorticosteroids using benzamidine.

A fluorometric determination of urinary 17-hydroxycorticosteroids using a reaction of benzamidine with compounds carrying the dihydroxyacetone side chain is described. The fluorescent compounds have excitation and emission maxima at 370 and 480 nm, respectively. The method includes enzymatic hydrolysis with beta-glucuronidase (EC 3.2.1.31, from Escherichia coli) and extraction with methylene chloride and generation of fluorescence in alkaline solution (pH 13.4). The specificity of the reaction was examined and the results were compared with those of an accepted method based on the Porter-Silber reaction (C. C. Porter and R. H. Silber, 1950, J. Biol. Chem. 185, 201-207). The coefficient of correlation was 0.945 with regression line of y = 0.91x + 0.7 mg/day (y, present method; x, Porter-Silber reaction method). Sensitivity of the reaction was 0.5 microgram/ml of standard or sample, mean recovery of cortisol added to five urine samples (5-micrograms addition) was 95%, and the coefficient of variation of the method (five repeated assays of sample with a value of 5.2 mg/liter) was 6.2%.

Clinical evaluation of the liquid-chromatographic determination of urinary free cortisol.

We recently reported (Clin. Chem. 28: 1497-1500, 1982) a liquid-chromatographic method for quantifying free cortisol in urine. We have since evaluated the clinical utility of our method by assaying cortisol in urine from normal subjects, patients, and subjects undergoing endocrine tests. We found that, in contrast with plasma cortisol, urinary cortisol is not bound to protein. It shows some correlation with 17-hydroxycorticosteroids in urine, but is independent of creatinine excretion. The amount of cortisol excreted daily by a particular individual was found to be fairly constant during nine or 10 days. Normal values determined for 203 apparently healthy individuals were 35.8 (SD 18.7) micrograms/day, with no significant sex-related differences but a tendency for a gradual decrease of cortisol excretion with age. We also report urinary cortisol excretion by patients with pituitary-adrenal disorders and some other diseases, and the pattern of response to dexamethasone and metyrapone administration.

Estimation of urinary unconjugated androstenedione, dehydroepiandrosterone, testosterone, cortisol, aldosterone and 18-hydroxycorticosterone as a potential tool for assessing adrenal status.

A method is described for the simultaneous assay of non-conjugated androstenedione, dehydroepiandrosterone, testosterone, cortisol, aldosterone and 18-hydroxycorticosterone in urine. The method involves solid-phase extraction, automatic high performance liquid chromatography and subsequent radioimmunological quantitation of the individual steroids. Excretion rates of these urinary free steroids were determined in normal males and females. There were no significant sex differences in excretion rates, although both urinary free testosterone and dehydroepiandrosterone were distinctly lower in females than in males. Representative measurements of the excretion rates of patients with Cushing's disease, Addison's disease, ectopic corticotropin syndrome and hirsutism were made. The present method has been shown to be well suited for routine purposes. Its final diagnostic significance for monitoring alterations in glucocorticoid, mineralocorticoid and androgenic activity of the adrenal cortex has yet to be explored.

[Circadian rhythm of free catecholamine excretion in disturbed adrenal function (author's transl)]. / Untersuchungen zur circadianen Rhythmik der Ausscheidung freier Katecholamine bei gestörter Nebennierenfunktion.

The daily time course of urinary catecholamine excretion was determined for hyperactivity of the sympathoadrenal system (3 phaeochromocytomas, 1 neuroblastoma), disturbed adrenal function (M. Addison and partial adrenal insufficiency), bilateral adrenalectomy (one patient), in 8 healthy patients receiving dexamethasone, and in a control group. All groups showed a circadian rhythm of catecholamine excretion. In the patients with phaeochromocytoma, the excretion of catecholamines and vanilmandelic acid showed a shift of phase compared with the control group. In patients with hyperfunction of the sympathoadrenal system, catecholamines and vanilmandelic acid fluctuated with similar amplitudes, whereas in healthy patients vanilmandelic acid and dopamine showed much smaller fluctuations of concentration than adrenaline and noradrenaline.