Resolution of Signs of Epiglottic Retroversion Following Medical Management of Hyperadrenocorticism in a Dog.

A 6 yr old spayed female Chihuahua was referred for a 10 mo history of chronic respiratory compromise. Decreased serum thyroxine and thyroid-stimulating hormone concentrations had been confirmed at a primary clinic, but no treatment was initiated. Serum biochemistries revealed elevated alkaline phosphatase and cholesterol concentrations. An adrenocorticotropic hormone-stimulating test revealed elevated preserum and postserum cortisol concentrations. Fluoroscopy revealed marked epiglottic retroversion (ER) during inhalation. Enlarged bilateral adrenal glands were found on abdominal ultrasonography. Based on these findings, ER and hyperadrenocorticism (HAC) were diagnosed and surgical correction of the ER was planned. Trilostane administration was initiated before surgery to reduce the risk of thrombosis due to HAC. Seven days after the initiation of trilostane therapy, clinical signs of chronic respiratory compromise were resolved. The patient had remained clinically stable without recurrence of respiratory compromise for at least 15 mo at the time of this case report. This case suggests that HAC could contribute to the development of clinical signs of ER, which could potentially be successfully controlled by medical treatment of HAC.

Utility of a corticotropin-releasing hormone test to differentiate pituitary-dependent hyperadrenocorticism from cortisol-producing adrenal tumors in dogs.

BACKGROUND: Hyperadrenocorticism (HAC) is a common endocrine disorder in dogs; however, there are no reports on the use of the corticotropin-releasing hormone test (CRHT) to differentiate between pituitary-dependent hyperadrenocorticism (PDH) and cortisol-producing adrenal tumors (CPATs), both causative of HAC. OBJECTIVES: To evaluate the usefulness of CRHT as a tool to differentiate between PDH and CPAT in dogs and to determine the reference intervals for CRHT in healthy, PDH, and CPAT dogs. ANIMALS: Dogs diagnosed with PDH (n = 21), CPAT (n = 6), and healthy beagle dogs (n = 33). METHODS: This prospective study included dogs with a definitive diagnosis of PDH and CPAT and healthy beagle dogs, in which CRHT was performed, were prospectively evaluated. We investigated the correlations of CRHT (endogenous adrenocorticotropic hormone [ACTH] concentration, endogenous ACTH concentration [EAC], and poststimulation ACTH concentration [PAC]) with pituitary-to-brain ratio (PBR) (in PDH) and with indices of adrenal ultrasonography (smaller and larger adrenal gland dorsoventral thickness in PDH and CPAT). RESULTS: For EAC, the area under the curve (AUC) was 0.95, with a cutoff value of 26.3 pg/mL (sensitivity: 90.62%, specificity: 87.50%). The AUC for PAC was 0.96 with a cutoff value of 54.5 pg/mL (sensitivity: 100.00%, specificity: 66.67%). The 95% reference interval for CRHT in healthy (control) dogs ranged 5.00 to 79.8 pg/mL (1.10-17.57 pmol/L) for EAC, and 1.92 to 153.42 pg/mL (0.42-33.78 pmol/L) for PAC. There was no significant correlation between PBR and CRHT, nor adrenal size and CRHT. CONCLUSIONS AND CLINICAL IMPORTANCE: CRHT appears to be a rapid and reliable test for differentiating PDH from CPAT in dogs.

Diagnostic accuracy of the different hormonal tests used for the diagnosis of autonomous cortisol secretion.

To evaluate the diagnostic accuracy of the different tests commonly used in the evaluation of adrenal incidentalomas (AIs) for the identification of autonomous cortisol secretion (ACS) and comorbidities potentially related to ACS. In a retrospective study of patients with AIs ≥ 1 cm, we evaluated the diagnostic reliability and validity of the dexamethasone suppression test (DST), urinary free cortisol (UFC), ACTH, late-night salivary cortisol (LNSC), and dehydroepiandrosterone-sulphate (DHEAS) for the diagnosis of comorbidities potentially related to ACS. Diagnostic indexes were also calculated for UFC, ACTH, LNSC, and DHEAS considering DST as the gold standard test for the diagnosis of ACS, using three different post-DST cortisol thresholds (138 nmol/L, 50 nmol/L and 83 nmol/L). We included 197 patients with AIs in whom the results of the five tests abovementioned were available. At diagnosis, 85.9% of patients with one or more AIs had any comorbidity potentially related to ACS, whereas 9.6% had ACS as defined by post-DST cortisol > 138 nmol/L. The reliability of UFC, ACTH, LNSC, and DHEAS for the diagnosis of ACS was low (kappa index < 0.30). Of them, LNSC reached the highest diagnosis accuracy for ACS identification (AUC = 0.696 [95% CI 0.626-0.759]). The diagnostic performances of these tests for comorbidities potentially related to ACS was poor; of them, the DST was the most accurate (AUC = 0.661 [95% CI 0.546-0.778]) and had the strongest association with these comorbidities (OR 2.6, P = 0.045). Patients presenting with increased values of both DST and LNSC had the strongest association with hypertension (OR 7.1, P = 0.002) and with cardiovascular events (OR 3.6, P = 0.041). In conclusion, LNSC was the test showing the highest diagnosis accuracy for the identification of ACS when a positive DST was used as the gold standard for its diagnosis. The DST test showed the strongest association with comorbidities potentially related to ACS. The definition of ACS based on the combination of elevated DST and LNSC levels improved the identification of patients with increased cardiometabolic risk.

Association between ACTH stimulation test results and clinical signs in dogs with hyperadrenocorticism treated with trilostane.

Trilostane is the recommended medical treatment for dogs with hyperadrenocorticicm (HAC). The objective of this study was to investigate the association between ACTH stimulation test (ACTHST) results, and relevant clinical signs, in dogs treated with trilostane. A disease-specific questionnaire was developed, which included the owner's assessment of polydipsia, polyuria, polyphagia, panting, and satisfaction with the treatment, based on a 5-response category rating scale. Forty-nine dogs with HAC were prospectively enrolled. Dogs were grouped according to their recheck appointment (first recheck, 710 days after commencement of treatment or change of trilostane dose; second recheck, 4 weeks after the first recheck; third recheck, performed at 3-6 months intervals once the dog was well controlled). At the recheck appointment, the owner's questionnaire responses were recorded, and an ACTHST was performed, along with urine specific gravity measurement. Linear mixed effects models were used to assess differences among the three recheck time points and to test possible associations between ACTHST results and clinical signs. Significant differences between rechecks were present for stimulated cortisol (first to third recheck, P < 0.001; second to third recheck, P < 0.01), polydipsia (first to second recheck, P = 0.001), polyuria (first to second recheck, P < 0.001; first to third recheck, P = 0.001), and owner satisfaction (first to second recheck, P < 0.001; first to third recheck, P < 0.001). Backward stepwise variable elimination did not identify any significant associations between ACTHST results and clinical signs. Therefore, clinical signs of HAC were not predicted based on the ACTHST results.

Emphysematous Cystitis and Pneumoperitoneum in a Dog with Escherichia coli Urinary Tract Infection and Hyperadrenocorticism.

A 9 yr old male neutered Staffordshire bull terrier with a history of poorly controlled hyperadrenocorticism, urinary tract infections, and emphysematous cystitis (EC) was presented to a veterinary referral teaching hospital for vomiting. Abdominal radiographs revealed EC and a pneumoperitoneum. The urinary bladder was found to be intact based on ultrasound and a pre- and postiohexol contrast computed tomography study with retrograde contrast cystogram. Urine culture confirmed the presence of a recurrent Escherichia coli urinary tract infection. The patient was managed medically, primarily as an outpatient, and had complete resolution of all problems. This case represents an extremely rare form of EC with pneumoperitoneum, without evidence of concurrent urinary bladder rupture. Only six similar cases have been reported in humans, with no previous cases reported in veterinary medicine. This case demonstrated that surgery is not necessarily indicated in all cases of pneumoperitoneum. The patient remained alive at 2 mo follow-up, with no evidence of recurrence of EC.

Patterns of the low-dose dexamethasone suppression test in canine hyperadrenocorticism revisited.

BACKGROUND: The low-dose dexamethasone suppression test (LDDT) is considered an accurate screening and valuable differentiation test in dogs with suspected hyperadrenocorticism (HAC). A recent study showed that the different response patterns not only provide complementary information about etiology, but also the probability of HAC in these patients. OBJECTIVES: We aimed to determine the diagnostic test performance of LDDT response patterns in a population of dogs from an animal hospital. METHODS: The electronic database was retrospectively searched for dogs suspected of HAC that were given an LDDT. Dogs with acute non-adrenal illnesses during the test were excluded. Response patterns were classified as complete suppression, lack of suppression, partial suppression, escape, inverse, and increasing patterns. Cortisol concentrations ≥ 27.59 nmol/L (≥1 µg/dL) 8 hours after dexamethasone administration were considered positive results irrespective of the patterns observed. Calculations included likelihood ratios (LRs) and predictive values (PVs). RESULTS: HAC and non-adrenal illness were diagnosed in 115 (54%) and 62 (46%) dogs, respectively. The positive (+) LRs (95% CI) for the lack of suppression, partial suppression, escape, and an inverse pattern to diagnose HAC were infinite, 8.09 (2-32.72), 3.23 (0.75-14), and 0.2 (0.06-0.73), respectively. CONCLUSIONS: The study confirms that the "lack of suppression" pattern strongly supports a diagnosis of HAC. It shows that the "partial suppression" pattern moderately increases, and the "inverse" pattern decreases the likelihood of HAC. The fact that the study found no association between the "escape" pattern and a diagnosis of HAC, does not support its integration into decision making.

Stress as cause of signs and symptoms of pseudo-Cushing's syndrome in buffy-tufted marmosets (Callithrix aurita).

Hyperadrenocorticism is a medical condition caused by the increase in cortisol production by the cortex of the adrenal gland. Although infrequently described in most animal species, its naturally occurring form, called Cushing's syndrome, is the most prevalent endocrinopathy in dogs. Cushing's syndrome is also present in humans and might be confused with the pseudo-Cushing's syndrome (PCS), rarely described in animals. PCS shares many of the clinical and biochemical features of Cushing's syndrome. However, the hypercortisolemia seen is usually idiopathic and, in some circumstances, associated with psychological disruptions. This report describes PCS-like disorder in two marmosets Callithrix aurita that were exposed to environmental changes, suggesting stress as the main cause of the process and reviewing the mechanisms involved in the pathogeny of the two syndromes.

Feline comorbidities: Recognition, diagnosis and management of the cushingoid diabetic.

PRACTICAL RELEVANCE: Diabetes mellitus (DM) is a common feline endocrinopathy, and is often driven by underlying insulin resistance with associated pancreatic beta (ß)-cell dysfunction. Although spontaneous hyperadrenocorticism (HAC) with hypercortisolemia (hypercortisolism) is relatively uncommon in cats, it is a well-established cause of insulin resistance and is routinely associated with DM in this species. CLINICAL CHALLENGES: Many of the clinical signs associated with feline HAC are subtle and may be attributed to concurrent DM or the aging process. Failure to recognize HAC in the diabetic cat can impact patient wellbeing and predispose the patient to progressive compromise. Unfortunately, it can be difficult to establish a diagnosis of HAC, as test results may be influenced by poor diabetic regulation, and protocols are different to those used in canine patients. Treatment options depend on the underlying cause, and often require careful, ongoing assessment and modulation of both adrenal function and insulin requirements. However, various approaches have been shown to either improve glycemic control in cats with sustained insulin dependence, or facilitate diabetic remission. EVIDENCE BASE: This review summarizes the current literature on feline HAC, with a particular focus on cats with concurrent DM. The clinical findings that suggest HAC are discussed, along with an outline of diagnostic options and their limitations. Published outcomes for various medical options, surgical procedures and radiation therapy are provided. The authors also share their thoughts on the safe and effective management of cats with HAC and DM, with an emphasis on the anticipation and recognition of changing insulin requirements.

Diagnostic contribution of individual components of adrenal function tests to diagnose canine hyperadrenocorticism.

There is limited information regarding the value of constitutive components of the ACTH stimulation test (ACTHST) and low-dose dexamethasone suppression test (LDDST) including serum baseline cortisol (BC), difference between post-ACTH stimulation cortisol (PC) and BC (ΔACTHC), cortisol concentration 4h after dexamethasone administration (4HC), difference between 4HC and BC (Δ4C), and the difference between cortisol concentration 8h after dexamethasone administration and 4HC (Δ8C). Therefore, the objective of this study was to determine if these components can predict hyperadrenocorticism, pituitary-dependent hyperadrenocorticism (PDH), or functional adrenocortical tumor (FAT) in dogs. Cortisol concentrations were normalized, as fold change (FC), to the PC reference interval upper limit. A total of 1267 dogs were included, with hyperadrenocorticism diagnosed in 537 (PDH, n=356; FAT, n=28; undetermined, n=153) and excluded in 730. The area under the receiver operating curves for BC, ΔACTHC, 4HC, Δ4C, and Δ8C to predict hyperadrenocorticism were 0.76 (95% confidence interval (CI), 0.73-0.79), 0.91 (95% CI, 0.89-0.93), 0.83 (95% CI, 0.80-0.87), 0.55 (95% CI, 0.50-0.60), and 0.67 (95% CI, 0.62-0.72), respectively. A diagnostic limit of ≥0.78 FC for ΔACTHC had excellent sensitivity (1.00; 95% CI, 0.74-1.00), but poor specificity (0.67; 95% CI, 0.64-0.71), to predict FAT in dogs with a positive ACTHST. A diagnostic limit of ≥-0.26 FC for Δ4C had excellent sensitivity (1.00; 95% CI, 0.79-1.00), but poor specificity (0.21; 95% CI, 0.18-0.26), to predict FAT in dogs with a positive LDDST. In hyperadrenocorticoid dogs that have positive ACTHST or LDDST results, ΔACTHC or Δ4C, respectively, could be used to exclude FAT.

Influence of dental restoration under general anaesthesia on the low-dose dexamethasone suppression test in dogs.

It was the aim of the study to assess the impact of a minor surgical intervention under general anaesthesia on results of a low-dose dexamethasone suppression test (LDDST) in dogs. Five clinically healthy dogs underwent a LDDST (standard protocol) prior and 1, 4, 7, 14 and 28 days after a dental restoration under general anaesthesia. All LDDSTs revealed negative results. On all test days after intervention some dogs had basal cortisol concentrations below the reference range. Accordingly, plasma cortisol concentrations 4 and 8 h after dexamethasone injection were noticeably lower than before surgery and often even below the lower detection limit of 2.0 ng/ml. The study results may indicate a suppressive effect of a minor surgery under general anaesthesia on cortisol measurements during LDDSTs. It may be speculated that this could possibly lead to false negative test results in the postsurgical period, although transfer of these results to clinical cases is subject to limitations.

Diagnosis of spontaneous hyperadrenocorticism in dogs. Part 2: Adrenal function testing and differentiating tests.

Hyperadrenocorticism is a relatively common endocrine disorder in dogs that has been extensively described. However, its diagnosis remains challenging because there is no true reference standard test, and a myriad factors can affect the diagnostic performance of the commonly used adrenal function tests. Ultimately, the diagnosis is based on a combination of signalment, history and clinical findings, and a variety of diagnostic test results. The second part of this review aims to appraise available data on diagnostic performance of adrenal function tests in naturally occurring canine hyperadrenocorticism.

Diagnosis of spontaneous hyperadrenocorticism in dogs. Part 1: Pathophysiology, aetiology, clinical and clinicopathological features.

Hyperadrenocorticism is a relatively common endocrine disorder in dogs. It occurs as a result of a functional pituitary or adrenal tumour, although other causes have been rarely reported. Canine hyperadrenocorticism has been extensively described but diagnosing this disease remains challenging. Few studies have investigated the clinical and clinicopathological features helpful in differentiating dogs with hyperadrenocorticism from dogs in which the disease is suspected but eventually excluded. Ultimately the diagnosis is based on a combination of multiple pieces of information emanating from the signalment, history, clinical findings, and a variety of diagnostic tests. The first part of this review aims to critically appraise the available data on epidemiology, clinical and laboratory features of naturally occurring canine hyperadrenocorticism.

[Surgical treatment of ACTH-ectopic syndrome]. / Khirurgicheskoe lechenie AKTG-éktopicheskogo sindroma.

ACTH-ectopic syndrome is a severe, multiple-symptom disease characterized by secretion of adrenocorticotropic hormone (ACTH) by ectopic tumor, increased release of adrenal cortical hormones and clinical picture of hypercorticism. Diagnosis and treatment of ACTH-ectopic syndrome is still difficult problem despite the achievements of modern medicine. There are several unresolved issues including optimal diagnostic algorithm, indications for various surgical procedures and their optimal dates. This review is devoted to these questions.

Hyperadrenocorticism of calorie restriction contributes to its anti-inflammatory action in mice.

Calorie restriction (CR), which lengthens lifespan in many species, is associated with moderate hyperadrenocorticism and attenuated inflammation. Given the anti-inflammatory action of glucocorticoids, we tested the hypothesis that the hyperadrenocorticism of CR contributes to its attenuated inflammatory response. We used a corticotropin-releasing-hormone knockout (CRHKO) mouse, which is glucocorticoid insufficient. There were four controls groups: CRHKO mice and wild-type (WT) littermates fed either ad libitum (AL) or CR (60% of AL food intake), and three experimental groups: (a) AL-fed CRHKO mice given corticosterone (CORT) in their drinking water titrated to match the integrated 24-hr plasma CORT levels of AL-fed WT mice, (b) CR-fed CRHKO mice given CORT to match the 24-hr CORT levels of AL-fed WT mice, and (c) CR-fed CHRKO mice given CORT to match the 24-hr CORT levels of CR-fed WT mice. Inflammation was measured volumetrically as footpad edema induced by carrageenan injection. As previously observed, CR attenuated footpad edema in WT mice. This attenuation was significantly blocked in CORT-deficient CR-fed CRHKO mice. Replacement of CORT in CR-fed CRHKO mice to the elevated levels observed in CR-fed WT mice, but not to the levels observed in AL-fed WT mice, restored the anti-inflammatory effect of CR. These results indicate that the hyperadrenocorticism of CR contributes to the anti-inflammatory action of CR, which may in turn contribute to its life-extending actions.

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-3ß,17ß-diol, and conjugated 5α-androstane-3α,17ß-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.

The interpretive contribution of the baseline serum cortisol concentration of the ACTH stimulation test in the diagnosis of pituitary dependent hyperadrenocorticism in dogs.

BACKGROUND: Current recommendation for performing the ACTH stimulation test (ACTHST) for diagnosis of hyperadrenocorticism (HAC) advocates the collection of baseline serum cortisol concentration (BC), but no references for interpretation of its results exist. OBJECTIVE: Evaluate the contribution of BC of the ACTHST to the diagnosis of HAC. ANIMALS: Fifty-four dogs were evaluated for suspected HAC at a referral hospital. METHODS: Records of dogs that had been evaluated by ACTHST for suspected HAC were reviewed. Receiver operator characteristics (ROC) analyses were used to assess the performance of BC, post-stimulation serum cortisol concentrations (PC), post-to-baseline cortisol concentration difference (DeltaC) and quotient (RatioC) for the diagnosis of HAC by comparing the area under the ROC curve (AUC) of PC to each of the other tests. RESULTS: The AUC of PC (95% confidence interval [CI]: 0.92; 95% CI, 0.81-0.98) was significantly higher than AUCs of BC (0.70; 95% CI, 0.56-0.82; P = .01) and RatioC (0.55; 95% CI, 0.41-0.69; P < .001), and was not significantly different from AUC of DeltaC (0.86; 95% CI, 0.74-0.94; P = .09). An optimal cutoff value of 683 nmol/L (24.8 µg/dL) for PC yielded a sensitivity of 86% and a specificity of 94%, respectively, and a cutoff value of 718 nmol/L (26.0 µg/dL) yielded a specificity of 100% with of 81% sensitivity for the diagnosis of pituitary-dependent HAC. CONCLUSION AND CLINICAL IMPORTANCE: The PC had good discriminatory ability for the diagnosis of HAC. It was comparable to DeltaC, whereas BC and RatioC were ineffective. Current recommendations to collect samples for BC appear redundant.

Physiolgic hypercortisolism at onset of celiac disease in a girl: A case report.

RATIONALE: Celiac disease (CD) is an autoimmune disorder induced by dietary gluten in genetically predisposed subjects. Activation of the hypothalamic-pituitary-axis (HPA) can occur in patients with CD; however, this condition has never been described in overweight/obese CD children. PATIENT CONCERNS: A 12-year-old girl with CD was admitted with mild acanthosis nigricans of the armpits, groin and neck. Recently, extra fat appeared around the neck, and moon face was observed. The abdomen was globular and meteoric, treatable and not aching. She weighed 64 kilos (75°-97° percentile) and was 146 centimeters tall (3°-25° percentile) with a body mass index of 30 kg/mq. Laboratory tests revealed hypertriglyceridemia and positive anti-transglutaminase IgA. Cortisoluria was determined. Serum ACTH was normal. DIAGNOSES: This paper reports a case of a girl with CD in which both obesity and activation of HPA activity were noted. INTERVENTIONS: During follow-up, anti-transglutaminase IgA increased to 201.5 UI/mL. The patient was positive for anti-endomysium antibodies, and the HLA DQ2 haplotype was identified, confirming a diagnosis of CD. OUTCOMES: Despite a gluten-free diet, obesity and hyperadrenalism persisted, and anti-transglutaminase antibodies remained elevated. In addition, high cortisoluria persisted. A high-dose suppression dexamethasone test (8 mg) produced negative results with a morning cortisol value of 1 ng/mL, suggesting the diagnosis of pseudo-Cushing's syndrome. LESSONS: This case highlights that the first manifestation of CD could be being overweight, and this finding seems to support the need to prescribe laboratory tests for CD not only to children with failure to thrive, as commonly recommended, but also to those with increased body weight.

Urinary calculi in a shih tzu dog with hyperadrenocorticism.

An 11-year-old spayed female shih tzu dog was presented with pollakiuria, stranguria, and hematuria. Radiographs revealed a large number of radiodense urinary calculi within the bladder. Physical examination, complete blood cell count, biochemistry and ACTH stimulation test suggested possible hyperadrenocorticism. A cystotomy was performed and the patient was treated for hyperadrenocorticism.

Calculs urinaires chez une chienne Shih Tzu atteinte d'hyperadrénocorticisme. Une chienne Shih Tzu stérilisée âgée de 11 ans a été présentée avec de la pollakiurie, de la strangurie et de l'hématurie. Les radiographies ont révélé un grand nombre de calculs urinaires radio-opaques dans la vessie. L'examen physique, une formule sanguine complète et la biochimie ont suggéré la possibilité d'hyperadrénocorticisme. Une cystotomie a été réalisée et la patiente a été traitée pour l'hyperadrénocorticisme.(Traduit par Isabelle Vallières).

Evaluation of individual low-dose dexamethasone suppression test patterns in naturally occurring hyperadrenocorticism in dogs.

BACKGROUND: Dogs with hyperadrenocorticism (HAC) may be more mildly affected at the time of diagnosis today, which could influence the prevalence of associated clinical and clinicopathological abnormalities and diagnostic test performance. Different low-dose dexamethasone suppression test (LDDST) result patterns have not been evaluated individually. OBJECTIVES: To assess the current features of HAC and evaluate if the diagnostic test performance of individual LDDST result patterns differ. ANIMALS: One hundred and twenty-three dogs undergoing investigation for HAC. METHODS: Retrospective evaluation of dogs in which a LDDST was performed and HAC confirmed or excluded by alternative means. Cases with basal cortisol concentrations (t0 ) < 1 µg/dL were excluded. Each LDDST result was classified as (a) complete suppression (t3 and t8 < 1 µg/dL), (b) lack of suppression (t3 and t8 > 1 µg/dL and both > 50% t0 ), (c) partial suppression (t3 and t8 > 1 µg/dL but either < 50% t0 ), (d) escape (t8 > 1 µg/dL and t3 < 1 µg/dL) or (e) inverse (t3 > 1 µg/dL and t8 < 1 µg/dL) pattern. RESULTS: Fifty-nine (48%) dogs were diagnosed with HAC and 64 (52%) with non-adrenal illness. Hyperadrenocorticism cases had similar clinicopathological abnormalities compared to previous reports. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) (95% confidence interval [CI]) of the LDDST for diagnosing HAC were 96.6 (91.9-100)%, 67.2 (55.7-78.7)%, 73.1 (63.2-82.9)%, and 95.6 (89.5-100)%, respectively. Lack of suppression pattern had the highest PPV (93.9 [85.8-100]%) followed by the partial suppression pattern (67.9 [50.6-85.2]%) and escape or inverse pattern (36.8 [15.1-58.5]%). CONCLUSIONS AND CLINICAL IMPORTANCE: A lack of suppression LDDST pattern has the highest PPV for diagnosing HAC followed by a partial suppression pattern. By contrast, the escape or inverse pattern provided limited support of HAC.

The Diagnostics of Human Steroid Hormone Disorders.

Disturbances of the steroidogenesis or altered peripheral metabolism of steroids may result in severe clinical manifestations. Therefore, prompt diagnosis and initiation of medical treatment are desirable. The diagnostics of disorders of steroid hormone production, metabolism, and action have been previously based on immunoassay tests. However, in a modern medical laboratory, due to low accuracy of immunoassays, this technique is continuously replaced by chromatographic separation methods coupled to mass spectrometric detection systems. In this review we present current advances in the diagnostics of adrenal gland disorders, focusing on the role of mass spectrometry in prenatal and newborn screening, and in the diagnostics of sexual maturation disorders.