Ovine Corticotropin-releasing Hormone Research Articles

The diagnostic yield of inferior petrosal sinus sampling in Cushing syndrome in the era of ovine CRH shortage

PurposeThe ovine corticotropin-releasing hormone (oCRH) stimulation test has been routinely used in the diagnostic work-up of ACTH-dependent Cushing syndrome (CS). With oCRH currently being out-of-stock in Europe, we aimed at evaluating the diagnostic performance of inferior petrosal sinus sampling (IPSS) without oCRH stimulation.MethodsWe compared the values of 40 patients with ACTH-dependent CS and negative MRI findings in whom ACTH was measured before and after oCRH stimulation.ResultsThe ratio of central-to-peripheral ACTH measurement (IPS:P) before the combined 3, 5, and 10 min of oCRH stimulation yielded diminished sensitivity (85% vs. 97%), alongside markedly decreased specificity (57% vs. 71%), as well as reduced positive and negative predictive values (90% vs. 94% and 44% vs. 83%), respectively.ConclusionsWith the current drug shortages in Europe, ACTH measurements without oCRH stimulation in IPSS cannot be recommended. Thus, we call for desmopressin or the commercially available human CRH as a potential alternative in the confirmation of ACTH excess by IPSS in equivocal MRI findings.

The hypothalamic-pituitary-adrenal axis response to ovine corticotropin-releasing-hormone stimulation tests in healthy and hospitalized foals.

The hypothalamic-pituitary-adrenocortical axis (HPAA) response to sepsis can be impaired in critical illness. Corticotropin-releasing hormone (CRH) stimulation test might assess HPAA function in foals. To evaluate plasma cortisol, ACTH, arginine vasopressin (AVP), and endogenous CRH (eCRH) response to different doses of ovine CRH (oCRH). Healthy (n=14) and hospitalized (n=15) foals <7 days of age. In this prospective randomized study, oCRH (0.1, 0.3, and 1μg/kg) was administered intravenously and blood samples were collected before, 15, 30, 60, and 90 minutes after administration of oCRH to determine plasma hormone concentrations. The hormonal response was evaluated as the difference (Delta; μg/dL or pg/mL) or percent change between baseline hormone concentration and each time point after oCRH stimulation. Cortisol concentrations increased from baseline at 15 minutes with 0.1 and 0.3μg/kg and at 30 and 60 minutes from baseline with 1μg/kg oCRH (P < .05) in healthy and hospitalized foals. ACTH concentrations increased from baseline at 15 minutes with 0.1μg/kg and at 30 minutes with 1μg/kg oCRH (P < .05) in hospitalized foals. Delta cortisol 0 - 30, ACTH 0 - 30, and eCRH 0 - 30 was higher for the 1μg/kg compared with 0.1μg/kg oCRH in healthy foals (P < .05). Delta ACTH 0 - 15 and eCRH 0 - 30 was higher for the 1μg/kg compared with the lower doses of oCRH in hospitalized foals (P < .05). Cortisol, ACTH, and eCRH concentrations increased in response to administration of all doses of oCRH. One microgram per kilogram of oCRH appears to be optimal for the assessment of HPAA in healthy and hospitalized foals.

Hypothalamic-pituitary-adrenal (HPA) axis response to exogenous corticotropin-releasing hormone (CRH) is attenuated in men with chronic insomnia.

Although insomnia is by far the most common sleep disorder, our understanding of its neurobiology is limited. Insomnia, particularly when associated with objective sleep disturbance, has been associated with activation of the hypothalamic-pituitary-adrenal axis. The objective of this experimental study was to compare the response of the hypothalamic-pituitary-adrenal axis to ovine corticotropin-releasing hormone, a stress test, in men with insomnia versus controls. Circulating adrenocorticotropic hormone and cortisol levels were assayed before (-30min, -15min), at (0min) and after (+5min, +15min, +30min, +60min, +90min, +120min) exogenous ovine corticotropin-releasing hormone administration in 23men (11 insomnia, 12 controls), who underwent four consecutive nights of in-lab polysomnography. Men with insomnia compared with controls demonstrated markedly and significantly shorter total sleep time (368.4±8.99 min versus 411.61±8.61min; p<0.01) and lower sleep efficiency (76.77±1.80% versus 86.04±1.72%; p<0.01) on polysomnography, and showed decreased adrenocorticotropic hormone and cortisol levels after ovine corticotropin-releasing hormone administration. Adrenocorticotropic hormone levels at 15 min and 30min were significantly lower in men with insomnia than in controls (p<0.05). Similarly, the peak levels of cortisol at +60min, and the total and net area under the curve levels of this hormone were significantly lower in men with insomnia than controls (all p<0.01). Adrenocorticotropic hormone and cortisol response to ovine corticotropin-releasing hormone administration was attenuated in men with insomnia associated with objective sleep disturbance, suggesting that objectively defined insomnia subtypes have a disrupted hypothalamic-pituitary-adrenal axis function and highlight the need to develop treatments targeting the underlying hypothalamic-pituitary-adrenal axis dysregulation.

The Dexamethasone-CRH Stimulation Test: A Single-Center Experience

Background: The diagnostic value of adding a Corticotropin Releasing Hormone (CRH) Stimulation Test to the 2-day Low Dose Dexamethasone Suppression Test (Dex-CRH Test) has been debated in the literature. We hypothesized that adding CRH to LDDST would provide additional case detection in patients suspected of having Cushing’s disease (CD). Methods: We identified 118 patients who underwent the Dex-CRH test to evaluate ACTH-dependent CS from a prospectively maintained pituitary database over 12 years. Seven patients were excluded (2 lost to follow up, 2 were on Dilantin with no available Dexamethasone (Dex) level, 2 had cyclic CD, and 1 suspected noncompliance with Dex intake). Three patients with ectopic ACTH Syndrome had very high cortisol levels after both LDDST and Dex-CRH tests. The remaining 108 patients are the subjects of this analysis. Patients were instructed to take 8 doses of Dex 0.5 mg PO every 6 hours starting at noon with the last dose of Dex taken at 6 AM. Ovine CRH injection (1 µg/kg, max 100 mcg) was given IV 2 hours afterwards. Cortisol was measured 2 hours after the last Dex dose prior to and 15 minutes after CRH administration. CD diagnosis was made based on positive ACTH staining on pituitary pathology and/or development of hypocortisolism postoperatively. Patients with no Cushing disease (NCD) are the group of patients in whom CD diagnosis could not be confirmed after a minimum follow up of 30 months. Results: Among 108 patients who underwent Dex-CRH test, 66 had CD and 42 had NCD. The female sex ratio, and median (range) for each of age, BMI, and follow-up duration in months were as follows with no statistically significant difference between the two groups: CD: 83%, 40 (15–82), 34 (30–42) and 63 (24–102). NCD: 88%, 40 (20–71), 37 (31–43) and 52 (30–67). Among 66 patients with CD, 5 patients (7.6%) had a cortisol level ≤ 1.4 µg/dl after LDDST but were appropriately classified as CD with a cortisol level >1.4 µg/dL at 15-min post CRH stimulation. In contrast, 3/42 patients (7.1%) in NCD had an abnormal Dex-CRH test. In only one of these three patients the LDDST was normal (cortisol post-Dex was 1.4 µg/dL and increased to 3.1 µg/dL 15-min post CRH). A cortisol cut-off value of > 1.4 µg/dL at 15 min during Dex-CRH test provided a sensitivity of 100%, specificity of 93%, and diagnostic accuracy of 97% to diagnose CD. When patients without a Dex level were excluded from the analysis (n=74), the sensitivity did not change but specificity and accuracy of Dex-CRH test further increased to 97% and 99%, respectively. Conclusion: The CRH test addition to the 2-day LDDST provided additional case detection in 5/66 (7.6%) of patients with CD. It resulted in one additional false-positive case compared to LDDST. Measurement of Dex level provided improved diagnostic accuracy of DEX-CRH test.

Hypothalamic-Pituitary-Adrenal Axis Responses in Women with Endometriosis-Related Chronic Pelvic Pain.

Some chronic pain conditions and comorbidities suppress the hypothalamic-pituitary-adrenal (HPA) axis and response to dynamic testing. We measured HPA axis responses to corticotropin-releasing hormone (CRH) administration in relation to chronic pelvic pain and endometriosis. In a cross-sectional study of women (n = 54) with endometriosis-associated chronic pelvic pain (n = 22), chronic pelvic pain alone (n = 12), or healthy volunteers (n = 20), adrenocorticotropic-releasing hormone (ACTH) and cortisol levels were measured at 0, 15, 30, and 45min after intravenous ovine CRH administration. ACTH and cortisol delta (peak-baseline) and area under the curve (AUC) were compared by study group and assessed for association with race and menstrual and non-menstrual pain severity. HPA axis responses did not differ among the racially diverse groups or in those with pain compared with healthy volunteers. However, when stratified by race, ACTH delta (129.9 ± 130.7 vs. 52.5 ± 66.0pg/mL; p = 0.003), ACTH AUC (4813 ± 4707 vs. 2290 ± 2900min*pg/mL; p = 0.013), and cortisol delta (26.3 ± 21.5 vs. 13.2 ± 9.7μg/mL; p = 0.005) were significantly higher in black (n = 10) than predominately white (non-black) subjects (n = 44; 39/44 white). In analyses among primarily white (non-black) women, greater menstrual pain severity was associated with blunted ACTH delta (p = 0.015) and cortisol delta (p = 0.023), and greater non-menstrual pain severity with blunted cortisol delta (p = 0.017). Neuroendocrine abnormalities in women with chronic pelvic pain may differ by pain manifestations and may vary by race. The higher HPA axis response in black women merits investigation in pelvic pain studies stratified by race. In white (non-black) women experiencing pain, a blunted response was related to pain severity suggesting pain affects women independently of endometriosis lesions.

Alcohol Use Disorder Masks the Effects of Childhood Adversity, Lifetime Trauma, and Chronic Stress on Hypothalamic-Pituitary-Adrenal Axis Reactivity.

Individuals with alcohol use disorder (AUD) and those who have experienced traumas or chronic stress exhibit dysregulated hypothalamic-pituitary-adrenal (HPA) axis reactivity. Whether and how trauma and stress histories interact with AUD to affect HPA axis reactivity has not been assessed. In the present study, 26 healthy male controls and 70 abstinent men with AUD were administered a pharmacologic probe [ovine corticotropin-releasing hormone (oCRH)] and psychosocial stressor to assess HPA axis reactivity. Plasma adrenocorticotropin hormone (ACTH) and cortisol were assessed every 10-20minutes. Hierarchical clustering of multiple measures of trauma and stress identified 3 distinct clusters: childhood adversity, lifetime trauma, and chronic stress. General linear model procedures were used to examine main effects of group (AUD/control) and interaction effects of the 3 clusters upon net-integrated ACTH and cortisol response. We found that higher levels of childhood adversity, lifetime trauma, and chronic stress were each associated with blunted oCRH-induced ACTH reactivity in controls, but not in the AUD group. Recent chronic stress within the prior 6months had the strongest influence upon ACTH reactivity in the control group, and lifetime trauma, the least. Childhood adversity, lifetime trauma, and chronic stress likely exert persistent, measurable effects upon HPA axis functioning in healthy controls. This association appears to be masked in individuals with AUD, potentially confounding studies examining the effects of stress, adversity, and/or trauma upon the HPA axis in this population during the protracted withdrawal phase of recovery. Future work targeting stress exposure and reactivity should consider the heightened effect of previous alcohol use relative to past adversity and trauma.

Predictive factors for the recurrence of Cushing's disease after surgical treatment in childhood.

Cushing's disease (CD) is a rare cause of hypercortisolaemia caused by excessive adrenocorticotropic hormone (ACTH) excretion by a pituitary adenoma. Data on the predictive factors for the recurrence of the disease are limited in comparison with those for the adult population. The identification of the predictive factors for CD recurrence in patients after surgical treatment in childhood was the aim of the presented study. A retrospective analysis of 26 CD patients, mean age at the time of diagnosis 13.46 years, treated at the Children's Memorial Health Institute (CMHI) in the years 1994-2018. Two time points were set at which the follow-up (FU) of patients was finished. The first time point (shorter FU, 24 patients) was set when the patients completed their treatment at the CMHI. The second time point (longer FU, 26 patients) was determined on the basis on the time when adult patients (previous CMHI patients) completed the author's questionnaire. In the case of the other patients (current CMHI paediatric patients and patients who did not respond to the questionnaire), the latest FU in this second time point was made during the last visit to the CMHI. The predictors of disease recurrence were evaluated by the construction of a logistic regression model and receiver operating characteristics. The average FU after transsphenoidal pituitary surgery (TSS) of 26 patients was 10.23 years (0.67-24.50). Recurrence of CD occurred in four out of 26 patients (15.4%) after an average time of 3.6 years (0.92-8.08) following definitive treatment. The results of the statistical analysis of potential predictive factors for CD recurrence were not conclusive, with no variables confirmed above the statistical significance threshold of p < 0.05. As regards the longer FU, two potential predictors: mean cortisol level at night (p = 0.10) and max. ACTH level after ovine corticotropin-releasing hormone (oCRH) test (p = 0.10), were the closest to meeting the assumed threshold of statistical significance. Recurrence of CD may be diagnosed even a long time after its effective treatment. It is possible that cortisol levels at night and ACTH values in oCRH test before TSS may be helpful to predict which patients may experience a recurrence after successful initial treatment. However, further studies on a larger sample are needed to confirm this hypothesis.

Influence of inferior petrosal sinus drainage symmetry on detection of adenomas in Cushing's syndrome

BackgroundAsymmetric inferior petrosal sinuses (IPS) are not infrequently encountered during bilateral IPS sampling. There is little data on whether IPS symmetry influences success in predicting the adenoma side in patients with ACTH-dependent Cushing's syndrome (CS). ObjectiveTo assess the influence of IPS drainage patterns on detection of an adenoma in CS. MethodsRetrospective single-center cohort analysis reviewing records of patients with CS and negative MRI findings who subsequently underwent BIPSS. ResultsBIPSS was performed in 38 patients with a mean age of 45±15 years. The overall technical success rate was 97% for bilateral cannulation. Asymmetric IPS were observed in 11 (39%) patients with Cushing's disease (CD). A side-to-side ACTH ratio was not significantly different between patients with symmetric outflow and those with asymmetric outflow at baseline (8.6±2.7 versus 16.4±6.0; P=0.45), but ratios were significantly different after ovine corticotropin-releasing hormone (oCRH) stimulation (6.0±2.5 versus 35.7±22.5; P=0.03). BIPSS correctly predicted the side of the adenoma in 25 (96%) patients with CD. Prediction was better when the venous outflow was symmetric (100%) rather than asymmetric (93%), although the difference was not significant (P=0.42). Remission from CS was achieved in 32 patients (87%), independent of the symmetry of IPS. ConclusionsBearing in mind the sample size of this audit, asymmetric IPS at least do not seem to diminish the accuracy of diagnosis of ACTH-dependent CS, nor do they influence the clinical outcome.

SUN-397 A Rare Case of Ectopic Adrenocorticotropic Hormone (ACTH) Syndrome Due to Thymic Large Cell Neuroendocrine Carcinoma Presenting as Severe Hypokalemia in a Taiwanese Man

Background Ectopic ACTH syndrome (EAS) represented 5% of Cushing syndrome. EAS is rapid onset, severe, associated with hypercortisolism related life-threatening infections and hypokalemia. In 60% of cases, the tumor is located in intrathoracic organ (lung, bronchus and thymus). Large cell neuroendocrine tumor of thymus secreting ACTH is a high grade, aggressive, poor prognosis and only few case reports in literature. Here we report a case of thymic LCNEC related EAS, which presented as severe hypokalemia, metabolic alkalosis and muscle weakness. Clinical Case A 71-year-old man presented with 12-kg weight loss, progressive generalized weakness and bilateral legs edema for two months.He has medical histories of hypertension and diabetes mellitus. Physical examination revealed generalized weakness without Cushingoid appearance. Laboratory examination showed metabolic alkalosis and severe hypokalemia (1.7 mmol/L, range 3.4-4.7).Hypokalemia work-up showed high morning ACTH 497 pg/mL (normal <46.0), cortisol 87.8 μg/dL (range 3.7-19.4), and normal limits of other pituitary hormones. Cushing syndrome survey showed lack of ACTH/cortisol circadian rhythm, markedly increased 24h urinary free cortisol excretion on two consecutive days ( 21429, 17061 μg). Low-dose and high-dose dexamethasone suppression tests showed non-suppressible. Ovine corticotrophin-releasing hormone stimulation test and desmopressin (DDAVP) test showed ectopic ACTH source. Pituitary MRI revealed negative findings. Bilateral inferior petrosal sinus sampling showed no central-to-peripheral ACTH gradient. Ectopic ACTH syndrome was impressed. Etomidate continuous infusion was prescribed.Fournier gangrene of left scrotum occurred during hospitalization and antibiotic and surgical treatment were given. Chest CT scan revealed tiny lobulated nodule in left lower lung field and soft tissue nodule in prevascular of mediastium. In-111 Octreoscan revealed several nodular lesions with increased In-111 uptake in the paraortic and prevascular region considering neuroendocrine tumor. Anterior mediastinal tumor excision was performed and histopathological report showed large cell neuroendocrine carcinoma of thymus with mitotic count 13/10 HPF and positive immunohistochemical stain for synaptophysin, chromogranin, DD-56, SSTR2 and ACTH. Sandostain LAR injection was administered afterward. Unfortunately, tumor progression with hypercortisolemia occurred after 6 months . External radiation and systemic chemotherapy were performed later. Clinical Lessons Although rare, Cushing syndrome must be considered in differential diagnosis of hypokalemia like our case, a challenging case of EAS. Early diagnosis and treatment was important to avoid life-threatening infections and metabolic complications. Moreover recurrence free survival with Sandostain LAR alone was only 6 months for LCNEC.

Fast Feedback Inhibition of Adrenocorticotropic Hormone Secretion by Endogenous Cortisol in Humans

Background: Using high-frequency blood sampling, we demonstrate glucocorticoid fast feedback (FF) mediated by endogenous cortisol in 6 normal humans. Methods: We stimulated adrenocorticotropic hormone (ACTH) secretion by ovine corticotropin-releasing hormone (oCRH) with the experimental paradigm in which a high-frequency blood sampling was designed for plasma ACTH and cortisol determinations. Results: We saw previously unrecognized variability in the timing of key events such as onsets of ACTH and cortisol secretion, onset and offset of FF, and in FF duration. This variability mandated analyses referenced to case-wise event times rather than referenced simply to time since oCRH administration. The mean time of FF onset was 4.0 min (range 0–9; median 3) after cortisol secretion began, and the mean FF duration was 7.5 min (range 3–18; median 6.0). The FF effect was rate-sensitive and does not reflect level-sensitive cortisol feedback. In agreement with previous estimates using hydrocortisone infusions, the rate of rise of cortisol that triggered FF was approximately 44 nmol/L/min or 1.6 µg/dL/min. FF onset followed the trigger cortisol slope with an average lag of 1 min (range 0–3; median 0). Unexpectedly, this trigger cortisol slope quickly declined within the FF period. Conclusions: This experimental design may enable new physiological studies of human FF that is mediated by endogenous cortisol, including mechanisms, reproducibility, and generalizability to other activating stimuli.

Differences in pituitary-adrenal reactivity in Black and White men with and without alcohol use disorder

BackgroundTreatment-seeking men with alcohol use disorder (AUD) classically exhibit a blunted hypothalamic-pituitary-adrenal (HPA) axis response to pharmacologic and behavioral provocations during the early phases of abstinence from alcohol. Independent of alcohol, a significant muting of HPA axis reactivity is also observed among racial minority (e.g. Black) individuals. The effect of AUD upon the altered HPA axis response of racial minority individuals has not been explored. The current work represents a secondary analysis of race and AUD status among a sample of men. MethodsHealthy male controls (17 White, 7 Black) and four-to six-week abstinent men with AUD (49 White, 13 Black) were administered a psychosocial stressor and two pharmacologic probes [ovine corticotropin releasing hormone (oCRH) and cosyntropin] to assess HPA axis reactivity. Plasma cortisol and adrenocorticotropin hormone (ACTH) were assessed at 10–20 min intervals prior to and following behavioral and pharmacological stimulation. Basal and net-integrated responses following provocations were analyzed to identify potential group differences. A measure of childhood adversity was also obtained to consider the implications of prior stressors upon HPA axis function. ResultsA three-fold increase in oCRH-induced ACTH was seen in Black men relative to White men regardless of AUD status. Adversity exerted a dampening effect on this pituitary sensitivity within Black controls only. Adjusted for adversity, a significant blunting effect of AUD status on ACTH reactivity was identified within White participants following oCRH. No group differences were present following cosyntropin administration. In response to the psychosocial stressor, White, but not Black, men with AUD experienced the expected blunting of cortisol reactivity relative to White controls. Rather, Black men with AUD exhibited greater cortisol reactivity relative to White men with AUD. ConclusionsDifferences in HPA axis reactivity associated with race were present in men with and without AUD. Explanatory biological mechanisms of the relationship between alcohol use and/or stress, in both healthy and unhealthy populations, may require a reassessment in different racial populations.

Psychological vulnerability to stress in carriers of congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

Carriers of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) demonstrate increased secretion of cortisol precursors following ACTH stimulation, suggestive of impaired cortisol production and compensatory increases in hypothalamic corticotropin-releasing hormone (CRH) secretion. Both cortisol and CRH have behavioral effects, and hypothalamic CRH hypersecretion has been associated with chronic states of anxiety and depression. We performed an endocrinologic and psychological evaluation in carriers of 21-OHD and matched control subjects. We recruited 29 parents of children with classic CAH (14 males, 15 females; age (mean±SD): 41.8±5.7 yr), and hence 21-OHD carriers, and 13 normal subjects (5 males, 8 females; age: 43.8±6.1 yr). All subjects underwent a formal ovine (o) CRH stimulation test with measurement of ACTH, cortisol, 17-hydroxyprogesterone (17-OHP) and androstenedione concentrations, which was preceded by determination of 24-hour urinary free cortisol (UFC) excretion. Psychometric assessment was performed by administering the State-Anxiety (STAI 1) and Trait-Anxiety (STAI 2) Inventory, Beck Depression Inventory, Symptom Checklist-90R and Temperament and Character Inventory. Carriers of 21-OHD had significantly higher 17-OHP concentrations following oCRH stimulation and higher STAI 1 (47.6±5.6 vs. 43.3±5.4, P=0.023) scores than control subjects. Mean 24-hour UFC concentrations were positively correlated with paranoid ideation (r=0.435; P=0.023) and psychoticism (r=0.454; P=0.017). Stepwise multiple linear regression analysis revealed that the single independent predictor of STAI 1 was peak stimulated 17-OHP concentrations (β: 0.055, SE: 0.023, R2: 0.290, P=0.031). Carriers of 21-OHD may be predisposed to the development of anxiety disorders.

Adaptations in Basal and Hypothalamic-Pituitary-Adrenal-Activated Deoxycorticosterone Responses Following Ethanol Self-administration in Cynomolgus Monkeys.

Acute ethanol activates the hypothalamic–pituitary–adrenal (HPA) axis, while long-term exposure results in a blunted neuroendocrine state, particularly with regards to the primary endpoint, cortisol, the primary glucocorticoid produced in the adrenal cortex. However, it is unknown if this dampened neuroendocrine status also influences other adrenocortical steroids. Plasma concentration of the mineralocorticoid and neuroactive steroid precursor deoxycorticosterone (DOC) is altered by pharmacological challenges of the HPA axis in cynomolgus monkeys. The present study investigated HPA axis regulation of circulating DOC concentration over the course of ethanol (4% w/v) induction and self-administration in non-human primates (Macaca fasciculata, n = 10). Plasma DOC, measured by radioimmunoassay, was compared at baseline (ethanol naïve), during schedule-induced polydipsia, and following 6-months of 22 h/day access to ethanol and water. The schedule induction of ethanol drinking did not alter basal DOC levels but selectively dampened the DOC response to pharmacological challenges aimed at the anterior pituitary (ovine corticotrophin-releasing hormone) and adrenal gland (post-dexamethasone adrenocorticotropin hormone), while pharmacological inhibition of central opioid receptors with naloxone greatly enhanced the DOC response during induction. Following 6 months of ethanol self-administration, basal DOC levels were increased more than twofold, while responses to each of the challenges normalized somewhat but remained significantly different than baseline. These data show that HPA axis modulation of the neuroactive steroid precursor DOC is markedly altered by the schedule induction of ethanol drinking and long-term voluntary ethanol self-administration. The consequences of chronic ethanol consumption on HPA axis regulation of DOC point toward allostatic modification of hypothalamic and adrenal function.

A significant proportion of thalassemia major patients have adrenal insufficiency detectable on provocative testing.

Advances in chelation therapy and noninvasive monitoring of iron overload have resulted in substantial improvements in the survival of transfusion-dependent patients with thalassemia major. Myocardial decompensation and sepsis remain the major causes of death. Although endocrine abnormalities are a well-recognized problem in these iron-overloaded patients, adrenal insufficiency and its consequences are underappreciated by the hematology community. The aims of this study were to determine the prevalence of adrenal insufficiency in thalassemia major subjects, to identify risk factors for adrenal insufficiency, and to localize the origin of the adrenal insufficiency within the hypothalamic-pituitary-adrenal axis. Eighteen subjects with thalassemia major (18.9±9.3 y old, 7 female) were tested for adrenal insufficiency using a glucagon stimulation test. Those found to have adrenal insufficiency (stimulated cortisol <18 µg/dL) subsequently underwent an ovine corticotropin-releasing hormone (oCRH) stimulation test to define the physiological basis for the adrenal insufficiency. The prevalence of adrenal insufficiency was 61%, with an increased prevalence in males over females (92% vs. 29%, P=0.049). Ten of 11 subjects who failed the glucagon stimulation test subsequently demonstrated normal ACTH and cortisol responses to oCRH, indicating a possible hypothalamic origin to their adrenal insufficiency.

Paradoxical Results after Inadvertent Use of Cosyntropin [Adrenocorticotropin Hormone (1-24)] Rather than Acthrel (Ovine Corticotropin Releasing Hormone) during Inferior Petrosal Sinus Sampling

The use of ovine corticotropin releasing hormone (oCRH) maximizes the diagnostic accuracy of inferior petrosal sinus sampling (IPSS) in patients with adrenocorticotropin hormone (ACTH)-dependent Cushing's syndrome (CS). oCRH is marketed as ACTHrel and, understandably, may be confused with cosyntropin [ACTH (1-24)]. The inadvertent substitution of synthetic ACTH(1-24) for oCRH (ACTHrel) during IPSS may cause unexpected and misleading results. The aim of this report is to raise awareness of the potential confounding results created when synthetic ACTH(1-24) is mistakenly used during IPSS. We present 3 patients treated at 3 different centers with ACTH-dependent CS in whom ACTH(1-24) was mistakenly substituted for oCRH (ACTHrel) during IPSS. In all patients, there was an abrupt and unexpected decrease in plasma ACTH in the inferior petrosal sinus (IPS) samples after presumptive stimulation with oCRH. Re-evaluation of the patients' pharmacy records confirmed that synthetic ACTH(1-24) had been used rather than oCRH during each procedure. Because "sandwich" immunometric assays for ACTH measure the entire pool of endogenous ACTH, the administration of synthetic ACTH(1-24) artifactually decreases the endogenous plasma ACTH(1-39) measurement by binding only to the N-terminal antibody raised against ACTH(1-17) and not to the C-terminal antibody raised against ACTH(34-39). This results in a lack of a detectable sandwich complex and explains the apparent reduction in ACTH concentration. An abrupt decrease in ACTH during IPSS suggests that synthetic ACTH(1-24) rather than oCRH (ACTHrel) has been administered. The labeling of oCRH as ACTHrel poses a potential patient safety problem about which endocrinologists, interventional radiologists, and pharmacists should be aware.

Comparison of Intravenous versus Intramuscular Administration of Corticotropin‐Releasing Hormone in Healthy Cats

Because of the lack of a current validated assay for feline endogenous adrenocorticotropic hormone (ACTH) in response to administration of currently available ovine corticotropin-releasing hormone (oCRH) preparations, a complete evaluation of the hypothalamic-pituitary-adrenal axis in cats has not been possible. This study was undertaken to (1) determine the pituitary (ACTH) and adrenal (cortisol) response to both IV and IM administration of a currently available oCRH product in healthy cats, and (2) validate an endogenous ACTH assay for use in cats. Seventeen healthy cats receiving oCRH (n = 11) or placebo (n = 6). Prospective, randomized, placebo-controlled study. oCRH at 1 μg/kg or placebo was given either IM or IV. Endogenous cortisol and ACTH concentrations were evaluated after the injection. A comparison of IM versus IV and placebo versus treatment was made. The DiaSorin immunoradiometric assay (IRMA) assay for ACTH performed well, showing both parallelism and acceptable intra- and interassay coefficients of variation. There was a significant difference between groups (P = .025) and a significant difference between times (P = .025) when endogenous ACTH concentrations were compared after oCRH IV or IM. No significant differences were observed in cortisol concentrations comparing IV to IM oCRH. IM administration of oCRH results in significantly greater ACTH concentrations but not cortisol concentrations when compared with IV administration. Samples should be drawn before and at 60 minutes after the injection. The Diasorin IRMA is valid for feline endogenous ACTH measurements.

Ovine corticotropin-releasing hormone (oCRH) exerts an anxiogenic-like action in the goldfish, Carassius auratus

Corticotropin-releasing hormone (CRH) is a member of the hypothalamic neuropeptide family that includes urocortins, urotensin I and sauvagine in vertebrates. CRH and urocortin act as anorexigenic factors for satiety regulation in rodents. In a goldfish model, intracerebroventricular (ICV) administration of ovine CRH (oCRH) affects not only food intake, but also locomotor activity. However, there is no information regarding the psychophysiological roles of CRH in goldfish. Therefore, we investigated the effect of oCRH on psychomotor activity in this species. ICV administration of synthetic oCRH at 20pmol/g body weight (BW) enhanced locomotor activity. Since intact goldfish prefer the lower to the upper area of a tank, we developed a method for measuring the time taken for fish to move from the lower to the upper area. ICV administration of oCRH at 20pmol/g BW and the central-type benzodiazepine receptor inverse agonist FG-7142 (an anxiogenic agent) at 1–4pmol/g BW both increased the time taken to move from the lower to the upper area. This anxiogenic-like effect of oCRH was abolished by the CRH receptor antagonist α-helical CRH(9–41) (100pmol/g BW). These results indicate that CRH can potently affect locomotor and psychomotor activities in goldfish.

What Predicts Adrenal Insufficiency in Patients with Thalassemia Major?

Abstract 5299 Background:Thalassemia is one of the most common genetic blood disorders worldwide. With recent improvements in medical therapy, patients with transfusion-dependent thalassemia, i.e., thalassemia major, are living longer. As a result, there is a greater need to address endocrine complications related to chronic iron overload. Adrenal insufficiency (AI), in particular, is important to identify because therapies are available and can be life-saving. Objectives:The objectives of this study are to determine the prevalence of AI in our population of subjects with thalassemia major; to identify risk factors that predict AI in these individuals; and to localize the origin of the AI within the hypothalamic-pituitary-adrenal (HPA) axis. Methods:This is a prospective study of individuals with thalassemia major with an enrollment goal of 30 subjects. All subjects enrolled were initially tested for AI using a glucagon stimulation test. Those found to have AI (stimulated cortisol <18 mcg/dL) subsequently underwent an ovine corticotrophin-releasing hormone (oCRH) stimulation test for confirmatory purposes and to define the physiological basis for the AI. Results:Eleven subjects (8 - 29 years old, 6 female) have been enrolled to date. In our population of patients with TM, the prevalence of AI was 55%. There was no correlation between age, number of years transfused, or ferritin levels and AI. All male patients failed the glucagon stimulation test, whereas 5 of 6 females passed the glucagon stimulation test, p = 0.0024. There was no correlation between 8 AM ACTH levels and 8 AM cortisol levels. There was a significant correlation (p = 0.025) between 8 AM cortisol level and peak cortisol level following glucagon stimulation testing. Of the six subjects with AI, two subjects subsequently failed the oCRH stimulation test (peak cortisol < 21.9 mcg/dL). In these two subjects, peak oCRH ACTH levels were elevated, 144 and 164 pg/mL, respectively, suggesting primary adrenal insufficiency. Conclusions:We conclude that 8 AM cortisol level is a good predictor of adrenal insufficiency in our population, and can potentially be used as a simple screening test for AI with a strong negative predictive value. There appears to be a male predominance of AI in our population. This may indicate a protective role of female sex in this population. Two subjects had classic primary AI with robust ACTH levels in the face of inadequate cortisol production following oCRH testing. Four subjects (all males) who failed the glucagon stimulation test subsequently demonstrated normal ACTH and cortisol response to oCRH, indicating a possible hypothalamic origin to their AI. This dysfunction is likely independent of iron overload and warrants further investigation. Alternatively, these subjects may have impaired sympathetic nervous system function leading to hypoglycemic unawareness. Both outcomes are novel to the field and of medical significance. Disclosures:Geffner:Daiichi- Sankyo: Steering Committee for Clinical Trial; Eli Lilly, Inc.: Research Contract; Endo Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Genentech, Inc: Membership on an entity's Board of Directors or advisory committees, Research Funding; Ipsen: Data Safety Monitoring Board and Research Contract; Novo Nordisk: Research Funding; Pfizer, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Selective inferior petrosal sinus sampling without venous outflow diversion in the detection of a pituitary adenoma in Cushing’s syndrome

Conventional MRI may still be an inaccurate method for the non-invasive detection of a microadenoma in adrenocorticotropin (ACTH)-dependent Cushing's syndrome (CS). Bilateral inferior petrosal sinus sampling (BIPSS) with ovine corticotropin-releasing hormone (oCRH) stimulation is an invasive, but accurate, intervention in the diagnostic armamentarium surrounding CS. Until now, there is a continuous controversial debate regarding lateralization data in detecting a microadenoma. Using BIPSS, we evaluated whether a highly selective placement of microcatheters without diversion of venous outflow might improve detection of pituitary microadenoma. We performed BIPSS in 23 patients that met clinical and biochemical criteria of CS and with equivocal MRI findings. For BIPSS, the femoral veins were catheterized bilaterally with a 6-F catheter and the inferior petrosal sinus bilaterally with a 2.7-F microcatheter. A third catheter was placed in the right femoral vein. Blood samples were collected from each catheter to determine ACTH blood concentration before and after oCRH stimulation. In 21 patients, a central-to-peripheral ACTH gradient was found and the affected side determined. In 18 of 20 patients where transsphenoidal partial hypophysectomy was performed based on BIPSS findings, microadenoma was histologically confirmed. BIPSS had a sensitivity of 94% and a specificity of 67% after oCRH stimulation in detecting a microadenoma. Correct localization of the adenoma was achieved in all Cushing's disease patients. BIPSS remains the gold standard in the detection of a microadenoma in CS. Our findings show that the selective placement of microcatheters without venous outflow diversion might further enhance better recognition to localize the pituitary tumor.

3 Tesla magnetic resonance imaging with and without corticotropin releasing hormone stimulation for the detection of microadenomas in Cushing’s syndrome

We sought to determine if higher resolution 3 Tesla (T) magnetic resonance imaging (MRI) with or without ovine corticotropin releasing hormone (o-CRH) stimulation would increase the sensitivity for detection of pituitary microadenomas in ACTH-dependent Cushing's syndrome (CS). We prospectively identified 23 patients over a 2-year period with clinical and biochemical evidence of ACTH-dependent CS with no lesion (n = 11) or equivocal lesion (n = 10) on 1.5T MRI. Subsequently, two additional MRIs were performed in random order: 3T nonstimulated MRI or 3T MRI with o-CRH in all patients. Three neuroradiologists reviewed all examinations in a randomized blinded fashion. Patients were divided into four groups, depending on the outcome of their evaluation and treatment for CS. Two patients had to be excluded, and so we report on 21 subjects. Both 3T MRI without (P < 0.016) and with o-CRH stimulation (P < 0.013) was significantly more sensitive for detection of pituitary microadenomas than 1.5T MRI for Group 1 (definitive proof of Cushing's disease, n = 10). Group 2 (those in group 1, plus three patients where dynamic/invasive testing suggested pituitary source) also showed a significant (P < 0.012) advantage for 3T. There was no difference between the 3T and the 3T o-CRH examinations for any of the pulse sequences. We did not observe a statistically significant difference in other patient groups [patients with recurrent CD (n = 6) and patients with ectopic CS (n = 2)]. The results of our prospective blinded studies suggest that 3T MRI of pituitary gland should be considered in evaluation of patients with ACTH-dependent CD when 1.5T imaging is negative or equivocal.