Long-acting pasireotide improves clinical signs and quality of life in Cushing's disease: results from a phase III study.

PURPOSE: Cushing's disease (CD) is associated with significant clinical burden, increased mortality risk, and impaired health-related quality of life (HRQoL). This analysis explored the effect of long-acting pasireotide on clinical signs of hypercortisolism and HRQoL in a large subset of patients with CD. METHODS: In this phase III study (clinicaltrials.gov: NCT01374906), 150 adults with CD and a mean urinary free cortisol (mUFC) level between 1.5 and 5.0 times the upper limit of normal (ULN) started long-acting pasireotide 10 or 30 mg every 28 days with dose increases/decreases permitted based on mUFC levels/tolerability (minimum/maximum dose: 5/40 mg). Changes in clinical signs of hypercortisolism and HRQoL were assessed over 12 months of treatment and were stratified by degree of mUFC control for each patient. RESULTS: Patients with controlled mUFC at month 12 (n = 45) had the greatest improvements from baseline in mean systolic (- 8.4 mmHg [95% CI - 13.9, - 2.9]) and diastolic blood pressure (- 6.0 mmHg [- 10.0, - 2.0]). Mean BMI, weight, and waist circumference improved irrespective of mUFC control. Significant improvements in CushingQoL total score of 5.9-8.3 points were found at month 12 compared with baseline, irrespective of mUFC control; changes were driven by improvements in physical problem score, with smaller improvements in psychosocial score. CONCLUSIONS: Long-acting pasireotide provided significant improvements in clinical signs and HRQoL over 12 months of treatment, which, in some cases, occurred regardless of mUFC control. Long-acting pasireotide represents an effective treatment option and provides clinical benefit in patients with CD. CLINICAL TRIAL REGISTRATION NUMBER: NCT01374906.

Black swans - neuroendocrine tumors of rare locations.

Neuroendocrine neoplasms (NEN) are rare and heterogeneous. Therefore, they often remain unrecognized for many years, causing significant disease burden. We here report on four unusual NEN presentations including a metastatic NEN of the kidney, hypoglycemia caused by an insulin-like growth factor-2-oma (previously called non-islet-cell tumor hypoglycemia), multifocal pheochromocytoma in von Hippel Lindau syndrome, and ileal NEN metastatic to the heart. One could say that each one of these tumors were "black swans" and learning about them will increase further awareness of the spectrum of NEN.

[Diagnostics and treatment of acromegaly : Necessity for targeted monitoring of comorbidities]. / Diagnostik und Therapie der Akromegalie : Notwendigkeit der gezielten Überwachung von Komorbiditäten.

Acromegaly is a rare and severe condition, presenting with typical signs and symptoms. The diagnosis is often initially made years after the first manifestations of the disease. In more than 99% of patients the disease is caused by a benign pituitary tumor that secretes growth hormone (GH). The diagnosis is based on the presence of increased insulin-like growth factor 1 (IGF-1) levels and a lack of GH suppression in the oral glucose tolerance test. The standard imaging procedure for tumor detection is magnetic resonance imaging in the region of the sella turcica. Treatment includes surgical, drug and radiation therapy. Important factors are an intensive aftercare of the patient, controls for detection of tumor recurrence and pituitary insufficiency as well as assessment of various organ functions and risk constellations. Patient care should involve close cooperation between endocrinologists, neurosurgeons and general practitioners as well as other specialist disciplines.

Total Testosterone and Calculated Estimates for Free and Bioavailable Testosterone: Influence of Age and Body Mass Index and Establishment of Sex-Specific Reference Ranges.

Measurement of sex steroids is required to evaluate gonadal function, but normative data are lacking (especially for estimates of physiologically active testosterone). Using modern immunoassays, this study established sex-specific reference ranges (2.5% and 97.5% percentiles) for total testosterone (TOT), bioactive testosterone Vermeulen (BTV), free androgen index (FAI), free testosterone Sartorius (FTS), free testosterone Vermeulen (FTV), and sex hormone binding globulin (SHBG). In the comparative study, subjects were grouped by age (18-30; 31-50; >50 years), BMI (<25; 25-30; >30 kg/m(2)), and sex. Study participants were selected in such a way that each group comprised 12 subjects (e.g., 12 males between 18 and 30 years with a BMI of <25 kg/m(2), and so on), resulting in a total of 216 controls (108 males, 108 females; age: 40.3 ± 1.0; BMI: 27.8 ± 0.4). Multiple stepwise regression analyses were performed (covariates: age, BMI, sex), and sex-specific reference ranges were applied to 50 males (age: 46.1 ± 2.3; BMI: 27.4 ± 0.7) with suspected hypogonadism. Regression analysis identified the strongest predictor of each parameter apart from sex, resulting in age-specific (males: FAI, SHBG, BTV, FTV; females: TOT, FTS, SHBG), BMI-specific (males: TOT, FTS; females: FAI, BTV, FTV) and overall cutoffs for both sexes. In male patients, overall agreement between the results derived from the estimates (i.e., BTV, FTS, FTV) was high (with discordant results in only 4%). In summary, if both the endocrine workup and the clinical presentation were taken into account, the newly established reference ranges allowed reliable identification of hypogonadal males.

High variability in baseline urinary free cortisol values in patients with Cushing's disease.

OBJECTIVE: Twenty-four-hour urinary free cortisol (UFC) sampling is commonly used to evaluate Cushing's syndrome. Because there are few data on UFC variability in patients with active Cushing's disease, we analysed baseline UFC in a large patient cohort with moderate-to-severe Cushing's disease and assessed whether variability correlates with hypercortisolism severity. These data will help clinicians establish the minimum number of UFC samples required to obtain reliable data. DESIGN: Observational study (enrolment phase of Phase III study). METHODS: Patients (n = 152) with persistent/recurrent or de novo Cushing's disease and mean UFC (mUFC) ≥1·5×ULN (normal: 30-145 nmol/24 h) were included. Mean UFC level was calculated from four 24-h urine samples collected over 2 weeks. RESULTS: Over 600 24-h UFC samples were analysed. The mUFC levels of samples 1 and 2 and samples 3 and 4 were 1000 nmol/24 h (SD 1872) and 940 nmol/24 h (SD 2148), respectively; intrapatient coefficient of variation (CV) was 38% for mUFC. The intrapatient CV using all four samples was 52% (95% CI: 48-56). The intrapatient CV was 51% (95% CI: 44-58) for samples 1 and 2, 49% (95% CI: 43-56) for samples 3 and 4 and 54% (95% CI: 49-59) for samples 1, 2 and 3. Variability in mUFC increased as UFC levels increased. There were no correlations between UFC and clinical features of hypercortisolism. CONCLUSIONS: There is intrapatient variability of approximately 50% in 24-h UFC measurements, which is relevant to targets set to estimate any treatment effect. Analysing more than two 24-h collection periods in individual patients does not result in a relevant decrease in variability. Interestingly, UFC levels did not correlate with hypercortisolism severity.

Expression analysis of GADD45γ, MEG3, and p8 in pituitary adenomas.

Preceding studies have indicated that aberrant expression levels rather than genetic changes of GADD45γ, MEG3, and p8 gene might play a role in the pathogenesis of pituitary adenomas. We analysed their expression in various normal human tissues and in different pituitary tumour types, and investigated GADD45γ mutations in a subset of adenomas. Absolute quantification by real-time RT-PCR was performed in 24 normal tissues as well as in 34 nonfunctioning, 24 somatotroph, 12 corticotroph adenomas, 4 prolactinomas, 1 FSHoma, and in 6 normal pituitaries. Furthermore, we investigated the relationship between clinical data and gene expression. A subset was screened for GADD45γ mutations by single strand conformation polymorphism analysis (SSCP) and sequencing. All normal human tissues expressed GADD45γ, MEG3, and p8 mRNA. For GADD45γ, significantly lower expression levels were found in nonfunctioning adenomas compared with normal pituitary and somatotroph adenomas. P8 and MEG3 mRNA levels were significantly lower in nonfunctioning and corticotroph adenomas compared with normal pituitary. Expression of GADD45γ was significantly higher in pituitary adenomas of female patients. No mutation was found in the GADD45γ gene. GADD45γ, MEG3, and p8 appear to have physiological functions in a variety of human tissues. GADD45γ, MEG3, and P8 may be involved in the pathogenesis of nonfunctioning and corticotroph pituitary tumours. Female gender seems to predispose to slightly higher GADD45γ expression in pituitary adenomas. Mutations of the GADD45γ are unlikely to be involved in the pathogenesis of pituitary adenomas.

Extended treatment of Cushing's disease with pasireotide: results from a 2-year, Phase II study.

In a previous 15-day, Phase II study of patients with de novo or persistent/recurrent Cushing's disease (core study), treatment with pasireotide 600 µg sc bid reduced urinary free cortisol (UFC) levels in 76% of patients and normalized UFC in 17%. The objective of this study was to evaluate the efficacy and safety of extended treatment with pasireotide. This was a planned, open-ended, single-arm, multicenter extension study (primary endpoint: 6 months). Patients aged ≥18 years with Cushing's disease who completed the core study could enter the extension if they achieved UFC normalization at core study end and/or obtained significant clinical benefit. Of the 38 patients who completed the core study, 19 entered the extension and 18 were included in the efficacy analyses (three responders, 11 reducers, four non-reducers in the core study). At data cut-off, median treatment duration in the extension was 9.7 months (range: 2 months to 4.8 years). At extension month 6, 56% of the 18 patients had lower UFC than at core baseline and 22% had normalized UFC. Of the four patients who remained on study drug at month 24, one had normalized UFC. Reductions in serum cortisol, plasma adrenocorticotropic hormone, body weight and diastolic blood pressure were observed. The most common adverse events were mild-to-moderate gastrointestinal disorders and hyperglycemia. Pasireotide offers a tumor-directed medical therapy that may be effective for the extended treatment of some patients with Cushing's disease.

Screening for Cushing's syndrome: new immunoassays require adequate normative data.

Cushing's syndrome results from chronic inappropriate exposure to excessive glucocorticoid concentrations. Low-dose dexamethasone suppression, late-night salivary cortisol, and 24-h urinary free cortisol are regarded as screening tests of first choice. Consequently, measurement of circulating cortisol (e. g., in serum, saliva, and urine) is mandatory in the diagnostic workup of suspected patients. The particular analytical procedure needs to be chosen carefully. Antibody-based immunoassays offer several potential advantages: they require small volumes and are widely available, relatively cheap, and easy to handle. Modern (ideally automated) systems also have a rapid turnaround time on a large number of samples and demonstrate high analytical accuracy. However, there are some important pitfalls. Inadequate standardization and poor interlaboratory performance remain problematic and precise reference ranges are lacking for some of the newer assays. Immunoassays are also susceptible to error due to cross-reactivity with cortisol metabolites or exogenous glucocorticoids. In contrast, steroid analysis by modern chromatographic and mass spectrometric techniques is largely independent from such interference and is therefore regarded as diagnostic gold standard. To date, however, these procedures are costly, time-consuming, and at least at present restricted to a limited number of specialized centers. This review puts special emphasis on the potential advantages of salivary cortisol analysis by immunoassays. It has been shown in numerous studies that such an approach allows excellent identification of hypercortisolemic states. In this context, use of automated systems may allow for broader use of this diagnostic tool.

Expression of neuropeptide hormone receptors in human adrenal tumors and cell lines: antiproliferative effects of peptide analogues.

Peptide analogues targeting various neuropeptide receptors have been used effectively in cancer therapy. A hallmark of adrenocortical tumor formation is the aberrant expression of peptide receptors relating to uncontrolled cell proliferation and hormone overproduction. Our microarray results have also demonstrated a differential expression of neuropeptide hormone receptors in tumor subtypes of human pheochromocytoma. In light of these findings, we performed a comprehensive analysis of relevant receptors in both human adrenomedullary and adrenocortical tumors and tested the antiproliferative effects of peptide analogues targeting these receptors. Specifically, we examined the receptor expression of somatostatin-type-2 receptor, growth hormone-releasing hormone (GHRH) receptor or GHRH receptor splice variant-1 (SV-1) and luteinizing hormone-releasing hormone (LHRH) receptor at the mRNA and protein levels in normal human adrenal tissues, adrenocortical and adrenomedullary tumors, and cell lines. Cytotoxic derivatives of somatostatin AN-238 and, to a lesser extent, AN-162, reduced cell numbers of uninduced and NGF-induced adrenomedullary pheochromocytoma cells and adrenocortical cancer cells. Both the splice variant of GHRH receptor SV-1 and the LHRH receptor were also expressed in adrenocortical cancer cell lines but not in the pheochromocytoma cell line. The GHRH receptor antagonist MZ-4-71 and LHRH antagonist Cetrorelix both significantly reduced cell growth in the adrenocortical cancer cell line. In conclusion, the expression of receptors for somatostatin, GHRH, and LHRH in the normal human adrenal and in adrenal tumors, combined with the growth-inhibitory effects of the antitumor peptide analogues, may make possible improved treatment approaches to adrenal tumors.

Measurement of urinary free cortisol by current immunoassays: need for sex-dependent reference ranges to define hypercortisolism.

Urinary free cortisol (UFC) is used to assess disease activity in hypercortisolemic patients. However, reference ranges are often lacking, especially with respect to potential confounding variables. This study analyzed upper limits of normal (ULN, mean + 2 SD) for 2 newer immunoassays, using gas chromatography-mass spectrometry (GC-MS) as reference method. Each 10 healthy subjects were grouped by age (18-29; 30-49; ≥ 50 years), BMI (< 25; ≥ 25 kg/m2), and sex, resulting in a total of 120 controls (60 males; age: 39.3±1.3 years; BMI: 25.9±0.4 kg/m2). ULN were calculated for a radioimmunoassay (RIA, Immunotech) and an electrochemiluminescence immunoassay (ECLIA, Roche) and applied to 12 hypercortisolemic patients (4 males; age: 53.1±3.1 years; BMI: 29.1±1.8 kg/m2). To determine degradation, samples were stored at 4°C (without light) or 22°C (with and without light) for 0, 24, and 72 h. Cortisol concentrations were significantly correlated: r=0.88 for RIA vs. ECLIA, r=0.75 for RIA vs. GC-MS, and r=0.77 for ECLIA vs. GC-MS (always p<0.0001). For each procedure, multiple stepwise regression analysis identified sex as the only significant predictor, resulting in sex-dependent ULN (males vs. females): 294 vs. 208 nmol/24 h (RIA), and 379 vs. 277 nmol/24 h (ECLIA). These ULN classified samples from patients as hypercortisolemic in 100% (RIA) and 95% (ECLIA). Different storage conditions over 72 h did not alter UFC levels significantly. Results of the 3 procedures were well correlated, and the use of assay- and sex-specific ULN allowed excellent identification of hypercortisolic states. UFC is stable over 72 h irrespective of the storage conditions applied.

Chemotherapy in patients with progressive, undifferentiated neuroendocrine tumors: a single-center experience.

Treatment of patients with undifferentiated and histologically confirmed neuroendocrine tumors (NET) usually includes chemotherapeutic intervention. This retrospective study evaluated the outcome of 2 such chemotherapies. 18 patients (11 males; age 56.2 ± 2.5) with proven progressive disease were enrolled (mean Ki-67 34 ± 5%). Patients were treated from 2005 to 2007 with regimen A (carboplatin, etoposide, paclitaxel), and from 2007 to 2009 with regimen B (cisplatin, etoposide). This change was due to low tolerability of regimen A. The standard imaging procedure was computed tomography. 8 patients underwent treatment with regimen A (mean 3.3 ± 0.7 courses). Due to severe side effects, 3 patients had their therapy prematurely discontinued. The treatment responses of 6 patients who received more than 1 course were: 0% complete response (CR), 17% partial response (PR), 50% stable disease (SD), and 33% progressive disease (PD). The median progression free survival (PFS) was 6.7 months (range 3.2-10.0). In contrast, 12 patients received regimen B (mean 3.8 ± 0.4 courses), and none of them dropped out because of side effects. The overall responses were: 0% CR, 17% PR, 42% SD, and 42% PD. The median PFS was 6.3 months (range 2.8-26.4). The response rates of both regimes were not statistically different. Patients who were treated with regimen B demonstrated comparable PFS and less severe side effects than patients who received regimen A. However, patients need to be aware of the relatively short PFS time. In order to improve therapeutic outcome of patients with progressive undifferentiated NET, new therapeutic approaches and larger multi-center studies are needed.

Diagnosis of adrenal insufficiency using the GHRP-6 Test: comparison with the insulin tolerance test in patients with hypothalamic-pituitary-adrenal disease.

The insulin tolerance test (ITT) is considered the gold standard for the diagnosis of adrenal insufficiency (AI). However, the test is unpleasant to perform and has the risk of serious complications. We therefore evaluated the clinical applicability of GHRP6, which is a known activator of the hypothalamic-pituitary-adrenal (HPA) axis, to test for AI. For this purpose a comparative clinical study was designed. Forty-nine patients with suspected dysfunction of the HPA axis and 20 healthy controls were enrolled. The ITT was performed in patients, and GHRP6 (1 microg/kg) testing in patients and controls. Serum cortisol over 90 min after GHRP6, in comparison to the ITT, was the main outcome measure. Thirty-one patients had a peak cortisol response of less than 500 nmol/l during ITT and were considered adrenal insufficient. For GHRP6, the mean cortisol peak was 227+/-25.7 nmol/l in the AI group versus 395+/-35.3 nmol/l in the adrenal sufficient (AS) group. ROC analysis of peak cortisol levels during GHRP6 test suggested an optimal threshold of 299 nmol/l for the diagnosis of AI (Sens. 71.0%, Spec. 77.8%). Applying upper (416 nmol/l) and lower (137 nmol/l) thresholds with high specificities in combination with early morning cortisol established the diagnosis in nearly half of the patients, even when the GHRP6 test is limited to 30 min duration. GHRP6 led to significant activation of the HPA axis with no detectable side effects, but had limited accuracy in comparison to the ITT.

Chemotherapy with paclitaxel and gemcitabine in progressive medullary and thyroid carcinoma of the follicular epithelium.

Nine patients (mean age 53) with metastasizing, progressive, medullary (MTC), thyroid carcinoma and progressive, nonradioiodine accumulating thyroid carcinoma of the follicular epithelium (follicular carcinoma, FTC and papillary carcinoma, PTC) were treated with a combination of paclitaxel and gemcitabine between 2004 and 2006. Tumors were histologically classified as follicular in 5 patients (56%), as papillary in 2 patients (22%), and medullary in 2 patients (22%). Paclitaxel (90-100 mg/m (2)) and gemcitabine (1,000 mg/m (2)) were applied for two, three, or 6 cycles every three weeks, depending on response and side effects. The effect of therapy was evaluated by radiographic imaging (CT images) and [(18)F]FDG-PET. All patients with papillary, follicular, or medullary thyroid carcinoma had continuous progression during restaging 14.8+/-8.8 weeks after initiation of chemotherapy, including one patient with stable disease after 3 cycles, but continuous progression after 6 cycles of chemotherapy. Paclitaxel and gemcitabine are not a valid chemotherapy option, in particular in patients with progressive, nonradioiodine-accumulating follicular thyroid carcinoma, who were already treated by other chemotherapeutic agents.

Association of somatostatin receptor 2 immunohistochemical expression with [111In]-DTPA octreotide scintigraphy and [68Ga]-DOTATOC PET/CT in neuroendocrine tumors.

In the absence of preoperative somatostatin receptor ( SST) scans, knowledge of immunohistochemical SST2 tumor expression may help predicting the success of somatostatin analogue-based follow-up studies and treatment of neuroendocrine tumors (NET). We studied the association between SST immunostaining and tracer uptake in [(111)In]-DTPA octreotide (DTPAOC) scintigraphy and [(68)Ga]-DOTA-D-Phe(1)-Tyr(3)-octreotide (DOTATOC) positron emission tomography (PET)/computed tomography (CT). Retrospective analy-sis of 36 NET patients was carried out. In 40 tumors, immunohistochemical SST2, SST3, and SST5 expressions were analyzed using a pathological scoring, applying monoclonal ( SST2) or polyclonal antibodies (SST3, SST5). In 14 lesions, [(111)In]-DTPAOC uptake was assessed by a semiquantitative score. In 26 tumors, [(68)Ga]-DOTATOC PET/CT was quantified using an uptake score and maximal standard uptake value (SUV(max)). Combined and separate qualitative analysis of SST scans revealed significant associations between increased tracer uptake and immunohistochemical SST2 detection (combined: rho=0.56, p=0.0002, [(111)In]-DTPAOC: rho=0.63, p=0.0152, and [(68)Ga]-DOTATOC: rho=0.52, p=0.0065, respectively). In contrast, SST3 and SST5 immunostaining was not associated with tracer uptake (all p>0.14). The semiquantitative immunohistochemical score for SST2 was associated with the [(68)Ga]-DOTATOC uptake score and SUV (max) values (rho=0.67, p=0.0002 and rho=0.63, p=0.0010, respectively), but not with the [(111)In]-DTPAOC uptake score (rho=0.24, p=0.4). In patients without preoperative SST scans, knowledge of immunohistochemical SST2 expression may help estimating the value of SST imaging in the clinical follow-up, in particular in those lesions with positive SST2 immunostaining. Negativity for SST2, however, does not rule out tracer uptake in some patients, with heterogeneous SST2 expression within the tumor as a potential explanation.

Treatment of pituitary-dependent Cushing's disease with the multireceptor ligand somatostatin analog pasireotide (SOM230): a multicenter, phase II trial.

CONTEXT: There is currently no medical therapy for Cushing's disease that targets the pituitary adenoma. Availability of such a medical therapy would be a valuable therapeutic option for the management of this disorder. OBJECTIVE: Our objective was to evaluate the short-term efficacy of the novel multireceptor ligand somatostatin analog pasireotide in patients with de novo, persistent, or recurrent Cushing's disease. DESIGN: We conducted a phase II, proof-of-concept, open-label, single-arm, 15-d multicenter study. PATIENTS: Thirty-nine patients with either de novo Cushing's disease who were candidates for pituitary surgery or with persistent or recurrent Cushing's disease after surgery without having received prior pituitary irradiation. INTERVENTION: Patients self-administered sc pasireotide 600 microg twice daily for 15 d. MAIN OUTCOME MEASURE: Normalization of urinary free cortisol (UFC) levels after 15 d treatment was the main outcome measure. RESULTS: Of the 29 patients in the primary efficacy analysis, 22 (76%) showed a reduction in UFC levels, of whom five (17%) had normal UFC levels (responders), after 15 d of treatment with pasireotide. Serum cortisol levels and plasma ACTH levels were also reduced. Steady-state plasma concentrations of pasireotide were achieved within 5 d of treatment. Responders appeared to have higher pasireotide exposure than nonresponders. CONCLUSIONS: Pasireotide produced a decrease in UFC levels in 76% of patients with Cushing's disease during the treatment period of 15 d, with direct effects on ACTH release. These results suggest that pasireotide holds promise as an effective medical treatment for this disorder.

Age and sex as predictors of biochemical activity in acromegaly: analysis of 1485 patients from the German Acromegaly Register.

OBJECTIVE: We evaluated the German Acromegaly Register for clinical variables associated with the initial biochemical activity of patients with acromegaly. DESIGN: Retrospective analysis of data in the registry. PATIENTS: A total of 1485 patients with acromegaly (males 45.6%, females 54.4%) were treated in 42 German endocrine centres until November 2005. Linear regression models were used to estimate the influence of various parameters on biochemical activity. RESULTS: Male patients with acromegaly were significantly younger at the time of diagnosis than female patients (41 vs. 47 years, P < 0.0001) and had significantly higher random GH levels than females (21 vs. 14 ng/ml, P < 0.005) and IGF-1 levels (773 vs. 679 ng/ml, P < 0.0001), respectively. Age at initial presentation turned out to be the most important independent risk factor associated with random GH levels, oral glucose tolerance test-suppressed GH levels, IGF-1 levels, body mass index (BMI), tumour size and prevalence of hypopituitarism. Sex was an independent risk factor for IGF-1 levels, BMI and prevalence of hypopituitarism. Tumour size was an independent risk factor for both GH and IGF-1 levels. CONCLUSIONS: In summary, initial biochemical activity of acromegaly is influenced by patient's age and to a lesser degree by patient's sex. Male patients are on an average 6 years younger than females.

Diagnosis of growth hormone deficiency in adults: provocative testing with GHRP6 in comparison to the insulin tolerance test.

The aim of the study was to evaluate the clinical applicability of growth hormone releasing peptide 6 (GHRP6) for the diagnosis of GH deficiency in adults. Forty-nine patients with suspected hypothalamic or pituitary disease underwent both ITT and GHRP6 (1 microg/kg) testing. In addition, 20 healthy controls were tested by GHRP6 only. Blood samples were analyzed for GH levels. Thirty patients had a GH peak response of less than 3 microg/l during ITT and were considered growth hormone deficient (GHD). For the GHRP6 test, the GH mean peak was 3.0 microg/l (+/-0.8, 0.5-20.9) in the GHD group vs. 14.8 microg/l (+/-4.7, 1.8-95.3) in the growth hormone sufficient (GHS) group. Receiver operating characteristics (ROC) analysis suggested an optimal peak GH cut-point of 3.5 microg/l with 80% sensitivity and 95% specificity. Applying upper (11.3 microg/l) and lower (3.5 microg/l) cutoffs with high specificities established the diagnosis in nearly two third of the patients. During administration of GHRP6 no side effects were observed. GHRP6 alone as a provocative test is highly specific, but with limited sensitivity for the diagnosis of GH deficiency in adults. Using upper and lower cutoffs, further testing by ITT may be necessary in only one-third of patients.

Diagnosis of secondary adrenal insufficiency: unstimulated early morning cortisol in saliva and serum in comparison with the insulin tolerance test.

Unstimulated early morning cortisol has been suggested as a first line parameter to assess adrenal function in patients with suspected secondary adrenal insufficiency. The measurement of basal salivary cortisol (BSaC) instead of basal serum cortisol (BSeC) offers some advantages, such as painless sampling and the determination of the free hormone. The objective of this study was to evaluate the diagnostic value of BSeC and BSaC in comparison to the insulin tolerance test (ITT). Seventy-seven patients with hypothalamic-pituitary disease and 184 healthy controls were enrolled. ITT were performed in patients, and BSeC as well as BSaC levels were measured in patients and controls. Upper and lower thresholds (with >or=95% specificity either for adrenal sufficiency or adrenal insufficiency) were calculated by ROC analysis both for BSeC and BSaC. The ITT identified 41 patients as adrenal insufficient and 36 patients as adrenal sufficient. Upper and lower cutoffs were 470 and 103 nmol/l for BSeC, and 21.1 and 5.0 nmol/l for BSaC, respectively. Thereby, basal cortisol allowed a highly specific diagnosis (i.e., similar to the ITT result) in either 23% (BSeC) or 27% (BSaC) of patients. We suggest the determination of unstimulated early morning cortisol as first-line screening method for the diagnosis of secondary adrenal insufficiency. If upper and lower cutoffs are used, dynamic testing could be obviated in about one fourth of cases. Due to its easy and painless collection BSaC may be preferable to BSeC.

Expression of ghrelin and its receptor in human tissues.

Ghrelin is a peptide thought to be involved in the regulation of appetite. Furthermore, significant effects on the release of growth hormone (GH) and ACTH were demonstrated. Contributing to the physiological relevance of this hormone, we investigated the expression of ghrelin and its receptor (GHS-R) in several normal human tissues. RNA samples (BD Biosciences) underwent one-step TaqMan Real-Time RT-PCR. Immunohistochemistry was performed on paraffin-embedded tissues using specific primary antibodies against ghrelin and its receptor. Relevant ghrelin mRNA levels were detected in all human tissues with the highest levels in stomach, pituitary, and small intestine. By immunohistochemistry, ghrelin peptide expression was detectable in reproductive and endocrine organs (ovary, anterior pituitary, adrenal gland), and organs of the gastrointestinal tract (stomach, pancreas). GHS-R1a mRNA expression was demonstrated in 10 of 24 human organs analyzed with the highest levels in pituitary, adrenal gland, and spinal cord. Expression of the receptor peptide was detected by immunohistochemistry in endocrine and reproductive organs (anterior pituitary, thyroid, pancreas, testis), parts of the CNS (cerebrum, cerebellum), and in single cells of bone marrow. Expression of both ghrelin and its receptor in endocrine and reproductive organs may indicate new endocrine or paracrine mechanisms of regulation in these tissues.