Differences in somatostatin receptor subtype expression in patients with acromegaly: new directions for targeted therapy?

PURPOSE: To analyze the expression of somatostatin receptor (SSTR)2a and 5 by immunohistochemistry (IHC) in surgically resected somatotrophic pituitary adenomas and to associate expression rates with tumor size and clinical, biochemical, and histological parameters and response to somatostatin analog (SA) therapy. METHODS: Forty-three microsurgically treated patients with histopathologically proven growth hormone (GH)-producing pituitary adenoma were included (WHO 2017). SSTR subtype expression was analyzed in adenoma tissues using monoclonal antibodies (Abcam, SSTR2a-UMB1, SSTR5-UMB4). Expression rates were classified as low (≤ 20% staining positivity), moderate (21-50%), and high (> 50%). Furthermore, biochemical parameters such as human growth hormone (hGH) and insulin-like growth factor-1 (IGF-1) levels were measured and clinical, biochemical, radiological, and histological data were evaluated. RESULTS: Of the 43 patients included in this study, 28 were female and 15 were male. The median age was 52 years (range 17-72 years). The median tumor size was 1.2 cm (range: 0.13-3.93 cm). All resected tumors showed positivity for somatotrophic hormone (STH). In all tissue samples, SSTR2a signal expression was detectable in immunohistochemistry, while only 39 samples were positive for SSTR5. Thirty-six samples had a high expression of SSTR2a, while three had a moderate and four a low SSTR2a signal. In comparison, SSTR5 signal was high in 26 out of 43 samples, while seven adenomas showed a moderate and six cases a low expression rate of SSTR5. The median IGF-1 was 714.2 µg/l and the median GH 19.6 mU/l (= 6.53 µg/l). The present study indicates that there is no significant relationship between the expression rates of receptor subtypes and the parameters we analyzed. However, our study revealed that smaller adenomas have a lower baseline GH level (p = 0.015), CONCLUSION: IHC with monoclonal antibodies appears to be a suitable method to determine the expression rates of SSTR2a and 5 at protein levels, as it is not possible to draw conclusions regarding receptor subtypes solely on the basis of the parameters analyzed.

Dual-release hydrocortisone and its benefits on cognitive function and quality of sleep.

PURPOSE: Patients with adrenal insufficiency are usually treated with conventional hydrocortisone replacement therapy which fails to mimic the circadian rhythm of cortisol secretion. Dual-release hydrocortisone (DR-HC) resembles the daily normal cortisol profile improving metabolic parameters and quality of life. However, currently little is known about its impact on cognitive function. Aim of this study was to evaluate cognitive function and well-being in DR-HC treated patients compared to healthy controls and conventional HC treatment. METHODS: Twenty adults with adrenal insufficiency treated with DR-HC (Plenadren®) underwent 10 neuropsychological tests, evaluating cognitive functions. Furthermore, demographic data, quality of life, symptoms of depression, and quality of sleep were evaluated by well-established questionnaires. Patients were compared by diagnosis (PAI/SAI) and dose (≥20 mg). In addition, eighteen DR-HC treated adults were compared to eighteen matched conventionally treated adults. RESULTS: With respect to diagnosis patients with PAI performed significantly better on intellectual abilities (p = 0.038) and on executive functioning (p = 0.026) and reported a significant longer time to fall asleep (p = 0.026). Regarding DR-HC dosage, there were no significant differences in cognitive functions. Patients on high dose reported a better subjective quality of sleep (p = 0.028) than patients on low dose. In comparison to conventional HC treatment, patients with DR-HC tended to show better results in executive functioning (p = 0.099). CONCLUSION: Patients with PAI reached better results in several cognitive functions and had a worse quality of sleep than patients with SAI. Our data suggest a positive impact of DR-HC on quality of sleep. DR-HC may be better for executive functioning.

Improved cognitive function after kidney transplantation compared to hemodialysis.

End-stage renal disease is associated with chronic stress that in turn may result in endocrine changes, affect cognitive, and physical capacities and increase the risk for cardiovascular events. The objective of this study was to evaluate and characterize possible stress parameters and compare cognitive function in those patients. Physiological and biochemical stress parameters as well as cognitive function were assessed in 17 hemodialysis and 18 renal transplant patients and both groups were compared. Serum cortisol and interleukin-6 levels were elevated in both groups but showed no significant difference. Cholesterol and low-density lipoprotein levels were significantly higher in patients following renal transplantation. While heart rate variability was comparable in both groups, most cognitive tests showed better results in renal transplant patients. We showed that: (1) cognitive function may improve following renal transplantation; (2) standard biochemical stress parameters are not useful to discriminate stress in patients with chronic kidney disease; and (3) heart rate variability is unaltered in this setting.

Real-life analysis of 280 patients with surgically treated acromegaly: a single-center experience from 2008 to 2015.

OBJECTIVE: The purpose of this study was to analyze the clinical and biochemical outcome of consecutive patients with acromegaly after microscopic transsphenoidal surgery (MTS) at a single center over an 8-year period. METHODS: A retrospective analysis of patients with acromegaly treated via MTS between 2008 and 2015 at the authors' center was performed. The mean follow-up was 29 months (range 1-120 months). Parameters investigated included tumor size, pre- and postoperative insulin-like growth factor-I, growth hormone levels, pretreatment, perioperative complications, and clinical outcome. RESULTS: A total of 280 patients with acromegaly were treated surgically at the authors' center over the abovementioned time frame and were included in analyses. For 231 of these patients, complete follow-up data were available for evaluation. One hundred eighty-eight patients (81%) showed remission initially according to current criteria. So far, 23 of these patients relapsed in the further course, so that on follow-up 165 patients (71%) demonstrated full remission by surgery alone. Most patients in whom remission after surgery failed were treated with somatostatin receptor ligands and/or dopamine agonists as second-line treatment. The main postoperative complications included transient hyponatremia and diabetes insipidus (13/280; 4.6%). CSF leakage only occurred in 2 cases (2/280; 0.7%). No surgery-related death occurred. CONCLUSIONS: The data underline the effectiveness of MTS in acromegaly. Many patients with recurrent disease or incomplete tumor resection can be successfully managed pharmacologically.

Life-threatening endocrine emergencies during pregnancy - management and therapeutic features.

Endocrine emergencies during pregnancy may be life-threatening events for both mother and fetus. Besides pregnancy-associated endocrine disorders, several pre-existing endocrinopathies such as type-1 diabetes and Grave's disease or adrenal failure may acutely deteriorate during pregnancy. Since "classical" signs are often modified by pregnancy, early diagnosis and management may be hampered. In addition, laboratory tests show altered physiologic ranges and pharmacologic options are limited while therapeutic goals are mostly tighter than in the non-pregnant patient. Though subclinical endocrinopathies are more frequent and worth consideration due to their related adverse sequelae, this article focuses on endocrine emergencies complicating pregnancy.

Increased Cardiovascular Risk in Patients with Adrenal Insufficiency: A Short Review.

Cardiovascular disease (CVD) is the most common cause of death in the world. Recent studies have shown an association between adrenal insufficiency (AI) and increased cardiovascular risk (CVR). Patients with AI receive glucocorticoid (GC) replacement therapy which can lead to varying levels of blood cortisol. It was shown that these imbalances in blood cortisol may lead to a higher prevalence of coronary heart disease, major adverse coronary events, and increased mortality. GC substitution is essential in the treatment of AI without which the disease has been shown to be fatal. The most frequently used GC formula for replacement therapy is hydrocortisone (HC). There is no uniform opinion on hydrocortisone replacement therapy. Alternative GC such as prednisolone is also in use. Overreplacement of GC may lead to adverse effects including obesity, high blood pressure, and hyperglycaemia. Outcome may vary between primary and secondary AI mainly due to differences in the renin-angiotensin-aldosterone system (RAAS). Furthermore, decreased blood levels of cortisol may lead to a compensatory secretion of inflammatory mediators such as Interleukin-1 (IL-1), Interleukin-6 (IL-6), and/or tumor-necrosis factor (TNF). Physicians and patients should be properly educated about the increased risk of CVD in patients with AI.

Prevalence and Predictors of Overweight and Obesity in Patients with Pituitary Dysfunctions.

BACKGROUND: Patients with hypothalamic-pituitary disorders (HPD) may be of increased risk to develop overweight and obesity, thereby fostering cardiovascular events. However, it remains unclear if patients with pituitary dysfunctions per se have an increased risk of becoming obese. OBJECTIVE: The objective of this study was to evaluate prevalence and to identify possible predictors of overweight and obesity in patients with pituitary dysfunctions. METHODS: A total of 121 out-patients having various causes for HPD were assessed for height and body weight; body mass index (BMI) was calculated and correlated with clinical features. Patients were divided into various subgroups depending on underlying conditions and therapeutic modalities. RESULTS: Most of the HPD patients were overweight or obese with males being significantly more affected. Of interest, patients with macroadenomas suffered significantly more often from overweight and obesity than individuals with microadenomas (73.4% vs. 43.5%, p= 0.006). Increased BMI (≥25 kg/m2) tended to be more common in patients with prolactinomas (70.0%), hormone deficiencies (76.1%) and hormone replacement therapies (76.6%) than in a healthy population. CONCLUSION: In conclusion, we showed that patients with HPD: (i) frequently suffer from overweight and obesity; (ii) prevalence of overweight and obesity however is comparable to that in the general population; (iii) only patients with macroadenomas seem to have a significantly higher risk; (iv) hormone deficiencies and hormonal replacement therapy may foster weight gain and (v) radiation and surgical tumour therapy per se do not seem to be additional risk factors for weight gain.

Exploring the Impact of Short- and Long-Term Hydrocortisone Replacement on Cognitive Function, Quality of Life and Catecholamine Secretion: A Pilot Study.

Hydrocortisone (HC) substitution is essential in the treatment for patients with adrenal insufficiency (AI). Current replacement regimens however only incompletely mimic the physiological circadian rhythm of cortisol secretion, thereby resulting in subclinical temporary hypo- and hypercortisolism. Several studies point toward impairment of cognitive functions under these conditions, in part due to affected catecholamine secretion. Aim of this study was to evaluate the influence of long-term versus short-term HC replacement therapy on the adrenomedullary system and cognitive functions. Fourteen patients with primary or secondary AI were divided into two groups, depending on the duration of disease and HC replacement therapy (<15 years). All subjects underwent standardized neurocognitive testing; in addition, cortisol and catecholamine levels as well as physiological parameters and quality of life (QoL) were assessed. Patients with HC replacement therapy ≥15 years (n = 7) received significantly higher equivalent glucocorticoid doses than those with a shorter lasting therapy (n = 7; p = 0.048). Neuropsychological tests, QoL, physiological parameters, and cortisol levels did not differ significantly between both groups. Of note, norepinephrine levels were significantly lower in patients on short-term HC replacement therapy (p = 0.025). However, there were no significant differences in catecholamines with respect to the underlying pathophysiology, gender, or age. Irrespective of the duration of use, male patients scored significantly better for single aspects of QoL, whereas females performed significantly better in the attention test. Overall, we showed that duration of cortisol replacement therapy may have an impact on catecholamine release, but does not seem to affect cognitive functions and QoL.

ßIII-tubulin overexpression is linked to aggressive tumor features and shortened survival in clear cell renal cell carcinoma.

AIMS: ßIII-tubulin (TUBB3) is a microtubule component overexpression of which is found in many solid cancer types, often linked to poor patient prognosis, and has been suggested to predict failure of microtubule-targeting chemotherapeutics. This study was designed to determine prevalence and prognostic impact of TUBB3 expression in kidney cancers. METHODS AND RESULTS: A tissue microarray (TMA) containing more than 1,200 renal tumors was analyzed by immunohistochemistry. TUBB3 expression varied markedly between the different histological subtypes and was more frequent in 105 papillary cancers (75.2 %, p < 0.0001), 38 oncocytomas (52.6 %, p < 0.0001), and 22 chromophobic carcinomas (36.4 %, p = 0.1221) than in 555 clear cell RCC (16.4 %). In clear cell cancers, strong TUBB3 positivity was linked to high Fuhrman grade (p < 0.0001), advanced stage (0.002), nodal metastases (p = 0.0433), hematogenous metastases (p = 0.0016), and shortened overall survival (p < 0.0001). Associations with outcome and tumor phenotype were inversely for papillary RCC, where TUBB3 immunostaining was linked to low tumor stage (p = 0.0012) and prolonged survival (p = 0.0043). CONCLUSIONS: TUBB3 expression levels and their effects are strikingly different between ccRCC and papillary RCC. These differences may be caused by differences in VHL function between these RCC subtypes, because VHL (like TUBB3) is another strong regulator of microtubule function.