The Effect of the Exon-3-Deleted Growth Hormone Receptor on Pegvisomant-Treated Acromegaly: A Systematic Review and Meta-Analysis.

BACKGROUND: The common exon 3 deletion polymorphism of the growth hormone receptor (d3-GHR) is associated with disease severity in acromegaly patients. The GHR antagonist pegvisomant (PEGV) is highly effective in treating severe acromegaly. Response to PEGV treatment seems to be influenced by d3-GHR and appears to be more responsive to PEGV, although available results remain conflicting. OBJECTIVE: To assess the influence of d3-GHR on the responsiveness of acromegaly patients to PEGV by compiling the evidence derived from the largest available studies. DESIGN: A systematic review of the literature identified three published studies and one conference abstract. Acromegaly patients (n = 324, 49.7% d3-GHR carriers) were treated with either PEGV monotherapy or PEGV combined with long-acting somatostatin analogues and/or cabergoline. A meta-analysis of raw data from these studies was performed. RESULTS: No significant effect of the d3-GHR was observed while bringing insulin-like growth factor I (IGF-I) levels below the upper limit of normal with PEGV, which was defined as the lowest IGF-I level during PEGV treatment (mean difference: -2.3%; 95% CI: -6.5 to 1.8, p = 0.270). The PEGV dose required to achieve the lowest IGF-I levels was also not significantly influenced by individuals carrying d3-GHR (mean difference: 4.1 mg weekly; 95% CI: -5.1 to 13.2, p = 0.385). For both outcomes, separate analysis of PEGV monotherapy and combination treatment gave similar results. CONCLUSION: Our findings suggest that the d3-GHR polymorphism has no effect on biochemical disease control in acromegaly, as it is not of added value for either the prediction of PEGV responsiveness or the determination of the required PEGV dose.

Hypothalamic-Pituitary Axis in Non-Functioning Pituitary Adenomas: Focus on the Prevalence of Isolated Central Hypoadrenalism.

INTRODUCTION: Non-functioning pituitary adenomas (NFPA) account for about 40% of pituitary tumors. Pituitary deficiencies are present at diagnosis in 60-80% of NFPA, and, classically, growth hormone (GH) secretion is lost first, while adrenocorticotropic hormone is expected to disappear last. The aim of this study was to evaluate the incidence of multiple or isolated pituitary deficiencies in a large series of NFPA. MATERIALS AND METHODS: We retrospectively analyzed data on 218 NFPA cases (59% females, 59% with macroadenomas, average age: 50.2 ± 17 years) followed up at our center from 1990 to 2013. At diagnosis all patients had a complete evaluation of pituitary function in basal conditions and provocative tests for the hypothalamic-pituitary-adrenal axis, while tests for GH deficiency (GHD) were carried out in 38%. RESULTS: 52.3% of patients (65.6% of macroadenomas, 33.3% of microadenomas) presented at least 1 pituitary deficiency: isolated deficiency in 29.8%, multiple deficiencies in 30% and panhypopituitarism in 9%. Isolated deficiencies were hypogonadism in 11.5% of patients (8% in micro-, 14% in macroadenomas), hypoadrenalism in 10.1% (14% in micro-, 7% in macroadenomas) and GHD in 8.3% (8.9% in micro-, 7.8% in macroadenomas). About 30% of microadenomas had at least 1 pituitary deficiency at diagnosis, independently of tumor localization within the sellar region. CONCLUSIONS: The presence of isolated hypoadrenalism suggests that the order of appearance of hypopituitarism does not always follow the one expected. Given the relatively high prevalence of isolated hypoadrenalism even in microadenomas, we suggest a full assessment of basal and dynamic pituitary function in all NFPA regardless of tumor size.

Role of IGF1-(CA)19 promoter microsatellite in the clinical presentation of acromegaly.

BACKGROUND: A highly polymorphic Cytosine-Adenosine (CA) repeat sequence microsatellite has been identified in the promoter region of IGF1 gene. Several studies investigated the relationship between IGF1-(CA)n polymorphism and IGF1 levels, with conflicting results. Aim of this study was to investigate the influence of this polymorphism on clinical and biochemical characteristics of acromegalic patients. METHODS: Eighty-eight acromegalic patients and 104 normal subjects were included in the study. Blood DNA was extracted and analysed by microsatellite technique using capillary electrophoresis. Patients and controls were subdivided in 19/19 [homozygous for the (CA)19 allele], 19/X [heterozygous for the (CA)19 allele] and X/X (any other genotype). RESULTS: The genotype frequency was significantly different between patients and controls, the proportion of 19/19 being lower (28·4% vs. 50·0%) and 19/X and X/X higher in acromegalic patients than in controls (P = 0·004). There were no significant differences in age, gender, basal and nadir GH, IGF1-SDS, tumour size, metabolic parameters, outcome and treatment among the three groups. The different frequency of genotypes in acromegalic patients vs. controls, as well as the lack of relationship between IGF1-(CA)n polymorphism and clinical and biochemical data in acromegalic patients, was confirmed using an additional alternative genotyping considering (CA)19 and (CA)20 homozygotes and heterozygotes vs. alleles with more than 19 of 20 repeats or less. CONCLUSIONS: Our results do not support the hypothesis that IGF-(CA)n alleles may have a significant role in determining clinical, biochemical and outcome of patients with acromegaly. The possible role of IGF1 polymorphism on susceptibility to acromegaly remains to be investigated.

Hypercoagulability in patients with Cushing disease detected by thrombin generation assay is associated with increased levels of neutrophil extracellular trap-related factors.

Patients with Cushing disease (CD) are at increased risk of venous thromboembolism (VTE). It was surmised, but not conclusively shown that the risk is related to plasma hypercoagulability secondary to the glucocorticoids effect. This study is aimed at detecting hypercoagulability in patients with CD. Case-control study of 48 CD patients and controls enrolled at two Italian clinics for whom we assessed the thrombin-forming-potential in the presence of optimal activation of protein C obtained by adding into the assay system its main endothelial activator, thrombomodulin. These experimental conditions mimic more closely than any other test the in vivo situation. We observed enhanced thrombin-generation in CD patients, as shown by the modification of thrombin-generation parameters [i.e., shortened lag-time and time-to-peak, increased thrombin peak and endogenous thrombin potential (ETP)]. Moreover, the ETP ratio (with/without thrombomodulin), recognized as an index of hypercoagulability, was increased in patients as compared to controls. We attempted to explain such hypercoagulability by measuring both procoagulant and anticoagulant factors, and some other non-coagulation parameters (i.e., neutrophil extracellular traps (NET), recently associated with the VTE risk and/or increased hypercoagulability. We showed that the hypercoagulability in patients with CD is associated with increased levels of factor VIII and NET-related variables. We detected plasma hypercoagulability in patients with CD and found experimental explanation for its occurrence. Whether this hypercoagulability can entirely explain the occurrence of VTE in patients with CD should be investigated by ad-hoc clinical trials. However, until these studies will be available the evidence supports the concept that patients with CD are candidates for antithrombotic prophylaxis.

Acromegaly is associated with increased cancer risk: a survey in Italy.

It is debated if acromegalic patients have an increased risk to develop malignancies. The aim of the present study was to assess the standardized incidence ratios (SIRs) of different types of cancer in acromegaly on a large series of acromegalic patients managed in the somatostatin analogs era. It was evaluated the incidence of cancer in an Italian nationwide multicenter cohort study of 1512 acromegalic patients, 624 men and 888 women, mean age at diagnosis 45 ± 13 years, followed up for a mean of 10 years (12573 person-years) in respect to the general Italian population. Cancer was diagnosed in 124 patients, 72 women and 52 men. The SIRs for all cancers was significantly increased compared to the general Italian population (expected: 88, SIR 1.41; 95% CI, 1.18-1.68, P < 0.001). In the whole series, we found a significantly increased incidence of colorectal cancer (SIR 1.67; 95% CI, 1.07-2.58, P = 0.022), kidney cancer (SIR 2.87; 95% CI, 1.55-5.34, P < 0.001) and thyroid cancer (SIR 3.99; 95% CI, 2.32-6.87, P < 0.001). The exclusion of 11 cancers occurring before diagnosis of acromegaly (all in women) did not change remarkably the study outcome. In multivariate analysis, the factors significantly associated with an increased risk of malignancy were age and family history of cancer, with a non-significant trend for the estimated duration of acromegaly before diagnosis. In conclusion, we found evidence that acromegaly in Italy is associated with a moderate increase in cancer risk.

Thyrotropin-secreting pituitary adenomas: outcome of pituitary surgery and irradiation.

OBJECTIVE: Our objective was to describe the effects of surgery and radiotherapy on hormonal control and tumor mass in short- and long-term follow-up of TSH-secreting pituitary adenomas (TSHomas). METHODS: This was a retrospective multicenter study. RESULTS: We collected data of 70 TSHomas (70% macroadenomas). The mean follow-up was 64.4 (range 3-324) months. Overall, 97% of patients were treated with surgery; in 27% of them radiotherapy was associated. After surgery, 75% of patients normalized thyroid function, 58% normalized both pituitary imaging and hormonal profile, 9% developed pituitary deficiencies, and 3% had tumor or hormonal recurrence, all within the first 2 years after surgery. Presurgical medical treatment did not significantly improve surgical outcome (63% vs 57%). Radiotherapy controlled hypersecretion in 37% of patients within 2 years, whereas 32% of patients developed new pituitary deficiencies from 18 to 96 months from treatment. At last follow-up, 80% of patients normalized thyroid function, whereas 20% were currently on medical treatment: 85% with somatostatin analog (SSA) alone and 15% with SSA combined with methimazole. Subjects who achieved disease control had surgery as the only treatment in 80% of cases and surgery combined with irradiation in 20%. CONCLUSIONS: Surgery remains the first-choice treatment for TSHoma. If surgery is successful, recurrence is rare. When surgery is unsuccessful or contraindicated, SSA and radiotherapy are effective in controlling hyperthyroidism and tumor growth in the majority of patients. The effects of radiotherapy on TSH secretion and tumor mass are greater within the first years after treatment, whereas pituitary deficiencies may occur several years later.

Reevaluation of Acromegalic Patients in Long-Term Remission according to Newly Proposed Consensus Criteria for Control of Disease.

Acromegaly guidelines updated in 2010 revisited criteria of disease control: if applied, it is likely that a percentage of patients previously considered as cured might present postglucose GH nadir levels not adequately suppressed, with potential implications on management. This study explored GH secretion, as well as hormonal, clinical, neuroradiological, metabolic, and comorbid profile in a cohort of 40 acromegalic patients considered cured on the basis of the previous guidelines after a mean follow-up period of 17.2 years from remission, in order to assess the impact of the current criteria. At the last follow-up visit, in the presence of normal IGF-I concentrations, postglucose GH nadir was over 0.4 µg/L in 11 patients (Group A) and below 0.4 µg/L in 29 patients (Group B); moreover, Group A showed higher basal GH levels than Group B, whereas a significant decline of both GH and postglucose GH nadir levels during the follow-up was observed in Group B only. No differences in other evaluated parameters were found. These results seem to suggest that acromegalic patients considered cured on the basis of previous guidelines do not need a more intensive monitoring than patients who met the current criteria of disease control, supporting instead that the cut-off of 0.4 mcg/L might be too low for the currently used GH assay.

Severe water intoxication secondary to the concomitant intake of non-steroidal anti-inflammatory drugs and desmopressin: a case report and review of the literature.

Most of the clinical data on the safety profile of desmopressin (DDAVP), which is an effective treatment for both polyuric conditions and bleeding disorders, originate from studies on the tailoring of drug treatment, whereas few reports exist describing severe side effects secondary to drug-drug interaction. We herein describe a case of severe hyponatremia complicated by seizure and coma due to the intake of non-steroidal anti-inflammatory drugs (NSAIDs) in a patient on DDAVP replacement therapy for central diabetes insipidus (DI). A 50-yr-old Caucasian man, with congenital central DI, developed an episode of generalized tonic-clonic seizure, resulting in coma immediately after being admitted to the Emergency Unit for weakness and emesis. Based on his medical history and clinical findings, water intoxication secondary to ketoprofen intake (200 mg/day for the last 3 days) concomitant with DDAVP replacement therapy (Minirin(®) 60 mcg 4 tablets a day) was hypothesized as being the cause of the severe euvolemic hypotonic hyponatremia (natremia 113 mEq/l, plasma osmolality 238 mOsm/Kg). After standard emergency procedures, appropriate gradual restoration of serum sodium levels to the normal range was achieved in 72 hours. Hydratation was maintained according to water excretion and desmopressin therapy was re-introduced. We discuss this case report in the context of the published literature. The present report first highlights the potentially life-threatening side effects associated with over-the-counter NSAIDs during DDAVP replacement therapy for central DI. Risks and benefits of co-treatment should be carefully considered and therapeutic alternatives to NSAIDs should be recommended to patients with central DI in order to improve DDAVP safety.

Growth hormone-releasing hormone-producing pancreatic neuroendocrine tumor in a multiple endocrine neoplasia type 1 family with an uncommon phenotype.

The objective of this study was to describe a multiple endocrine neoplasia type 1 (MEN1) family characterized by primary hyperparathyroidism, in association with acromegaly because of ectopic growth hormone-releasing hormone (GHRH) secretion by a pancreatic neuroendocrine tumor in a young man and with a bronchial carcinoid in his mother. We investigate the clinical, radiological imaging, histopathologic findings, and therapy. An 18-year-old man successfully underwent subtotal parathyroidectomy for primary hyperparathyroidism. A subsequent genetic analysis showed a MEN1 gene mutation. Three years later, acromegaly because of ectopic GHRH secretion was diagnosed (pituitary MRI negative and elevated GHRH levels). A search for an ectopic tumor was unsuccessful and somatostatin analog therapy was started. Successively, scintigraphy with somatostatin analogs (68-Ga-DOTATOC-PET) showed three focal areas in the pancreatic tail. Distal pancreatectomy showed multiple pancreatic neuroendocrine tumors and hormonal status was normalized. Afterwards, the evaluation of the patient's mother, carrying the same mutation, indicated a primary hyperparathyroidism and a 4 cm lung mass. The patient underwent subtotal pneumonectomy and the histological analysis was consistent with the diagnosis of a typical bronchial carcinoid. In conclusion, an atypical phenotype may be recorded in MEN1 families, thus emphasizing the importance of the new imaging and surgical techniques in the diagnosis and treatment of such a rare disease.

GH replacement improves quality of life and metabolic parameters in cured acromegalic patients with growth hormone deficiency.

OBJECTIVE: Effects of GH replacement in patients with GH deficiency (GHD) after a cure for acromegaly so far have been poorly studied, although its prevalence among acromegalic patients may reach the 60%. The aim of the study was to evaluate whether metabolic parameters and quality of life are improved by GH replacement in patients with prior acromegaly and severe GHD. DESIGN AND METHODS: This was a prospective study on 42 GHD subjects [22 men, mean age (sd): 48 ± 10]: 10 acromegalics treated with recombinant human GH (group A), 12 acromegalics who refused treatment (group B), and 20 subjects operated for nonfunctioning pituitary adenoma on recombinant human GH (group C). Serum IGF-I levels, lipid profile, glucose levels (fasting and after an oral glucose tolerance test), glycosylated hemoglobin, insulin resistance (homeostasis model assessment insulin resistance index), anthropometric parameters (body mass index, waist circumference, body composition), and quality of life (Questions on Life Satisfaction-Hypopituitarism Z-scores) were evaluated at baseline and after 12 and 36 months. RESULTS: At baseline, group B showed higher IGF sd score than group A and C, as well as better quality of life and higher post-oral glucose tolerance test glucose levels than group A. After 12-months, similarly in group A and C, the IGF-I sd score significantly increased, and body composition and lipid profile improved, without deterioration of glucose tolerance. Quality of life significantly improved too, and the baseline difference between group A and B disappeared. Results were confirmed after 36 months. CONCLUSIONS: In GHD acromegalic patients, GH therapy improved body composition, lipid profile, and quality of life as in patients with GHD due to nonfunctioning pituitary adenoma, without negative effects on glucose metabolism. GH replacement therapy should be considered in these patients, as in patients with GHD from other causes.