IGF-2 mediated hypoglycemia and the paradox of an apparently benign lesion: a case report & review of the literature.

BACKGROUND: Non-islet cell tumour hypoglycemia (NICTH) is rarely encountered in clinical practice. Insulin-like growth factor 2 (IGF2) is the most common cause of NICTH observed in the setting of mesenchymal and epithelial neoplasia. This is a paraneoplastic syndrome caused by IGF2 activation of the insulin receptor. CASE PRESENTATION: An 80 year old female presented with a short history of recurrent episodes of confusion with laboratory confirmed hypoglycemia with a plasma glucose of 2.7 mmol/L on fasting which fulfilled Whipple's triad. Diagnostic clues to the aetiology at presentation include the fasting pattern of hypoglycemia, hypokalaemia and the absence of weight gain. A 72 hour fast with results showed early hypoglycemia and suppression of serum insulin, c-peptide, and proinsulin. Serum insulin antibody was not detected. Subsequent measurement of the serum IGF2:IGF1 ratio was elevated at 22.3 and consistent with IGF-2 mediated hypoglycemia and imaging studies demonstrated a pelvic mass. Dietary intervention and oral prednisolone abated hypoglycemia prior to surgery. Ultimately, hypoglycemia resolved following operative intervention and steroid therapy was successfully withdrawn. Histopathology was remarkable for dual neoplastic processes with uterine solitary fibrous tumour (SFT) confirmed as the source of IGF2 hypersecretion on IGF-2 immunohistochemistry and a coincidental invasive high grade serous carcinoma involving the fimbria of the right fallopian tube. CONCLUSION: The paradox in this case is that the benign solitary fibrous tumour accounted for patient morbidity through secretion of IGF2 and without treatment, posed a mortality risk. This is despite the synchronous presence of a highly malignant fallopian tube neoplasm. This case reinforces the need for thorough clinical evaluation of hypoglycemia to allow prompt and definitive management.

Clinical features and autoimmune associations in patients presenting with Idiopathic Isolated ACTH deficiency.

OBJECTIVE: Idiopathic Isolated ATCH deficiency (IIAD) is a rare cause of secondary adrenal insufficiency. As the condition is rare, and the diagnostic criteria ill-defined, there are few good clinical descriptions in the literature. We have described presenting features, autoimmune associations, natural history and responses to CRF, in a large case series of patients presenting with IIAD. DESIGN: This is a retrospective case note analysis with data derived from the recently commenced National Pituitary Database of Ireland. PATIENTS: Twenty-three patients with isolated ACTH deficiency were identified. A thorough chart and biochemistry review was performed. RESULTS: Twenty-three patients were examined (18 women and 5 men). Age at presentation ranged from 17 to 88 years, (median 48 years). Most patients complained of fatigue; 9 patients presented with hyponatraemia, 13 had autoimmune illnesses (primary hypothyroidism, n = 9). CRF stimulation testing was available in 12 of the 23 patients, 5 of whom demonstrated a rise in plasma ACTH concentrations, indicating hypothalamic, rather than pituitary aetiology. Two patients recovered ACTH secretion, and 2 patients progressed to have other pituitary hormone deficiencies. CONCLUSIONS: IIAD typically presents with insidious symptoms. Euvolaemic hyponatraemia is common at diagnosis. It is associated with autoimmune diseases, particularly primary hypothyroidism. As two patients recovered ACTH secretion, and two progressed to other pituitary hormone deficits, repeat pituitary testing should be considered, to identify recovery of function, or progression to other hormone deficits.

Adaptor protein-2 sigma subunit mutations causing familial hypocalciuric hypercalcaemia type 3 (FHH3) demonstrate genotype-phenotype correlations, codon bias and dominant-negative effects.

The adaptor protein-2 sigma subunit (AP2σ2) is pivotal for clathrin-mediated endocytosis of plasma membrane constituents such as the calcium-sensing receptor (CaSR). Mutations of the AP2σ2 Arg15 residue result in familial hypocalciuric hypercalcaemia type 3 (FHH3), a disorder of extracellular calcium (Ca(2+) o) homeostasis. To elucidate the role of AP2σ2 in Ca(2+) o regulation, we investigated 65 FHH probands, without other FHH-associated mutations, for AP2σ2 mutations, characterized their functional consequences and investigated the genetic mechanisms leading to FHH3. AP2σ2 mutations were identified in 17 probands, comprising 5 Arg15Cys, 4 Arg15His and 8 Arg15Leu mutations. A genotype-phenotype correlation was observed with the Arg15Leu mutation leading to marked hypercalcaemia. FHH3 probands harboured additional phenotypes such as cognitive dysfunction. All three FHH3-causing AP2σ2 mutations impaired CaSR signal transduction in a dominant-negative manner. Mutational bias was observed at the AP2σ2 Arg15 residue as other predicted missense substitutions (Arg15Gly, Arg15Pro and Arg15Ser), which also caused CaSR loss-of-function, were not detected in FHH probands, and these mutations were found to reduce the numbers of CaSR-expressing cells. FHH3 probands had significantly greater serum calcium (sCa) and magnesium (sMg) concentrations with reduced urinary calcium to creatinine clearance ratios (CCCR) in comparison with FHH1 probands with CaSR mutations, and a calculated index of sCa × sMg/100 × CCCR, which was ≥ 5.0, had a diagnostic sensitivity and specificity of 83 and 86%, respectively, for FHH3. Thus, our studies demonstrate AP2σ2 mutations to result in a more severe FHH phenotype with genotype-phenotype correlations, and a dominant-negative mechanism of action with mutational bias at the Arg15 residue.

Quantitative whole-body MRI in familial partial lipodystrophy type 2: changes in adipose tissue distribution coincide with biochemical improvement.

OBJECTIVE: Familial partial lipodystrophy type 2 (Online Mendelian Inheritance in Man no. 151660) is a systemic disorder characterized by regional lipoatrophy and lipohypertrophy, severe insulin resistance, and early cardiovascular death. At initial presentation, whole-body MRI allows the radiologist to accurately characterize patients with familial partial lipodystrophy and helps differentiate familial partial lipodystrophy from many other subtypes of lipodystophy. We present the findings of serial quantitative MRI analysis in two patients with familial partial lipodystrophy type 2 and outline the objective imaging changes that occur during medical therapy with oral rosiglitazone. CONCLUSION: Cervical adipose volume and visceral adipose area increased by 105% and 60% in the two patients and hepatic fat fraction decreased by 55% during a 21-month period of medical therapy. These changes coincided with a decrease in biochemical indexes of insulin resistance. Whole body quantitative MRI may therefore help to demonstrate the subclinical changes in fat deposition that occur as a result of novel treatment of familial partial lipodystrophy and with continued research may play a role in guiding the choice, duration, and intensity of novel medical therapy.

Retrospective national cohort study of pregnancy outcomes for women with type 1 and type 2 diabetes mellitus in Republic of Ireland.

AIM: Report the outcomes of pregnant women with type 1 and type 2 diabetes and to identify modifiable and non-modifiable factors associated with poor outcomes. METHODS: Retrospective analysis of pregnancy preparedness, pregnancy care and outcomes in the Republic of Ireland from 2015 to 2020 and subsequent multivariate analysis. RESULTS: In total 1104 pregnancies were included. Less than one third attended pre-pregnancy care (PPC), mean first trimester haemoglobin A1c was 7.2 ± 3.6% (55.5 ± 15.7 mmol/mol) and 52% received pre-conceptual folic acid. Poor preparation translated into poorer pregnancy outcomes. Livebirth rates (80%) were comparable to the background population however stillbirth rates were 8.7/1000 (four times the national rate). Congenital anomalies occurred in 42.5/1000 births (1.5 times the background rate). More than half of infants were large for gestational age and 47% were admitted to critical care. Multivariate analyses showed strong associations between non-attendance at PPC, poor glycaemic control and critical care admission (adjusted odds ratio of 1.68 (1.48-1.96) and 1.61 (1.43-1.86), p < 0.05 respectively) for women with type 1 diabetes. Smoking and teratogenic medications were also associated with critical care admission and hypertensive disorders of pregnancy. CONCLUSION: Pregnancy outcomes in women with diabetes are suboptimal. Significant effort is needed to optimize the modifiable factors identified in this study.

Oxidative and inflammatory status in Type 2 diabetes patients with periodontitis.

AIM: To determine the impact of periodontitis on oxidative/inflammatory status and diabetes control in Type 2 diabetes. MATERIALS AND METHODS: A comparative study of 20 Type 2 diabetes patients with periodontitis [body mass index (BMI) 31+5], 20-age/gender-matched, non-periodontitis Type 2 diabetes controls (BMI 29+6) and 20 non-diabetes periodontitis controls (BMI 25+4) had periodontal examinations and fasting blood samples collected. Oxidative stress was determined by plasma small molecule antioxidant capacity (pSMAC) and protein carbonyl levels; inflammatory status by total/differential leucocytes, fibrinogen and high sensitivity C-reactive protein (hsCRP); diabetes status by fasting glucose, HbA1c, lipid profile, insulin resistance and secretion. Statistical analysis was performed using SPSS. RESULTS: pSMAC was lower (p=0.03) and protein carbonyls higher (p=0.007) in Type 2 diabetes patients with periodontitis compared with those without periodontitis. Periodontitis was associated with significantly higher HbA1c (p=0.002) and fasting glucose levels (p=0.04) and with lower ß-cell function (HOMA-ß; p=0.01) in diabetes patients. Periodontitis had little effect on inflammatory markers or lipid profiles, but Type 2 diabetes patients with periodontitis had higher levels of hsCRP than those without diabetes (p=0.004) and the lowest levels of HDL-cholesterol of all groups. CONCLUSION: Periodontitis is associated with increased oxidative stress and compromised glycaemic control in Type 2 diabetes patients.

Case report of a phantom pheochromocytoma.

Plasma free metanephrines or urinary fractionated metanephrines are the biochemical tests of choice for the diagnosis of pheochromocytoma as they have greater sensitivity and specificity than catecholamines for pheochromocytoma detection. This case highlights the preanalytical factors which can influence metanephrine measurement and cause a false positive result. It describes a patient with a high pre-test probability of pheochromocytoma due to hypertension and a past medical history of adrenalectomy for a purported pheochromocytoma in her home country. When biochemical screening revealed grossly elevated urine normetanephrine in the presence of a previously identified right adrenal lesion, there was high clinical suspicion of a pheochromocytoma. However, functional imaging did not support this view which prompted additional testing with plasma metanephrines. Results for plasma and urine metanephrines were discordant and preanalytical drug interference was suspected. Patient medications were reviewed and sulfasalazine, an anti-inflammatory drug was identified as the most likely analytical interferent. Urinary fractionated metanephrines were re-analysed using liquid chromatography tandem mass spectrometry (LC-MS/MS) and all metanephrines were within their reference intervals. This case illustrates how method-specific analytical drug interference prompted unnecessary expensive imaging, heightened patient anxiety and resulted in lengthy investigations for what turned out to be a phantom pheochromocytoma.

Inheritance of a paternal ABCC8 variant and maternal loss of heterozygosity at 11p15 retrospectively unmasks the etiology in a case of Congenital hyperinsulinism.

Advances in genomics and 18F-DOPA PET-CT imaging have transformed the management of infants with Congenital Hyperinsulinism. Preoperative diagnosis of focal hyperinsulinism permits limited pancreatectomy with improved clinical outcomes while knowledge of the molecular etiology informs genetic counseling and provides a more accurate recurrence risk to families.

Octreotide use for rescue of vision in a pregnant patient with acromegaly.

Pregnancy in acromegaly is rare and generally safe, but tumour expansion may occur. Managing tumour expansion during pregnancy is complex, due to the potential complications of surgery and side effects of anti-tumoural medication. A 32-year-old woman was diagnosed with acromegaly at 11-week gestation. She had a large macroadenoma invading the suprasellar cistern. She developed bitemporal hemianopia at 20-week gestation. She declined surgery and was commenced on 100 µg subcutaneous octreotide tds, with normalisation of her visual fields after 2 weeks of therapy. She had a further deterioration in her visual fields at 24-week gestation, which responded to an increase in subcutaneous octreotide to 150 µg tds. Her vision remained stable for the remainder of the pregnancy. She was diagnosed with gestational diabetes at 14/40 and was commenced on basal bolus insulin regimen at 22/40 gestation. She otherwise had no obstetric complications. Foetal growth continued along the 50th centile throughout pregnancy. She underwent an elective caesarean section at 34/40, foetal weight was 3.2 kg at birth with an APGAR score of 9. The neonate was examined by an experienced neonatologist and there were no congenital abnormalities identified. She opted not to breastfeed and she is menstruating regularly post-partum. She was commenced on octreotide LAR 40 mg and referred for surgery. At last follow-up, 2 years post-partum, the infant has been developing normally. In conclusion, our case describes a first presentation of acromegaly in pregnancy and rescue of visual field loss with somatostatin analogue therapy. Learning points: Tumour expansion may occur in acromegaly during pregnancy. Treatment options for tumour expansion in pregnancy include both medical and surgical options. Somatostatin analogues may be a viable medical alternative to surgery in patients with tumour expansion during pregnancy.

Pregnancy in acromegaly is safe and is associated with improvements in IGF-1 concentrations.

Pregnancy is rarely reported in acromegaly. Many patients are diagnosed in later life and younger patients may have subfertility due to hypopituitarism. We present a case series of 17 pregnancies in 12 women with acromegaly. Twelve women with acromegaly who completed pregnancy were identified from centres involved in the Irish Pituitary Study. Eleven women had pituitary macroadenomas and one woman had a microadenoma. Only 5/17 pregnancies had optimal biochemical control of acromegaly preconception, as defined by IGF-1 concentration in the age-related reference level and plasma GH concentration of <2 µg/L. In 6/17 pregnancies, dopamine agonist treatment was continued during pregnancy; all other acromegaly treatments were discontinued during pregnancy. Effect of pregnancy on acromegaly: No patient developed new visual field abnormalities, or symptoms suggestive of tumour expansion during pregnancy. In 9/12 patients, plasma IGF-1 concentrations that were elevated preconception normalised during pregnancy. There was a reduction in plasma IGF-1 concentrations, though not into the normal range, in a further two pregnancies. Effect of acromegaly on pregnancy: 15 healthy babies were born at term; one patient underwent emergency C-section at 32 weeks for pre-eclampsia, and one twin pregnancy had an elective C-section at 35 weeks' gestation. Blood pressure remained within normal limits in the remainder of the pregnancies. Gestational diabetes did not develop in any pregnancy. Our data suggests that pregnancy in women with acromegaly is generally safe, from a maternal and foetal perspective. Furthermore, biochemical control tends to improve despite the withdrawal of somatostatin analogue therapy during pregnancy.

Universal genetic screening uncovers a novel presentation of an SDHAF2 mutation.

CONTEXT: Hereditary pheochromocytoma/paraganglioma (PC/PGL) accounts for up to 60% of previously considered sporadic tumors. Guidelines suggest that phenotype should guide genetic testing. Next-generation sequencing technology can simultaneously sequence 9 of the 18 known susceptibility genes in a timely, cost-efficient manner. OBJECTIVE: Our aim was to confirm that universal screening is superior to targeted testing in patients with histologically confirmed PC and PGL. METHODS: In two tertiary referral hospitals in Ireland, NGS was carried out on all histologically confirmed cases of PC/PGL diagnosed between 2004 and 2013. The following susceptibility genes were sequenced: VHL, RET, SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, and MAX. A multiplex ligation-dependent probe amplification analysis was performed in VHL, SDHB, SDHC, SDHD, and SDHAF2 genes to detect deletions and duplications. RESULTS: A total of 31 patients were tested, 31% (n = 10) of whom were found to have a genetic mutation. Of those patients with a positive genotype, phenotype predicted genotype in only 50% (n = 5). Significant genetic mutations that would have been missed in our cohort by phenotypic evaluation alone include a mutation in TMEM127, two mutations in SDHAF2, and two mutations in RET. Target testing would have identified three of the latter mutations based on age criteria. However, 20% of patients (n = 2) would not have satisfied any criteria for targeted testing including one patient with a novel presentation of an SDHAF2 mutation. CONCLUSION: This study supports the value of universal genetic screening for all patients with PC/PGL.

The diabetes drug liraglutide ameliorates aberrant insulin receptor localisation and signalling in parallel with decreasing both amyloid-ß plaque and glial pathology in a mouse model of Alzheimer's disease.

Alzheimer's disease (AD) has been shown to involve desensitised insulin receptor (IR) signalling. Liraglutide, a novel glucagon-like peptide 1 (GLP-1) analogue that facilitates insulin signalling, is currently approved for use in type 2 diabetes mellitus. In the present study, we show that distinctive alterations in the localisation and distribution of the IR and increased levels of insulin receptor substrate (IRS)-1 phosphorylated at serine 616 (IRS-1 pS(616)), a key marker of insulin resistance, are associated with amyloid-ß plaque pathology in the frontal cortex of a mouse model of AD, APPSWE/PS1dE9. Altered IR status in APPSWE/PS1dE9 is most evident in extracellular deposits with the appearance of dystrophic neurites, with significantly increased IRS-1 pS(616) levels detected within neurons and neurites. The IR and IRS-1 pS(616) changes occur in the vicinity of all plaques in the APPSWE/PS1dE9 brain, and a significant upregulation of astrocytes and microglia surround this pathology. We show that liraglutide treatment for 8 weeks at 25 nmol/kg body weight i.p. once daily in 7-month-old mice significantly decreases IR aberrations in conjunction with a concomitant decrease in amyloid plaque load and levels of IRS-1 pS(616). Liraglutide also induces a highly significant reduction in astrocytosis and microglial number associated with both plaques and IR pathology. The amelioration of IR aberrations and attenuation of IRS-1 pS(616) upregulation, plaque and glial activation in APPSWE/PS1dE9 mice treated with liraglutide support the investigation of the therapeutic potential of liraglutide and long-lasting GLP-1 agonists in patients with AD.