Amyloidosis is a disease with many faces.

Amyloidosis is a severe disease caused by protein misfolding and deposition in tissues and organs. Thirty-eight different proteins are known to be amyloidogenic. Amyloidosis is categorized into inherited or acquired, and systemic or localized. Light-chain (AL)- and transthyretin (ATTR) amyloidosis are the two most common subtypes. Awareness, early diagnosis, accurate subtyping and relevant treatment are crucial for the management. Novel therapies of systemic AL and ATTR amyloidosis have considerably improved outcome and survival. The aim of this review is to increase awareness and knowledge on diagnosing amyloidosis.

Syndrome of Congenital Insulin Resistance Caused by a Novel INSR Gene Mutation

Mutations in the INSR gene result in rare inherited syndromes causing insulin resistance, such as leprechaunism (Donohue syndrome), Rabson-Mendenhall syndrome and insulin resistance type A. Leprechaunism is an autosomal recessive disorder associated with extreme insulin resistance that leads to hyperinsulinemia, impaired glucose homeostasis, fasting hypoglycemia and postprandial hyperglycemia. Impaired insulin action causes prenatal and postnatal growth retardation. Lipoatrophy, dysmorphic facies, hypertrichosis, macrogenitosomia and hypertrophy of internal organs are also present. A male infant with congenital insulin resistance was born at term after a normal pregnancy with a weight of 1905 g (<3 c), a length of 48 cm (<3 c), and an Apgar score of 10. Intrauterine growth retardation, transient hypoglycemia, pneumonia, urinary tract infection and heart defects [patent foramen ovale (PFO); patent ductus arteriosus (PDA)] were diagnosed after birth. At 5 weeks of age, he was admitted to the regional hospital with severe fever, diarrhea and dehydration. Hyperglycemia was observed (672 mg/dL), and insulin was administered. He was referred to a hospital at 7 weeks of age for suspected neonatal diabetes and hypertrophic cardiomyopathy. The physical examination revealed a loud systolic heart murmur, tachycardia, tachypnea, dysmorphic facies, hypertrichosis, acanthosis nigricans, hypotonia, swollen nipples and enlarged testicles. Glycemic fluctuations (50-250 mg/dL) were observed. The serum insulin concentration was high (maximum 1200 IU/mL) at normoglycemia. Ultrasound of the heart confirmed progressive hypertrophic cardiomyopathy. Leprechaunism was confirmed by genetic analysis of INSR, in which a novel c.320C>G; p. Thr107Arg homozygous missense mutation was found in exon 2.

Stone heart syndrome after prolonged cardioplegia induced cardiac arrest in open-heart surgery - a pilot study on pigs.

OBJECTIVES: To investigate Stone Heart Syndrome (SHS) as consequence of prolonged ischemic arrest in an experimental study on pigs in regards to onset of SHS and pathological changes. Outcomes defined as aortic cross clamp (ACC) time until onset of SHS and cellular changes characterized by SHS. METHODS: Eight pigs were included to undergo normothermic cardioplegia induced cardiac arrest ranging from 80 to 240 minutes of ACC. Duration of ACC was defined as time from initiation of aortic cross clamping until cessation. Normothermic, cardioplegic solution administered directly into the arterial system, though in a reduced dose compared to clinical practice. Myocardial contracture evaluated by palpation of the myocardium. Biopsies were collected from the left ventricle just after the induction of cardiac arrest and after reperfusion. Biopsies were evaluated for pathological changes indicative of SHS by electron microscopy. RESULTS: Six pigs completed the full trial, while two were lost to bleeding. Pigs undergoing 80 to 120 minutes of ACC regained heart rhythm either spontaneously or after defibrillation. Pigs undergoing more than 180 minutes of ACC had contracted hearts with no electrocardiographic response indicating the development of SHS. Electron microscopy findings after ACC of 80 to 120 minutes showed no or low degrees of cellular changes, whereas pig hearts with more than 180 minutes of ACC showed severe mitochondrial changes, endothelial damage, and shortening of sarcomeres consistent with SHS. CONCLUSION: Development of SHS in pigs was ACC time dependent and solely avoided when ACC was limited to a maximum of 120 minutes.

Combined Subcutaneous Fat Aspirate and Skin Tru-Cut Biopsy for Amyloid Screening in Patients with Suspected Systemic Amyloidosis.

Screening for systemic amyloidosis is typically carried out with abdominal fat aspirates with varying reported sensitivities. Fat aspirates are preferred for use in primary screening instead of organ biopsies as they are less invasive and thereby minimize the potential risk of complications. At Odense Amyloidosis Center, we performed a prospective study on whether the combined use of fat aspirate and tru-cut skin biopsy could increase the diagnostic sensitivity. Both fat aspirates and skin biopsies were screened with Congo Red staining, and positive biopsies were subsequently subtyped using immunoelectron microscopy and mass spectrometry. Seventy-six patients were included. In total, 24 patients had systemic amyloidosis (11 AL, 12 wtATTR, 1 AA), and 6 patients had localized amyloidosis. Combined fat aspirate and skin biopsy were Congo Red-positive in 15 patients (overall sensitivity (OS) 62.5%). Fat aspirates were positive in 14 patients (OS 58.3%), and the skin biopsy was positive in 5 patients (OS 20.8%). In only one patient did the skin biopsy add extra diagnostic information. The sensitivity differed between AL and ATTR amyloidosis-81.8% and 41.7%, respectively. Using skin biopsy as the only screening method is not recommended.

The Mechanism Switching the Osteoclast From Short to Long Duration Bone Resorption.

The current models of osteoclastic bone resorption focus on immobile osteoclasts sitting on the bone surface and drilling a pit into the bone matrix. It recently appeared that many osteoclasts also enlarge their pit by moving across the bone surface while resorbing. Drilling a pit thus represents only the start of a resorption event of much larger amplitude. This prolonged resorption activity significantly contributes to pathological bone destruction, but the mechanism whereby the osteoclast engages in this process does not have an answer within the standard bone resorption models. Herein, we review observations that lead to envision how prolonged resorption is possible through simultaneous resorption and migration. According to the standard pit model, the "sealing zone" which surrounds the ruffled border (i.e., the actual resorption apparatus), "anchors" the ruffled border against the bone surface to be resorbed. Herein, we highlight that continuation of resorption demands that the sealing zone "glides" inside the cavity. Thereby, the sealing zone emerges as the structure responsible for orienting and displacing the ruffled border, e.g., directing resorption against the cavity wall. Importantly, sealing zone displacement stringently requires thorough collagen removal from the cavity wall - which renders strong cathepsin K collagenolysis indispensable for engagement of osteoclasts in cavity-enlargement. Furthermore, the sealing zone is associated with generation of new ruffled border at the leading edge, thereby allowing the ruffled border to move ahead. The sealing zone and ruffled border displacements are coordinated with the migration of the cell body, shown to be under control of lamellipodia at the leading edge and of the release of resorption products at the rear. We propose that bone resorption demands more attention to osteoclastic models integrating resorption and migration activities into just one cell phenotype.

Classification of Amyloidosis by Model-Assisted Mass Spectrometry-Based Proteomics.

Amyloidosis is a rare disease caused by the misfolding and extracellular aggregation of proteins as insoluble fibrillary deposits localized either in specific organs or systemically throughout the body. The organ targeted and the disease progression and outcome is highly dependent on the specific fibril-forming protein, and its accurate identification is essential to the choice of treatment. Mass spectrometry-based proteomics has become the method of choice for the identification of the amyloidogenic protein. Regrettably, this identification relies on manual and subjective interpretation of mass spectrometry data by an expert, which is undesirable and may bias diagnosis. To circumvent this, we developed a statistical model-assisted method for the unbiased identification of amyloid-containing biopsies and amyloidosis subtyping. Based on data from mass spectrometric analysis of amyloid-containing biopsies and corresponding controls. A Boruta method applied on a random forest classifier was applied to proteomics data obtained from the mass spectrometric analysis of 75 laser dissected Congo Red positive amyloid-containing biopsies and 78 Congo Red negative biopsies to identify novel "amyloid signature" proteins that included clusterin, fibulin-1, vitronectin complement component C9 and also three collagen proteins, as well as the well-known amyloid signature proteins apolipoprotein E, apolipoprotein A4, and serum amyloid P. A SVM learning algorithm were trained on the mass spectrometry data from the analysis of the 75 amyloid-containing biopsies and 78 amyloid-negative control biopsies. The trained algorithm performed superior in the discrimination of amyloid-containing biopsies from controls, with an accuracy of 1.0 when applied to a blinded mass spectrometry validation data set of 103 prospectively collected amyloid-containing biopsies. Moreover, our method successfully classified amyloidosis patients according to the subtype in 102 out of 103 blinded cases. Collectively, our model-assisted approach identified novel amyloid-associated proteins and demonstrated the use of mass spectrometry-based data in clinical diagnostics of disease by the unbiased and reliable model-assisted classification of amyloid deposits and of the specific amyloid subtype.

X-linked hypophosphataemic rickets in children: clinical phenotype, therapeutic strategies, and molecular background.

INTRODUCTION: X-linked hypophosphataemic rickets (XLHR) is the most common form of hypophosphataemic rickets (HR), which is caused by mutations in the PHEX gene. The aim of this work was to investigate the clinical phenotype, therapeutic strategies, and molecular background of HR in children hospitalised in our clinic. MATERIAL AND METHODS: Eleven patients aged 5.7-18.25 years were included in this study. Molecular analysis was performed using polymerase chain reaction (PCR) and direct sequencing. The PHEX gene was examined in all of the patients, whereas the FGF23 gene was analysed in 5 patients. All of them were treated with alphacalcidol and phosphorus, and 3 were additionally treated with recombinant human growth hormone (rhGH). RESULTS: The mean age at HR diagnosis was 4.05 ± 3.35 years. The mean htSDS was -2.99 ± 1.19. In 2 of the 3 patients treated with rhGH the height gain was +0.4SD and +0.3SD, respectively. In 10 of 11 patients, PHEX gene mutations were found. In 2 children, novel mutations in the PHEX gene were identified: c.325_326dupCA, N110Ifs*7 in one patient and c.899_900delTG, M300Kfs*4 in the remaining one, which coexisted with a known polymorphism c.1769-10C > T, rs3752433. In one patient, a novel deletion of exon 14 and 2 polymorphisms were detected: c.1646-46T > C, g.180417T > C, rs3213493 in intron 15 (known) and g.189156C > T in intron 17 (novel). CONCLUSION: We report 3 novel mutations in the PHEX responsible for HR. Additionally, this study reports the effects of rhGH therapy for growth promotion in HR.

Immunoelectron microscopy and mass spectrometry for classification of amyloid deposits.

Amyloidosis is a shared name for several rare, complex and serious diseases caused by extra-cellular deposits of different misfolded proteins. Accurate characterization of the amyloid protein is essential for patient care. Immunoelectron microscopy (IEM) and laser microdissection followed by tandem mass spectrometry (LMD-MS) are new gold standards for molecular subtyping. Both methods perform superiorly to immunohistochemistry, but their complementarities, strengths and weaknesses across amyloid subtypes and organ biopsy origin remain undefined. Therefore, we performed a retrospective study of 106 Congo Red positive biopsies from different involved organs; heart, kidney, lung, gut mucosa, skin and bone marrow. IEM, performed with gold-labelled antibodies against kappa light chains, lambda light chains, transthyretin and amyloid A, identified specific staining of amyloid fibrils in 91.6%; in six biopsies amyloid fibrils were not identified, and in two, the fibril subtype could not be established. LMD-MS identified amyloid protein signature in 98.1%, but in nine the amyloid protein could not be clearly identified. MS identified protein subtype in 89.6%. Corresponding specificities ranged at organ level from 94-100%. Concordance was 89.6-100% for different amyloid subtypes. Importantly, combined use of both methods increased the diagnostic classification to 100%. Some variety in performances at organ level was observed.

Association of central blood pressure with left atrial structural and functional abnormalities in hypertensive patients: Implications for atrial fibrillation prevention.

AIMS: Functional and structural abnormalities of the left atrium have been demonstrated to be clinically and prognostically significant in a range of cardiovascular disorders, increasing the risk of atrial fibrillation. Among the potential contributors to these aberrations, central arterial factors remain insufficiently defined. Accordingly, we sought to investigate the determinants of left atrium abnormalities in hypertension, with special focus on central haemodynamics. METHODS: In this retrospective, cross-sectional study, 263 patients (age 63.8 ± 8.0 years) with uncomplicated hypertension underwent echocardiography including left atrium strain (LAS) and volume analysis, and central haemodynamics assessment using radial tonometry. RESULTS: Patients were grouped depending on LAS and left atrium volume index (LAVI), using externally validated cutpoints (34.1% for LAS and 34 ml/m2 for LAVI). The subset with lower LAS (n = 124) demonstrated higher central (cPP) and brachial pulse pressure (bPP), ventricular- arterial coupling, left ventricular mass index (LVMI) and LAVI, and lower global left ventricular longitudinal strain and early diastolic tissue velocity (e'). Patients with higher LAVI (n = 119) presented higher systolic blood pressure, cPP, bPP, central augmentation pressure, LVMI and E/e' ratio and lower LAS. In multivariable analysis, cPP was independently associated with both LAS (ß = -0.22; p = 0.002) and LAVI (ß = 0.21; p = 0.003). No independent associations with left atrium parameters were shown for bPP. CONCLUSION: Higher cPP is detrimentally associated with left atrium structural and functional characteristics, thus providing a possible pathophysiological link with the development of substrate for atrial fibrillation. Prophylaxis of atrial fibrillation might be another argument for consideration in the treatment strategy in hypertension targeted measures addressing central blood pressure.

Comparison of the Diastolic Stress Test With a Combined Resting Echocardiography and Biomarker Approach to Patients With Exertional Dyspnea: Diagnostic and Prognostic Implications.

OBJECTIVES: This study sought to establish the diagnostic and prognostic value of a strategy for prediction of abnormal diastolic response to exercise (AbnDR) using clinical, biochemical, and resting echocardiographic markers in dyspneic patients with mild diastolic dysfunction. BACKGROUND: An AbnDR (increase in left ventricular filling pressure) may indicate heart failure with preserved ejection fraction as the cause of symptoms in dyspneic patients, despite a nonelevated noncardiac at rest. However, exercise testing may be inconclusive in patients with noncardiac limitations to physical activity. METHODS: In 171 dyspneic patients (64 ± 8 years) with suspected heart failure with preserved ejection fraction but resting peak early diastolic mitral inflow velocity/peak early diastolic mitral annular velocity ratio (E/e') <14, a complete echocardiogram (including assessment of myocardial deformation and rotational mechanics) and blood assays for biomarkers were performed. Echocardiography following maximal exercise was undertaken to assess AbnDR (exertional E/e' >14). Patients were followed over 26.2 ± 4.6 months for endpoints of cardiovascular hospitalization and death. RESULTS: AbnDR was present in 103 subjects (60%). Independent correlates of AbnDR were resting E/e' (odds ratio [OR]: 8.23; 95% confidence interval [CI]: 3.54 to 9.16; p < 0.001), left ventricular untwisting rate (OR: 0.60; 95% CI: 0.42 to 0.86; p = 0.006), and galectin-3-a marker of fibrosis (OR: 1.80; 95% CI: 1.21 to 2.67; p = 0.004). The use of resting E/e' >11.3 and galectin-3 <1.17 ng/ml to select patients for further diagnostic processing would have allowed exercise testing to be avoided in 65% of subjects, at the cost of misclassification of 13%. The composite outcome of cardiovascular hospitalization or death occurred in 47 patients (27.5%). The predictive value of an AbnDR response and the combined strategy (resting echocardiography and galectin-3 or exercise testing in case of an inconclusive first step) showed similar event prediction (36 vs. 34; p = 0.95). CONCLUSIONS: The implementation of a 2-step algorithm (echocardiographic evaluation of resting E/e' followed by the assessment of galectin-3) may improve the diagnosis and prognostic assessment of individuals with suspected heart failure with preserved ejection fraction who are unable to perform a diagnostic exercise test.

Integrating clinical and genetic approaches in the diagnosis of 46,XY disorders of sex development.

46,XY differences and/or disorders of sex development (DSD) are clinically and genetically heterogeneous conditions. Although complete androgen insensitivity syndrome has a strong genotype-phenotype correlation, the other types of 46,XY DSD are less well defined, and thus, the precise diagnosis is challenging. This study focused on comparing the relationship between clinical assessment and genetic findings in a cohort of well-phenotyped patients with 46,XY DSD. The study was an analysis of clinical investigations followed by genetic testing performed on 35 patients presenting to a single center. The clinical assessment included external masculinization score (EMS), endocrine profiling and radiological evaluation. Array-comparative genomic hybridization (array-CGH) and sequencing of DSD-related genes were performed. Using an integrated approach, reaching the definitive diagnosis was possible in 12 children. The correlation between clinical and genetic findings was higher in patients with a more severe phenotype (median EMS 2.5 vs 6; P = 0.04). However, in 13 children, at least one variant of uncertain significance was identified, and most times this variant did not correspond to the original clinical diagnosis. In three patients, the genetic studies guided further clinical assessment which resulted in a reclassification of initial clinical diagnosis. Furthermore, we identified eight patients harboring variants in more than one DSD genes, which was not seen in controls (2.5%; P = 0.0003). In summary, taking into account potential challenges in reaching the definitive diagnosis in 46,XY DSD, only integrated approach seems to be the best routine practice.

The choroid plexus sodium-bicarbonate cotransporter NBCe2 regulates mouse cerebrospinal fluid pH.

KEY POINTS: Normal pH is crucial for proper functioning of the brain, and disorders increasing the level of CO2 in the blood lead to a decrease in brain pH. CO2 can easily cross the barriers of the brain and will activate chemoreceptors leading to an increased exhalation of CO2 . The low pH, however, is harmful and bases such as HCO3- are imported across the brain barriers in order to normalize brain pH. We show that the HCO3- transporter NBCe2 in the choroid plexus of the blood-cerebrospinal fluid barrier is absolutely necessary for normalizing CSF pH during high levels of CO2 . This discovery represents a significant step in understanding the molecular mechanisms behind regulation of CSF pH during acid-base disturbances, such as chronic lung disease. ABSTRACT: The choroid plexus epithelium (CPE) is located in the brain ventricles where it produces the majority of the cerebrospinal fluid (CSF). The hypothesis that normal brain function is sustained by CPE-mediated CSF pH regulation by extrusion of acid-base equivalents was tested by determining the contribution of the electrogenic Na+ -HCO3- cotransporter NBCe2 to CSF pH regulation. A novel strain of NBCe2 (Slc4a5) knockout (KO) mice was generated and validated. The base extrusion rate after intracellular alkalization was reduced by 77% in NBCe2 KO mouse CPE cells compared to control mice. NBCe2 KO mice and mice with CPE-targeted NBCe2 siRNA knockdown displayed a reduction in CSF pH recovery during hypercapnia-induced acidosis of approximately 85% and 90%, respectively, compared to control mice. NBCe2 KO did not affect baseline respiration rate or tidal volume, and the NBCe2 KO and wild-type (WT) mice displayed similar ventilatory responses to 5% CO2 exposure. NBCe2 KO mice were not protected against pharmacological or heating-induced seizure development. In conclusion, we establish the concept that the CPE is involved in the regulation of CSF pH by demonstrating that NBCe2 is necessary for proper CSF pH recovery after hypercapnia-induced acidosis.

Association of Abnormal Left Ventricular Functional Reserve With Outcome in Heart Failure With Preserved Ejection Fraction.

OBJECTIVES: This study sought to determine the prognostic value of abnormal diastolic and systolic responses to exercise (on the basis of exertional E/e' and global longitudinal strain rate [GSR]) in a well-characterized population of patients with heart failure with preserved ejection fraction (HFpEF). BACKGROUND: Impaired cardiovascular functional reserve is believed to contribute to adverse outcomes in HFpEF. However, the exact characteristics of pathophysiological profiles associated with increased clinical risk are still poorly defined. METHODS: A complete echocardiogram (including assessment of myocardial deformation) was performed at rest in 205 patients (64 ± 8 years of age) with symptomatic HFpEF. Echocardiography following maximal exercise was undertaken to assess abnormal diastolic reserve (AbnDR) (exertional E/e' >14) and exercise GSR. Patients were followed over 26 ± 5 months for death and cardiovascular or heart failure (HF) hospitalization. RESULTS: Cardiovascular hospitalization or death occurred in 64 patients (31%), including 51 (25%) with HF hospitalization. The composite endpoint was associated with AbnDR (hazard ratio: 2.69; 95% confidence interval: 1.44 to 5.04; p = 0.002) and reduced exercise GSR (hazard ratio: 0.14; 95% confidence interval: 0.04 to 0.49; p = 0.002). Both exercise parameters showed prognostic value, independent from and incremental to clinical data and B-type natriuretic peptide. The ability of E/e' and GSR measurements to predict outcomes on exertion exceeded their prognostic value at rest, and the presence of reduced exertional GSR in patients with AbnDR was associated with worse prognosis (p = 0.03 for the composite endpoint and p = 0.01 for HF hospitalization). CONCLUSIONS: Both left ventricular systolic and diastolic reserves contribute to risk prediction in HFpEF. The inclusion of the exertional assessment of left ventricular function to diagnostic algorithms may improve the prognostication process in this disease condition.

Molecular Detection and Incidence of Y Chromosomal Material in Patients with Turner Syndrome.

The presence of a Y chromosome in patients with Turner syndrome (TS) is a risk factor for the development of gonadal tumor and/or virilization. With conventional cytogenetic analysis, some cells containing a Y chromosome can be missed. The aim of this study was to determine the presence and incidence of Y chromosome-derived material in TS patients using PCR and the markers SRY, DYZ1, DYZ3, DYS132, ZFY, and TSPY. Fifty-five TS patients (aged 5.5-26.75 years) were analyzed. A total of 17/55 (30.9%) were Y-positive, but only 7/17 had a Y chromosome in their karyotype and underwent gonadectomy. In 2 of these patients (28.6%), histopathologic examination revealed gonadoblastoma and dysgerminoma, respectively. In 8 patients in the studied group (8/55; 14.5%), the TSPY gene was detected, and the SRY gene (or a fragment) was identified in 9(3)/55 patients. No coding region mutations were observed in these SRY-positive patients. In conclusion, we have shown a high prevalence of Y chromosomal material in TS. Y markers were also observed in patients who had no Y chromosome in their karyotype, and PCR is very precise in detecting the presence of genetic material from the Y chromosome. Further follow-up of these Y-positive TS patients is mandatory.

[Y chromosome in Turner syndrome]. / Chromosom Y w zespole Turnera.

Turner syndrome (TS) is an inherited genetic disorder caused by numerical and/or structural chromosome X aberrations occurring at a frequency of 1:1200-1:2500 live-born girls. The most common karyotype is X chromosome monosomy (45,X) (approximately 50-60% of cases). Approximately 5-6% of patients may have abnormal Y chromosome or mosaicism characterized by the coexistence of 45,X cell line with cell line in which all or part of chromosome Y is present. In patients with TS who have all or fragmented genetic material from chromosome Y there is a substantial risk of cancerous lesions in these dysgenetic gonads. This paper stands for the review of the current knowledge on the genetic material of the Y chromosome in TS, especially in view of the risk of developing malignancies such as gonadoblastoma and dysgerminoma.

Temporal deletion of Aqp11 in mice is linked to the severity of cyst-like disease.

Aquaporin 11 (AQP11) is a channel protein with unknown biological function that is expressed in multiple tissues, including the kidney proximal tubule (PT) epithelium. Constitutive deletion of Aqp11 in mice (Aqp11-/-) results in early postnatal vacuolization in the PT and development of apparent cysts at 2 wk of age. Electron microscopy of adult Aqp11-/- mouse PT cells revealed a dilated rough endoplasmic reticulum. These changes may cause renal failure and premature death. This study examined 1) whether postnatal deletion of Aqp11 affects PT injury and cyst formation, 2) the temporal role of Aqp11 deletion on cyst development, and 3) the nature of apparent cysts. Tamoxifen-inducible Aqp11-/- mice were generated (Ti-Aqp11-/-). Deletion of Aqp11 at postnatal days (P) P2, P4, P6, P8, and P12 was investigated. Deranged renal development, especially in kidney cortex, PT cell vacuolization, and apparent tubular cysts developed only in mice where Aqp11 gene disruption was induced until P8. Aqp11 gene deletion from P12 onward did not result in a clear deficiency in renal development, PT injury, or cyst formation. Intraperitoneal injection of biotinylated-dextran (10 kDa) into adult mice resulted in extensive endocytic dextran uptake in both cystic Aqp11-/- and control PT epithelium, respectively. This suggests that apparent cysts are not membrane-enclosed structures but represent PT dilations. We conclude that Aqp11-/- mice develop cyst-like dilated proximal tubules without documented cysts at time of death.

Effect of Aldosterone Antagonism on Exercise Tolerance in Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Impaired functional capacity is a hallmark of patients with heart failure with preserved ejection fraction (HFpEF). Despite the association of HFpEF with reduced myocardial compliance attributed to fibrosis, spironolactone has not been shown to alter outcomes-perhaps reflecting the heterogeneity of underlying pathological mechanisms. OBJECTIVES: The authors sought to identify improvement in exercise capacity with spironolactone in the subset of patients with HFpEF with exercise-induced increase in ratio between early mitral inflow velocity and mitral annular early diastolic velocity (E/e') reflecting elevation of left ventricular (LV) filling pressure. METHODS: In this randomized, blinded, parallel-group, placebo-controlled trial, 150 subjects (age 67 ± 9 years) with exertional dyspnea (New York Heart Association functional class II to III, left ventricular ejection fraction >50%, diastolic dysfunction, and exertional E/e' >13), excluding those with ischemic heart disease, were recruited in a tertiary cardiology center. Patients were randomized to 6 months of oral spironolactone 25 mg/day or matching placebo. Primary outcomes were improvements in peak oxygen uptake (VO2) and exertional E/e' ratio, and secondary outcomes were improvements in exercise blood pressure response and global LV longitudinal strain. RESULTS: At follow-up, 131 patients completed therapy-64 taking spironolactone and 67 placebo. At baseline, subjects had substantial exercise limitation (peak VO2 64 ± 17% predicted). The spironolactone group showed improvement in exercise capacity (increment in peak VO2 [2.9 ml/min/kg (95% confidence interval [CI]: 1.9 to 3.9 ml/min/kg) vs. 0.3 ml/min/kg (95% CI: -0.5 to 1.1 ml/min/kg); p < 0.001], anaerobic threshold [2.0 ml/min/kg (95% CI: 0.9 to 3.2 ml/min/kg) vs. -0.9 ml/min/kg (95% CI: -3.4 to 1.6 ml/min/kg); p = 0.03], and O2 uptake efficiency [0.19 (95% CI: 0.06 to 0.31) vs. -0.07 (95% CI: -0.17 to 0.04); p = 0.002]), with reduction in exercise-induced increase in E/e' (-3.0 [95% CI: -3.9 to -2.0] vs. 0.5 [95% CI: -0.6 to 1.6]; p < 0.001). There was a significant interaction of spironolactone and change in E/e' on VO2 (p = 0.039). CONCLUSIONS: In patients with HFpEF and abnormal diastolic response to exertion, improvement in exercise E/e' mediates the beneficial effect of spironolactone on exercise capacity. Identification of exercise-induced increase in LV filling pressure in patients with HFpEF may define a subgroup with warranting trial of spironolactone.

X-Linked Adrenal Hypoplasia Congenita in a Boy due to a Novel Deletion of the Entire NR0B1 (DAX1) and MAGEB1-4 Genes.

X-linked Adrenal Hypoplasia Congenita (AHC) is caused by deletions or point mutations in the NR0B1 (DAX1) gene. We present a boy with AHC who came at the age of 25 days in a severe state due to prolonged vomiting and progressive dehydration. Laboratory studies showed prominent hyponatremia and hyperkaliemia but not hypoglycemia. Primary adrenal insufficiency was confirmed with low serum cortisol levels and high plasma ACTH levels. Hydrocortisone therapy combined with saline and glucose infusions was started immediately after blood collection. Two exons of the NR0B1 (DAX1) gene were impossible to amplify using the standard PCR method. Array CGH was used to confirm the putative copy-number variation of NR0B1 (DAX1) revealing a novel hemizygous deletion encompassing the entire NR0B1 (DAX1) gene together with the MAGEB genes. This genetic defect was also present in heterozygosity in the patient's mother. We show that NR0B1 (DAX1) gene analysis is important for confirmation of AHC diagnosis and highlights the role of genetic counseling in families with AHC patients, particularly those with X chromosome microdeletions, covering more than NR0B1 (DAX1) alone. We hope that further clinical follow-up of this patient and his family will shed a new light on the role of MAGEB genes.

Prolonged Starvation Causes Up-Regulation of AQP1 in Adipose Tissue Capillaries of AQP7 Knock-Out Mice.

Aquaporins (AQPs) are membrane proteins involved in the regulation of cellular transport and the balance of water and glycerol and cell volume in the white adipose tissue (WAT). In our previous study, we found the co-expression of the AQP1 water channel and AQP7 in the mouse WAT. In our present study, we aimed to find out whether prolonged starvation influences the AQP1 expression of AQP7 knock-out mice (AQP7 KO) in the WAT. To resolve this hypothesis, immunoperoxidase, immunoblot and immunogold microscopy were used. AQP1 expression was found with the use of immunohistochemistry and was confirmed by immunogold microscopy in the vessels of mouse WAT of all studied groups. Semi-quantitative immunoblot and quantitative immunogold microscopy showed a significant increase (by 2.5- to 3-fold) in the abundance of AQP1 protein expression in WAT in the 72 h starved AQP7 KO mice as compared to AQP7+/+ (p < 0.05) and AQP7-/- (p < 0.01) controls, respectively. In conclusion, the AQP1 water channel located in the vessels of WAT is up-regulated in response to prolonged starvation in the WAT of AQP7 KO mice. The present data suggest that an interaction of different AQP isoforms is required for maintaining proper water homeostasis within the mice WAT.

Contributions of Nondiastolic Factors to Exercise Intolerance in Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) has a complex etiology. Factors responsible for development of impaired exercise tolerance and disease progression are incompletely defined. OBJECTIVES: The authors sought to define the contributions of contractile reserve, ventriculo-arterial coupling (VAC) reserve, and chronotropic response to the progression of HFpEF. METHODS: We performed echocardiography at rest and immediately post-cardiopulmonary exercise test in 207 patients (63 ± 8 years of age) with stage C heart failure (HF) (exertional dyspnea, New York Heart Association functional class II to III, exercise capacity <80% of normal, left ventricular ejection fraction >50%, and diastolic dysfunction) and 60 patients with stage B HF (normal exercise tolerance with left ventricular hypertrophy, and/or reduced global longitudinal strain, with diastolic dysfunction). RESULTS: Symptomatic patients were grouped as stage C1 (ratio of peak early diastolic mitral flow velocity to peak early diastolic mitral annular velocity [E/e'] <13 both at rest and exercise; n = 63), C2 (E/e' >13 only at exercise; n = 118), and C3 (E/e' >13 both at rest and exercise; n = 26) HF. Exercise capacity and cardiovascular functional reserve were less impaired in stage C1 than in stages C2 and C3. Chronotropic response was more disturbed in stage C3 than C1 and C2. Changes from rest to exercise in E/e' (-0.6 ± 1.7 vs. 3.7 ± 2.8; p < 0.0001), global longitudinal strain (2.9 ± 2.0 vs. 1.6 ± 2.8; p < 0.002), VAC (-0.21 ± 0.17 vs. -0.09 ± 0.15; p < 0.0001), and in VO2-HR gradient (0.30 ± 0.07 vs. 0.26 ± 0.11; p < 0.01) were significantly different in stages B and C. CONCLUSIONS: Normal E/e' response to exertion in symptomatic HFpEF is associated with less profound impairment of exercise capacity and is accompanied by derangements of contractile state and VAC. The transition from asymptomatic to overt HFpEF is linked to diastolic, systolic, and chronotropic deficits and an increasing degree of hemodynamic disturbances in stage C HF.