Search

Background and Objective BC 007 is a substance with a novel and innovative mode of action for the first-time causal treatment of chronic heart failure, associated with the occurrence of autoantibodies against the β1-adrenoceptor, and other diseases of mostly the heart and vascular system, being accompanied by the occurrence of functionally active agonistic autoantibodies against G-protein-coupled receptors (fGPCR-AAb). The proposed mechanism of action of BC 007 is the neutralisation of these pathogenic autoantibodies which stimulate the respective receptor. To evaluate the safety, tolerability, pharmacokinetics and mode of action of BC 007, single intravenous infusions of increasing concentration were given to healthy young males and healthy elderly autoantibody-negative and autoantibody-positive participants of both sexes. Methods This study was subdivided into three parts. Part A was a single-centre, randomised, double-blind, placebo-controlled safety and tolerability study including healthy young male autoantibody-negative Whites (N = 23) and Asians (N = 1), testing doses of 15, 50 and 150 mg BC 007 (Cohorts 1–3) and elderly male and female Whites (N = 8), testing a dose of 150 mg BC 007 (Cohort 4), randomly assigned in a 3:1 ratio to BC 007 or placebo. Open-label Part B included fGPCR-AAb-positive subjects (50 and 150 mg BC 007, Cohorts 1 and 2, respectively). Open-label Part C included fGPCR-AAb-positive subjects for testing doses of 300, 450, 750, 1350 mg and 1900 mg BC 007. Lower doses were either given as an infusion or divided into a bolus plus infusion up to a dose of 300 mg followed by a constant bolus of 150 mg up to a dose of 750 mg, while at doses of 1350 mg and 1900 mg it was a slow infusion with a constant infusion rate. Infusion times increased with increasing dose from 20 min (15, 50 or 150 mg) to 40 min (300, 450 or 750 mg), 75 min (1350 mg) and 105 min (1900 mg). Results The mean observed BC 007 area under the concentration–time curve (AUC0–24) increased with increasing dose in a dose proportional manner (slope estimate of 1.039). No serious adverse events were observed. Drug-related adverse events were predominantly the expected mild-to-moderate increase in bleeding time (aPTT), beginning with a dose of 50 mg, which paralleled the infusion and returned to normal shortly after infusion. fGPCR-AAb neutralisation efficiency increased with increasing dose and was achieved for all subjects in the last cohort. Conclusion BC 007 is demonstrated to be safe and well tolerated. BC 007 neutralised fGPCR-AAb, showing a trend for a dose-response relationship in elderly healthy but fGPCR-AAb-positive subjects. ClinicalTrials.gov Registration Number NCT02955420.

Aims Aptamer BC 007, a 15‐mer single‐strand DNA oligonucleotide (5'‐GGTTGGTGTGGTTGG‐3'), was developed to neutralize functional autoantibodies that bind to the extracellular domains of G protein‐coupled receptors (GPCR‐AAB), leading to the modulation of receptor‐mediated signalling cascades that induce pathophysiological states. Among the GPCR‐AAB, there are those directed against the β1‐adrenergic receptor (β1‐AAB) that are highly present in patients with dilated cardiomyopathy (DCM) and are increasingly accepted as disease drivers. Using Doberman Pinschers (DP) with DCM, which possess similarities with human DCM among these β1‐AAB positivity for that the disease‐driving role in DP DCM was demonstrated, the safety of BC 007, efficacy for neutralizing β1‐AAB, and the DP's outcome were investigated. Methods and results Fourteen client‐owned β1‐AAB‐positive DP with electrocardiographically and echocardiographically indicated DCM were treated with BC 007. For controlling, two groups were created: 14 β1‐AAB‐positive DP with DCM not treated with BC 007 (Control 1) and 14 DP with DCM closely matched to the BC 007‐treated DP (Control 2), retrospectively selected from the institutional database of DP. After treatment, DP were monitored both echocardiographically, and for β1‐AAB, and survival curves were calculated. Based on clinical and laboratory examination, no adverse effects associated with BC 007 treatment were observed during the study. Forty‐eight hours after treatment, the DP's blood was free of β1‐AAB, which led to a reduction or stabilization of left ventricular end‐systolic volume (ESVI) during β1‐AAB free time in 10 of the treated DP. In one DP, where β1‐AAB returned after 3 months and ESVI worsened again, a second BC 007 treatment after 9 months again cleared the blood from β1‐AAB and improved the ESVI. Compared with the controls, DP treated with BC 007 showed a significantly longer survival time [572 days, interquartile range (IQR) 442–840 days] vs. Control group 1 (266 days, IQR 97–438 days; logrank: P = 0.009) and Control group 2 (229 days, IQR 174–319 days; logrank: P = 0.012). Conclusions Treatment with BC 007 for β1‐AAB neutralization was safe, resulted in a long‐lasting reduction of β1‐AAB combined with improved cardiac function and prolonged the survival of DP with DCM. Using a natural large animal model of DCM considered superior to small animal models of immunization‐induced cardiomyopathy, combined with a study design comparable with clinical trials, we believe that our results provide the basis for optimism that treatment with BC 007 might also be effective in human patients with DCM.

ObjectiveTo determine contributions and functions of autoantibodies (Abs) directed to the angiotensin receptor type 1 (AT1R), which are suggested to be involved in the pathogenesis of AT1R Abs-related diseases such as systemic sclerosis (SSc).MethodsC57BL/6J mice were immunised with membrane-embedded human AT1R or empty membrane as control. Mice deficient for CD4+or CD8+T cells and B cells were immunised with membrane-embedded AT1R or an AT1R peptide proposed to be a dominant T cell epitope. A monoclonal (m)AT1R Ab was generated by hybridoma technique and transferred into C57BL/6J and AT1Ra/b knockout mice. The induced phenotype was examined by histology, immunohistochemistry, immunofluorescence, apoptosis assay and ELISA. In vitro, Abs responses towards AT1R were measured in cells of different origins and species.ResultsAT1R-immunised mice developed perivascular skin and lung inflammation, lymphocytic alveolitis, weak lung endothelial apoptosis and skin fibrosis accompanied by Smad2/3 signalling, not present in controls or mice deficient for CD4+T and B cells. The AT1R peptide 149–172 provoked lung inflammation. Application of the mAT1R Ab induced skin and lung inflammation, not observed in AT1Ra/b knockout mice. In vitro, AT1R Abs activated rat cardiomyocytes and human monocytes, enhanced angiotensin II-mediated AT1R activation in AT1R-transfected HEK293 cells via AT1R binding and mAT1R Ab-activated monocytes mediated the induction of profibrotic markers in dermal fibroblasts.ConclusionOur immunisation strategy successfully induced AT1R Abs, contributing to inflammation and, possibly, to fibrosis via activation of AT1R. Therefore, AT1R Abs are valuable targets for future therapies of SSc and other AT1R Ab-related diseases.

Background For prostate cancer, signaling pathways induced by over-boarding stimulation of G-protein coupled receptors (GPCR) such as the endothelin, α1- and β-adrenergic, muscarinic and angiotensin 1 receptors were accused to support the carcinogenesis. However, excessive receptor stimulation by physiological receptor ligands is minimized by a control system that induces receptor sensitization and down-regulation. This system is missing when so-called “functional autoantibodies” bind to the GPCR (GPCR-AAB). If GPCR-AAB were found in patients with prostate cancer, uncontrolled GPCR stimulation could make these autoantibodies an additional supporter in prostate cancer. Methods Using the bioassay of spontaneously beating cultured rat neonatal cardiomyocytes, GPCR-AAB were identified, quantified and characterized in the serum of 25 patients (aged 56–78 years, median 70 years) with prostate cancer compared to 10 male patients (aged 48–82 years, median 64) with urinary stone disorders (controls). Results Of the cancer patients, 24 (96%) and 17 (68%), respectively, carried autoantibodies directed against the α1-adrenergic receptor (α1-AAB) and endothelin receptor A (ETA-AAB). No patient was negative for both GPCR-AAB. In contrast, ETA-AAB and α1-AAB were absent in all (100%) and 9 (90%) of the 10 control patients, respectively. While α1-AAB targeted a specific epitope of the first extracellular loop of the α1-adrenergic receptor subtype A, an epitope of the second extracellular loop of the ETA receptor was identified as a target of ETA-AAB. As demonstrated in vitro, the functional activity of both autoantibodies found in prostate cancer can be neutralized by the aptamer BC007. Conclusions We hypothesized that α1-AAB and ETA-AAB, which are highly present in prostate cancer patients, could by their functional activity support carcinogenesis by excessive receptor stimulation. The in vitro demonstrated neutralization of α1- and ETA-AAB by the aptamer BC007 could open the door to complement the treatments already available for prostate cancer.

In the 1970s, autoantibodies directed against G-protein-coupled receptors (GPCR, GPCR-AAB) were discovered. After receptor binding, GPCR-AAB trigger uncontrolled receptor mediated signal cascades, thus producing pathologies. Diseases associated with such functionally active autoantibody type (functional autoantibodies) can be called "functional autoantibody diseases". Here we focus exclusively on GPCR-AAB directed against the GPCR's extracellular loops. The GPCR's role in the pathogenesis and progression is accepted in idiopathic dilated cardiomyopathy and is increasingly considered in diseases such as Chagas' cardiomyopathy, peripartum cardiomyopathy, hypertension, diabetes mellitus and scleroderma and even dementia, complex regional pain syndrome and postural orthostatic tachycardia syndrome. We briefly summarize the mechanistic background of GPCR-AAB induced pathologies, mainly focused on autoantibodies targeting the β1-adrenergic and muscarinic 2 receptors, due to their importance for cardiomyopathies. Furthermore, treatment strategies for "functional autoantibody diseases", such as for GPCR-AAB removal (therapeutic plasma exchange, immunoadsorption) and in vivo GPCR-AAB attack (intravenous IgG treatment, B-cell depletion, GPCR-AAB in vivo binding and neutralization) are critically reflected with respect to their patient benefits focused on but not exclusive to patients with dilated cardiomyopathy.

Autoantibodies directed against G-protein-coupled receptors (GPCR-AAB), an autoantibody type discovered in the 1970s, affect functionally their targets and are therefore called functional autoantibodies. GPCR-AAB are increasingly accepted as the origin or amplifier of various diseases. Here, we describe the present "gold standard" for measurement of GPCR-AAB in human blood. This bioassay monitors the chronotropic activity of GPCR-AAB by recording the spontaneous beating of cultured neonatal rat cardiomyocytes. The construction of this bioassay and its procedure and standardization for GPCR-AAB measurement are described in detail and also include the application of the bioassay for GPCR-AAB differentiation related to first the targeted receptors and IgG subclasses carrying the GPCR-AAB and second the extracellular receptor-binding site and specific epitopes targeted by the GPCR-AAB.

BackgroundAutoimmunity associated with autoantibodies directed against the β1-adrenergic receptor (β1-AAB) is increasingly accepted as driving human dilated cardiomyopathy (DCM). Unfortunately, animal models of DCM are lacking, preventing our knowledge about β1-AAB autoimmunity in DCM from being extended and hindering the development of related treatment strategies.ObjectivesTo introduce an animal model, we studied Doberman pinschers, which develop cardiomyopathy (DoCM), with similarities to human DCM, with regard to their β1-AAB autoimmunity.MethodsEighty-seven DP with DoCM and 31 (at enrolment) healthy controls were analyzed for β1-AAB; the receptor binding site and sensitivity to inhibition were determined. In controls who developed cardiomyopathy during the follow-up, β1-AAB were analyzed during the DoCM progress.ResultsFifty-nine (67.8%) DoCM dogs and 19 (61.3%) controls were β1-AAB positive. Excluding the 9 controls who developed DoCM in the follow-up, β1-AAB positivity tended to be more pronounced in DoCM.From the controls who developed DoCM, 8 were β1-AAB positive (p=0.044 vs. dogs remaining healthy); their β1-AAB level increased with the cardiomyopathy progress. Overall mortality and mortality exclusively due to cardiac reasons during the study period, were higher (p=0.002; p=0037) in β1-AAB positive dogs. The dogs’ β1-AAB targeted a specific epitope centralized on the second extracellular receptor and were sensitive to inhibition by drugs already successful tested for the corresponding human autoantibody.ConclusionsDoberman pinschers presented β1-AAB associated autoimmunity similar to that driving the pathogenesis of human DCM. Consequently, DP could remove the lack of animal models available for studying β1-AAB autoimmunity in DCM.

BACKGROUND Over-stimulation of G-protein coupled receptors (GPCRs) such as α1-adrenergic, muscarinic, endothelin, and AT1 receptors is considered to drive benign prostatic hyperplasia (BHP) which is often associated with lower urinary tract syndrome (LUTS). However, in addition to physiologic GPCR ligands, there is a new class of autoantibodies called functional autoantibodies that target the same GPCRs (GPCR-AABs) for over-stimulation, thus, presenting pathogenic potency. We hypothesize that patients with BPH/LUTS could carry GPCR-AABs representing potential targets for treatment. METHODS GPCR-AABs were identified, quantified, and characterized in the serum from 20 patients (aged 55–82 years, median 71 years) with BPH using the bioassay of spontaneously beating cultured neonatal rat cardiomyocytes. RESULTS A sum of 60% of the patients were positive for agonistic autoantibodies directed against the endothelin A receptor (ETA-AABs). ETA-AABs were associated with the IgG 1 subclass, targeted an epitope located on the second extracellular receptor loop and their agonistic activity could be neutralized by the aptamer BC007. CONCLUSIONS Agonistic ETA-AABs could—via uncontrolled over-boarding endothelin A receptor stimulation—contribute to the pathogenesis of BPH/LUTS. The in vitro demonstrated ETA-AAB neutralization by the aptamer BC007 could open the door for a new treatment strategy in patients with BPH/LUTS. Prostate © 2016 Wiley Periodicals, Inc.

Autoantibodies directed against G-protein-coupled receptors (GPCR-AAB), an autoantibody type discovered in the 1970s, affect functionally their targets and are therefore called functional autoantibodies. GPCR-AAB are increasingly accepted as the origin or amplifier of various diseases. Here, we describe the present "gold standard" for measurement of GPCR-AAB in human blood. This bioassay monitors the chronotropic activity of GPCR-AAB by recording the spontaneous beating of cultured neonatal rat cardiomyocytes. The construction of this bioassay and its procedure and standardization for GPCR-AAB measurement are described in detail and also include the application of the bioassay for GPCR-AAB differentiation related to first the targeted receptors and IgG subclasses carrying the GPCR-AAB and second the extracellular receptor-binding site and specific epitopes targeted by the GPCR-AAB.

Objectives Functional autoantibodies against Angiotensin II Receptor type 1 (AT1-AA) and Endothelin-1 Receptor type A (ETA-AA), which belong to the class of functional autoantibodies, have been discovered in patients with preeclampsia and in rodent models of pregnancy-induced hypertension. The aim of the study was to investigate the expression of these autoantibodies in relation to disease progression. Study design We included 10 controls and 41 cases defined as patients with gestational-induced hypertension, preeclampsia or HELLP syndrome. Main outcome Serum obtained in the first trimester as well as at the time of disease development were analyzed by means of a biological assay of beating cardiomyocytes. We also measured the protein expression of IL-17A in these samples. Results 100% of samples from patients with gestational induced hypertension, preeclampsia or HELLP syndrome expressed AT1-AA when they presented with clinical symptoms but not in samples from the first trimester. 44% of samples from patients with severe preeclampsia or HELLP syndrome expressed ETA-AA but only when they presented with clinical symptoms. The controls expressed neither AT1-AA nor ETA-AA. Approximately 40% of patients with severe preeclampsia or HELLP syndrome expressed IL-17A, both at the time of the onset of symptoms and in the first trimester. Conclusion Autoantibodies against the Angiotensin II receptor 1 and Endothelin receptor are developed in relation to pregnancy-induced hypertension and not present at the start of the pregnancy in these patients. IL-17A is increased in some patients with severe preeclampsia, but the expression is not related to the development of clinical symptoms.

Objectives Functional autoantibodies against the Angiotensin II Receptor type 1 (AT1-AA), and the Endothelin-1 Receptor type A (ETA-AA) which belong to the class of functional autoantibodies, has been discovered in patients with preeclampsia and in rodent models of pregnancy induced hypertension. The aim of the study was to investigate the expression of these autoantibodies in relation to disease progressionStudy designWe included 10 controls and 41 cases defined as patients with gestational induced hypertension, preeclampsia/HELLP Syndrome. Main outcome Serum obtained in the first trimester as well as serum obtained at the time of disease development were analyzed by the means of a biological assay of beating cardiomyocytes. Furthermore, we measured the protein expression of IL-17A in these samples. Results100% of samples from patients with gestational induced hypertension, preeclampsia and HELLP syndrome expressed AT1-AA at time of clinical symptoms, but not in samples from the first trimester. 44% of samples from patients with severe preeclampsia or HELLP syndrome expressed ETA-AA but only at time of clinical symptoms. The controls expressed neither AT1-AA nor ETA-AA. Approximately 40% of patients with severe preeclampsia of HELLP syndrome expressed IL-17A both at time at onset of symptoms, and in the first trimester. ConclusionAutoantibodies against the Angiotensin II receptor 1 and Endothelin receptor are developed in relation to pregnancy induced hypertension and not present in the start of the pregnancy in these patients. IL-17A is increased in some patients with severe preeclampsia but the expression is not related to development of clinical symptoms.

Cardiomyopathies such as idiopathic dilated cardiomyopathy (DCM), Chagas' cardiomyopathy and Peripartum cardiomyopathy present with autoantibodies against G-protein coupled receptors (GPCR-AABs) that agonistically activate their receptors. For the treatment of "agonistic autoantibody diseases" and in particular DCM, the removal of the GPCR-AABs by immunoadsorption (IA) has been studied with convincing patient benefit. To overcome cost and logistics problems of IA, the application of the aptamer BC007 for in vivo neutralization of GPCR-AABs could help. We demonstrate here, that the aptamer neutralized, in vitro, the presently known cardiovascular-pathogenic GPCR-AABs. In spontaneously hypertensive rats, the aptamer demonstrated its GPCR-AAB neutralizing potency in vivo. In the serum of DCM patients, the same GPCR-AAB reduction was achieved when patients were either immunoadsorbed or patient's serum was ex vivo treated with the aptamer. In our view, aptamer BC007 treatment in GPCR-AAB-positive patients would have a comparable benefit as that seen after IA. Not knowing all that interfering with our idea of aptamer-dependent neutralization of GPCR-AABs, the first preliminary steps have been taken for bringing the idea closer to patients.

Reflex sympathetic dystrophy, also known as complex regional pain syndrome (CRPS), has recently been shown to be associated with autoantibodies against β2-adrenergic and muscarinic M2 receptors. In addition to pain and sudomotor/vasomotor symptoms, dysautonomia is also observed in a subset of CRPS patients. Despite its severity, there are few effective therapies for CRPS described to date. We report a case of a 14-year-old girl with CRPS of her right leg and dysautonomia (gastroparesis, postural tachycardia) refractory to multiple therapies, successfully treated with therapeutic plasma exchange (TPE) with albumin replacement. The patient, who has serum anti β2-adrenergic and muscarinic M2 receptor autoantibodies in addition to nicotinic acetylcholine receptor ganglionic autoantibodies, underwent an initial course of five TPEs over a 2-week period. She demonstrated a clinical response to TPE as manifested by a rapid improvement in her fatigue and gastroparesis, with a gradual yet significant improvement in her leg pain and sudomotor/vasomotor flares. Following the loading procedures, the patient was treated with rituximab. She continues to require periodic TPE to maintain a remission, with additional immunosuppression being considered long term. Although further studies are needed, TPE (in combination with immunosuppression) may be an appropriate therapy for CRPS patients with detectable autoantibodies, as it is for better characterized diseases with autoantibodies against neuronal surface receptors such as myasthenia gravis or Lambert Eaton myasthenic syndrome. J. Clin. Apheresis 31:368-374, 2016. © 2015 Wiley Periodicals, Inc.

[This corrects the article DOI: 10.1371/journal.pone.0192778.].

The cardiac specific troponins (cTn) are the preferred biomarkers for the diagnosis of myocardial infarction. They are measured quantitatively in the serum. The use of highly sensitive cTn assays made the measurement of other markers (such as myoglobin, CK-MB mass, fatty acid binding protein) redundant, because they confer no added diagnostic benefit. To date, highly sensitive cTn assays are available only on two POCT benchtop devices. Laboratory assays used in heart failure include the use of BNP and NT-pro-BNP markers as recommended by the European and American Associations for the screening and diagnosis of heart failure. POCT methods are now becoming capable of measuring these cardiac markers with high sensitivity.

Background: Invasive measurement of left ventricular filling pressure is the gold standard for determining diastolic dysfunction and predicting subsequent outcomes. For repetitive assessment of diastolic function during long-term management, noninvasive surrogates are used. Their reliability and reproducibility should be validated separately for different cardiovascular diseases and conditions. The aim of this study was to identify noninvasive surrogates of invasively derived left ventricular filling pressure and to relate these surrogates to outcomes (death or valve replacement) in patients with stable, asymptomatic valvular heart disease and preserved ejection fraction. Materials and Methods: In a first cohort, we investigated 54 patients who had spiroergometry, echocardiography, and left heart catheterization within a range of 100 days. In a second cohort (n = 64), noninvasive measures were related to outcomes after follow-up of 694 ± 576 days. Transmitral doppler E/tissue doppler E’ (E/E’), E/flow propagation velocity (E/Vp), isovolumetric relaxation time/time to E’-time to E (IVRT/TE’-TE), ventilatory efficiency (VE/VCO2slope), O2 consumption at anaerobic threshold and at peak exercise (VO2AT, VO2peak) as well as NT-pro brain natriuretic peptide (NTpro-BNP) were assessed in relation to left ventricular filling pressure and outcome. Results: NT-proBNP, VO2AT, VE/VCO2slope as well as echocardiographic surrogates E/E’ and E/flow propagation velocity were indicators of elevated end diastolic filling pressure. In multivariable analysis, VO2AT was the only independent predictor. NT-proBNP was the only surrogate of left ventricular filling pressure which predicted outcome. Conclusion: In patients with asymptomatic valvular heart disease and preserved systolic function, spiroergometric parameters and NT-proBNP performed best to assess filling pressure. Only NT-proBNP showed prognostic value in this cohort.

Zusammenfassung Berichtet wird über das von der Deutschen Gesellschaft für Klinische Chemie und Laboratoriumsmedizin (DGKL) im Rahmen der „Analytica Conference, München 2014 “organisiertes Symposium „Autoantikörper gegen G-Protein gekoppelte Rezeptoren und Herz-Kreislauf-Krankheiten“, in dem Informationen zur Epidemiologie, Biochemie und Pathobiochemie von Erkrankungen, die mit dem Auftreten von Autoantikörpern gegen G-Protein gekoppelte Rezeptoren (GPCR-AAK) assoziiert sind, vermittelt wurden. In sechs Vorträgen, fokussiert auf Herz-Kreislauf-Krankheiten insbesondere auf Kardiomyopathien, wurde über a) diagnostische Möglichkeiten zum Nachweis von GPCR-AAK, b) zelluläre Untersuchungen zu den pathogenetischen Mechanismen von GPCR-AAK, c) die Etablierung eines Tiermodells zum Nachweis der Kausalität von GPCR-AAK-Bildung und Krankheitspathogenese sowie d) bereits existierende GPCR-AAK bezogene Therapien (Immunapherese) bzw. „under study“ befindliche neue Konzepte für die in vivo Neutralisation von GPCR-AAK berichtet.

Agonistic autoantibodies (AABs) against G-protein-coupled receptor (GPCR) are present mainly in diseases of the cardiovascular system or in diseases associated with cardiovascular disturbances. The increasing knowledge about the role of autoantibodies against G-protein-coupled receptor (GPCR-AABs) as pathogenic drivers, the resulting development of strategies aimed at their removal or neutralization, and the evidenced patient benefit associated with such therapies have created the need for a summary of GPCR-AAB-associated diseases. Here, we summarize the present knowledge about GPCR-AABs in cardiovascular diseases. The identity of the GPCR-AABs and their prevalence in each of several specific cardiovascular diseases are documented. The structure of GPCR is also briefly discussed. Using this information, differences between classic agonists and GPCR-AABs in their GPCR binding and activation are presented and the resulting pathogenic consequences are discussed. Furthermore, treatment strategies that are currently under study, most of which are aimed at the removal and in vivo neutralization of GPCR-AABs, are indicated and their patient benefits discussed. In this context, immunoadsorption using peptides/proteins or aptamers as binders are introduced. The use of peptides or aptamers for in vivo neutralization of GPCR-AABs is also described. Particular attention is given to the GPCR-AABs directed against the adrenergic beta1-, beta2-, and α1-receptor as well as the muscarinic receptor M2, angiotensin II-angiotensin receptor type I, endothelin1 receptor type A, angiotensin (1-7) Mas-receptor, and 5-hydroxytryptamine receptor 4. Among the diseases associated with GPCR-AABs, special focus is given to idiopathic dilated cardiomyopathy, Chagas' cardiomyopathy, malignant and pulmonary hypertension, and kidney diseases. Relationships of GPCR-AABs are indicated to glaucoma, peripartum cardiomyopathy, myocarditis, pericarditis, preeclampsia, Alzheimer's disease, Sjörgren's syndrome, and metabolic syndrome after cancer chemotherapy.

Autoantibodies (AABs) against the second extracellular loop of the beta1-receptor (beta1(II)-AABs) are found as a pathogenic driver in patients with idiopathic dilated cardiomyopathy, Chagas cardiomyopathy, peripartum cardiomyopathy, and myocarditis, and have been increasingly seen as a treatment target. We recently identified an aptamer (single short DNA strand) that specifically binds and neutralizes beta1(II)-AABs. Via application of this aptamer, a new treatment strategy for diseases associated with the cardio-pathogenic beta1(II)-AABs could be developed. Spontaneously hypertensive rats (SHR) positive for beta1(II)-AABs were treated five times at weekly intervals (bolus application of 2 mg/kg body weight followed by an infusion of the same amount over 20 min). SHR responded to aptamer treatment with a strong reduction in the cardio-pathogenic beta1(II)-AABs. The AABs did not substantially return within the study period. No signs for aptamer toxicity were observed by visual examination of the heart, liver, and kidney, or by measurement of plasma CK, ALT, and creatinine. The aptamer's potential for beta1(II)-AAB neutralization and consequently for cardiomyopathy treatment has been shown for the first time in vivo.

Objective Chronic Chagas disease afflicts millions of patients in Latin America of which 70% remain asymptomatic but 30% develop fatal heart injury. To evaluate the impact of laboratory medicine for diagnosis and guiding of patients with Chagas' heart disease, we measured N-terminal B-type natriuretic peptide (NT-proBNP) and cardiac troponin T (cTnT). Design and methods NT-proBNP and cTnT using the highly sensitive assay (hs-cTnT) were measured in 48 asymptomatic Chagas' patients (control group; (−) CM), and in symptomatic patients who suffered from mild/moderate (group (+/++) CM, n = 62) or severe cardiomyopathy (group (+++) CM, n = 27). Results Both markers were higher in (+/++) CM and (+++) CM vs. (−) CM and increased in the cardiomyopathy severity. Values of 3 ng/L cTnT and 160 ng/L NT-proBNP were calculated as optimal cut-offs to distinguish (−) CM vs. CM. The NT-proBNP cut-off of 125 ng/L, as recommended by international guidelines, was additionally incorporated in the analysis. Cardiomyopathy was most successfully predicted by dual positivity of both markers (positive predictive value = 1.0). Negativity of both markers effectively excluded cardiomyopathy (negative predictive value of 0.85). Positivity for at least one of the markers is the best for overall correct classification. Conclusions Combined measurement of hs-cTnT and NT-proBNP can be used for diagnosis and monitoring of cardiomyopathy in chronic Chagas' patients. In this way, laboratory medicine increases the pre-test probability of the cardiologic diagnostics, which would reduce its time, cost, and logistical problems.

Autoimmunity is increasingly accepted as the origin or amplifier of various diseases. In contrast to classic autoantibodies (AABs) that induce immune responses resulting in destruction of the affected tissue, the additional class of “agonist-like AABs” is directed against G-protein-coupled receptors (GPCRs; GPCR-AABs) and innervate their related receptors. Diseases characterized by the presence of GPCR-AABs and evidence for their disease-specific pathogenic activity could called “agonistic autoantibody disease.” Here, we summarize basic information about GPCR-AABs in cardiovascular diseases. Among these, the identity of the GPCR-AABs, their prevalence in cardiovascular diseases, the mechanisms for GPCR-AABs receptor binding and activation, and the resulting pathogenic consequences are discussed. Thereafter GPCR-AABs assays applicable for patient diagnostics and monitoring are critically reflected such as indirect assays (cells preparations bind GPCR-AABs and the resulting changes in eg, pulsation and contraction or in specific signaling molecules such as Ca2+ or cAMP were monitored) and direct assays based on enzyme linked immunosorbent assay technologies using GPCR epitope mimics for GPCR-AAB binding. Unfortunately, none of the assays fulfill all the requirements of laboratory medicine.

Der bevorzugte Biomarker in der Herzinfarktdiagnostik ist das quantitativ im Serum gemessene kardiale Troponin (cTn) wegen seiner Gewebespezifitat. Bei Verwendung hochsensitiver cTn-Assays wird die Bestimmung weiterer Marker wie Myoglobin, CK-MB Masse, FABP nicht empfohlen, da diese Biomarker keinen diagnostischen Zusatznutzen bringen. Hochsensitive cTn-Assays werden bislang von zwei POCT-Benchtop-Geraten angeboten. Fur die labormedizinische Begleitung der chronischen Herzinsuffizienz stehen heute mit dem BNP und dem NT-pro-BNP Marker zur Verfugung, deren Einsatz von Europaischen und Amerikanischen Fachgesellschaften fur Screening und Diagnostik der Herzinsuffizienz empfohlen wird. POCT-Methoden zur Messung sind bereits entwickelt worden.

Autoimmunity is increasingly accepted as the origin or amplifier of various diseases. In contrast to classic autoantibodies (AABs), which induce immune responses resulting in the destruction of the affected tissue, an additional class of AABs is directed against G-protein-coupled receptors (GPCRs; GPCR-AABs). GPCR-AABs functionally affect their related GPCRs for activation of receptor mediated signal cascades. Diseases which are characterized by the presence of GPCR-AABs with evidence for disease-specific pathogenic activity could be named "functional autoantibody disease". We briefly summarize here the historical view on autoimmunity in cardiomyopathy, followed by an approach to the mechanistic autoimmunity background. Furthermore, autoantibodies with outstanding importance for cardiomyopathies as a functional autoantibody disease, such as GPCR-AABs, and mainly those directed against the beta1-adrenergic and muscarinic 2 receptor autoantibodies, are introduced. Anti-cardiac myosin and anti-cardiac troponin autoantibodies, as further potential players in autoimmune cardiomyopathy, are additionally taken into account. The basic view on the autoantibodies, their related receptor interactions and pathogenic consequences are presented. Focused specifically on GPCR-AABs, "pros and cons" of assays such as indirect assays (functional changes of cell preparations are monitored after GPCR-AAB receptor binding) and direct assays based on the ELISA technologies (GPCR epitope mimics for GPCR-AAB binding) are critically discussed. Last but not least, treatment strategies for "functional autoantibody disease", such as for GPCR-AAB removal (therapeutic plasma exchange, immunoadsorption) and in vivo GPCR-AAB attack such as intravenous IgG treatment (IVIG), B-cell depletion and GPCR-AAB binding and neutralization, are critically reflected with respect to their patient benefits.

Over-stimulation of G-protein coupled receptors (GPCRs) such as α1-adrenergic, muscarinic, endothelin, and AT1 receptors is considered to drive benign prostatic hyperplasia (BHP) which is often associated with lower urinary tract syndrome (LUTS). However, in addition to physiologic GPCR ligands, there is a new class of autoantibodies called functional autoantibodies that target the same GPCRs (GPCR-AABs) for over-stimulation, thus, presenting pathogenic potency. We hypothesize that patients with BPH/LUTS could carry GPCR-AABs representing potential targets for treatment.GPCR-AABs were identified, quantified, and characterized in the serum from 20 patients (aged 55-82 years, median 71 years) with BPH using the bioassay of spontaneously beating cultured neonatal rat cardiomyocytes.A sum of 60% of the patients were positive for agonistic autoantibodies directed against the endothelin A receptor (ETA-AABs). ETA-AABs were associated with the IgG 1 subclass, targeted an epitope located on the second extracellular receptor loop and their agonistic activity could be neutralized by the aptamer BC007.Agonistic ETA-AABs could-via uncontrolled over-boarding endothelin A receptor stimulation-contribute to the pathogenesis of BPH/LUTS. The in vitro demonstrated ETA-AAB neutralization by the aptamer BC007 could open the door for a new treatment strategy in patients with BPH/LUTS. Prostate 77:458-465, 2017. © 2016 Wiley Periodicals, Inc.

Managing patients with asymptomatic severe aortic stenosis (AS) remains a major challenge. Myocardial as well as cardiocirculatory reserve have been hypothesized to predict outcome in patients with asymptomatic AS.A total of 48 patients (indexed aortic valve area 0.39 +/- 0.12 cm2/m2; ejection fraction (EF) 67 +/- 7%) underwent spiroergometry and dobutamine stress echocardiography. Death or valve surgery served as a combined endpoint for follow up.Thirty-seven patients reached the endpoint after a mean of 756 days (range: 100-2146 days). Age- and gender-corrected univariate Cox proportional analysis revealed the presence of mild obstructive lung disease, stroke work loss (SWL), end-systolic diameter index, and E/Flow propagation velocity as the best predictive clinical, valvular, cardiostructural, and left ventricular filling pressure parameters, respectively. After inclusion of these parameters into a baseline multivariable Cox proportional hazard model, SWL (HR 1.21 per rise of 1 unit, CI 1.08-1.35, p = 0.0005) and female gender (HR 3.37, CI 1.50-7.59, p = 0.0044) were independently predictive. Similarly, the best-performing myocardial parameter, EF after dobutamine, was independently predictive (HR 0.75 per 5 units, CI 0.57-0.99, p = 0.035) after inclusion. The best-performing exercise capacity parameter, Watt(max), was of borderline significance (HR 0.93 per 5 units, CI 0.86-1.00, p = 0.0505). For each parameter, cut-off values were determined by time-dependent receiver-operator characteristics. The Kaplan-Meier curves of the patients above versus below the cut-offs differed significantly for SWL (p = 0.001), Wattm (p = 0.001), and gender (p = 0.013).Besides SWL and female gender, the EF after dobutamine as well as highest exercise stress intensity reached are helpful in determining the prognosis of asymptomatic patients with moderate-severe AS.

The effect of autoantibodies on G-protein coupled receptors in the pathogenesis of diseases, especially of the heart and vascular system, is an increasingly accepted fact today. Dilated cardiomyopathy (DCM) is the most intensively investigated pathological situation of these. With DCM, autoantibodies against the β1-adrenoceptor and the muscarinic M2-receptor have been found in high percentage of investigated patients. Immunoadsorption for autoantibody removal has already shown a long-term beneficial therapeutic effect, but has remained limited in its application because of the complexity of this method. A new easy applicable treatment strategy has, therefore, been discovered. Because of intra- and inter-loop epitope variability of the β1-adrenoceptor specific autoantibodies and also the occurrence of further autoantibodies of this class such as the ones against the β2- and α1-adrenoceptor, the ETA-, proteinase activated-, and the AT1-receptors in different pathological situations, this newly discovered broad-spectrum neutralizer of all these autoantibodies - aptamer BC 007 - is under development. The binding and neutralizing effect was investigated applying a bioassay of spontaneously beating neonatal rat cardiomyocytes and enzyme-linked immunosorbent assay (ELISA) - technology. The usefulness of aptamer BC 007 to specify column technology for the removal of serum autoantibodies was also demonstrated. The presented data suggest that aptamer BC 007 might be an appropriate molecule candidate to support future research about the meaning of G-protein-coupled receptor autoantibodies.

Nagatomo et al. [(1)][1] demonstrated that autoantibodies (AAbs) targeting β1-adrenoceptors (β1ARs), which are detectable in the immunoglobulin-G3 (IgG3) subclass (IgG3-β1AR-AAbs) versus non−IgG3-β1AR-AAbs, predicted better outcome when patients were treated contemporarily, including

Autoantibodies directed against the second extracellular receptor loop of the β 1 receptor (β 1 -ECII-AABs) that belong to the superfamily of G protein–coupled receptors have been frequently found in patients with idiopathic dilated cardiomyopathy, Chagas' cardiomyopathy, and peripartum cardiomyopathy and have been clearly evidenced to be related to disease pathogenesis. Consequently, specific proteins or peptides used as binders in immunoapheresis or as in vivo neutralizers of β 1 -ECII-AABs have been suggested for patient treatment. Aptamers, which are target specifically selected short single- or double-stranded RNA or DNA sequences, are a recently introduced new molecule class applicable to bind and neutralize diverse molecule species, including antibodies. This article reviews selection technologies and characteristics of aptamers with respect to a single-stranded DNA aptamer recently identified as having a very high affinity against β 1 -ECII-AABs. The potential of this aptamer for the elimination of β 1 -ECII-AABs and in vivo neutralization is critically analyzed in view of its potential for future use in cardiomyopathy treatment.

80 percent of patients with non-ischemic heart failure (HF) and reduced ejection fraction have autoantibodies against β1-adrenoceptos (β1-AAB), which cause and/or sustain HF. The removal of β1-AAB by immunoadsorption (IA) leads to an improvement of cardiac function and significantly reduced

Immature granulocytes (IGs) and differences between reticulocyte and erythrocyte haemoglobin content (delta-He) are now available as modern parameters on routine haematology analysers for detecting inflammation. Are these markers more suitable to detect mild inflammation when compared with traditional inflammation markers such as leukocyte count, C-reactive protein (CRP), procalcitonin (PCT), interleukin-6 (IL-6) or diverse leukocyte surface molecules mainly used in research programs? To answer this question, a marathon race was used as a model of mild inflammation. Full blood counts, CRP, PCT, IL-6, expression of surface molecules on granulocytes, monocytes and lymphocytes were measured before and immediately after the race (inflammatory state) and were compared with each other. A further blood sample was taken after a 10-day rest. In the inflammatory state leukocytes, neutrophil counts and IL-6 concentration were considerably increased compared with basic conditions. Diagnostic sensitivity and specificity came up to 100%. CRP was not increased and delta-He did not drop to negative values, as it occurs in severe inflammation. Leukocyte surface molecules were able to indicate a mild inflammatory state induced by the marathon race, but these markers did not achieve the same discriminatory power when compared with IL-6 levels or neutrophil count. In conclusion, leukocytes, neutrophils and IG counts as well as IL-6 levels are the best indicators in a mild inflammation model similar to a marathon race.

Objectives Distinguishing the patterns of autoantibodies (AAB) against G-protein–coupled receptors in Chagas' cardiomyopathy and megacolon and the discovery of such a pattern in patients who are as yet asymptomatic could help to identify patients at high risk of developing the life-threatening complications of Chagas' disease. Background Such AAB against receptors as beta 1 (beta1-AAB), beta 2 (beta2-AAB), and muscarinergic 2 (M2-AAB) are thought to be involved in the pathogenesis of Chagas' cardiomyopathy and megacolon, the predominant manifestations of Chagas' disease, which is the most serious parasitic disease in Latin America. Methods Beta1-AAB, beta2-AAB, and M2-AAB were measured in the serum of asymptomatic Chagas' patients and in those with cardiomyopathy and/or megacolon. Results Nearly all Chagas' patients with cardiomyopathy and/or megacolon had AAB. Predominance of beta1-AAB combined with M2-AAB in Chagas' cardiomyopathy and beta2-AAB with M2-AAB in megacolon was found. Such patterns were also found in 34% of the asymptomatic patients, of whom 85% possessed a beta1-AAB level typical for Chagas' cardiomyopathy. Conclusions The percentage of asymptomatic Chagas' patients who had a specific AAB pattern and had a beta1-AAB level above a defined cutoff point mirrors very well the epidemiological situation, which showed that clinical manifestations develop in nearly 30% of Chagas' patients and cardiomyopathy in nearly 90% of them. We hypothesize that beta1-, beta2-, and M2-AAB measurement might be a useful tool for risk assessment in the indeterminate state of Chagas' disease to select patients for earlier involvement in care programs. However, prospective studies are needed to further evaluate this hypothesis.

Participation of older men in endurance races continues to increase. Recent studies on marathon runners raised concerns about a transient myocardial dysfunction and damage. The aim of our study was to compare the extent of marathon-induced myocardial dysfunction in young and older runners and to identify its potential correlation to elevated cardiac biomarkers.Twenty-eight older (aged 60-72 years) and 50 younger (22-59 years) male amateur athletes who participated in the 2006 Berlin Marathon were included in the study and examined by echocardiography (including tissue Doppler and speckle tracking echocardiography) and blood tests (including troponin T [TnT], N-terminal pro brain natriuretic peptide [NT-proBNP]) before, immediately after, and 2 weeks after the race.Immediately after the marathon, there was no sign of systolic myocardial dysfunction (increase in fractional shortening, baseline 39.9% +/- 7.6% vs post 46.8% +/- 9.2%, P.001, unchanged septal basal longitudinal 2-dimensional strain: 17.1% +/- 2.9%, 17.7% +/- 3.2%, P = .11). As a marker of diastolic function, E/E' was not altered significantly (7.6 +/- 2.1, 8.7 +/- 3.5, P = .15). The deceleration time of E and E' decreased in both groups immediately after the race, indicating a transient adaptation of diastolic myocardial function. Strain of the right ventricular free wall was decreased in the mid and apical segments after the race in both groups with normalization during follow-up. Tricuspid annular plane systolic excursion was not altered. Some 53.8% of all runners had increases in TnT or NT-proBNP after the race. Some 32% of controls and 29% of older runners had elevated levels of NT-proBNP (P = .75, TnT: 44% vs 29% P = .18). There was no correlation between NT-proBNP and TnT increase. The increases in biomarkers were not correlated to echocardiography parameters of systolic, diastolic, or right-sided heart dysfunction or to age, training level, running time, or renal function. All parameters returned to normal ranges after 2 weeks.Left ventricular systolic function is preserved after a marathon in older runners. There are right ventricular functional changes as a sign of prolonged myocardial work load. There is no significant difference between older and young runners regarding transient diastolic dysfunction or biomarker release. The latter is not associated with echocardiography parameters of myocardial dysfunction.

Octreotide is a somatostatin analogue binding on two receptor subtypes. In previous trials Octreotide showed inhibitory effects on tumour growth and liver metastasis in experimental pancreatic cancer. Thus we evaluated whether the new somatostatin analogue SOM-230 binding on 4 receptor subtypes has superior effects on carcinogenesis in pancreatic carcinoma. About 120 Syrian hamsters were randomised into six groups (n = 20): Gr.1: Aqua/Aqua, Gr.2: BOP/Aqua, Gr.3: Aqua/Octreotide, Gr.4: BOP/Octreotide, Gr.5: Aqua/SOM-230, Gr.6: BOP/SOM-230. Tumour groups 2,4,6 subcutaneously received 10 mg/kg body weight N-nitrosobis-2-oxopropylamin (BOP) weekly for 10 weeks, healthy control Gr.1,3,5 were given aqua. In the 17th week therapy started with Octreotide and SOM-230 for 16 weeks, after 32 weeks animals were sacrificed. Pancreas and liver were histopathologically analysed. Hepatic lipidperoxidation was determined by activities of antioxidative enzymes gluthation-peroxidase (GSH-Px) and superoxiddismutase (SOD) as well as concentration of thiobarbituric-acid reactive substances (TBARS). Incidence of liver metastases was 88.2% in Gr.2 (BOP/Aqua), it was decreased in Gr.4 (BOP/Octreo: 40%) and Gr.6 (BOP/SOM-230: 50%) (P < 0.05). Mean number/animal and mean-2-dimensional size of liver metastases did not differ between tumour groups. Comparing GSH-Px-activity in intrametastatic and extrametastatic hepatic tissue revealed a significant increase extrametastatically in Gr.2 (BOP/Aqua) and Gr.6 (BOP/SOM-230). SOD-activity in liver metastases was decreased in Gr.2 (1,801) (P < 0.05) versus Gr.4 (8,304) and Gr.6 (7,038). Intrametastatic TBARS concentration was increased in Gr.2 compared to Gr.4 (BOP/Octreotid) and Gr.6 (BOP/SOM-230) (P < 0.05). Octreotide and SOM-230 equally reduced liver metastasis in ductal pancreatic adenocarcinoma probably by a reduction of lipidperoxidation.

Successful therapy in chronic clinically stable heart failure is reflected by decreasing serum NT-proBNP levels. This study evaluates therapy monitoring by NT-proBNP in comparison to invasively measured hemodynamic parameters in acutely decompensated heart failure patients.In 25 acutely decompensated chronic heart failure patients (NYHA III-IV, Cardiac Index (CI)or=2.5 l/min/m(2) and a PCWPor=15 mm Hg) changes in NT-proBNP and invasive hemodynamics were compared. Hemodynamic improvement in the first 24 h (CIor=30% and PCWPor=30%, compared to baseline) was associated with decreasing NT-proBNP levels; which was not seen in patients without hemodynamic improvement. To discriminate between responders and non-responders, a decline to80% of the baseline NT-proBNP in the first 24 h was the best cut-off.Hemodynamic improvement in acutely decompensated heart failure patients is associated with decreasing NT-proBNP levels.

Cardiac troponins play a major role in the diagnostic work-up of acute coronary syndrome/myocardial infarction. Elevations were demonstrated also in other, rather nonischemic diseases like pulmonary embolism or acute heart failure. Stepwise improvement in the accuracy of the commercially available assays allowed detection of low-level concentrations of cardiac troponins, which were previously partially classified to be normal (between the limit of detection and the 99 th percentile by < 10% coefficient of variance). These low concentrations were associated with the detection of chronic cardiovascular pathologies and an increased risk of future cardiovascular events. Recently, ten to 100 times more sensitive assays (so-called high sensitive or ultra sensitive assays) have been developed. The clinical importance of those now measurable troponin values is currently under intensive investigation. The expected additional clinical and prognostic information from such low- and even lowest-level troponin values pose a special challenge. Specifically, the question has been raised, whether the established single cutoff approach for diagnosing myocardial infarction should not be complemented by another, lower cutoff usable for the detection of other (stable) cardiovascular pathologies with lower but still substantial risk.