Effects of physiotherapy and home-based training in parkinsonian syndromes: protocol for a randomised controlled trial (MobilityAPP)

INTRODUCTION

Gait and mobility impairment are pivotal signs of parkinsonism, and they are particularly severe in atypical parkinsonian disorders including multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). A pilot study demonstrated a significant improvement of gait in patients with MSA of parkinsonian type (MSA-P) after physiotherapy and matching home-based exercise, as reflected by sensor-based gait parameters. In this study, we aim to investigate whether a gait-focused physiotherapy (GPT) and matching home-based exercise lead to a greater improvement of gait performance compared with a standard physiotherapy/home-based exercise programme (standard physiotherapy, SPT).

METHODS AND ANALYSIS

This protocol was deployed to evaluate the effects of a GPT versus an active control undergoing SPT and matching home-based exercise with regard to laboratory gait parameters, physical activity measures and clinical scales in patients with Parkinson's disease (PD), MSA-P and PSP. The primary outcomes of the trial are sensor-based laboratory gait parameters, while the secondary outcome measures comprise real-world derived parameters, clinical rating scales and patient questionnaires. We aim to enrol 48 patients per disease group into this double-blind, randomised-controlled trial. The study starts with a 1 week wearable sensor-based monitoring of physical activity. After randomisation, patients undergo a 2 week daily inpatient physiotherapy, followed by 5 week matching unsupervised home-based training. A 1 week physical activity monitoring is repeated during the last week of intervention.

ETHICS AND DISSEMINATION

This study, registered as 'Mobility in Atypical Parkinsonism: a Trial of Physiotherapy (Mobility_APP)' at clinicaltrials.gov (NCT04608604), received ethics approval by local committees of the involved centres. The patient's recruitment takes place at the Movement Disorders Units of Innsbruck (Austria), Erlangen (Germany), Lausanne (Switzerland), Luxembourg (Luxembourg) and Bolzano (Italy). The data resulting from this project will be submitted to peer-reviewed journals, presented at international congresses and made publicly available at the end of the trial.

TRIAL REGISTRATION NUMBER

NCT04608604.

Early Screening for the Parkinson Variant of Multiple System Atrophy: A 6-Item Score

BACKGROUND

A 4-item score based on ≥2 features out of orthostatic hypotension, overactive bladder, urinary retention and postural instability was previously shown to early distinguish the Parkinson-variant of multiple system atrophy (MSA-P) from Parkinson's disease (PD) with 78% sensitivity and 86% specificity.

OBJECTIVES

To replicate and improve the 4-item MSA-P score.

METHODS

We retrospectively studied 161 patients with early parkinsonism [ie, ≤2 years disease duration or no postural instability, aged 64 (57; 68) years, 44% females] and a diagnosis of clinically established MSA-P (n = 38) or PD (n = 123) after ≥24 months follow-up.

RESULTS

The 4-item MSA-P score had a 92% sensitivity and 78% specificity for a final MSA-P diagnosis. By including dopaminergic responsiveness and postural deformities into a 6-item score (range: 0-6), reaching ≥3 points at early disease identified MSA-P patients with 89% sensitivity and 98% specificity.

CONCLUSIONS

The 6-item MSA-P score is a cost-effective tool to pinpoint individuals with early-stage MSA-P.

Development and Validation of a Prognostic Model to Predict Overall Survival in Multiple System Atrophy

Background

Multiple system atrophy (MSA) is a devastating disease characterized by a variable combination of motor and autonomic symptoms. Previous studies identified numerous clinical factors to be associated with shorter survival.

Objective

To enable personalized patient counseling, we aimed at developing a risk model of survival based on baseline clinical symptoms.

Methods

MSA patients referred to the Movement Disorders Unit in Innsbruck, Austria, between 1999 and 2016 were retrospectively analyzed. Kaplan-Meier curves and multivariate Cox regression analysis with least absolute shrinkage and selection operator penalty for variable selection were performed to identify prognostic factors. A nomogram was developed to estimate the 7 years overall survival probability. The performance of the predictive model was validated and calibrated internally using bootstrap resampling and externally using data from the prospective European MSA Study Group Natural History Study.

Results

A total of 210 MSA patients were included in this analysis, of which 124 patients died. The median survival was 7 years. The following clinical variables were found to significantly affect overall survival and were included in the nomogram: age at symptom onset, falls within 3 years of onset, early autonomic failure including orthostatic hypotension and urogenital failure, and lacking levodopa response. The time-dependent area under curve for internal and external validation was >0.7 within the first 7 years of the disease course. The model was well calibrated showing good overlap between predicted and actual survival probability at 7 years.

Conclusion

The nomogram is a simple tool to predict survival on an individual basis and may help to improve counseling and treatment of MSA patients.

Localization and Registration of 2D Histological Mouse Brain Images in 3D Atlas Space

To accurately explore the anatomical organization of neural circuits in the brain, it is crucial to map the experimental brain data onto a standardized system of coordinates. Studying 2D histological mouse brain slices remains the standard procedure in many laboratories. Mapping these 2D brain slices is challenging; due to deformations, artifacts, and tilted angles introduced during the standard preparation and slicing process. In addition, analysis of experimental mouse brain slices can be highly dependent on the level of expertise of the human operator. Here we propose a computational tool for Accurate Mouse Brain Image Analysis (AMBIA), to map 2D mouse brain slices on the 3D brain model with minimal human intervention. AMBIA has a modular design that comprises a localization module and a registration module. The localization module is a deep learning-based pipeline that localizes a single 2D slice in the 3D Allen Brain Atlas and generates a corresponding atlas plane. The registration module is built upon the Ardent python package that performs deformable 2D registration between the brain slice to its corresponding atlas. By comparing AMBIA's performance in localization and registration to human ratings, we demonstrate that it performs at a human expert level. AMBIA provides an intuitive and highly efficient way for accurate registration of experimental 2D mouse brain images to 3D digital mouse brain atlas. Our tool provides a graphical user interface and it is designed to be used by researchers with minimal programming knowledge.

Anatomically Standardized Detection of MRI Atrophy Patterns in Early-Stage Alzheimer's Disease

MRI studies have consistently identified atrophy patterns in Alzheimer’s disease (AD) through a whole-brain voxel-based analysis, but efforts to investigate morphometric profiles using anatomically standardized and automated whole-brain ROI analyses, performed at the individual subject space, are still lacking. In this study we aimed (i) to utilize atlas-derived measurements of cortical thickness and subcortical volumes, including of the hippocampal subfields, to identify atrophy patterns in early-stage AD, and (ii) to compare cognitive profiles at baseline and during a one-year follow-up of those previously identified morphometric AD subtypes to predict disease progression. Through a prospectively recruited multi-center study, conducted at four Austrian sites, 120 patients were included with probable AD, a disease onset beyond 60 years and a clinical dementia rating of ≤1. Morphometric measures of T1-weighted images were obtained using FreeSurfer. A principal component and subsequent cluster analysis identified four morphometric subtypes, including (i) hippocampal predominant (30.8%), (ii) hippocampal-temporo-parietal (29.2%), (iii) parieto-temporal (hippocampal sparing, 20.8%) and (iv) hippocampal-temporal (19.2%) atrophy patterns that were associated with phenotypes differing predominately in the presentation and progression of verbal memory and visuospatial impairments. These morphologically distinct subtypes are based on standardized brain regions, which are anatomically defined and freely accessible so as to validate its diagnostic accuracy and enhance the prediction of disease progression.

Changing the dietary composition improves inflammation but not adipocyte thermogenesis in diet-induced obese mice

Pronounced weight loss was shown to improve adipocyte dysfunction and insulin sensitivity in obese subjects. While bariatric surgery is frequently accompanied by adverse side effects, weight loss due to caloric restriction is often followed by weight regain. Here we aimed to determine whether switching the diet from a metabolically harmful Western type diet to a balanced standard diet is sufficient to reverse adipocyte dysfunction in diet-induced obese mice. Male C57BL/6 mice were fed a Western diet for 10 weeks and afterwards switched to a standard diet for eight more weeks (WD/SD mice) or continued to be fed a Western diet (WD/WD mice) ad libitum. Mice fed SD for 18 weeks served as control group (SD/SD). Insulin sensitivity was similar in WD/SD and SD/SD mice despite increased body weight in WD/SD mice. Beiging markers Ucp-1, Cidea and Cox8b were drastically reduced in subcutaneous adipose tissue of WD/SD mice when compared with SD/SD mice. Also, in brown adipose tissue morphologic features and markers of thermogenesis were still altered in both WD/SD and WD/WD mice. However, adipocyte size, Hif1α and macrophage infiltration were significantly lower in both, brown and white adipose tissues of WD/SD compared to WD/WD mice and additionally, a shift toward anti-inflammatory M2 phenotype was found in WD/SD mice only. In conclusion our data suggest that switching the diet is sufficient to improve adipose tissue inflammation, while western diet negatively affects thermogenic capacity of brown adipose tissue, and inhibits beiging of white adipose tissue in the long-term.

Screening for Open Spina Bifida in a Routine Clinical Setting at the First-Trimester Scan: A Prospective Multicentre Cohort Study

OBJECTIVE

The aim of this study was to investigate the performance of screening for open spina bifida (OSB) integrated into the routine first-trimester screening.

METHOD

This is a prospective multicentre study of 4,755 women undergoing first-trimester ultrasound scans over a 4-year period. Measurements of the brainstem (BS) diameter and brainstem-to-occipital-bone (BSOB) distance were performed. The cisterna magna (CM) was measured in the tilted axial view.

RESULTS

Pregnancy outcome data were available for 4,658 fetuses included in this study. There were 5 fetuses with OSB, and in all of them, the BS/BSOB ratio and the CM measurements were abnormal. The sensitivity and specificity of a BS/BSOB ratio >1 were 100%. The sensitivity of a CM width <5th centile was 100%, and the specificity was 95.1%. In 4.6% of cases, the BS/BSOB ratio was between the 95th percentile and 1. In 87.1% of these cases, the CM was normal, and 12.9% had a CM below the 5th percentile.

CONCLUSION

Screening for OSB is feasible in routine first-trimester scans. The BS/BSOB ratio shows a very good sensitivity and specificity. In cases with near-normal values for the BS/BSOB ratio, the CM width might be helpful for further assessment.

Association of transient orthostatic hypotension with falls and syncope in patients with Parkinson disease

OBJECTIVES

To assess the frequency of transient orthostatic hypotension (tOH) and its clinical impact in Parkinson disease (PD), we retrospectively studied 173 patients with PD and 173 age- and sex-matched controls with orthostatic intolerance, who underwent cardiovascular autonomic function testing under continuous noninvasive blood pressure (BP) monitoring.

METHODS

We screened for tOH (systolic BP fall ≥20 mm Hg or diastolic ≥10 mm Hg resolving within the first minute upon standing) and classic OH (cOH, sustained systolic BP fall ≥20 mm Hg or diastolic ≥10 mm Hg within 3 minutes upon standing). In patients with PD, we reviewed the medical records of the 6 months preceding and following autonomic testing for history of falls, syncope, and orthostatic intolerance.

RESULTS

tOH occurred in 24% of patients with PD and 21% of controls, cOH in 19% of patients with PD and in none of the controls, independently of any clinical-demographic or PD-specific characteristic. Forty percent of patients with PD had a history of falls, in 29% of cases due to syncope. Patients with PD with history of orthostatic intolerance and syncope had a more severe systolic BP fall and lower diastolic BP rise upon standing, most pronounced in the first 30-60 seconds.

CONCLUSIONS

tOH is an age-dependent phenomenon, which is at least as common as cOH in PD. Transient BP falls when changing to the upright position may be overlooked with bedside BP measurements, but contribute to orthostatic intolerance and syncope in PD. Continuous noninvasive BP monitoring upon standing may help identify a modifiable risk factor for syncope-related falls in parkinsonian patients.

Automated Analysis of Diffusion-Weighted Magnetic Resonance Imaging for the Differential Diagnosis of Multiple System Atrophy from Parkinson's Disease

Background

Manual region‐of‐interest analysis of putaminal and middle cerebellar peduncle diffusivity distinguishes patients with multiple system atrophy (MSA) and Parkinson's disease (PD) with high diagnostic accuracy. However, a recent meta‐analysis found substantial between‐study heterogeneity of diagnostic accuracy due to the lack of harmonized imaging protocols and standardized analyses pipelines.

Objective

Evaluation of diagnostic accuracy of observer‐independent analysis of microstructural integrity as measured by diffusion‐tensor imaging in patients with MSA and PD.

Methods

A total of 29 patients with MSA and 19 patients with PD (matched for age, gender, and disease duration) with 3 years of follow‐up were investigated with diffusion‐tensor imaging and T1‐weighted magnetic resonance imaging. Automated localization of relevant brain regions was obtained, and mean diffusivity and fractional anisotropy values were averaged within the regions of interest. The classification was performed using a C5.0 hierachical decision tree algorithm.

Results

Mean diffusivity of the middle cerebellar peduncle and cerebellar gray and white matter compartment as well as the putamen were significantly increased in patients with MSA and showed superior effect sizes compared to the volumetric analysis of these regions. A classifier model identified mean diffusivity of the middle cerebellar peduncle and putamen as the most predictive parameters. Cross‐validation of the classification model yields a Cohen's κ and overall diagnostic accuracy of 0.823 and 0.914, respectively.

Conclusion

Analysis of microstructural integrity within the middle cerebellar peduncle and putamen yielded a superior effect size compared to the volumetric measures, resulting in excellent diagnostic accuracy to discriminate patients with MSA from PD in the early to moderate disease stages. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Non-Motor Symptoms in Parkinson's Disease are Reduced by Nabilone

OBJECTIVE

The objective of this study was to assess the efficacy and safety of nabilone, a synthetic tetrahydrocannabinol analogue, as a treatment for non-motor symptoms (NMS) in Parkinson's disease (PD).

METHODS

This was a phase II placebo-controlled, double-blind, parallel-group, enriched enrollment randomized withdrawal trial conducted at the Medical University Innsbruck. A random sample of 47 patients with PD with stable motor disease and disturbing NMS defined by a score of ≥4 points on the Movement Disorder Society - Unified PD Rating Scale-I (MDS-UPDRS-I) underwent open-label nabilone titration (0.25 mg once daily to 1 mg twice daily, phase I). Responders were randomized 1:1 to continue with nabilone or switch to placebo for 4 weeks (phase II). The primary efficacy criterion was the change of the MDS-UPDRS-I between randomization and week 4. Safety was analyzed in all patients who received at least one nabilone dose.

RESULTS

Between October 2017 and July 2019, 19 patients received either nabilone (median dose = 0.75 mg) or placebo. At week 4, mean change of the MDS-UPDRS-I was 2.63 (95% confidence interval [CI] 1.53 to 3.74, p = 0.002, effect size = 1.15) in the placebo versus 1.00 (95% CI -0.16 to 2.16, p = 0.280, effect size = 0.42) in the nabilone-group (difference: 1.63, 95% CI 0.09 to 3.18, p = 0.030, effect size = 0.66). Seventy-seven percent of patients had adverse events (AEs) during open-label titration, most of them were transient. In the double-blind phase, similar proportions of patients in each group had AEs (42% in the placebo group and 32% in the nabilone group). There were no serious AEs.

INTERPRETATION

Our results highlight the potential efficacy of nabilone for patients with PD with disturbing NMS, which appears to be driven by positive effects on anxious mood and night-time sleep problems.

TRIAL REGISTRY

ClinicalTrials.gov (NCT03769896) and EudraCT (2017-000192-86). ANN NEUROL 2020;88:712-722.

Intrafractional 6D head movement increases with time of mask fixation during stereotactic intracranial RT-sessions

BACKGROUND

The present study investigates the intrafractional accuracy of a frameless thermoplastic mask used for head immobilization during stereotactic radiotherapy. Non-invasive masks cannot completely prohibit head movements. Previous studies attempted to estimate the magnitude of intrafractional inaccuracy by means of pre- and postfractional measurements only. However, this might not be sufficient to accurately map also intrafractional head movements.

MATERIALS AND METHODS

Intrafractional deviation of mask-fixed head positions was measured in five patients during a total of 94 fractions by means of close-meshed repeated ExacTrac measurements (every 1.4 min) conducted during the entire treatment session. A median of six (range: 4 to 11) measurements were recorded per fraction, delivering a dataset of 453 measurements.

RESULTS

Random errors (SD) for the x, y and z axes were 0.27 mm, 0.29 mm and 0.29 mm, respectively. Median 3D deviation was 0.29 mm. Of all 3D intrafractional motions, 5.5 and 0.4% exceeded 1 mm and 2 mm, respectively. A moderate correlation between treatment duration and mean 3D displacement was determined (rs = 0.45). Mean 3D deviation increased from 0.21 mm (SD = 0.26 mm) in the first 2 min to a maximum of 0.53 mm (SD = 0.31 mm) after 10 min of treatment time.

CONCLUSION

Pre- and post-treatment measurement is not sufficient to adequately determine the range of intrafractional head motion. Thermoplastic masks provide both reliable interfractional and intrafractional immobilization for image-guided stereotactic hypofractionated radiotherapy. Greater positioning accuracy may be obtained by reducing treatment duration (< 6 min) and applying intrafractional correction.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT03896555, Registered 01 April 2019 - retrospectively registered.

Cleansing efficacy of waist-shaped inter-dental brushes. A randomized-controlled crossover study

OBJECTIVE

To compare the cleansing efficacy of waist-shaped versus cylindric inter-dental brushes in patients receiving supportive periodontal therapy.

MATERIALS AND METHODS

After sample size estimation, 20 periodontal maintenance patients diagnosed with periodontitis stage 3 were recruited. Brushing efficacy of waist-shaped and cylindric inter-dental brushes was evaluated in a randomized-controlled, examiner-blinded, two-period crossover study by assessment of the Turesky modification of Quigley-Hein plaque index (T-QHI) and the papillary bleeding index (PBI) at four sites per tooth.

RESULTS

Seventeen probands with 1,474 tooth sites finished the study. At baseline, median of overall T-QHI scores was 1.4 (interquartile range 1.38-1.92). After 1 month, T-QHI for waist-shaped inter-dental brushes was 1.24 (1.03-1.52); in 15 individuals, T-QHI 0 was the grade most often measured. T-QHI for cylindric brushes was 1.71 (1.18-2.29; p = .042), with T-QHI 0 being the grade most often measured only in seven individuals. The odds ratio for establishing plaque-free inter-dental sites with waist-shaped relative to cylindric brushes was 1.8 [95% CI 1.6-1.9] (p < .001; logistic regression analysis). There were no statistically significant differences between PBI levels of waist-shaped and cylindric brushes.

CONCLUSION

This study has demonstrated the superiority in cleansing efficacy of waist-shaped over cylindric inter-dental brushes in individuals receiving supportive periodontal treatment.

Physiotherapy improves motor function in patients with the Parkinson variant of multiple system atrophy: A prospective trial

BACKGROUND AND OBJECTIVES

Gait impairment and reduced mobility are disabling symptoms of multiple system atrophy. While physiotherapy is increasingly recognized as a valuable supplement to pharmacotherapy for patients with Parkinson's disease, data on the efficacy of physiotherapy for multiple system atrophy are lacking. This study aimed to explore the feasibility of two consecutive exercise-based interventions in patients with multiple system atrophy.

SUBJECTS AND METHODS

We included 10 patients with the parkinsonian variant of multiple system atrophy and 10 patients with Parkinson's disease, matched for gender and Hoehn & Yahr stage (≤3). Interventions consisted of a five-day inpatient physiotherapy program followed by a five-week unsupervised home-based exercise program. Outcomes included instrumented gait analysis, patient questionnaires, clinical rating scales and physical tests. Patients were examined at baseline, after the first inpatient treatment and again after the home-based intervention. Additionally, a structured telephone interview was performed immediately after the second intervention period.

RESULTS

Both patient groups exhibited a similar improvement of gait after the interventions, as measured by instrumented gait analysis. These effects reached their maximum level after inpatient physiotherapy and remained stable following the home-based exercise program. Patient questionnaires also showed improvements after the interventions, but motor clinical rating scales did not.

CONCLUSION

Our pilot results suggest that a short-term bout of physiotherapy is feasible, safe and improves gait performance in patients with multiple system atrophy. This highlights the potential of physiotherapy for this disabling condition where pharmacotherapy typically achieves poor effects. The present findings warrant a larger controlled study.

Evaluation of mitochondrial function in chronic myofascial trigger points - a prospective cohort pilot study using high-resolution respirometry

Background

Myofascial trigger points (MTrPs) are hyperirritable areas in the fascia of the affected muscle, possibly related to mitochondrial impairment. They can result in pain and hypoxic areas within the muscle. This pilot study established a minimally invasive biopsy technique to obtain high-quality MTrP tissue samples to evaluate mitochondrial function via high-resolution respirometry. Secondary objectives included the feasibility and safety of the biopsy procedure.

Methods

Twenty healthy males participated in this study, 10 with a diagnosis of myofascial pain in the musculus (m.) trapezius MTrP (TTP group) and 10 with a diagnosis of myofascial pain in the m. gluteus medius (GTP group). Each participant had 2 muscle biopsies taken in one session. The affected muscle was biopsied followed by a biopsy from the m. vastus lateralis to be used as a control. Measurements of oxygen consumption were carried out using high-resolution respirometry.

Results

Mitochondrial respiration was highest in the GTP group compared to the TTP group and the control muscle whereas no differences were observed between the GTP and the control muscle. When normalizing respiration to an internal reference state, there were no differences between muscle groups. None of the participants had hematomas or reported surgical complications. Patient-reported pain was minimal for all 3 groups. All participants reported a low procedural burden.

Conclusions

This pilot study used a safe and minimally invasive technique for obtaining biopsies from MTrPs suitable for high-resolution respirometry analysis of mitochondrial function. The results suggest that there are no qualitative differences in mitochondrial function of MTrPs of the trapezius and gluteus medius muscles compared to the vastus lateralis control muscle, implying that alterations of mitochondrial function do not appear to have a role in the development of MTrPs.

Trial registration

Registered as No. 20131128–850 at the Coordinating Center for Clinical Studies of the Medical University of Innsbruck, trial registration date: 28th November 2013 and retrospectively registered on 11th of October 2018 at ClinicalTrials.gov with the ID NCT03704311.

Circulating Wnt inhibitory factor 1 levels are associated with development of cardiovascular disease

BACKGROUND AND AIMS

Wnt signaling is involved in atherosclerotic plaque formation directly and indirectly by modulating cardiovascular risk factors. We investigated whether circulating concentrations of Wnt inhibitors are associated with cardiovascular events in subjects with intermediate cardiovascular risk.

METHODS

904 non-diabetic subjects participating in the SAPHIR study were assessed. In the SAPHIR study, middle-aged women without overt atherosclerotic disease at study entry were followed up for 10 years. 88 patients of our study cohort developed cardiovascular disease at follow-up (CVD group). Subjects of the CVD group were 1:2 case-control matched for age, sex, BMI and smoking behavior with subjects without overt cardiovascular disease after a 10 year-follow-up (control group). 18 patients of the CVD group and 19 subjects of the control group were retrospectively excluded due to fulfilling exclusion criteria. Baseline circulating sclerostin, dickkopf (DKK)-1, secreted frizzled-related protein (SFRP)-1 and Wnt inhibitory factor (WIF)-1 levels were assessed by ELISA.

RESULTS

Baseline systemic SFRP-1 and WIF-1 levels were significantly higher in patients with cardiovascular events (n = 70) when compared to healthy controls (n = 157) while DKK-1 and sclerostin levels were similar in both groups. Logistic regression analysis revealed WIF-1 as a significant predictor of future cardiovascular events.

CONCLUSIONS

Our data suggest that increased SFRP-1 and WIF-1 levels precede the development of symptomatic atherosclerotic disease. Assessment of systemic WIF-1 levels, which turned out to be independently associated with CVD, might help to early identify patients at intermediate cardiovascular risk.

Diagnostic potential of dentatorubrothalamic tract analysis in progressive supranuclear palsy

BACKGROUND

The differentiation of progressive supranuclear palsy-parkinsonism (PSP-P) from Parkinson's disease (PD) remains a major clinical challenge.

OBJECTIVES

To evaluate the diagnostic potential of observer-independent assessments of microstructural integrity within infratentorial brain regions to differentiate PSP-Richardson's syndrome (PSP-RS), PSP-P and PD.

METHODS

3T MRI parameters of mean diffusivity, fractional anisotropy, grey and white matter volumes from patients with PSP-RS (n = 12), PSP-P (n = 12) and mean disease duration of 2.4 ± 1.7 years were compared with PD patients (n = 20) and healthy controls (n = 23) by using statistical parametric mapping and the spatially unbiased infratentorial template. Subsequently MRI measurements of the dentatorubrothalamic tract were determined observer-independently by a validated probabilistic infratentorial atlas. The impairment of gait and postural stability was evaluated by a sum-score derived from the Unified Parkinson Disease Rating Scale.

RESULTS

Significant mean diffusivity increases, fractional anisotropy decreases and corresponding volume loss were localized in mesencephalic tegmentum, superior cerebellar peduncle, decussation of superior cerebellar peduncle and dentate nucleus in PSP-RS and PSP-P compared to PD and healthy controls. Altered microstructural integrity of the dentatorubrothalamic tract in PSP-RS was significantly more pronounced compared to PSP-P and correlated significantly with the gait and postural stability sum-score. Linear discriminant analysis identified diffusion tensor imaging measures of the dentatorubrothalamic tract and the gait and postural stability sum-score to classify correctly 95.5% of PRP-RS, PSP-P and PD patients.

CONCLUSIONS

Observer-independent analysis of microstructural integrity within the dentatorubrothalamic tract in combination with assessments of gait and postural stability differentiate PSP-P from PSP-RS and PD in early to moderately advanced stages.

Gene Methylation Data – a New Challenge for Bioinformaticians?

Objectives: Changes in the status of DNA methylation, known as epigenetic alterations, are among the most common molecular alterations in human neoplasia. For the first time, we reported on the analysis of fecal DNA from patients with CRC to determine the feasibility, sensitivity and specificity of this approach. We want to present basic information about DNA methylation analysis in the context of bioinformatics, the study design and several statistical experiences with gene methylation data. Additionally we outline chances and new research questions in the field of DNA methylation.

Methods: We present current approaches to DNA methylation analysis based on one reference study. Its study design and the statistical analysis is reflected in the context of biomarker development. Finally we outline perspectives and research questions for statisticians and bioinformaticians.

Results: Identification of at least three genes as potential DNA methylation-based tumor marker genes (SFRP2, SFRP5, PGR).

Conclusions: DNA methylation analysis is a rising topic in molecular genetics. Gene methylation will push the extension of biobanks to include new types of genetic data. Study design and statistical methods for the detection of methylation biomarkers must be improved. For the purpose of establishing methylation analysis as a new diagnostic/prognostic tool the adaptation of several approaches has become a challenging field of research activity.

Development of a novel prognostic score for breast cancer patients using mRNA expression of CHAC1

AIM

To develop a prognostic score for primary breast cancer patients integrating conventional predictors and the novel biomarker CHAC1 to aid adjuvant chemotherapy decisions.

PATIENTS & METHODS

A prognostic score for overall survival was developed using: conventional predictors from a dataset of 1777 patients and the weight of CHAC1 mRNA expression from an independent dataset of 106 patients using multivariate Cox regression.

RESULTS

The new score includes: CHAC1 mRNA expression, age, tumor size, HER2 neu status, lymph node status and degree of malignancy. Using a cut-off value of 11 score points, 10-year survival was 82% in low-risk (n = 34) and 43% in high-risk patients (n = 72). The addition of CHAC1 resulted in 16% reclassification.

CONCLUSION

Including CHAC1 in prognostic prediction may aid (and change) personalized treatment selection.

Conception and Implementation of an Austrian Biobank Directory Integration Framework

INTRODUCTION

Sample collections and data are hosted within different biobanks at diverse institutions across Europe. Our data integration framework aims at incorporating data about sample collections from different biobanks into a common research infrastructure, facilitating researchers' abilities to obtain high-quality samples to conduct their research. The resulting information must be locally gathered and distributed to searchable higher level information biobank directories to maximize the visibility on the national and European levels. Therefore, biobanks and sample collections must be clearly described and unambiguously identified. We describe how to tackle the challenges of integrating biobank-related data between biobank directories using heterogeneous data schemas and different technical environments.

METHODS

To establish a data exchange infrastructure between all biobank directories involved, we propose the following steps: (A) identification of core entities, terminology, and semantic relationships, (B) harmonization of heterogeneous data schemas of different Biobanking and Biomolecular Resources Research Infrastructure (BBMRI) directories, and (C) formulation of technical core principles for biobank data exchange between directories.

RESULTS

(A) We identified the major core elements to describe biobanks in biobank directories. Since all directory data models were partially based on Minimum Information About BIobank Data Sharing (MIABIS) 2.0, the MIABIS 2.0 core model was used for compatibility. (B) Different projection scenarios were elaborated in collaboration with all BBMRI.at partners. A minimum set of mandatory and optional core entities and data items was defined for mapping across all directory levels. (C) Major core data exchange principles were formulated and data interfaces implemented by all biobank directories involved.

DISCUSSION

We agreed on a MIABIS 2.0-based core set of harmonized biobank attributes and established a list of data exchange core principles for integrating biobank directories on different levels. This generic approach and the data exchange core principles proposed herein can also be applied in related tasks like integration and harmonization of biobank data on the individual sample and patient levels.

Reduced mRNA expression levels of NFE2L2 are associated with poor outcome in breast cancer patients

Background

The transcription factor nuclear factor erythroid 2-related factor 2 (NFE2L2; previously known as NRF2) is a crucial regulator of the intracellular antioxidant response. It controls the expression of genes involved in the detoxification and elimination of reactive oxidants and electrophilic agents. The role of NFE2L2 in cancer is subject of controversial discussion, as it has been reported to have both pro-and anti-tumourigenic functions. To shed some light on this paradox, we analysed the NFE2L2 mRNA expression levels in breast cancer and its association with clinicopathological features and survival.

Methods

We retrospectively evaluated the NFE2L2 mRNA expression levels in tumour tissue of two independent breast cancer patient cohorts. In the training set we analysed data from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC). In the test set we measured the NFE2L2 mRNA expression levels in 176 breast tumour tissues by quantitative real-time reverse transcription PCR (qRT-PCR). Group differences were analysed using Mann–Whitney U-test, and associations between NFE2L2 mRNA expression levels and clinicopathological features were examined by means of univariate and multivariate survival analyses. Furthermore, we compared NFE2L2 mRNA expression levels between tumour and normal breast tissue samples by means of 108 paired samples from the The Cancer Genome Atlas (TCGA) dataset.

Results

In the training set we identified an independent predictive value for high NFE2L2 mRNA expression levels [HR_{disease specific death} 0.8 (0.6–1.0), P = 0.041; HR_death 0.8 (0.6–1.0), P = 0.023] especially in the subgroup of oestrogen receptor (ER) positive tumours [HR_{disease specific death} 0.6 (0.4–0.9), P = 0.008; HR_death 0.6 (0.4–0.8), P = 0.001]. Similarly, we found this association also in the test set [HR_relapse 0.4 (0.2–0.9), P = 0.031] and again, more pronounced in patients with ER positive tumours [HR_relapse 0.2 (0.1–0.7), P = 0.012]. In addition, we observed generally lower NFE2L2 expression levels in tumour tissues than in normal breast tissues.

Conclusion

We concluded that reduced NFE2L2 mRNA expression in tumour tissues is an independent predictor of shortened survival in breast cancer patients.

Pain perception during debridement of hypersensitive teeth elicited by two ultrasonic scalers

OBJECTIVES

The ultrasonic NO PAIN technology (Electro Medical Systems, Nyon, CH) promises minimal pain during debridement due to linear oscillating action combined with a sinusoidal power output and feedback control. The aim of the present study was to measure pain perception on a visual analogue scale (VAS) during supportive periodontal therapy including debridement of hypersensitive teeth. Two ultrasonic scalers were used, one with and one without NO PAIN technology.

MATERIAL AND METHODS

In a randomized-controlled clinical study with split-mouth design, 100 hypersensitive teeth matched for air blast hypersensitivity were either treated with the ultrasonic device Piezon Master 700 or the Mini Piezon (both EMS, Nyon, CH). Pain perception during debridement was assessed by a VAS (range 0-10).

RESULTS

The average VAS for the test device Piezon Master 700 with NO PAIN technology was 3.16 ± 2.10, and for the control device Mini Piezon without NO PAIN technology 3.40 ± 2.59 (p = 0.490). Placing an arbitrary threshold at the VAS score of 3 for significant pain experience, 60 % of the subjects experienced no significant pain with either instrument.

CONCLUSION

No statistically significant difference in perceived pain between the instruments used was found.

CLINICAL RELEVANCE

Both ultrasonic devices showed very small pain intensities during debridement of highly hypersensitive teeth and can therefore be recommended for supportive periodontal therapy.

Sagittal Wrist Motion of Carpal Bones Following Intraarticular Fractures of the Distal Radius

Forty patients (mean age, 37 years) with intraarticular C2 and C3 Colles fractures were treated by open reduction, internal fixation and bone grafting. At a mean follow-up of 8 years radiocarpal and midcarpal motion was evaluated, the depth of the articular surface of the distal radius in the sagittal plane was measured and the presence of arthritis was noted. The fractures healed with a mean palmar tilt of 6°, a mean ulnar tilt of 18° and ulna variance within 1 mm of the contralateral side. The depth of the articular surface of the distal radius was 1.3 mm greater than the uninvolved side. Measurement of carpal bone angles relative to the radius in maximum flexion and extension revealed lunate extension of 23°, lunate flexion of 15°, capitate extension of 62°, capitate flexion of 40°. There was a significant correlation between articular surface depth and radiocarpal motion.

Semi-Automated Annotation of Biobank Data Using Standard Medical Terminologies in a Graph Database

Data describing biobank resources frequently contains unstructured free-text information or insufficient coding standards. (Bio-) medical ontologies like Orphanet Rare Diseases Ontology (ORDO) or the Human Disease Ontology (DOID) provide a high number of concepts, synonyms and entity relationship properties. Such standard terminologies increase quality and granularity of input data by adding comprehensive semantic background knowledge from validated entity relationships. Moreover, cross-references between terminology concepts facilitate data integration across databases using different coding standards. In order to encourage the use of standard terminologies, our aim is to identify and link relevant concepts with free-text diagnosis inputs within a biobank registry. Relevant concepts are selected automatically by lexical matching and SPARQL queries against a RDF triplestore. To ensure correctness of annotations, proposed concepts have to be confirmed by medical data administration experts before they are entered into the registry database. Relevant (bio-) medical terminologies describing diseases and phenotypes were identified and stored in a graph database which was tied to a local biobank registry. Concept recommendations during data input trigger a structured description of medical data and facilitate data linkage between heterogeneous systems.

Elastic Abdominal Binders Attenuate Orthostatic Hypotension in Parkinson's Disease

Background and Methods

To investigate the possible efficacy of an elastic abdominal binder to control orthostatic hypotension (OH) associated with Parkinson's disease (PD), 15 patients with PD and OH were enrolled in a single-blind crossover study with elastic abdominal versus placebo binder on two different days, separated by a 1-day interval, followed by a 4-week open-label follow-up.

Results

Intervention significantly reduced blood pressure fall upon tilting. The mean difference (standard deviation; 95% confidence intervals) between abdominal binder versus placebo was +10 mm Hg (10.2; +3.5, +16.5; P = 0.006). No significant effect on supine mean blood pressure values was observed compared to placebo (P = 0.3). Symptoms of OH decreased significantly during follow-up (P = 0.003), as assessed by means of the Orthostatic Hypotension Questionnaire.

Conclusions

Our findings suggest that elastic abdominal binders may be a simple complementary tool to alleviate OH in PD.

[On the interdisciplinary S3 guidelines for the treatment of chronic idiopathic tinnitus]

INTRODUCTION

Tinnitus is a frequent symptom, which, particularly in combination with comorbidities, can result in a severe disease-related burden. Chronic idiopathic tinnitus (CIT) is the most frequent type of tinnitus. A considerable number of treatment strategies are used to treat CIT-for many of which there is no evidence of efficacy. In order to enable scientific evidence-based treatment of CIT, German interdisciplinary S3 guidelines have recently been constructed for the first time. Here we present a short form of these S3 guidelines.

MATERIALS AND METHODS

The guidelines were constructed based on a meta-analysis of the treatment of chronic tinnitus performed by the authors. Additionally, a systematic literature search was performed in the PubMed and Cochrane Library databases. Furthermore, a systematic search for international guidelines was performed in Google, as well as in the Guidelines International Network and National Guideline Clearinghouse (USA) database. Evidence was classified according to the Oxford Centre for Evidence-Based Medicine system.

RESULTS

According to the guidelines, alongside counselling, manualized structured tinnitus-specific cognitive behavioral therapy (tCBT) with a validated treatment manual is available as evidence-based therapy. In addition, the guidelines recommend concurrent treatment of comorbidities, including drug-based treatment, where appropriate. Particularly important is treatment of anxiety and depression. Where a psychic or psychiatric comorbidity is suspected, further diagnosis and treatment should be performed by an appropriately qualified specialist (psychiatrist, neurologist, psychosomatic medicine consultant) or psychological psychotherapist. In cases accompanied by deafness or hearing loss bordering on deafness, cochlear implants may be indicated.

CONCLUSION

No recommendations can be made for drug-based treatment of CIT, audiotherapy, transcranial magnetic or electrical stimulation, specific forms of acoustic stimulation or music therapy; or such recommendations must remain open due to the lack of available evidence. Polypragmatic tinnitus treatment with therapeutic strategies for which there is no evidence of efficacy from controlled studies is to be refused.

Olfactory dysfunction predicts early transition to a Lewy body disease in idiopathic RBD

OBJECTIVE

The aim of the present study was to determine the predictive value of olfactory dysfunction for the early development of a synuclein-mediated neurodegenerative disease in subjects with idiopathic REM sleep behavior disorder (iRBD) over an observational period of 5 years.

METHODS

Thirty-four patients with polysomnography-confirmed iRBD underwent olfactory testing using the entire Sniffin' Sticks test assessing odor identification, odor discrimination, and olfactory threshold. Patients with iRBD were prospectively followed up over a period of 4.9 ± 0.3 years (mean ± SD). The diagnosis of neurodegenerative diseases was based on current clinical diagnostic criteria.

RESULTS

After 2.4 ± 1.7 years (mean ± SD), 9 patients (26.5%) with iRBD developed a Lewy body disease (6 Parkinson disease and 3 dementia with Lewy bodies). The entire Sniffin' Sticks test and the identification subtest had the same overall diagnostic accuracy of 82.4% (95% confidence interval: 66.1%-92.0%) in predicting conversion. The relative risk for a Lewy body disease in the lowest tertile of olfactory function was 7.3 (95% confidence interval: 1.8-29.6) compared with the top 2 tertiles.

CONCLUSIONS

Assessment of olfactory function, particularly odor identification, may help to predict the development of a Lewy body disease in patients with iRBD over a relatively short time period and thus to identify patients suitable for future disease modification trials.

Association of TNFRSF10D DNA-methylation with the survival of melanoma patients

In this retrospective pilot study, the DNA-methylation status of genes that have been demonstrated to be involved in melanoma carcinogenesis was analyzed in order to identify novel biomarkers for the risk assessment of melanoma patients. We analyzed DNA extracted from punch-biopsies from 68 formalin-fixed paraffin-embedded (FFPE) melanoma specimens. Using MethyLight PCR, we examined 20 genes in specimens from a training set comprising 36 melanoma patients. Selected candidate genes were validated in a test set using FFPE tissue samples from 32 melanoma patients. First, we identified the TNFRSF10D DNA-methylation status (TNFRSF10D methylated vs. unmethylated) as a prognostic marker for overall (p = 0.001) and for relapse-free survival (p = 0.008) in the training set. This finding was confirmed in the independent test set (n = 32; overall survival p = 0.041; relapse-free survival p = 0.012). In a multivariate Cox-regression analysis including all patients, the TNFRSF10D DNA-methylation status remained as the most significant prognostic parameter for overall and relapse-free survival (relative-risk (RR) of death, 4.6 (95% CI: 2.0–11.0; p < 0.001), RR of relapse, 7.2 (95% CI: 2.8–18.3; p < 0.001)). In this study, we demonstrate that TNFRSF10D DNA-methylation analysis of a small tissue-punch from archival FFPE melanoma tissue is a promising approach to provide prognostic information in patients with melanoma.

Progression types after antiangiogenic therapy are related to outcome in recurrent glioblastoma

OBJECTIVE

This retrospective study analyzed whether the type of radiologic progression, classified according to contrast enhancement on MRI T1-weighted sequences and changes in T2-hyperintense signal, is relevant for outcome in patients with progressive glioblastoma (pGB) treated with bevacizumab.

METHODS

MRI scans of 83 patients with pGB treated with bevacizumab were evaluated prior to and at disease progression. Based on initial decrease in and subsequent flare-up of contrast enhancement in T1 and 2 patterns of T2-hyperintense tumor progression, progression types (PTs) were categorized as cT1 flare-up, T2-diffuse, T2-circumscribed, or primary nonresponder. Overall survival (OS), survival from start of bevacizumab therapy (OS_Bev), survival after bevacizumab failure (OS_PostBev), time from initial diagnosis until initiation of bevacizumab therapy (StartBevT), and time to bevacizumab progression were evaluated using Kaplan-Meier curves, log-rank test, and Cox regression analyses.

RESULTS

The time observed for development of a T2-diffuse (n = 15) or a cT1 flare-up (n = 35) progression was longer than for progression in primary nonresponders (n = 16) or T2-circumscribed progression (n = 17). The T2-diffuse PT showed longer OS, OS_Bev, OS_PostBev, and StartBevT compared to the other PTs. Postprogression therapy tended to be relevant only for patients with a T2-circumscribed PT.

CONCLUSIONS

Radiologic PTs following bevacizumab treatment failure show differences in time to development and are related to outcome. We therefore hypothesize that these PTs reflect a different glioma biology, including differential resistance mechanisms to bevacizumab, and may be associated with different responses to postprogression therapy.

Ischemia and functional status of the left arm and quality of life after left subclavian artery coverage during stent grafting of thoracic aortic diseases

BACKGROUND

The objective of this study was to report on the incidence of left arm ischemia, left arm function, and quality of life after thoracic endovascular aortic repair (TEVAR) by stent grafting with and without coverage of the left subclavian artery (LSA).

METHODS

All patients who underwent TEVAR since 1996 in our institution were included. Basic demographic parameters, underlying disease, details of TEVAR, long-term left arm function (Disabilities of the Arm, Shoulder, and Hand [DASH] questionnaire), and quality of life (12-Item Short Form Health Survey) were analyzed. End points were left arm ischemia, need for LSA revascularization (before or after TEVAR), long-term functional impairment, and quality of life.

RESULTS

A total of 138 patients underwent TEVAR for degenerative aneurysm (n = 64), traumatic aortic injury (TAI; n = 38), or Stanford type B dissection (n = 36). Seventy-three patients (52.9%) had LSA coverage, which led to partial or complete LSA occlusion in 49 (35.5%). Selectively, nine patients (6.5%) had primary LSA revascularization. After TEVAR, left arm ischemia was observed in only one patient, who consecutively needed a left carotid to subclavian bypass. During a mean follow-up period of 4.1 ± 3.7 years, no additional patient needed secondary LSA revascularization. In comparing patients with occluded vs patent LSA, the Physical Component Summary (PCS) and Mental Component Summary (MCS) health scores (12-Item Short Form Health Survey) as well as DASH scores were similar. However, subgroup analysis showed better PCS scores for TAI patients with patent LSA, whereas MCS and DASH scores were similar in TAI patients, and scores were indifferent within thoracic aortic aneurysm and Stanford type B dissection subgroups. In comparing different subgroups, TAI patients had significantly better PCS, MCS, and DASH scores.

CONCLUSIONS

TEVAR is associated with a low risk of peri-interventional left arm ischemia. During long-term follow-up, secondary LSA revascularization is uncommon. Coverage of the LSA has no impact on left arm function and quality of life, probably with the exception of physical health scores in patients with TAI.

A concept of a MIABIS based register of biosample collections at the Medical University of Innsbruck

The knowledge about the quality of samples and associated clinical data in biospecimen collections is a premise of clinical research. An electronic biosample register aims to facilitate the discovery of information about biosample collections in a hospital. Moreover, it might improve scientific collaboration and research quality through a shared access to harmonized sample collection description data. The aim of this paper is to present a concept of a web-based biosample register of the existing biosample collections at the Medical University of Innsbruck. A uniform description model is built based on an analysis of the sample collection data of independent sample management systems from two departments within the hospital. An extended set of attributes of the minimum dataset used by the Swedish sample collection register (MIABIS) has been applied to all biosample collections as a common description model. The results of the analysis and the data model are presented together with a first concept of a sample collection search register.

Cardiac safety and efficacy of concomitant liposomal doxorubicin, docetaxel, and trastuzumab as neoadjuvant therapy in HER2-overexpressing breast cancer: A retrospective analysis

583

Background: Concurrent therapy of trastuzumab, anthracycline and taxane for the neoadjuvant treatment of breast cancer (BC) results in an improved rate of pathological complete response (pCR). However, there is considerable concern about the cardiac safety of this combination. The use of liposomal doxorubicin might be a valuable alternative with lower cardiotoxicity. We report cardiac safety and pCR-rate of a single arm, retrospective, multicenter analysis of neoadjuvant treatment for BC with liposomal doxorubicin, trastuzumab, and docetaxel. Methods: In this study 84 women with BC and HER2 overexpression were investigated in 3 oncological departments in Austria. All patients were treated with liposomal doxorubicin (50 - 60 mg/m²), docetaxel (75 mg/m²) and concurrent with trastuzumab for 6 cycles as neoadjuvant therapy. All patients were free of cardiovascular disease and had a left ventricular ejection fraction (LVEF) of ≥ 55%. Cardiac function was by LVEF and was examined at regular intervals(cycles 0-3, cycle 6, FU). Clinical response was evaluated by diagnostic breast imaging after cycles 3 and 6. All patients underwent surgery after neoadjuvant chemotherapy. The absence of any residual invasive cancer in the breast and axilla was defined as pathological complete response (pCR). Median follow up was 2.4 years. Results: Median age of the patients was 50 years. After 6 cycles of treatment the pCR rate was 46%. In this cohort a negative estrogen-and/or progesteron receptor was predictive for pCR (p<0.001). No patient progressed during treatment. None of the patients suffered symptomatic heart failure. Only one patient (1.6%) with asymptomatic LVEF of 45% was observed during follow-up. Conclusions: In this multicenter analysis we observed a considerably high rate of pCR in HER2-positive BC treated with liposomal doxorubicin, docetaxel and trastuzumab. The addition of liposomal doxorubicin instead of conventional doxorubicin or epirubicin entails a very favorable cardiotoxicity profile. This regimen is a safe treatment option in patients with HER-2 positive breast cancer.

The natural history of multiple system atrophy: a prospective European cohort study

BACKGROUND

Multiple system atrophy (MSA) is a fatal and still poorly understood degenerative movement disorder that is characterised by autonomic failure, cerebellar ataxia, and parkinsonism in various combinations. Here we present the final analysis of a prospective multicentre study by the European MSA Study Group to investigate the natural history of MSA.

METHODS

Patients with a clinical diagnosis of MSA were recruited and followed up clinically for 2 years. Vital status was ascertained 2 years after study completion. Disease progression was assessed using the unified MSA rating scale (UMSARS), a disease-specific questionnaire that enables the semiquantitative rating of autonomic and motor impairment in patients with MSA. Additional rating methods were applied to grade global disease severity, autonomic symptoms, and quality of life. Survival was calculated using a Kaplan-Meier analysis and predictors were identified in a Cox regression model. Group differences were analysed by parametric tests and non-parametric tests as appropriate. Sample size estimates were calculated using a paired two-group t test.

FINDINGS

141 patients with moderately severe disease fulfilled the consensus criteria for MSA. Mean age at symptom onset was 56·2 (SD 8·4) years. Median survival from symptom onset as determined by Kaplan-Meier analysis was 9·8 years (95% CI 8·1-11·4). The parkinsonian variant of MSA (hazard ratio [HR] 2·08, 95% CI 1·09-3·97; p=0·026) and incomplete bladder emptying (HR 2·10, 1·02-4·30; p=0·044) predicted shorter survival. 24-month progression rates of UMSARS activities of daily living, motor examination, and total scores were 49% (9·4 [SD 5·9]), 74% (12·9 [8·5]), and 57% (21·9 [11·9]), respectively, relative to baseline scores. Autonomic symptom scores progressed throughout the follow-up. Shorter symptom duration at baseline (OR 0·68, 0·5-0·9; p=0·006) and absent levodopa response (OR 3·4, 1·1-10·2; p=0·03) predicted rapid UMSARS progression. Sample size estimation showed that an interventional trial with 258 patients (129 per group) would be able to detect a 30% effect size in 1-year UMSARS motor examination decline rates at 80% power.

INTERPRETATION

Our prospective dataset provides new insights into the evolution of MSA based on a follow-up period that exceeds that of previous studies. It also represents a useful resource for patient counselling and planning of multicentre trials.

Interference of the new oral anticoagulant dabigatran with frequently used coagulation tests

BACKGROUND

Dabigatran etexilate is a new oral anticoagulant for the therapy and prophylaxis of venous thromboembolism and stroke prevention in patients with atrial fibrillation. To investigate the extent of interactions of this new anticoagulant with frequently used coagulation assays, we completed a multicenter in vitro trial with Conformité Européenne(CE)-labeled dabigatran-spiked plasma samples.

METHODS

Lyophilized plasma samples with dabigatran concentrations ranging from 0.00 to 0.48 μg/mL were sent to the coagulation laboratories of six major Austrian hospitals for evaluation. Coagulation assays were performed under routine conditions using standard reagents and analyzer.

RESULTS

Dabigatran led to a dose-dependent prolongation of the clotting times in coagulometric tests and influenced the majority of the parameters measured. Statistically significant interference could be observed with the prothrombin time (PT), activated partial thromboplastin time (aPTT) and PT/aPTT-based assays (extrinsic/intrinsic factors, APC-resistance test) as well as lupus anticoagulant testing. Even non-clotting tests, such as the colorimetric factor XIII activity assay and to a minor extent the amidolytic antithrombin activity assay (via factor IIa) were affected.

CONCLUSIONS

This multicenter trial confirms and also adds to existing data, demonstrating that laboratories should expect to observe strong interferences of coagulation tests with increasing concentrations of dabigatran. This finding might become particularly important in the elderly and in patients with renal impairment as well as patients whose blood is drawn at peak levels of dabigatran.