Long-term outcome of enzyme-replacement therapy in advanced Fabry disease: evidence for disease progression towards serious complications

OBJECTIVE

The long-term effects of enzyme-replacement therapy (ERT) in Fabry disease are unknown. Thus, the aim of this study was to determine whether ERT in patients with advanced Fabry disease affects progression towards 'hard' clinical end-points in comparison with the natural course of the disease.

METHODS

A total of 40 patients with genetically proven Fabry disease (mean age 40 ± 9 years; n = 9 women) were treated prospectively with ERT for 6 years. In addition, 40 subjects from the Fabry Registry, matched for age, sex, chronic kidney disease stage and previous transient ischaemic attack (TIA), served as a comparison group. The main outcome was a composite of stroke, end-stage renal disease (ESRD) and death. Secondary outcomes included changes in myocardial left ventricular (LV) wall thickness and replacement fibrosis, change in glomerular filtration rate (GFR), new TIA and change in neuropathic pain.

RESULTS

During a median follow-up of 6.0 years (bottom and top quartiles: 5.1, 7.2), 15 events occurred in 13 patients (n = 7 deaths, n = 4 cases of ESRD and n = 4 strokes). Sudden death occurred (n = 6) only in patients with documented ventricular tachycardia and myocardial replacement fibrosis. The annual progression of myocardial LV fibrosis in the entire cohort was 0.6 ± 0.7%. As a result, posterior end-diastolic wall thinning was observed (baseline, 13.2 ± 2.0 mm; follow-up, 11.4 ± 2.1 mm; P < 0.01). GFR decreased by 2.3 ± 4.6 mL min(-1) per year. Three patients experienced a TIA. The major clinical symptom was neuropathic pain (n = 37), and this symptom improved in 25 patients. The event rate was not different between the ERT group and the untreated (natural history) group of the Fabry Registry.

CONCLUSION

Despite ERT, clinically meaningful events including sudden cardiac death continue to develop in patients with advanced Fabry disease.

Whole-heart cine MRI in a single breath-hold--a compressed sensing accelerated 3D acquisition technique for assessment of cardiac function

PURPOSE

The aim of this study was to perform functional MR imaging of the whole heart in a single breath-hold using an undersampled 3 D trajectory for data acquisition in combination with compressed sensing for image reconstruction.

MATERIALS AND METHODS

Measurements were performed using an SSFP sequence on a 3 T whole-body system equipped with a 32-channel body array coil. A 3 D radial stack-of-stars sampling scheme was utilized enabling efficient undersampling of the k-space and thereby accelerating data acquisition. Compressed sensing was applied for the reconstruction of the missing data. A validation study was performed based on a fully sampled dataset acquired by standard Cartesian cine imaging of 2 D slices on a healthy volunteer. The results were investigated with regard to systematic errors and resolution losses possibly introduced by the developed reconstruction. Subsequently, the proposed technique was applied for in-vivo functional cardiac imaging of the whole heart in a single breath-hold of 27  s. The developed technique was tested on three healthy volunteers to examine its reproducibility.

RESULTS

By means of the results of the simulation (temporal resolution: 47  ms, spatial resolution: 1.4 × 1.4 × 8  mm, 3 D image matrix: 208 × 208 × 10), an overall acceleration factor of 10 has been found where the compressed sensing reconstructed image series shows only very low systematic errors and a slight in-plane resolution loss of 15 %. The results of the in-vivo study (temporal resolution: 40.5  ms, spatial resolution: 2.1 × 2.1 × 8  mm, 3 D image matrix: 224 × 224 × 12) performed with an acceleration factor of 10.7 confirm the overall good image quality of the presented technique for undersampled acquisitions.

CONCLUSION

The combination of 3 D radial data acquisition and model-based compressed sensing reconstruction allows high acceleration factors enabling cardiac functional imaging of the whole heart within only one breath-hold. The image quality in the simulated dataset and the in-vivo measurement highlights the great potential of the presented technique for an efficient assessment of cardiac functional parameters.

Classical swine fever

Classical swine fever is a serious and economically important transboundary disease threatening pig production globally. The infection may occur in backyard pigs, feral pig populations and domestic pigs. Whereas there are proven control strategies for the latter pig population, control in backyard pigs with poor biosecurity settings or in wild boar populations of high density still poses a problem in some parts of the world. Laboratory diagnostic methods, efficacious vaccines and contingency plans are in place in most industrialised countries. So far modified live vaccines (MLV) are still the first choice for rapid and reliable immune protection. Since antibodies elicited by conventional MLV cannot be distinguished from antibodies after natural infection, considerable efforts are put into the development of a live marker vaccine accompanied by a serological test. Nevertheless, some remaining gaps with respect to the diagnosis of and vaccination against classical swine fever have been identified.

[Insights into melanoma from a pathologist's perspective]

Malignant melanoma is the most common cause of death from skin cancer. Wide surgical excision of localized melanoma in its primary stages remains the main curative therapy. Identifying patients at an early tumour stage is therefore one of the most significant steps for treatment. In the last decades, molecular pathology rapidly established itself in melanoma research. We present new molecular methods, their significance and their application, especially focusing on BRAF( V600) mutation and BRAF-inhibiting tumor targeting therapy. Resistance to tumor targeting therapies and cell line experiments, which have evidenced a sub population with stem cell properties, illustrate melanoma heterogeneity. Efforts to develop drugs that target more than a single target gene are currently underway.

Schmallenberg virus, a novel orthobunyavirus infection in ruminants in Europe: potential global impact and preventive measures

In autumn 2011, Schmallenberg virus was the first orthobunyavirus detected in Europe. The virus belongs to the Simbu serogroup. Like other orthobunyaviruses, it is apparently transmitted by arthropod vectors, primarily by biting midges (Culicoides spp.). Ruminants and new-world camelids (alpacas) are susceptible to infection. Adult animals may develop mild disease, if any. However, transplacental infection can lead to severe congenital malformations such asarthrogryposis, malformation of the vertebral column (kyphosis, lordosis, scoliosis, torticollis) and of the skull (macrocephaly, brachygnathia inferior) as well as variable malformations of the brain (hydranencephaly, porencephaly, cerebellar hypoplasia, hypoplasia of the brain stem) and of the spinal cord in lambs, goat kids and calves. The infection spread rapidly over large parts of North-Western Europe. Belgium, Denmark, Germany, France, Italy, Luxembourg, the Netherlands, Spain and the United Kingdom were affected in the transmission season 2011/2012. The disease has re-emerged, at least in France, Germany and the United Kingdom during the vector-active season in 2012 and recently spread to Austria, Finland, Poland, Switzerland and Sweden. It remains to be seen whether the infection will establish permanently in the affected area. Measures have been proposed by the World Organisation for Animal Health (OIE) to help countries free from Schmallenberg virus to avoid the introduction of the infection without imposing inappropriate trade barriers. The aim of this article is to provide a state-of-the-art review on Schmallenberg virus 1 year after its first detection.

Efficacy of chimeric Pestivirus vaccine candidates against classical swine fever: protection and DIVA characteristics

Currently no live DIVA (Differentiating Infected from Vaccinated Animals) vaccines against classical swine fever (CSF) are available. The aim of this study was to investigate whether chimeric pestivirus vaccine candidates (CP7_E2alf, Flc11 and Flc9) are able to protect pigs against clinical signs, and to reduce virus shedding and virus transmission, after a challenge with CSF virus (CSFV), 7 or 14 days after a single intramuscular vaccination. In these vaccine candidates, either the E2 or the E(rns) encoding genome region of a bovine viral diarrhoea virus strain were combined with a cDNA copy of CSFV or vice versa. Furthermore, currently available serological DIVA tests were evaluated. The vaccine candidates were compared to the C-strain. All vaccine candidates protected against clinical signs. No transmission to contact pigs was detected in the groups vaccinated with C-strain, CP7_E2alf and Flc11. Limited transmission occurred in the groups vaccinated with Flc9. All vaccine candidates would be suitable to stop on-going transmission of CSFV. For Flc11, no reliable differentiation was possible with the current E(rns)-based DIVA test. For CP7_E2alf, the distribution of the inhibition percentages was such that up to 5% false positive results may be obtained in a large vaccinated population. For Flc9 vaccinated pigs, the E2 ELISA performed very well, with an expected 0.04% false positive results in a large vaccinated population. Both CP7_E2alf and Flc9 are promising candidates to be used as live attenuated marker vaccines against CSF, with protection the best feature of CP7_E2alf, and the DIVA principle the best feature of Flc9.

Serological survey in dogs and cats for influenza A(H1N1)pdm09 in Germany

A serological survey for the detection of antibodies to influenza A(H1N1)pdm09 was carried out in a population of dogs and cats in Germany. A total of 1150 sera collected in 2010 and 2011 were screened using an ELISA targeting anti-nucleoprotein NP antibodies. Those initially screened positive samples were subsequently tested for antibodies to N1 neuraminidase followed by a virus neutralization test using A/Bayern/74/2009 strain. A prevalence of A(H1N1)pdm09-specific antibodies of 0.13% and 1.93% was estimated among dogs and cats, respectively. Evidence of exposure to other influenza A virus subtypes was also observed.

Consecutive natural influenza a virus infections in sentinel mallards in the evident absence of subtype-specific hemagglutination inhibiting antibodies

Dabbling ducks, particularly Mallards (Anas platyrhynchos) have been frequently and consistently reported to play a pivotal role as a reservoir of low pathogenic avian influenza viruses (AIV). From October 2006 to November 2008, hand-raised Mallard ducks kept at a pond in an avifaunistically rich area of Southern Germany served as sentinel birds in the AIV surveillance programme in Germany. The pond was regularly visited by several species of dabbling ducks. A flock of sentinel birds, consisting of the same 16 individual birds during the whole study period, was regularly tested virologically and serologically for AIV infections. Swab samples were screened by RT-qPCR and, if positive, virus was isolated in embryonated chicken eggs. Serum samples were tested by the use of competitive ELISA and hemagglutinin inhibition (HI) assay. Sequences of full-length hemagglutinin (HA) and neuraminidase (NA) genes were phylogenetically analysed. Four episodes of infections with Eurasian-type AIV occurred in August (H6N8), October/November (H3N2, H2N3) 2007, in January (H3N2) and September (H3N8) 2008. The HA and NA genes of the H3N2 viruses of October 2007 and January 2008 were almost identical rendering the possibility of a re-introduction of that virus from the environment of the sentinel flock highly likely. The HA of the H3N8 virus of September 2008 belonged to a different cluster. As a correlate of the humoral immune response, titres of nucleocapsid protein-specific antibodies fluctuated in correlation with the course of AIV infection episodes. However, no specific systemic response of hemagglutination inhibiting antibodies could be demonstrated even if homologous viral antigens were used. Besides being useful as early indicators for the circulation of influenza viruses in a specific region, the sentinel ducks also contributed to gaining insights into the ecobiology of AIV infection in aquatic wild birds.

Organ distribution of Schmallenberg virus RNA in malformed newborns

A novel orthobunyavirus was first detected in German dairy cows in autumn 2011 and was subsequently found in the brains of malformed lambs, kids and calves in the Netherlands, Germany, Belgium, France, Italy, Great Britain, Luxembourg and Spain. For rapid detection of this novel virus, named Schmallenberg virus, a real time quantitative reverse transcription PCR (RT-qPCR) was developed at the Friedrich-Loeffler-Institut and provided to the federal veterinary state laboratories in Germany. For diagnostic purposes, the organ distribution of this new virus was analyzed in several organs and body fluids of 15 lambs and two calves showing typical malformations. Spleen, cerebrum, meconium, spinal cord, rib cartilage, umbilical cord, placental fluid out of the stomach as well as external placental fluid scraped from the coat of the foetuses were collected during necropsy. All animals were tested RT-qPCR positive in the external placental fluid, and all but one were also RT-qPCR positive in the cerebrum, the umbilical and the spinal cord. Our results suggest that both the external placental fluid and the umbilical cord could be suitable sample materials for the confirmation of an infection with Schmallenberg virus in malformed newborns, at least in lambs. This is of special interest since those samples can be collected very easily on the farm without the need of a necropsy.

[Consensus recommendations of the German Radiology Society (DRG), the German Cardiac Society (DGK) and the German Society for Pediatric Cardiology (DGPK) on the use of cardiac imaging with computed tomography and magnetic resonance imaging]

Cardiac magnetic resonance imaging (MRI) and computed tomography (CT) have been developed rapidly in the last decade. Technical improvements and broad availability of modern CT and MRI scanners have led to an increasing and regular use of both diagnostic methods in clinical routine. Therefore, this German consensus document has been developed in collaboration by the German Cardiac Society, German Radiology Society, and the German Society for Pediatric Cardiology. It is not oriented on modalities and methods, but rather on disease entities. This consensus document deals with coronary artery disease, cardiomyopathies, arrhythmias, valvular diseases, pericardial diseases and structural changes, as well as with congenital heart defects. For different clinical scenarios both imaging modalities CT and MRI are compared and evaluated in the specific context.

Clinical course and pathology in rats (Rattus norvegicus) after experimental cowpox virus infection by percutaneous and intranasal application

Recently, several cases of human cowpox virus (CPXV) infections were reported in France and Germany, which had been acquired through close contact with infected pet rats. The animals exhibited respiratory signs or skin lesions and died shortly after purchase. After natural infection of white rats with CPXV in the USSR in 1978, a peracute pulmonary form, a milder dermal form, and a mixed form exhibiting features of both have been described. To the best of the authors' knowledge, 3 experimental cowpox virus infection studies using rats have been performed to date; however, neither results of histomorphological examinations nor immunohistochemical analyses have yet been reported in rats after experimental infections. To investigate the impact of the infection route on the clinical course, the development of lesions, and tropism, rats were infected intradermally, intranasally, or by a combination of both routes. The authors found a correlation between clinical manifestation, pathology, and infection routes. Intradermal and contact exposure yielded a mild dermal form, characterized by the development of vesiculopustular dermatitis. In contrast, intranasally infected animals died peracutely, showing severe dyspnea. Occasionally, a combination of the dermal and the respiratory form occurred after intranasal infection. Immunohistochemically, CPXV antigen was detected in the epithelial and mesenchymal cells of the upper respiratory tract and affected skin lesions and rarely in mesenchymal cells of lymph nodes. This is the first histomorphological and immunohistochemical analysis of CPXV in rats after experimental infection.

Disease severity declines over time after a wild boar population has been affected by classical swine fever--legend or actual epidemiological process?

Classical swine fever (CSF) is a severe multi-systemic disease that can affect both domestic pigs and wild boar. Past outbreaks in European wild boar involved high-virulent CSF virus (CSFV) strains and were mostly self-limiting. In these cases, morbidity and mortality rates were high in the affected regions. In contrast, endemic infections have been observed in several European wild boar populations in recent decades. Morbidity and mortality rates were much lower despite the fact that outbreaks were still detected via diseased or fallen animals. The virus strains involved were mostly classified as genotype 2.3 strains of moderate virulence causing age-dependent disease outcomes. The mechanisms leading to the establishment and perpetuation of endemicity are still not fully understood, but the factor "moderate virulence" seems to be of considerable importance. In this study, we aim to clarify whether the perception of declined 'CSF severity' could hypothetically reflect the adaptation of an initially high-virulent virus or whether this might be better explained as a misinterpretation of observations. A mechanistic eco-epidemiological model was employed to follow up a highly virulent strain of CSFV introduced into large connected wild boar populations. In the model, the virulence of the CSF virus is represented by case mortality and life expectancy after lethal infection. Allowing for small stochastic variation, these two characteristics of the virus are passed on with every new simulated infection that occurs. Model analysis revealed a decrease from high to moderate case mortality within a few years of simulated perpetuation of the virus. The resulting mortality corresponded to the level where the population average of the infectious period and the basic reproduction number of the disease were maximal. This shift in virulence was sufficient to prolong virus circulation considerably beyond the epidemic phase of the simulated outbreaks. Alternative mechanistic explanations for the decrease in disease severity in a CSF-affected wild boar population were evaluated in the light of the simulation experiments and the available epidemiological or virological evidence. In conclusion, the current virus isolates of subgroup 2.3 might be the ideally adapted variants of the CSF virus for long-term perpetuation in wildlife and indeed may have evolved (once) during past outbreaks in large populations. A repeated perception of a declining severity of disease pattern during the course of a CSF outbreak, however, favours the explanation based on monitoring and detection biases rather than repeated observation of selection against highly virulent virus during the time of virus perpetuation.

MRI of the lung (2/3). Why … when … how?

BACKGROUND

Among the modalities for lung imaging, proton magnetic resonance imaging (MRI) has been the latest to be introduced into clinical practice. Its value to replace X-ray and computed tomography (CT) when radiation exposure or iodinated contrast material is contra-indicated is well acknowledged: i.e. for paediatric patients and pregnant women or for scientific use. One of the reasons why MRI of the lung is still rarely used, except in a few centres, is the lack of consistent protocols customised to clinical needs.

METHODS

This article makes non-vendor-specific protocol suggestions for general use with state-of-the-art MRI scanners, based on the available literature and a consensus discussion within a panel of experts experienced in lung MRI.

RESULTS

Various sequences have been successfully tested within scientific or clinical environments. MRI of the lung with appropriate combinations of these sequences comprises morphological and functional imaging aspects in a single examination. It serves in difficult clinical problems encountered in daily routine, such as assessment of the mediastinum and chest wall, and even might challenge molecular imaging techniques in the near future.

CONCLUSION

This article helps new users to implement appropriate protocols on their own MRI platforms. Main Messages • MRI of the lung can be readily performed on state-of-the-art 1.5-T MRI scanners. • Protocol suggestions based on the available literature facilitate its use for routine • MRI offers solutions for complicated thoracic masses with atelectasis and chest wall invasion. • MRI is an option for paediatrics and science when CT is contra-indicated.

Fatalities in wild goats in Kurdistan associated with Peste des Petits Ruminants virus

Between August 2010 and February 2011, over 750 deaths were recorded among wild goats (Capra aegagrus, the endangered progenitor of the domestic goat) in Kurdistan. Based on the clinical signs and post-mortem findings, the involvement of peste des petits ruminants virus (PPRV) was suspected. This was confirmed by laboratory analysis, and the virus was found to be closely related to a Turkish strain isolated in 2000. During the outbreak in wild goats, no disease in domestic animals was reported. Domestic ruminants in the region are routinely vaccinated with an attenuated vaccine based on the 'Nigeria/75/1' strain of PPRV. This is the first report of active PPRV infection in Kurdistan and most likely the immunity afforded by vaccination prevented spillover infections. It is therefore recommended to continue with the campaign. Conversely, there is no justification for the use of force to keep the endangered wild goats away from domestic flocks.

Right ventricular involvement in patients with Fabry's disease and the effect of enzyme replacement therapy

PURPOSE

According to echocardiography reports, Fabry cardiomyopathy not only affects the left ventricle (LV) but also the right ventricle (RV). Until now no MRI studies about the effect of enzyme replacement therapy (ERT) on the RV are available. We evaluated the effect of ERT on the RV.

MATERIALS AND METHODS

In this prospective trial 14 patients with genetically proven Fabry's disease were examined using a 1.5 T MR scanner before ERT and after 13 ± 1 months of ERT. All patients underwent cardiac MR imaging and the RV/LV cardiac morphology and function were analyzed.

RESULTS

At baseline examination the values were as follows: RV mass 31 ± 6 g/m (2), end-diastolic volume (EDV) 88 ± 13 ml/m (2), end-systolic volume (ESV) 39 ± 9 ml/m (2), stroke volume (SV) 49 ± 7 ml/m (2) and ejection fraction (EF) 56 ± 5 %. The RV mass and EDV decreased significantly after 13 ± 1 months on ERT (mass 27 ± 7 g/m (2), p < 0.05, EDV 76 ± 24 ml/m (2), p < 0.05), with no significant change of ESV (33 ± 13 ml/m (2)), SV (43 ± 12 ml/m (2)) and EF (57 ± 7 %). The LV mass (102 ± 26 g/m (2) vs. 94 ± 27 g/m (2), p < 0.05), EDV (76 ± 13 ml/m (2) vs. 66 ± 22 ml/m (2), p < 0.05) and ESV (29 ± 9 ml/m (2) vs. 23 ± 9 ml/m (2), p < 0.05) decreased significantly while the EF (64 ± 7 % vs. 66 ± 5 %; p < 0.05) increased significantly.

CONCLUSION

Besides the known beneficial effect on the LV, ERT improves RV mass and EDV.

Quantitative myocardial perfusion imaging with a MR cold pressor test

The response of myocardial blood flow to sympathetic stimulation with cold is modulated by endothelium-related factors. As endothelial dysfunction is an early step in patients with coronary artery disease, the aim of this study was to establish a cold pressor test (CPT) setting for quantitative analysis of myocardial perfusion in a MR scanner. First pass perfusion studies were performed in 10 healthy volunteers using a 1.5 T MR scanner with a multislice steady state free precession perfusion trueFISP sequence in prebolus technique (1 cc/4 cc gadobenate dimeglumine). MR-CPT was established using an over head ice-water bath of the left hand. First pass perfusion imaging was started after 1 min to assure an adequate stimulus followed by a second series after 15 min to evaluate the rest perfusion. After motion correction images were segmented with an adapted, automated tool, myocardial contours were determined. Perfusion was quantitatively evaluated after contamination and baseline correction by deconvolution with the arterial input function using an exponential function model as residuum. All data could be evaluated. Mean myocardial perfusion rose from 0.61 ± 0.22 cc/g/min at rest to 1.15 ± 0.34 cc/g/min under CPT. MR myocardial perfusion values show a comparable increase under CPT as published positron emission tomography data. Consequently, CPT for the presence of endothelial dysfunction is feasible in the MR environment.