@article{AllignolSchumacherWanneretal.2011, author = {Allignol, Arthur and Schumacher, Martin and Wanner, Christoph and Drechsler, Christiane and Beyersmann, Jan}, title = {Understanding competing risks: a simulation point of view}, series = {BMC Medical Research Methodology}, volume = {11}, journal = {BMC Medical Research Methodology}, number = {86}, doi = {10.1186/1471-2288-11-86}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-142811}, pages = {1-13}, year = {2011}, abstract = {Background: Competing risks methodology allows for an event-specific analysis of the single components of composite time-to-event endpoints. A key feature of competing risks is that there are as many hazards as there are competing risks. This is not always well accounted for in the applied literature. Methods: We advocate a simulation point of view for understanding competing risks. The hazards are envisaged as momentary event forces. They jointly determine the event time. Their relative magnitude determines the event type. 'Empirical simulations' using data from a recent study on cardiovascular events in diabetes patients illustrate subsequent interpretation. The method avoids concerns on identifiability and plausibility known from the latent failure time approach. Results: The 'empirical simulations' served as a proof of concept. Additionally manipulating baseline hazards and treatment effects illustrated both scenarios that require greater care for interpretation and how the simulation point of view aids the interpretation. The simulation algorithm applied to real data also provides for a general tool for study planning. Conclusions: There are as many hazards as there are competing risks. All of them should be analysed. This includes estimation of baseline hazards. Study planning must equally account for these aspects.}, language = {en} } @article{DrechslerMeinitzerPilzetal.2011, author = {Drechsler, Christiane and Meinitzer, Andreas and Pilz, Stefan and Krane, Vera and Tomaschitz, Andreas and Ritz, Eberhard and M{\"a}rz, Winfried and Wanner, Christoph}, title = {Homoarginine, heart failure, and sudden cardiac death in haemodialysis patients}, series = {European Journal of Heart Failure}, volume = {13}, journal = {European Journal of Heart Failure}, number = {8}, doi = {10.1093/eurjhf/hfr056}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-140495}, pages = {852-859}, year = {2011}, abstract = {Aims Sudden cardiac death (SCD) is a major contributor to the excess mortality of patients on maintenance dialysis. Homoarginine deficiency may lead to decreased nitric oxide availability and endothelial dysfunction. Based on this rationale we assessed whether homoarginine deficiency is a risk factor for SCD in dialysis patients. Methods and results This study examined the association of homoarginine with cardiovascular outcomes in 1255 diabetic haemodialysis patients from the German diabetes and dialysis study. During a median of 4 years of follow-up, hazard ratios (HR) (95\% CI) for reaching the following pre-specified, adjudicated endpoints were determined: SCD, myocardial infarction, stroke, death due to heart failure, and combined cardiovascular events. There was a strong association of low homoarginine concentrations with the presence of congestive heart failure and left ventricular hypertrophy as well as increased levels of brain natriuretic peptide. Per unit decrease in homoarginine, the risk of SCD increased three-fold (HR 3.1, 95\% CI 2.0-4.9), attenuating slightly in multivariate models (HR 2.4; 95\% CI 1.5-3.9). Patients in the lowest homoarginine quintile experienced a more than two-fold increased risk of SCD, and more than three-fold increased risk of heart failure death than patients in the highest quintile, which accounted for the high incidence of combined cardiovascular events. Low homoarginine showed a trend towards increased risk of stroke, however, myocardial infarction was not meaningfully affected. Conclusion Low homoarginine is a strong risk factor for SCD and death due to heart failure in haemodialysis patients. Further studies are needed to elucidate the underlying mechanisms, offering the potential to develop new interventional strategies.}, language = {en} } @article{KistlerSiwyFranketal.2011, author = {Kistler, Andreas D. and Siwy, Justyna and Frank, Breunig and Jeevaratnam, Praveen and Scherl, Alexander and Mullen, William and Warnock, David G. and Wanner, Christoph and Hughes, Derralynn A. and Mischak, Harald and W{\"u}thrich, Rudolf P. and Serra, Andreas L.}, title = {A Distinct Urinary Biomarker Pattern Characteristic of Female Fabry Patients That Mirrors Response to Enzyme Replacement Therapy}, series = {PLoS ONE}, volume = {6}, journal = {PLoS ONE}, number = {6}, doi = {10.1371/journal.pone.0020534}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133526}, pages = {e20534}, year = {2011}, abstract = {Female patients affected by Fabry disease, an X-linked lysosomal storage disorder, exhibit a wide spectrum of symptoms, which renders diagnosis, and treatment decisions challenging. No diagnostic test, other than sequencing of the alpha-galactosidase A gene, is available and no biomarker has been proven useful to screen for the disease, predict disease course and monitor response to enzyme replacement therapy. Here, we used urine proteomic analysis based on capillary electrophoresis coupled to mass spectrometry and identified a biomarker profile in adult female Fabry patients. Urine samples were taken from 35 treatment-naive female Fabry patients and were compared to 89 age-matched healthy controls. We found a diagnostic biomarker pattern that exhibited 88.2\% sensitivity and 97.8\% specificity when tested in an independent validation cohort consisting of 17 treatment-naive Fabry patients and 45 controls. The model remained highly specific when applied to additional control patients with a variety of other renal, metabolic and cardiovascular diseases. Several of the 64 identified diagnostic biomarkers showed correlations with measures of disease severity. Notably, most biomarkers responded to enzyme replacement therapy, and 8 of 11 treated patients scored negative for Fabry disease in the diagnostic model. In conclusion, we defined a urinary biomarker model that seems to be of diagnostic use for Fabry disease in female patients and may be used to monitor response to enzyme replacement therapy.}, language = {en} } @article{CarstenAGorskiLietal.2011, author = {Carsten A., B{\"o}ger and Gorski, Mathias and Li, Man and Hoffmann, Michael M. and Huang, Chunmei and Yang, Qiong and Teumer, Alexander and Krane, Vera and O'Seaghdha, Conall M. and Kutalik, Zolt{\´a}n and Wichmann, H.-Erich and Haak, Thomas and Boes, Eva and Coassin, Stefan and Coresh, Josef and Kollerits, Barbara and Haun, Margot and Paulweber, Bernhard and K{\"o}ttgen, Anna and Li, Guo and Shlipak, Michael G. and Powe, Neil and Hwang, Shih-Jen and Dehghan, Abbas and Rivadeneira, Fernando and Uitterlinden, Andr{\´e} and Hofman, Albert and Beckmann, Jacques S. and Kr{\"a}mer, Bernhard K. and Witteman, Jacqueline and Bochud, Murielle and Siscovick, David and Rettig, Rainer and Kronenberg, Florian and Wanner, Christoph and Thadhani, Ravi I. and Heid, Iris M. and Fox, Caroline S. and Kao, W.H.}, title = {Association of eGFR-Related Loci Identified by GWAS with Incident CKD and ESRD}, series = {PLoS Genetics}, volume = {7}, journal = {PLoS Genetics}, number = {9}, doi = {10.1371/journal.pgen.1002292}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133758}, pages = {e1002292}, year = {2011}, abstract = {Family studies suggest a genetic component to the etiology of chronic kidney disease (CKD) and end stage renal disease (ESRD). Previously, we identified 16 loci for eGFR in genome-wide association studies, but the associations of these single nucleotide polymorphisms (SNPs) for incident CKD or ESRD are unknown. We thus investigated the association of these loci with incident CKD in 26,308 individuals of European ancestry free of CKD at baseline drawn from eight population-based cohorts followed for a median of 7.2 years (including 2,122 incident CKD cases defined as eGFR < 60ml/min/1.73m(2) at follow-up) and with ESRD in four case-control studies in subjects of European ancestry (3,775 cases, 4,577 controls). SNPs at 11 of the 16 loci (UMOD, PRKAG2, ANXA9, DAB2, SHROOM3, DACH1, STC1, SLC34A1, ALMS1/NAT8, UBE2Q2, and GCKR) were associated with incident CKD; p-values ranged from p = 4.1e-9 in UMOD to p = 0.03 in GCKR. After adjusting for baseline eGFR, six of these loci remained significantly associated with incident CKD (UMOD, PRKAG2, ANXA9, DAB2, DACH1, and STC1). SNPs in UMOD (OR = 0.92, p = 0.04) and GCKR (OR = 0.93, p = 0.03) were nominally associated with ESRD. In summary, the majority of eGFR-related loci are either associated or show a strong trend towards association with incident CKD, but have modest associations with ESRD in individuals of European descent. Additional work is required to characterize the association of genetic determinants of CKD and ESRD at different stages of disease progression.}, language = {en} } @article{ReiterRitterPrinceetal.2012, author = {Reiter, Theresa and Ritter, Oliver and Prince, Martin R. and Nordbeck, Peter and Wanner, Christoph and Nagel, Eike and Bauer, Wolfgang R.}, title = {Minimizing Risk of Nephrogenic systemic fibrosis in Cardiovascular Magnetic Resonance}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75068}, year = {2012}, abstract = {Nephrogenic Systemic Fibrosis is a rare condition appearing only in patients with severe renal impairment or failure and presents with dermal lesions and involvement of internal organs. Although many cases are mild, an estimated 5 \% have a progressive debilitating course. To date, there is no known effective treatment thus stressing the necessity of ample prevention measures. An association with the use of Gadolinium based contrast agents (GBCA) makes Nephrogenic Systemic Fibrosis a potential side effect of contrast enhanced magnetic resonance imaging and offers the opportunity for prevention by limiting use of gadolinium based contrast agents in renal failure patients. In itself toxic, Gadolinium is embedded into chelates that allow its safe use as a contrast agent. One NSF theory is that Gadolinium chelates distribute into the extracellular fluid compartment and set Gadolinium ions free, depending on multiple factors among which the duration of chelates exposure is directly related to the renal function. Major medical societies both in Europe and in North America have developed guidelines for the usage of GBCA. Since the establishment of these guidelines and the increased general awareness of this condition, the occurrence of NSF has been nearly eliminated. Giving an overview over the current knowledge of NSF pathobiochemistry, pathogenesis and treatment options this review focuses on the guidelines of the European Medicines Agency, the European Society of Urogenital Radiology, the FDA and the American College of Radiology from 2008 up to 2011 and the transfer of this knowledge into every day practice.}, subject = {CMR}, language = {en} } @article{WarnockOrtizMaueretal.2012, author = {Warnock, David G. and Ortiz, Alberto and Mauer, Michael and Linthorst, Gabor E. and Oliveira, Jo{\~a}o P. and Serra, Andreas L. and Mar{\´o}di, L{\´a}szl{\´o} and Mignani, Renzo and Vujkovac, Bojan and Beitner-Johnson, Dana and Lemay, Roberta and Cole, J. Alexander and Svarstad, Einar and Waldek, Stephen and Germain, Dominique P. and Wanner, Christoph}, title = {Renal outcomes of agalsidase beta treatment for Fabry disease: role of proteinuria and timing of treatment initiation}, series = {Nephrology Dialysis Transplantation}, volume = {27}, journal = {Nephrology Dialysis Transplantation}, number = {3}, organization = {Fabry Registry}, doi = {10.1093/ndt/gfr420}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-124697}, pages = {1042-1049}, year = {2012}, abstract = {Background. The purpose of this study was to identify determinants of renal disease progression in adults with Fabry disease during treatment with agalsidase beta. Methods. Renal function was evaluated in 151 men and 62 women from the Fabry Registry who received agalsidase beta at an average dose of 1 mg/kg/2 weeks for at least 2 years. Patients were categorized into quartiles based on slopes of estimated glomerular filtration rate (eGFR) during treatment. Multivariate logistic regression analyses were used to identify factors associated with renal disease progression. Results. Men within the first quartile had a mean eGFR slope of -0.1 mL/min/1.73m2/year, whereas men with the most rapid renal disease progression (Quartile 4) had a mean eGFR slope of -6.7 mL/min/1.73m2/year. The risk factor most strongly associated with renal disease progression was averaged urinary protein:creatinine ratio (UP/Cr) ≥1 g/g (odds ratio 112, 95\% confidence interval (95\% CI) 4-3109, P = 0.0054). Longer time from symptom onset to treatment was also associated with renal disease progression (odds ratio 19, 95\% CI 2-184, P = 0.0098). Women in Quartile 4 had the highest averaged UP/Cr (mean 1.8 g/g) and the most rapid renal disease progression: (mean slope -4.4 mL/min/1.73m2/year). Conclusions. Adults with Fabry disease are at risk for progressive loss of eGFR despite enzyme replacement therapy, particularly if proteinuria is ≥1 g/g. Men with little urinary protein excretion and those who began receiving agalsidase beta sooner after the onset of symptoms had stable renal function. These findings suggest that early intervention may lead to optimal renal outcomes.}, language = {en} } @article{KirylukYifuSannaCherchietal.2012, author = {Kiryluk, Krzysztof and Yifu, Li and Sanna-Cherchi, Simone and Rohanizadegan, Mersedeh and Suzuki, Hitoshi and Eitner, Frank and Snyder, Holly J. and Choi, Murim and Hou, Ping and Scolari, Francesco and Izzi, Claudia and Gigante, Maddalena and Gesualdo, Loreto and Savoldi, Silvana and Amoroso, Antonio and Cusi, Daniele and Zamboli, Pasquale and Julian, Bruce A. and Novak, Jan and Wyatt, Robert J. and Mucha, Krzysztof and Perola, Markus and Kristiansson, Kati and Viktorin, Alexander and Magnusson, Patrik K. and Thorleifsson, Gudmar and Thorsteinsdottir, Unnur and Stefansson, Kari and Boland, Anne and Metzger, Marie and Thibaudin, Lise and Wanner, Christoph and Jager, Kitty J. and Goto, Shin and Maixnerova, Dita and Karnib, Hussein H. and Nagy, Judit and Panzer, Ulf and Xie, Jingyuan and Chen, Nan and Tesar, Vladimir and Narita, Ichiei and Berthoux, Francois and Floege, J{\"u}rgen and Stengel, Benedicte and Zhang, Hong and Lifton, Richard P. and Gharavi, Ali G.}, title = {Geographic Differences in Genetic Susceptibility to IgA Nephropathy: GWAS Replication Study and Geospatial Risk Analysis}, series = {PLoS Genetics}, volume = {8}, journal = {PLoS Genetics}, number = {6}, doi = {10.1371/journal.pgen.1002765}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130195}, pages = {e1002765}, year = {2012}, abstract = {IgA nephropathy (IgAN), major cause of kidney failure worldwide, is common in Asians, moderately prevalent in Europeans, and rare in Africans. It is not known if these differences represent variation in genes, environment, or ascertainment. In a recent GWAS, we localized five IgAN susceptibility loci on Chr.6p21 (HLA-DQB1/DRB1, PSMB9/TAP1, and DPA1/DPB2 loci), Chr.1q32 (CFHR3/R1 locus), and Chr.22q12 (HORMAD2 locus). These IgAN loci are associated with risk of other immune-mediated disorders such as type I diabetes, multiple sclerosis, or inflammatory bowel disease. We tested association of these loci in eight new independent cohorts of Asian, European, and African-American ancestry (N = 4,789), followed by meta-analysis with risk-score modeling in 12 cohorts (N = 10,755) and geospatial analysis in 85 world populations. Four susceptibility loci robustly replicated and all five loci were genome-wide significant in the combined cohort (P = 5x10\(^{-32}\) 3x10\(^{-10}\), with heterogeneity detected only at the PSMB9/TAP1 locus (I\(^{-2}\) = 0.60). Conditional analyses identified two new independent risk alleles within the HLA-DQB1/DRB1 locus, defining multiple risk and protective haplotypes within this interval. We also detected a significant genetic interaction, whereby the odds ratio for the HORMAD2 protective allele was reversed in homozygotes for a CFHR3/R1 deletion (P = 2.5x10\(^{-4}\)). A seven-SNP genetic risk score, which explained 4.7\% of overall IgAN risk, increased sharply with Eastward and Northward distance from Africa (r = 0.30, P = 3x10\(^{-128}\)). This model paralleled the known East-West gradient in disease risk. Moreover, the prediction of a South-North axis was confirmed by registry data showing that the prevalence of IgAN-attributable kidney failure is increased in Northern Europe, similar to multiple sclerosis and type I diabetes. Variation at IgAN susceptibility loci correlates with differences in disease prevalence among world populations. These findings inform genetic, biological, and epidemiological investigations of IgAN and permit cross-comparison with other complex traits that share genetic risk loci and geographic patterns with IgAN.}, language = {en} } @article{BetzSchneiderKressetal.2012, author = {Betz, Boris and Schneider, Reinhard and Kress, Tobias and Schick, Martin Alexander and Wanner, Christoph and Sauvant, Christoph}, title = {Rosiglitazone Affects Nitric Oxide Synthases and Improves Renal Outcome in a Rat Model of Severe Ischemia/Reperfusion Injury}, series = {PPAR Research}, volume = {2012}, journal = {PPAR Research}, number = {Article ID 219319}, doi = {10.1155/2012/219319}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130872}, pages = {12}, year = {2012}, abstract = {Background. Nitric oxide (NO)-signal transduction plays an important role in renal ischemia/reperfusion (I/R) injury. NO produced by endothelial NO-synthase (eNOS) has protective functions whereas NO from inducible NO-synthase (iNOS) induces impairment. Rosiglitazone (RGZ), a peroxisome proliferator-activated receptor (PPAR)-gamma agonist exerted beneficial effects after renal I/R injury, so we investigated whether this might be causally linked with NOS imbalance. Methods. RGZ (5 mg/kg) was administered i.p. to SD-rats (f) subjected to bilateral renal ischemia (60 min). Following 24 h of reperfusion, inulin-and PAH-clearance as well as PAH-net secretion were determined. Morphological alterations were graded by histopathological scoring. Plasma NOx-production was measured. eNOS and iNOS expression was analyzed by qPCR. Cleaved caspase 3 (CC3) was determined as an apoptosis indicator and ED1 as a marker of macrophage infiltration in renal tissue. Results. RGZ improves renal function after renal I/R injury (PAH-/inulin-clearance, PAH-net secretion) and reduces histomorphological injury. Additionally, RGZ reduces NOx plasma levels, ED-1 positive cell infiltration and CC3 expression. iNOS-mRNA is reduced whereas eNOS-mRNA is increased by RGZ. Conclusion. RGZ has protective properties after severe renal I/R injury. Alterations of the NO pathway regarding eNOS and iNOS could be an explanation of the underlying mechanism of RGZ protection in renal I/R injury.}, language = {en} } @article{deZeeuwAkizawaAgarwaletal.2013, author = {de Zeeuw, Dick and Akizawa, Tadao and Agarwal, Rajiv and Audhya, Paul and Bakris, George L. and Chin, Melanie and Krauth, Melissa and Lambers Heerspink, Hiddo J. and Meyer, Colin J. and McMurray, John J. and Parving, Hans-Henrik and Pergola, Pablo E. and Remuzzi, Giuseppe and Toto, Robert D. and Vaziri, Nosratola D. and Wanner, Christoph and Warnock, David G. and Wittes, Janet and Chertow, Glenn M.}, title = {Rationale and Trial Design of Bardoxolone Methyl Evaluation in Patients with Chronic Kidney Disease and Type 2 Diabetes: The Occurrence of Renal Events (BEACON)}, series = {American Journal of Nephrology}, volume = {37}, journal = {American Journal of Nephrology}, number = {3}, issn = {0250-8095}, doi = {10.1159/000346948}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196832}, pages = {212-222}, year = {2013}, abstract = {Background: Chronic kidney disease (CKD) associated with type 2 diabetes mellitus constitutes a global epidemic complicated by considerable renal and cardiovascular morbidity and mortality, despite the provision of inhibitors of the renin-angiotensin-aldosterone system (RAAS). Bardoxolone methyl, a synthetic triterpenoid that reduces oxidative stress and inflammation through Nrf2 activation and inhibition of NF-κB was previously shown to increase estimated glomerular filtration rate (eGFR) in patients with CKD associated with type 2 diabetes mellitus. To date, no antioxidant or anti-inflammatory therapy has proved successful at slowing the progression of CKD. Methods: Herein, we describe the design of Bardoxolone Methyl Evaluation in Patients with Chronic Kidney Disease and Type 2 Diabetes: the Occurrence of Renal Events (BEACON) trial, a multinational, multicenter, double-blind, randomized, placebo-controlled Phase 3 trial designed to determine whether long-term administration of bardoxolone methyl (on a background of standard therapy, including RAAS inhibitors) safely reduces renal and cardiac morbidity and mortality. Results: The primary composite endpoint is time-to-first occurrence of either end-stage renal disease or cardiovascular death. Secondary endpoints include the change in eGFR and time to occurrence of cardiovascular events. Conclusion: BEACON will be the first event-driven trial to evaluate the effect of an oral antioxidant and anti-inflammatory drug in advanced CKD.}, language = {en} } @article{DoerhoeferLammertKraneetal.2013, author = {D{\"o}rh{\"o}fer, Lena and Lammert, Alexander and Krane, Vera and Gorski, Mathias and Banas, Bernhard and Wanner, Christoph and Kr{\"a}mer, Bernhard K. and Heid, Iris M. and B{\"o}ger, Carsten A.}, title = {Study design of DIACORE (DIAbetes COhoRtE) - a cohort study of patients with diabetes mellitus type 2}, series = {BMC Medical Genetics}, volume = {14}, journal = {BMC Medical Genetics}, number = {25}, issn = {1471-2350}, doi = {10.1186/1471-2350-14-25}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122040}, year = {2013}, abstract = {Background: Diabetes mellitus type 2 (DM2) is highly associated with increased risk for chronic kidney disease (CKD), end stage renal disease (ESRD) and cardiovascular morbidity. Epidemiological and genetic studies generate hypotheses for innovative strategies in DM2 management by unravelling novel mechanisms of diabetes complications, which is essential for future intervention trials. We have thus initiated the DIAbetes COhoRtE study (DIACORE). Methods: DIACORE is a prospective cohort study aiming to recruit 6000 patients of self-reported Caucasian ethnicity with prevalent DM2 for at least 10 years of follow-up. Study visits are performed in University-based recruiting clinics in Germany using standard operating procedures. All prevalent DM2 patients in outpatient clinics surrounding the recruiting centers are invited to participate. At baseline and at each 2-year follow-up examination, patients are subjected to a core phenotyping protocol. This includes a standardized online questionnaire and physical examination to determine incident micro-and macrovascular DM2 complications, malignancy and hospitalization, with a primary focus on renal events. Confirmatory outcome information is requested from patient records. Blood samples are obtained for a centrally analyzed standard laboratory panel and for biobanking of aliquots of serum, plasma, urine, mRNA and DNA for future scientific use. A subset of the cohort is subjected to extended phenotyping, e. g. sleep apnea screening, skin autofluorescence measurement, non-mydriatic retinal photography and non-invasive determination of arterial stiffness. Discussion: DIACORE will enable the prospective evaluation of factors involved in DM2 complication pathogenesis using high-throughput technologies in biosamples and genetic epidemiological studies.}, language = {en} } @article{WeidemannSanchezNinoPoliteietal.2013, author = {Weidemann, Frank and Sanchez-Nino, Maria D. and Politei, Juan and Oliveira, Jo{\~a}o-Paulo and Wanner, Christoph and Warnock, David G. and Oritz, Alberto}, title = {Fibrosis: a key feature of Fabry disease with potential therapeutic implications}, series = {Orphanet Journal of Rare Diseases}, volume = {8}, journal = {Orphanet Journal of Rare Diseases}, number = {116}, issn = {1750-1172}, doi = {10.1186/1750-1172-8-116}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-124773}, year = {2013}, abstract = {Fabry disease is a rare X-linked hereditary disease caused by mutations in the AGAL gene encoding the lysosomal enzyme alpha-galactosidase A. Enzyme replacement therapy (ERT) is the current cornerstone of Fabry disease management. Involvement of kidney, heart and the central nervous system shortens life span, and fibrosis of these organs is a hallmark of the disease. Fibrosis was initially thought to result from tissue ischemia secondary to endothelial accumulation of glycosphingolipids in the microvasculature. However, despite ready clearance of endothelial deposits, ERT is less effective in patients who have already developed fibrosis. Several potential explanations of this clinical observation may impact on the future management of Fabry disease. Alternative molecular pathways linking glycosphingolipids and fibrosis may be operative; tissue injury may recruit secondary molecular mediators of fibrosis that are unresponsive to ERT, or fibrosis may represent irreversible tissue injury that limits the therapeutic response to ERT. We provide an overview of Fabry disease, with a focus on the assessment of fibrosis, the clinical consequences of fibrosis, and recent advances in understanding the cellular and molecular mechanisms of fibrosis that may suggest novel therapeutic approaches to Fabry disease.}, language = {en} } @article{DrechslerRitzTomaschitzetal.2013, author = {Drechsler, Christiane and Ritz, Eberhard and Tomaschitz, Andreas and Pilz, Stefan and Sch{\"o}nfeld, Stephan and Blouin, Katja and Bidlingmaier, Martin and Hammer, Fabian and Krane, Vera and M{\"a}rz, Winfried and Allolio, Bruno and Fassnacht, Martin and Wanner, Christoph}, title = {Aldosterone and cortisol affect the risk of sudden cardiac death in haemodialysis patients}, series = {European Heart Journal}, volume = {34}, journal = {European Heart Journal}, doi = {10.1093/eurheartj/ehs361}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132562}, pages = {578-585}, year = {2013}, abstract = {Background: Sudden cardiac death is common and accounts largely for the excess mortality of patients on maintenance dialysis. It is unknown whether aldosterone and cortisol increase the incidence of sudden cardiac death in dialysis patients. Methods and results: We analysed data from 1255 diabetic haemodialysis patients participating in the German Diabetes and Dialysis Study (4D Study). Categories of aldosterone and cortisol were determined at baseline and patients were followed for a median of 4 years. By Cox regression analyses, hazard ratios (HRs) were determined for the effect of aldosterone, cortisol, and their combination on sudden death and other adjudicated cardiovascular outcomes. The mean age of the patients was 66 ± 8 years (54\% male). Median aldosterone was <15 pg/mL (detection limit) and cortisol 16.8 µg/dL. Patients with aldosterone levels >200 pg/mL had a significantly higher risk of sudden death (HR: 1.69; 95\% CI: 1.06-2.69) compared with those with an aldosterone <15 pg/mL. The combined presence of high aldosterone (>200 pg/mL) and high cortisol (>21.1 µg/dL) levels increased the risk of sudden death in striking contrast to patients with low aldosterone (<15 pg/mL) and low cortisol (<13.2 µg/dL) levels (HR: 2.86, 95\% CI: 1.32-6.21). Furthermore, all-cause mortality was significantly increased in the patients with high levels of both hormones (HR: 1.62, 95\% CI: 1.01-2.62). Conclusions: The joint presence of high aldosterone and high cortisol levels is strongly associated with sudden cardiac death as well as all-cause mortality in haemodialysed type 2 diabetic patients. Whether a blockade of the mineralocorticoid receptor decreases the risk of sudden death in these patients must be examined in future trials.}, language = {en} } @article{DrechslerSchmiedekeNiemannetal.2013, author = {Drechsler, Christiane and Schmiedeke, Benjamin and Niemann, Markus and Schmiedeke, Daniel and Kr{\"a}mer, Johannes and Turkin, Irina and Blouin, Katja and Emmert, Andrea and Pilz, Stefan and Obermayer-Pietsch, Barbara and Wiedemann, Frank and Breunig, Frank and Wanner, Christoph}, title = {Potential role of vitamin D deficiency on Fabry cardiomyopathy}, series = {Journal of Inherited Metabolic Disease}, volume = {37}, journal = {Journal of Inherited Metabolic Disease}, number = {2}, doi = {10.1007/s10545-013-9653-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132102}, pages = {289-295}, year = {2013}, abstract = {Patients with Fabry disease frequently develop left ventricular (LV) hypertrophy and renal fibrosis. Due to heat intolerance and an inability to sweat, patients tend to avoid exposure to sunlight. We hypothesized that subsequent vitamin D deficiency may contribute to Fabry cardiomyopathy. This study investigated the vitamin D status and its association with LV mass and adverse clinical symptoms in patients with Fabry disease. 25-hydroxyvitamin D (25[OH]D) was measured in 111 patients who were genetically proven to have Fabry disease. LV mass and cardiomyopathy were assessed by magnetic resonance imaging and echocardiography. In cross-sectional analyses, associations with adverse clinical outcomes were determined by linear and binary logistic regression analyses, respectively, and were adjusted for age, sex, BMI and season. Patients had a mean age of 40 ± 13 years (42 \% males), and a mean 25(OH)D of 23.5 ± 11.4 ng/ml. Those with overt vitamin D deficiency (25[OH]D ≤ 15 ng/ml) had an adjusted six fold higher risk of cardiomyopathy, compared to those with sufficient 25(OH)D levels >30 ng/ml (p = 0.04). The mean LV mass was distinctively different with 170 ± 75 g in deficient, 154 ± 60 g in moderately deficient and 128 ± 58 g in vitamin D sufficient patients (p = 0.01). With increasing severity of vitamin D deficiency, the median levels of proteinuria increased, as well as the prevalences of depression, edema, cornea verticillata and the need for medical pain therapy. In conclusion, vitamin D deficiency was strongly associated with cardiomyopathy and adverse clinical symptoms in patients with Fabry disease. Whether vitamin D supplementation improves complications of Fabry disease, requires a randomized controlled trial.}, language = {en} } @article{SchneiderSchneiderScharnagletal.2013, author = {Schneider, Andreas and Schneider, Markus P. and Scharnagl, Hubert and Jardine, Alan G. and Wanner, Christoph and Drechsler, Christiane}, title = {Predicting erythropoietin resistance in hemodialysis patients with type 2 diabetes}, series = {BMC Nephrology}, volume = {14}, journal = {BMC Nephrology}, number = {67}, doi = {10.1186/1471-2369-14-67}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128695}, year = {2013}, abstract = {Background: Resistance to ESAs (erythropoietin stimulating agents) is highly prevalent in hemodialysis patients with diabetes and associated with an increased mortality. The aim of this study was to identify predictors for ESA resistance and to develop a prediction model for the risk stratification in these patients. Methods: A post-hoc analysis was conducted of the 4D study, including 1015 patients with type 2 diabetes undergoing hemodialysis. Determinants of ESA resistance were identified by univariate logistic regression analyses. Subsequently, multivariate models were performed with stepwise inclusion of significant predictors from clinical parameters, routine laboratory and specific biomarkers. Results: In the model restricted to clinical parameters, male sex, shorter dialysis vintage, lower BMI, history of CHF, use of ACE-inhibitors and a higher heart rate were identified as independent predictors of ESA resistance. In regard to routine laboratory markers, lower albumin, lower iron saturation, higher creatinine and higher potassium levels were independently associated with ESA resistance. With respect to specific biomarkers, higher ADMA and CRP levels as well as lower Osteocalcin levels were predictors of ESA resistance. Conclusions: Easily obtainable clinical parameters and routine laboratory parameters can predict ESA resistance in diabetic hemodialysis patients with good discrimination. Specific biomarkers did not meaningfully further improve the risk prediction of ESA resistance. Routinely assessed data can be used in clinical practice to stratify patients according to the risk of ESA resistance, which may help to assign appropriate treatment strategies.}, language = {en} } @article{DrechslerKolleritzMeinitzeretal.2013, author = {Drechsler, Christiane and Kolleritz, Barbara and Meinitzer, Andreas and M{\"a}rz, Winfried and Ritz, Eberhard and K{\"o}nig, Paul and Neyer, Ulrich and Pilz, Stefan and Wanner, Christoph and Kronenberg, Florian}, title = {Homoarginine and Progression of Chronic Kidney Disease: Results from the Mild to Moderate Kidney Disease Study}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {5}, organization = {MMKD Study Group}, doi = {10.1371/journal.pone.0063560}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130979}, pages = {e63560}, year = {2013}, abstract = {Background: Homoarginine is an amino acid derivative mainly synthesized in the kidney. It is suggested to increase nitric oxide availability, enhance endothelial function and to protect against cardiovascular diseases. We aimed to investigate the relation between homoarginine, kidney function and progression of chronic kidney disease (CKD). Methods: We measured plasma homoarginine concentrations in baseline samples of the Mild to Moderate Kidney Disease (MMKD) Study, a prospective cohort study of 227 patients with CKD in Europe. Homoarginine concentrations were available in 182 of the baseline samples and in 139 of the prospectively-followed patients. We correlated homoarginine concentrations to parameters of kidney function. The association between homoarginine and progression of CKD was assessed during a follow-up of up to seven years (median 4.45 years, interquartile range 2.54-5.19) using Cox regression analysis. Progression of CKD was defined as doubling of baseline serum creatinine and/or end-stage renal disease. Results: Study participants were at baseline on average 47 \(\pm\)13 years old and 65\% were male. Mean \(\pm\) standard deviation of homoarginine concentrations were \(2.5 \pm 1.1 \mu mol/L\) and concentrations were incrementally lower at lower levels of GFR with mean concentrations of \(2.90 \pm 1.02 \mu mol/L\) (GFR. 90 ml/min), \(2.64 \pm 1.06 \mu mol/L\) (GFR 60-90 ml/min), \(2.52 \pm 1.24 \mu mol/L\) (GFR 30-60 ml/min) and \(2.05 \pm 0.78 \mu mol/L\) (GFR, 30 ml/min), respectively (p = 0.002). The age-and sex-adjusted risk to reach the renal endpoint was significantly higher by 62\% with each decrease by one standard deviation (\(1.1 \mu mol/L\)) of homoarginine (HR 1.62, 95\% CI 1.16-2.27, p = 0.005). This association was independent of proteinuria (HR 1.56, 95\% CI 1.11-2.20, p = 0.01), and was slightly attenuated when adjusting for GFR (HR 1.40 (95\% CI 0.98-1.98, p = 0.06). Conclusions: Homoarginine concentrations are directly correlated with kidney function and are significantly associated with the progression of CKD. Low homoarginine concentrations might be an early indicator of kidney failure and a potential target for the prevention of disease progression which needs further investigations.}, language = {en} } @article{UeceylerKahnKrameretal.2013, author = {{\"U}{\c{c}}eyler, Nurcan and Kahn, Ann-Kathrin and Kramer, Daniela and Zeller, Daniel and Casanova-Molla, Jordi and Wanner, Christoph and Weidemann, Frank and Katsarava, Zaza and Sommer, Claudia}, title = {Impaired small fiber conduction in patients with Fabry disease: a neurophysiological case-control study}, series = {BMC Neurology}, journal = {BMC Neurology}, doi = {10.1186/1471-2377-13-47}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96527}, year = {2013}, abstract = {Background Fabry disease is an inborn lysosomal storage disorder which is associated with small fiber neuropathy. We set out to investigate small fiber conduction in Fabry patients using pain-related evoked potentials (PREP). Methods In this case-control study we prospectively studied 76 consecutive Fabry patients for electrical small fiber conduction in correlation with small fiber function and morphology. Data were compared with healthy controls using non-parametric statistical tests. All patients underwent neurological examination and were investigated with pain and depression questionnaires. Small fiber function (quantitative sensory testing, QST), morphology (skin punch biopsy), and electrical conduction (PREP) were assessed and correlated. Patients were stratified for gender and disease severity as reflected by renal function. Results All Fabry patients (31 men, 45 women) had small fiber neuropathy. Men with Fabry disease showed impaired cold (p < 0.01) and warm perception (p < 0.05), while women did not differ from controls. Intraepidermal nerve fiber density (IENFD) was reduced at the lower leg (p < 0.001) and the back (p < 0.05) mainly of men with impaired renal function. When investigating A-delta fiber conduction with PREP, men but not women with Fabry disease had lower amplitudes upon stimulation at face (p < 0.01), hands (p < 0.05), and feet (p < 0.01) compared to controls. PREP amplitudes further decreased with advance in disease severity. PREP amplitudes and warm (p < 0.05) and cold detection thresholds (p < 0.01) at the feet correlated positively in male patients. Conclusion Small fiber conduction is impaired in men with Fabry disease and worsens with advanced disease severity. PREP are well-suited to measure A-delta fiber conduction.}, language = {en} } @article{SchneiderGutjahrLengsfeldRitzetal.2014, author = {Schneider, Andreas and Gutjahr-Lengsfeld, Lena and Ritz, Eberhard and Scharnagl, Hubert and Gelbrich, G{\"o}tz and Pilz, Stefan and Macdougall, Iain C. and Wanner, Christoph and Drechsler, Christiane}, title = {Longitudinal Assessments of Erythropoietin-Stimulating Agent Responsiveness and the Association with Specific Clinical Outcomes in Dialysis Patients}, series = {Nephron Clinical Practice}, volume = {128}, journal = {Nephron Clinical Practice}, number = {1-2}, issn = {1660-2110}, doi = {10.1159/000367975}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196511}, pages = {147-152}, year = {2014}, abstract = {Background: Dose requirements of erythropoietin-stimulating agents (ESAs) can vary considerably over time and may be associated with cardiovascular outcomes. We aimed to longitudinally assess ESA responsiveness over time and to investigate its association with specific clinical end points in a time-dependent approach. Methods: The German Diabetes and Dialysis study (4D study) included 1,255 diabetic dialysis patients, of whom 1,161 were receiving ESA treatment. In those patients, the erythropoietin resistance index (ERI) was assessed every 6 months during a median follow-up of 4 years. The association between the ERI and cardiovascular end points was analyzed by time-dependent Cox regression analyses with repeated ERI measures. Results: Patients had a mean age of 66 ± 8.2 years; 53\% were male. During follow-up, a total of 495 patients died, of whom 136 died of sudden death and 102 of infectious death. The adjusted and time-dependent risk for sudden death was increased by 19\% per 5-unit increase in the ERI (hazard ratio, HR = 1.19, 95\% confidence interval, CI = 1.07-1.33). Similarly, mortality increased by 25\% (HR = 1.25, 95\% CI = 1.18-1.32) and infectious death increased by 27\% (HR = 1.27, 95\% CI = 1.13-1.42). Further analysis revealed that lower 25-hydroxyvitamin D levels were associated with lower ESA responsiveness (p = 0.046). Conclusions: In diabetic dialysis patients, we observed that time-varying erythropoietin resistance is associated with sudden death, infectious complications and all-cause mortality. Low 25-hydroxyvitamin D levels may contribute to a lower ESA responsiveness.}, language = {en} } @article{UeceylerHomolaGonzalezetal.2014, author = {{\"U}{\c{c}}eyler, Nurcan and Homola, Gy{\"o}rgy A. and Gonz{\´a}lez, Hans Guerrero and Kramer, Daniela and Wanner, Christoph and Weidemann, Frank and Solymosi, L{\´a}szl{\´o} and Sommer, Claudia}, title = {Increased Arterial Diameters in the Posterior Cerebral Circulation in Men with Fabry Disease}, doi = {10.1371/journal.pone.0087054}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-112614}, year = {2014}, abstract = {A high load of white matter lesions and enlarged basilar arteries have been shown in selected patients with Fabry disease, a disorder associated with an increased stroke risk. We studied a large cohort of patients with Fabry disease to differentially investigate white matter lesion load and cerebral artery diameters. We retrospectively analyzed cranial magnetic resonance imaging scans of 87 consecutive Fabry patients, 20 patients with ischemic stroke, and 36 controls. We determined the white matter lesion load applying the Fazekas score on fluid-attenuated inversion recovery sequences and measured the diameters of cerebral arteries on 3D-reconstructions of the time-of-flight-MR-angiography scans. Data of different Fabry patient subgroups (males - females; normal - impaired renal function) were compared with data of patients with stroke and controls. A history of stroke or transient ischemic attacks was present in 4/30 males (13\%) and 5/57 (9\%) females with Fabry disease, all in the anterior circulation. Only one man with Fabry disease showed confluent cerebral white matter lesions in the Fazekas score assessment (1\%). Male Fabry patients had a larger basilar artery (p<0.01) and posterior cerebral artery diameter (p<0.05) compared to male controls. This was independent of disease severity as measured by renal function and did not lead to changes in arterial blood flow properties. A basilar artery diameter of >3.2 mm distinguished between men with Fabry disease and controls (sensitivity: 87\%, specificity: 86\%, p<0.001), but not from stroke patients. Enlarged arterial diameters of the posterior circulation are present only in men with Fabry disease independent of disease severity.}, language = {en} } @article{WagnerKraemerBlohmetal.2014, author = {Wagner, Martin and Kr{\"a}mer, Johannes and Blohm, Elisabeth and Vergho, Dorothee and Weidemann, Frank and Breunig, Frank and Wanner, Christoph}, title = {Kidney function as an underestimated factor for reduced health related quality of life in patients with Fabry disease}, doi = {10.1186/1471-2369-15-188}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-111159}, year = {2014}, abstract = {Background: Impairments of health related quality of life (HRQoL) are frequently observed in Fabry disease (FD) and are known to be related to neuropathic pain and cardiovascular events. This study aimed to explore the role of chronic kidney disease (CKD) in a large cohort of patients with FD. Methods: In 96 patients (53\% female; age 40 ± 12 yrs) with genetically proven FD, HRQoL was assessed by the Medical Outcomes Study (SF-36) questionnaire. All patients were na{\"i}ve to enzyme replacement therapy. Three categories for kidney dysfunction were chosen, eGFR ≥/<60 ml/min/1.73 m2 or need of renal replacement therapy (RRT). Minor (e.g. arrhythmia, angina pectoris, etc.) and major (e.g. myocardial infarction, coronary artery bypass, stroke or implantable cardioverter-defibrillator) vascular events as well as pain and pain therapy were considered in linear regression analyses with the dimensions of HRQoL. Results: Ten patients (10\%) had impaired kidney function and a further nine were on RRT (9.4\%). Kidney function and pain emerged as the main factors associated with lower scores on the SF 36, in particular on physical components (PCS beta-coefficients for CKD -6.2, for RRT -11.8, for pain -9.1, p < 0.05, respectively), while controlling for gender, vascular event and pain-therapy. Relationships were found for mental aspects of HRQoL. Age and history of vascular events were not related to HRQoL. Conclusion: Cardiovascular events and pain are important factors related to HRQoL, social functioning and depression. Our study highlights impaired chronic kidney disease, in particular after initiation of RRT, as a strong determinant of reduced HRQoL in FD.}, language = {en} } @article{LocatelliSpasovskiDimkovicetal.2014, author = {Locatelli, Francesco and Spasovski, Goce and Dimkovic, Nada and Wanner, Christoph and Dellanna, Frank and Pontoriero, Giuseppe}, title = {The effects of colestilan versus placebo and sevelamer in patients with CKD 5D and hyperphosphataemia: a 1-year prospective randomized study}, series = {Nephrology Dialysis Transplantation}, volume = {29}, journal = {Nephrology Dialysis Transplantation}, number = {5}, doi = {10.1093/ndt/gft476}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121114}, pages = {1061-73}, year = {2014}, abstract = {BACKGROUND: This study compared the effects of short-term titrated colestilan (a novel non-absorbable, non-calcium, phosphate binder) with placebo, and evaluated the safety and efficacy of colestilan over 1 year compared with sevelamer, in patients with chronic kidney disease (CKD) 5D. METHODS: This prospective multicentre study comprised a 4-week phosphate binder washout period, a 16-week short-term, flexible-dose, treatment period (including a 4-week placebo-controlled withdrawal period) and a 40-week extension treatment phase. RESULTS: At Week 16 (the end of the 4-week placebo-controlled withdrawal period), serum phosphorus level was 0.43 mmol/L (1.32 mg/dL) lower with colestilan than placebo (P < 0.001; primary end point). Serum LDL-C level was also lower with colestilan than with placebo (P < 0.001). Both colestilan and sevelamer produced significant reductions from baseline in serum phosphorus levels (P < 0.001), maintained for 1 year, and the proportion of patients achieving target levels of ≤1.78 mmol/L (5.5 mg/dL) or ≤1.95 mmol/L (6.0 mg/dL) at study end were similar (65.3 and 73.3\%, respectively, for colestilan, and 66.9 and 77.4\%, respectively, for sevelamer). Serum calcium level remained stable in the colestilan group but tended to increase slightly in the sevelamer group (end-of-study increase of 0.035 mmol/L over baseline). Both binders produced similar reductions from baseline in LDL-C level (P < 0.001), and responder rates after 1 year, using a target of <1.83 mmol/L (70 mg/dL) or <2.59 mmol/L (100 mg/dL) were similar in both groups (50.7 and 85.3\% for colestilan and 54.0 and 80.6\% for sevelamer). Colestilan was generally well tolerated. CONCLUSIONS: Colestilan is effective and safe for the treatment of hyperphosphataemia in patients with CKD 5D, and affords similar long-term phosphorus and cholesterol reductions/responder rates to sevelamer.}, language = {en} }