No association of complement mannose-binding lectin deficiency with cardiovascular disease in patients with Systemic Lupus Erythematosus.

Cardiovascular (CV) morbidity is the major cause of death in patients with Systemic Lupus Erythematosus (SLE). Previous studies on mannose-binding lectin (MBL) gene polymorphisms in SLE patients suggest that low levels of complement MBL are associated with cardiovascular disease (CVD). However, as large studies on MBL deficiency based on resulting MBL plasma concentrations are lacking, the aim of our study was to analyze the association of MBL concentrations with CVD in SLE patients. Plasma MBL levels SLE patients included in the Swiss SLE Cohort Study were quantified by ELISA. Five different CV organ manifestations were documented. Of 373 included patients (85.5% female) 62 patients had at least one CV manifestation. Patients with MBL deficiency (levels below 500 ng/ml or 1000 ng/ml) had no significantly increased frequency of CVD (19.4% vs. 15.2%, P = 0.3 or 17.7% vs. 15.7%, P = 0.7). After adjustment for traditional CV risk factors, MBL levels and positive antiphospholipid serology (APL+) a significant association of CVD with age, hypertension, disease duration and APL+ was demonstrated. In our study of a large cohort of patients with SLE, we could not confirm previous studies suggesting MBL deficiency to be associated with an increased risk for CVD.

Externalized Percutaneous Stent Versus Internal Double J Stent: Short- and Long-term Complications After Kidney Transplantation.

BACKGROUND: In patients undergoing kidney transplantation, ureteral stents are an established technique to reduce major urologic complications such as leakage and stenosis of the ureter. However, the best technique for ureteral stenting remains unclear. The aim of this study was to compare the outcome of percutaneous ureteral stents (PS) with internal double J stents (JJS) after kidney transplantation. METHODS: All patients undergoing kidney transplantation between 2005 and 2014 were retrospectively analyzed. After excluding patients <18 years old, patients without stenting, and patients who underwent multiorgan transplantation, a total of 308 patients were included in the study. Two consecutive cohorts of patients were compared. In the cohort transplanted between 2005 and 2010, stenting was routinely performed using PS (216 patients), and in the second cohort, those transplanted after 2011, stenting was routinely performed using JJS (92 patients). For ureteric anastomosis, the Lich-Grégoir technique was used in all patients. RESULTS: There was no statistical difference in postoperative urinary tract infections (P = .239) between the 2 cohorts. In patients with PS, the incidence of major urologic complications (11.6% vs 3.3%; P = .018), vesicoureteral reflux (14.3% vs 2.2%; P < .001), and urologic reinterventions (14.4% vs 5.4%; P = .031) was significantly higher when compared with JJS patients. Multivariable logistic regression revealed increased incidence of major urologic complications (odds ratio [OR] 3.66, 95% confidence interval [CI] 1.07-12.55, P = .039) and vesicoureteral reflux (OR 5.29, 95% CI 1.21-23.10, P = .027) in patients with PS compared with JJS. CONCLUSION: Stenting of ureterovesical anastomosis using JJS is associated with reduced complications compared with PS after kidney transplantation.

[Assessment of kidney function : Creatinine is not the whole story]. / Beurteilung der Nierenfunktion : Kreatinin ist nicht alles.

Chronic renal insufficiency has a high prevalence and leads not only to a severe impairment in the quality of life but also to a higher mortality, mainly due to cardiovascular complications; however, in the early stages where there is still a chance for a therapeutic intervention, it is often underestimated because depending on endogenous factors (e.g. age and muscle mass), serum creatinine could falsely remain in the normal range while kidney function is already impaired. An exact measurement of the glomerular filtration rate (GFR) using radionuclide techniques is cumbersome and usually confined to rare cases, such as in clinical studies. Creatinine clearance measurement by 24-h urine collection requires good patient instructions and is error prone, thus it is limited to special circumstances. In routine clinical practice, estimation of the GFR by calculation algorithms provides the best approach. In recent years the chronic kidney disease epidemiology collaboration (CKD-EPI) formula has become established as the most accurate method. This should be used for screening and continuous surveillance. In addition, urinalysis including dipstick tests and urinary microscopy represent non-invasive, technically simple and economic screening tools. Due to its semiquantitative nature, the results of urinalysis should only to be interpreted after comprehensive consideration of the diagnostic and technical limitations, which are reviewed in this article.

Impact of cardio-renal syndrome on adverse outcomes in patients with Fabry disease in a long-term follow-up.

AIMS: Fabry disease (FD) is a rare X-linked lysosomal storage disease with a deficiency of α-galactosidase A leading to progressive sphingolipid accumulation in different organs, among them heart and kidney. We evaluated the impact of cardio-renal syndrome (CRS) on the incidence of major cardiovascular complications and death in a prospective FD cohort. METHODS AND RESULTS: A total of 104 genetically proven FD patients were annually followed at the University Hospitals Zurich and Bern. The main outcome was a composite of incident renal replacement therapy (RRT), hospitalisation due to decompensated Heart Failure, new onset atrial fibrillation, pacemaker/ICD implantation, stroke/TIA and death. Estimated glomerular filtration rate (eGFR) and left ventricular myocardial mass index (LVMMI) where explored as the primary exposure variables. During the median follow-up of 103 [59-155] months, events occurred in 27 patients. In a Cox regression analysis, both higher LVMMI and lower eGFR were independently associated with a greater risk of developing adverse events after adjustment for multiple confounders (HR 1.67 [1.04-2.73] P=0.03 per SD increase in LVMMI, HR 0.45 [0.25-0.83], P=0.01 per SD decrease in eGFR). In patients with CRS, the risk to develop events was significantly increased if adjusted for demographics and RRT (HR 4.46 [1.07-18.62], P=0.04), approaching significance if additionally adjusted for hypertension (HR 4.05 [0.95-17.29], P=0.06). In Kaplan-Meier-Analysis, the poorest event-free survival was observed among patients with CRS. CONCLUSIONS: CRS was associated with a high risk to develop cardiovascular complications and death, emphasizing the importance of its prevention and early recognition. A focus on cardio-reno-protective therapies is crucial.

BK Polyomavirus-Specific 9mer CD8 T Cell Responses Correlate With Clearance of BK Viremia in Kidney Transplant Recipients: First Report From the Swiss Transplant Cohort Study.

BK polyomavirus (BKPyV) causes premature kidney transplant (KT) failure in 1-15% of patients. Because antivirals are lacking, most programs screen for BKPyV-viremia and, if positive, reduce immunosuppression. To evaluate the relationship of viremia and BKPyV-specific immunity, we examined prospectively cryopreserved plasma and peripheral blood mononuclear cells at the time of transplantation (T0) and at 6 mo (T6) and 12 mo (T12) after transplant from 28 viremic KT patients and 68 nonviremic controls matched for the transplantation period. BKPyV IgG seroprevalence was comparable between cases (89.3%) and controls (91.2%; p = 0.8635), but cases had lower antibody levels (p = 0.022) at T0. Antibody levels increased at T6 and T12 but were not correlated with viremia clearance. BKPyV-specific T cell responses to pools of overlapping 15mers (15mer peptide pool [15mP]) or immunodominant CD8 9mers (9mer peptide pool [9mP]) from the early viral gene region were not different between cases and controls at T0; however, clearance of viremia was associated with stronger 9mP responses at T6 (p = 0.042) and T12 (p = 0.048), whereas 15mP responses were not informative (T6 p = 0.359; T12 p = 0.856). BKPyV-specific T cells could be expanded in vitro from all patients after transplant, permitting identification of 78 immunodominant 9mer epitopes including 50 new ones across different HLA class I. Thus, 9mP-responses may be a novel marker of reconstituting CD8 T cell function that warrants further study as a complement of plasma BKPyV loads for guiding immunosuppression reduction.

The guanine nucleotide exchange factor Tiam1: a Janus-faced molecule in cellular signaling.

The Rho family of GTPases consists of several small proteins that have been described as molecular switches, playing important roles in a wide variety of fundamental cellular processes and in human diseases such as cancer. These proteins, active in the GTP conformation and inactive in the GDP form, are in turn regulated by guanine nucleotide exchange factors (GEFs), guanine nucleotide activating proteins (GAPs) and guanine dissociation inhibitors (GDIs). Two decades ago, Tiam1 (T-lymphoma invasion and metastasis) was identified as a GEF specific for Rac1 activation, but also for Cdc42 and in a lesser extent RhoA. Acting principally upstream of Rac1, Tiam1 is mainly involved in the regulation of Rac1 mediated signaling pathways including cytoskeletal activities, cell polarity, endocytosis and membrane trafficking, cell migration, adhesion and invasion, cell growth and survival, metastasis and carcinogenesis. However, given the large number of protein interaction domains found in its structure, it is possible that Tiam1 affects cellular processes in another way than through its GEF activity by interactions with other signaling proteins. Due to its functional diversity, Tiam1 is involved in multiple steps of tumorigenesis. As its name suggests, Tiam1 has been shown to increase T-cell lymphoma invasion and metastasis. It also promotes migration of fibroblasts, neuronal and cancer cells. On the contrary, Tiam1-induced cell adhesion has also been described, as opposed to cell migration. Moreover, studies indicate that Tiam1 is involved in both anti-apoptotic and pro-apoptotic mechanisms. While increasing evidence has demonstrated Tiam1's contribution to tumorigenesis and metastasis, others suggest that Tiam1 could have anti-cancer properties. In the present review, we discuss the current knowledge about the controversial roles of Tiam1 in cellular signaling. In particular, we will focus on Tiam1's regulation, its biological functions and implication in cancer.

[Bleeding complication due to accumulation of low-molecular-weight heparin in a patient with renal insufficiency]. / Blutungskomplikation durch Akkumulation von niedermolekularem Heparin bei einer Patientin mit Niereninsuffizienz.

We report of a 71-year-old woman with a history of chronic analgesic nephropathy, who underwent coronary angiography. Because of anterior ventricular aneurysm, anticoagulation with nadroparine was installed. Continued ACE-inhibitor and ASA with additional intravenous contrast substance lead to acute tubular necrosis with rapid decline of the renal function. Due to accumulation of the low molecular weight heparin, the patient developed an extensive retroperitoneal haematoma with circulatory shock and temporary anuric kidney failure. Low molecular weight heparins are commonly used during percutaneous coronary interventions. They are as safe and efficient compared to unfractioned heparin. But due to their renal elimination, they have to be monitored by measuring anti-factor Xa-activity if creatinine-clearance is <30 ml/min.

[In Medea's gardens--two tales of colchicine]. / In den Gärten der Medea.

Colchicine is a highly active alkaloid used in the treatment of acute inflammatory syndromes such as Mediterranean fever, M. Behçet or gouty arthritis. The two cases we present here illustrate exemplarily the pros and contras of colchicine therapy. In the first case, colchicine was successfully given for recurrent febrile attacks due to acute rheumatic fever. The second patient unfortunately had a fatal colchicine intoxication. The pharmacology of colchicine, the clinical features associated with overdose and the options for treatment are discussed. Colchicine should not be given in combination with macrolides, especially in patients with renal insufficiency.

[Microalbuminuria--a new cardiovascular risk factor?]. / Mikroalbuminurie--ein neuer Marker für kardiovaskuläres Risiko?

Microalbuminuria is an established risk factor for renal disease, especially in the diabetic population. Recent studies have shown that microalbuminuria has also a highly relevant predictive value for cardiovascular morbidity and mortality. From normal to overt proteinuria levels, albuminuria shows a continuous marked increase in cardiovascular risk. This association is independent of other "classical" cardiovascular risk factors such as hypertension, hyperlipidemia or smoking. Furthermore it has a predictive value not only for patients with diabetic or renal disease, but also for hypertensive individuals or the general population. Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers have been shown to display not only reno--but also cardioprotective effects. Their unique ability to lower albuminuria by 40% is related to a significant risk reduction in cardiovascular mortality. New clinical trials are needed to define "normal" albuminuria levels and how low we should go.

Successful kidney transplantation from donor with Marfan's syndrome.

Marfan's syndrome is caused by mutations in the extracellular matrix protein fibrillin-1 with aortic aneurysm and dissection being its most life-threatening manifestations. Kidney transplantation from donors with Marfan's syndrome has never been reported in the literature, possibly because of reticences due to the underlying connective tissue disease. Here, we report two patients with end-stage renal disease, transplanted with the kidneys from a donor with Marfan's syndrome who died of aortic dissection and cerebral hemorrhage. After delayed graft function in both recipients, renal function normalized with no renovascular complications and negative proteinuria for 6 years in one patient and 2 years in the other patient, who died from an ischemic cerebrovascular insult. Kidneys from organ donors with Marfan's syndrome might be suitable for transplantation.

[Gout nephropathy--ghost or reality?]. / Chronische Uratnephropathie--Realität oder Phantom?

Until the past decades, end stage renal disease was considered a major cause of death among patients with gout. Modern long-term follow up studies of renal function however have indicated that hyperuricemia and gout rarely result in kidney damage unless other renal diseases supervene. Subsequently, the use of the EDTA lead mobilization test confirmed that gout in the presence of chronic renal failure is a useful marker of chronic lead intoxication. Chelation treatment with EDTA can slow the progression of renal insufficiency, without apparent damage associated with the use of the chelating agent. Since chronic lead intoxication may remain clinically concealed for years, a high index of suspicion is warranted. Occult lead intoxication should be sought actively in gouty patients with chronic renal insufficiency of unknown etiology.

Prophylactic hemodialysis after radiocontrast media in patients with renal insufficiency is potentially harmful.

PURPOSE: Acute renal failure induced by contrast media is an important cause of hospital-acquired renal insufficiency. Preexisting renal failure and the dose of contrast media are known risk factors for the development of radiocontrast nephropathy. We performed a randomized trial to test whether radiocontrast nephropathy can be avoided by prophylactic hemodialysis immediately after the administration of contrast media in patients with impaired renal function. SUBJECTS AND METHODS: Renal function and other parameters, hemodialysis requirement, and relevant clinical events were recorded before and during the 6 days after administration of contrast media in 113 patients with a baseline serum creatinine level >200 microm/L (>2.3 mg/dL). Patients were randomly assigned to either hemodialysis (n = 55) or nonhemodialysis (n = 58) treatment after parenteral low-osmolality contrast media. RESULTS: The characteristics of the patients in the two groups were similar. Compared with baseline levels, the mean [+/- SD] serum creatinine level decreased at day 1 (277 +/- 95 microm/L), peaked at day 4 (353 +/- 126 microm/L), and returned to baseline at day 6 (327 +/- 119 microm/L, P <0.05 by analysis of variance) after administration of contrast media in the hemodialysis group, whereas in the nonhemodialysis group, no significant changes in mean serum creatinine level were observed. Eleven patients required 1 or more hemodialyses (8 in the hemodialysis group and 3 in the nonhemodialysis group, P = 0.12), 6 of whom (4 vs. 2, P = 0.44) required 3 or more hemodialyses. Clinically relevant events included pulmonary edema (1 vs. 4 patients, P = 0.36), myocardial infarction (2 vs. 2), stroke (2 vs. 0, P = 0.24), and death (1 vs. 1). CONCLUSIONS: The strategy of performing hemodialysis immediately after the administration of low-osmolality contrast media in all patients with a reduced renal function did not diminish the rate of complications, including radiocontrast nephropathy.

[Potential dangers of diuretics...]. / Wo Diuretika gefährlich werden....

A chronic diuretic abuse is common among healthy young women. An acute cessation of diuretic intake causes renal sodium retention with formation of edema due to diuretic-induced secondary hyperaldosteronism. Therefore, diuretics should be tappered over weeks or even months in these patients. Other clinical situations where therapy with diuretics is potentially deleterious are pregnancy and systemic sclerosis. In pregnant women, diuretic-induced acute or chronic depletion of the plasma volume can lead to placental hypoperfusion and preeclampsia. Patients with systemic sclerosis have very high levels of blood renin. Diuretic-induced volume depletion provides another stimulus of the renin-angiotensin system and may cause a rapidly progressive renal failure requiring dialysis within days or weeks. The sclerodermal renal crisis is associated with a high early mortality. There is evidence that sclerodermal renal crisis can be avoided when patients are treated with an Angiotensin Converting Enzyme (ACE) inhibitor.

Nck-interacting Ste20 kinase couples Eph receptors to c-Jun N-terminal kinase and integrin activation.

The mammalian Ste20 kinase Nck-interacting kinase (NIK) specifically activates the c-Jun amino-terminal kinase (JNK) mitogen-activated protein kinase module. NIK also binds the SH3 domains of the SH2/SH3 adapter protein Nck. To determine whether Nck functions as an adapter to couple NIK to a receptor tyrosine kinase signaling pathway, we determined whether NIK is activated by Eph receptors (EphR). EphRs constitute the largest family of receptor tyrosine kinases (RTK), and members of this family play important roles in patterning of the nervous and vascular systems. In this report, we show that NIK kinase activity is specifically increased in cells stimulated by two EphRs, EphB1 and EphB2. EphB1 kinase activity and phosphorylation of a juxtamembrane tyrosine (Y594), conserved in all Eph receptors, are both critical for NIK activation by EphB1. Although pY594 in the EphB1R has previously been shown to bind the SH2 domain of Nck, we found that stimulation of EphB1 and EphB2 led predominantly to a complex between NIK/Nck, p62(dok), RasGAP, and an unidentified 145-kDa tyrosine-phosphorylated protein. Tyrosine-phosphorylated p62(dok) most probably binds directly to the SH2 domain of Nck and RasGAP and indirectly to NIK bound to the SH3 domain of Nck. We found that NIK activation is also critical for coupling EphB1R to biological responses that include the activation of integrins and JNK by EphB1. Taken together, these findings support a model in which the recruitment of the Ste20 kinase NIK to phosphotyrosine-containing proteins by Nck is an important proximal step in the signaling cascade downstream of EphRs.

Surface densities of ephrin-B1 determine EphB1-coupled activation of cell attachment through alphavbeta3 and alpha5beta1 integrins.

Receptors of the Eph family and their ligands (ephrins) mediate developmental vascular assembly and direct axonal guidance. Migrating cell processes identify appropriate targets within migratory fields based on topographically displayed ephrin gradients. Here, EphB1 regulated cell attachment by discriminating the density at which ephrin-B1 was displayed on a reconstituted surface. EphB1-ephrin-B1 engagement did not promote cell attachment through mechanical tethering, but did activate integrin-mediated attachment. In endothelial cells, attachment to RGD peptides or fibrinogen was mediated through alphavbeta3 integrin. EphB1 transfection conferred ephrin-B1-responsive activation of alpha5beta1 integrin-mediated cell attachment in human embryonic kidney cells. Activation-competent but signaling-defective EphB1 point mutants failed to stimulate ephrin-B1 dependent attachment. These findings lead us to propose that EphB1 functions as a 'ligand density sensor' to signal integrin-mediated cell-matrix attachment.

Renal microvascular assembly and repair: power and promise of molecular definition.

Developmental assembly of the renal microcirculation is a precise and coordinated process now accessible to experimental scrutiny. Although definition of the cellular and molecular determinants is incomplete, recent findings have reframed concepts and questions about the origins of vascular cells in the glomerulus and the molecules that direct cell recruitment, specialization and morphogenesis. New findings illustrate principles that may be applied to defining critical steps in microvascular repair following glomerular injury. Developmental assembly of endothelial, mesangial and epithelial cells into glomerular capillaries requires that a coordinated, temporally defined series of steps occur in an anatomically ordered sequence. Recent evidence shows that both vasculogenic and angiogenic processes participate. Local signals direct cell migration, proliferation, differentiation, cell-cell recognition, formation of intercellular connections, and morphogenesis. Growth factor receptor tyrosine kinases on vascular cells are important mediators of many of these events. Cultured cell systems have suggested that basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), and vascular endothelial growth factor (VEGF) promote endothelial cell proliferation, migration or morphogenesis, while genetic deletion experiments have defined an important role for PDGF beta receptors and platelet-derived growth factor (PDGF) B in glomerular development. Receptor tyrosine kinases that convey non-proliferative signals also contribute in kidney and other sites. The EphB1 receptor, one of a diverse class of Eph receptors implicated in neural cell targeting, directs renal endothelial migration, cell-cell recognition and assembly, and is expressed with its ligand in developing glomeruli. Endothelial TIE2 receptors bind angiopoietins (1 and 2), the products of adjacent supportive cells, to signals direct capillary maturation in a sequence that defines cooperative roles for cells of different lineages. Ultimately, definition of the cellular steps and molecular sequence that direct microvascular cell assembly promises to identify therapeutic targets for repair and adaptive remodeling of injured glomeruli.

Nck recruitment to Eph receptor, EphB1/ELK, couples ligand activation to c-Jun kinase.

Eph family receptor tyrosine kinases signal axonal guidance, neuronal bundling, and angiogenesis; yet the signaling systems that couple these receptors to targeting and cell-cell assembly responses are incompletely defined. Functional links to regulators of cytoskeletal structure are anticipated based on receptor mediated cell-cell aggregation and migratory responses. We used two-hybrid interaction cloning to identify EphB1-interactive proteins. Six independent cDNAs encoding the SH2 domain of the adapter protein, Nck, were recovered in a screen of a murine embryonic library. We mapped the EphB1 subdomain that binds Nck and its Drosophila homologue, DOCK, to the juxtamembrane region. Within this subdomain, Tyr594 was required for Nck binding. In P19 embryonal carcinoma cells, activation of EphB1 (ELK) by its ligand, ephrin-B1/Fc, recruited Nck to native receptor complexes and activated c-Jun kinase (JNK/SAPK). Transient overexpression of mutant EphB1 receptors (Y594F) blocked Nck recruitment to EphB1, attenuated downstream JNK activation, and blocked cell attachment responses. These findings identify Nck as an important intermediary linking EphB1 signaling to JNK.

[Is hemofiltration following acute kidney failure in elderly cardiovascular surgery patients justified?]. / Ist die Hämofiltration nach akutem nierenversagen bei Herz-Gefäss-chirurgischen Patienten im hohen Alter gerechtfertigt?

In a retrospective study, 47 patients with acute renal failure following cardiovascular surgery were evaluated in the Cardiovascular Surgery ICU of the University Hospital, Zurich, from 1991 to 1994. The object of the study was to investigate the contribution of hemofiltration for acute renal failure following cardiovascular surgery. The aim was further to identify risk factors which impair survival. We found that overall mortality was 70.2%, but was influenced by the patients' age. In patients under 60 (n = 9) the mortality rate was 55.6%; in patients from 60 to 69 (n = 19) the mortality rate was 57.9%. However, in patients aged 70 and over (n = 19), there was an increase in mortality to 89.5%. Specifically, the outcome was tested in a stepwise logistic regression and we found that recovery of renal function following hemofiltration was the most important factor favoring survival (p < 0.001). Further statistical analysis revealed that age 70 years or over was one of the main risk factors leading to death (p < 0.03), whereas preoperative renal insufficiency had no influence on postoperative outcome (p < 0.29). We conclude that postoperative renal function represents the crucial factor in survival. Although hemofiltration achieved adequate results in all groups, the patients of 70 years and more experienced a significantly higher mortality rate. This suggests that the increased mortality of the elderly was not due to renal failure in itself but rather was related to polymorbidity. Hence we propose that in the latter group of elderly patients candidates for hemofiltration are to be very carefully selected, particularly if they have additional complications.