[Dialysis and ultrafiltration therapy in patients with cardio-renal syndrome: recommendations of the working group "heart-kidney" of the German Cardiac Society and the German Society of Nephrology]. / Dialyse- und Ultrafiltrationsverfahren bei kardio-renalem Syndrom. Empfehlung der Arbeitsgemeinschaft "Herz--Niere" der Deutschen Gesellschaft für Kardiologie--Herz- und Kreislaufforschung e.V. und der Deutschen Gesellschaft für Nephrologie e.V.

Renal failure is common in patients with severe heart failure. This complex pathophysiological interaction has been classified as cardio-renal syndrome. In these patients hydropic decompensation is the main cause of hospitalization. In patients with refractory heart failure, characterized by diuretic resistance and congestion due to volume overload, ultrafiltration has to be considered. In acute decompensated heart failure with worsening of renal function, extracorporeal ultrafiltration is the preferred treatment modality. On the other hand, patients suffering from chronic decompensated heart failure, particularly patients with ascites, will profit from the treatment specific advantages of peritoneal ultrafiltration. Prerequisite for an optimized care of patients with cardio-renal syndrome is the close collaboration among intensive care doctors, cardiologists and nephrologists.

Leflunomide therapy for polyomavirus-induced allograft nephropathy: efficient BK virus elimination without increased risk of rejection.

BACKGROUND: Optimal treatment of polyomavirus-induced allograft nephropathy (PVAN) with immunosuppressive and antiviral therapy is uncertain at present. Reduced immunosuppression is accompanied by increased risk of rejection, and antiviral agents are nephrotoxic. Leflunomide has immunosuppressive and antiviral properties and may be an alternative treatment agent. We report a two-center experience with use of leflunomide for treatment of PVAN. PATIENTS AND METHODS: Thirteen renal allograft recipients were diagnosed with biopsy-proven PVAN. Treatment consisted of lowering the calcineurin-inhibitor trough level, discontinuing mycophenolate mofetil therapy, and initiating leflunomide therapy. In 8 of the 13 patients, the serum concentration of the leflunomide active metabolite A771726 was monitored. RESULTS: Exchange of mycophenolate mofetil with leflunomide in patients with PVAN was well tolerated and safe, with no serious adverse effects or episodes of graft rejection. Mean follow-up after transplantation was 717 days, and after initiation of leflunomide therapy was 465 days. With the modified therapy, 12 patients cleared the virus at a mean of 109 days. One graft was lost due to refractory rejection accompanied by a decreasing viral load. In the other 12 patients, graft function stabilized or improved (mean [median] creatinine concentration at diagnosis, 2.39 [2.5] mg/mL, vs 2.27 [2.0] mg/dL at follow-up). Leflunomide concentration did not correlate with treatment efficiency. CONCLUSIONS: Treatment of PVAN with leflunomide, a low-dose calcineurin inhibitor, and prednisone seems to reduce viral load and stabilize renal graft function without increasing the risk of rejection. Even low serum concentrations of leflunomide support viral elimination and prevention of graft rejection.

Tailoring the nature of magnetic coupling of Fe-porphyrin molecules to ferromagnetic substrates.

We demonstrate that an antiferromagnetic coupling between paramagnetic Fe-porphyrin molecules and ultrathin Co and Ni magnetic films on Cu(100) substrates can be established by an intermediate layer of atomic oxygen. The coupling energies have been determined from the temperature dependence of x-ray magnetic circular dichroism measurements. By density functional theory+U calculations the coupling mechanism is shown to be superexchange between the Fe center of the molecules and Co surface-atoms, mediated by oxygen.

Color Doppler indices of renal allografts depend on vascular stiffness of the transplant recipients.

A resistance index (RI) of 0.8 or higher was shown to be a strong predictor of kidney allograft and patient survival. Uncertainties persist since the intrarenal RI is closely associated with the vascular stiffness of the allograft recipient. To clarify the diagnostic value of RI further, we analyzed parameters of vascular stiffness of the recipient and intrarenal RI of the renal allograft. In a prospective study laboratory and clinical parameters, pulse wave velocity (PWV), intima media thickness (IMT) and RI were obtained in 76 kidney allograft patients. We found that the RI values significantly correlated with the PWV (p < 0.05) and the recipients age (p < 0.01) but not with the donor age and renal function. Using multiple regression analysis recipient age, PWV, pulse pressure (PP) and IMT were identified as independent factors influencing RI values. For a more correct interpretation of the RI values in renal allografts parameters of vascular stiffness such as IMT, PP or PWV should be included.

Atherosclerotic renal artery stenosis and reconstruction.

Renal artery stenosis is common especially in patients with generalized atherosclerosis. It is frequently associated with difficult-to-treat hypertension and with renal failure. There is an ongoing debate about the appropriate screening and treatment of atherosclerotic renal artery stenosis. Advances in imaging and interventional devices offer new opportunities, however, clinicians still have to decide individually in every patient to treat or not to treat stenosis with revascularization. This review evaluates the current literature in order to help the physician to find the right decision in this challenging clinical issue.

Design of the prospective randomized study for the treatment of patients with thrombotic microangiopathy. PRODROMI Study Group.

In thrombotic microangiopathies hemolytic uremic syndrome and thrombocytopenic purpura, plasma exchange (PE) therapy using fresh frozen plasma is standard. In almost 20% of the patients, however, this approach is ineffective. This prospective, randomized study for the treatment of patients with thrombotic microangiopathies (PRODROMI) compares PE with fresh frozen plasma (A) and cryosupernatant (B). The participating centers were the University Clinics of Freiburg, Hamburg, Düsseldorf, Essen, Göttingen, Mannheim, Ulm, Jena, Tübingen, Würzburg, Kreiskrankenhaus Offenburg, Städt Klinikum Karlsruhe, and Horst-Schmidt Kliniken in Wiesbaden, Germany. Patients (18 to 80 years) were diagnosed by the individual centers based on clinical and laboratory findings (thrombocyte/fragmentocyte count, hemoglobin, serum creatinine, haptoglobin and lactate dehydrogenase levels; negative Coombs-test is obligatory). HIV infection, bone marrow, or solid organ transplantation were exclusion criteria. After written consent, patients were randomized in the A or B group. All patients received 1.5 mg/kg methylprednisolone as a basic therapy. The first PE always was performed with fresh frozen plasma (50 ml/kg). A minimum of 5 and a maximum of 10 PEs were required. Thrombocyte count above 150,000/microl was considered to be a successful therapy. Treatment failure was defined as not responding to 10 PE with a thrombocyte count above 150,000/microl or a fall below this value within 30 days after stopping PE. Patients with clinical and laboratory signs of thrombotic microangiopathy occurring later than 30 days after having stopped PE were considered to have a relapse. Primary endpoints were survival, intensity of required PE sessions (duration, volume, and number), and relapse rate. Follow-up of clinical outcome was 2 years; von Willebrand Factor (vWF), vWF-cleaving-protease activity, and Factor H were determined.

Careful clinical monitoring in comparison to sequential Doppler sonography for the detection of acute rejection in the early phase after renal transplantation.

Acute rejection is the most frequent cause of early graft failure. There is unanimity that Doppler sonography is a helpful method for the detection of complications after kidney transplantation. In the past, the indication for renal biopsy relied mainly on clinical assessment, although this assessment has not been standardised. Therefore, we conducted this prospective study to compare the value of sequential Doppler measurements with a standardised clinical rejection score, based on renal function, weight gain, graft swelling and tenderness. Fifty-eight patients (37 males, 21 females, mean age 46 +/- 12 years) after kidney transplantation were consecutively enrolled into the study. Doppler investigations were obtained within the first 24 h after transplantation, followed by an interval of 48-72 h. At the same time, a clinical examination was scored by a transplant physician blinded to the Doppler results. Clinical score and Doppler results, both were referred to the histological results of renal biopsy. In 24 out of 58 patients 25 acute rejections occurred. In seven patients, acute rejection was superimposed on primary graft failure. The cut-off levels for rejection were set at RI > or = 0.80 and PI > or = 1.70 based on receiver-operator curves using data from 663 Doppler examinations. Sensitivity and specificity was 72% for RI, and 72% and 74% for PI, respectively. The calculation of the intraindividual increase (deltaRI > or = 3%, deltaPI > or = 10%) did not improve these values. The clinical score revealed a sensitivity and specificity of 82% and 87%, respectively. The combined analysis of Doppler indices and clinical score showed a sensitivity of 96% with a specificity of 66%. Careful clinical monitoring alone using a clinical score is an appropriate procedure with which to decide about renal biopsy. Our data show that Doppler sonography should be performed within the first 24 h after transplantation to evaluate graft perfusion and baseline values. Afterwards, it should be used when clinical signs of rejection occur to underline the decision for renal biopsy even in borderline cases.

Multiple intracranial aneurysms in a patient with autosomal recessive polycystic kidney disease.

Autosomal recessive polycystic kidney disease (ARPKD) is usually characterized by early onset chronic renal failure due to innumerable dilated collecting ducts. Hepatic fibrosis is an obligate sign. Here, for the first time, we report a 31-year-old female with ARPKD who was diagnosed with symptomatic multiple intracranial aneurysms, a manifestation previously only known to be associated with autosomal dominant polycystic kidney disease (ADPKD).

[Percutaneous revascularization of renal artery stenosis. Balloon angioplasty vs. stent implantation]. / Perkutane Revaskulärisation von Nierenarterienstenosen. Ballonangioplastie versus Stentimplantation.

Renal artery stenosis (RAS) is the most common cause of secondary hypertension, with a prevalence of about 1% in the general population of people with hypertension. Severe arterial stenosis may also lead to impairment of excretory renal function. In experienced hands renal artery revascularization with or without stent implantation may be a safe and effective treatment in patients with sustained hypertension resistant to intensive antihypertensive treatment. Conventional balloon angioplasty of non-ostial RAS caused by fibromuscular dysplasia with a high technical and functional success rate may be the treatment of choice. However, there is continuous discussion concerning the utility of balloon angioplasty and renal stenting, respectively, in patients with atherosclerotic disease. At the time being, there are 3 randomized European trials ongoing to analyze the benefit of medical treatment versus percutaneous intervention. Several prospective studies dealing with renal artery stenting in ostial RAS found that the implantation of endoprostheses leads to much better morphologic longterm results as compared to those of balloon angioplasty alone and may be a safe and effective alternative to surgery. In addition, the functional results suggest that stent implantation in patients with mild or severe renal dysfunction may slow progression of renal failure and, thus delay the need for renal replacement therapy. It is to note that renal artery stenting does not impede any further surgical intervention. However, prior to any interventional treatment the indication of an eventual catheter procedure in patients with RAS should be discussed between experienced nephrologists and interventionalists based on clinical, functional and duplexsonographic data.

Unusual cause of early graft dysfunction after kidney transplantation.

BACKGROUND/AIMS: Transplant renal artery stenosis usually develops in the later period after renal transplantation and is usually due to atherosclerosis and fibrosis at the anastomosis. A kinking renal artery stenosis, however, is a rare cause of early graft dysfunction. METHODS: In a 34-year-old-man early graft failure developed within 1 week after kidney transplantation. In the presence of histologically proven ischemic damage an arterial kinking stenosis was diagnosed by color Doppler sonography. Selective arteriography confirmed the sharp kinking of the transplant renal artery; however, a significant stenosis could not be visualized by arteriography. RESULTS: Due to progressive loss of renal function surgical resection of scar tissue in the kink of the transplant artery and nephropexy was performed. Immediately thereafter graft function and blood pressure significantly improved so that the successful clinical outcome of this unusual case of early graft failure confirmed the relevance of the arterial kinking stenosis. CONCLUSIONS: In this unusual case of early graft dysfunction relevant kinking renal artery stenosis could not be adequately visualized by arteriography, although color Doppler sonography clearly demonstrated the stenosis. Therefore, both methods should be considered if parenchymal causes of graft dysfunction are excluded by biopsy and a kinking renal artery stenosis is suspected.

Imaging of renal artery stenosis.

Renal artery stenosis is the cause of progressive ischemic nephropathy and of renovascular hypertension. Due to the invasiveness of arteriography, which is claimed to be the gold standard at the present time, several noninvasive imaging techniques are available. Colour Doppler sonography is cost-effective, but magnetic resonance angiography and computer tomography are more expensive; however, both are potential candidates for the definition of a new gold standard. Evaluation of renal vasculature by means of Doppler sonography includes intra- and extrarenal scanning as well as power Doppler and the use of contrast agents for enhancement of the Doppler signals. Computed tomography angiography is a minimally invasive method for the diagnosis of renal artery stenosis. There is high diagnostic accuracy that is not significantly different from that of angiography with respect to main and accessory renal arteries and detection of clinically significant renal artery stenoses. The main advantages over angiography are the use of an intravenous approach, and direct information provided about the vessel wall and adjacent structures. However, the nephrotoxicity of contrast material remains a major concern. Magnetic resonance angiography of the abdominal aorta and renal arteries has advanced considerably over the past few years. Recently developed breath-hold three-dimensional magnetic resonance angiography provides a new promising, noninvasive technique to evaluate the abdominal aorta and its large branch vessels. Using this technique, high sensitivity and specificity is achieved. The improved image quality and the ability to detect vascular lesions is due to short acquisition time with elimination of respiratory artifacts over an entire imaged volume by single breath-hold acquisition. Computed tomography angiography with its fast acquisition time and high spatial resolution compares favorably with magnetic resonance angiography and colour Doppler sonography. However, as compared with Doppler sonography and magnetic resonance angiography, computed tomography angiography images display only anatomic information and lack of flow sensitivity.