[Lupus nephritis]. / Lupusnephritis.

Lupus nephritis (LN) is the most frequent and one of the most severe organ manifestations of systemic lupus erythematosus. The central pathogenetic mechanism is characterized by the loss of immune tolerance against autoantigens of the cell nucleus, which can lead to renal inflammation via the formation of nuclear autoantibodies. The clinical manifestations of LN encompass nephritic syndrome with the special form of rapidly progressive glomerulonephritis, nephrotic syndrome and thrombotic microangiopathy. The diagnostic procedures consist of renal function and urine analysis as well as the determination of serum autoantibody profiles and complement components. An early renal biopsy enables a differentiation between the prognostically different forms of LN. In addition to supportive measures, a differentiated immunosuppressive treatment is the main approach for prognostically unfavorable forms. Important components are corticosteroids, cyclophosphamide and mycophenolate mofetil for induction treatment. Currently investigated treatment principles include next generation calcineurin inhibitors and anti-B cell treatment.

Effect of ABO incompatibility on T-cell flow cytometry cross-match results prior to living donor kidney transplantation.

BACKGROUND: Due to its high sensitivity, the flow cytometry cross-match (FCXM) has been described as valuable tool for identifying an optimal donor. We here focused on the impact of ABO incompatibility on FCXM results. METHODS: We analyzed 29 ABO incompatible and 89 ABO compatible donor-recipient pairs (73 and 175 datasets, respectively) prior to living donor kidney transplantation. In all patients, lymphocytotoxic cross-matches for B and T cells were negative. RESULTS: Recipients with blood group O (A to O and B to O) displayed significantly (P < 0.05) higher T-FCXM results than those with blood group A and B (A to B, B to A and AB to A), respectively. Donor-specific T-FCXM responses (ΔMFI values) were significantly higher (P < 0.05) in ABO incompatible vs. compatible pairs (ABO incompatible recipients with blood group O: 32 ± 6; with blood group A: 19 ± 7; with blood group B: 7 ± 4; recipients with ABO compatibility: 3 ± 2, respectively, data represent mean ± SEM). Consistent with the T-FCXM results donor-specific isohemagglutinins (IgG titers) were significantly higher in recipients with blood group O vs. A, both prior to rituximab treatment and plasmapheresis/immune adsorption (P = 0.004) and immediately prior to transplantation, i.e., after rituximab and antibody-depleting therapies (P = 0.04). CONCLUSIONS: ABO incompatibility was associated with higher T-FCXM responses, especially in recipients with blood group O. This finding has major impact on the interpretation of flow cross-match results. Current cut-off values need to be reassessed in the ABO incompatible setting. © 2016 International Clinical Cytometry Society.

Five-year outcomes in kidney transplant patients converted from cyclosporine to everolimus: the randomized ZEUS study.

ZEUS study was an open-label, 12-month, multicenter study in which 300 de novo kidney transplant recipients were randomized to continue receiving cyclosporine (CsA) or convert to everolimus at 4.5 months posttransplant. Five-year follow-up data were available for 245/269 patients (91.1%) who completed the core 12-month study (123 everolimus, 109 CsA). At 5 years, adjusted estimated GFR was 66.2 mL/min/1.73 m(2) with everolimus versus 60.9 mL/min/1.73 m(2) with CsA; the mean difference was 5.3 mL/min/1.73 m(2) in favor of everolimus (95% CI 2.4, 8.3; p < 0.001 [intent-to-treat population]). In a post hoc analysis of patients remaining on study drug at 5 years (everolimus 77, CsA 86), mean difference was 8.2 mL/min/1.73 m(2) (95% CI 4.3, 12.1; p < 0.001) in favor of everolimus. The cumulative incidence of biopsy-proven acute rejection postrandomization was 13.6% with everolimus versus 7.5% with CsA (p = 0.095), largely accounted for by grade I rejection (16/21 patients and 7/11 patients, respectively). Postrandomization, graft loss, mortality, serious adverse events and neoplasms were similar in both arms. In conclusion, conversion of kidney transplant patients to everolimus at 4.5 months posttransplant is associated with a significant improvement in renal function that is maintained to at least 5 years. The increase in early mild acute rejection did not affect long-term graft function.

Conversion from cyclosporine to everolimus at 4.5 months posttransplant: 3-year results from the randomized ZEUS study.

The long-term effect of conversion from calcineurin inhibitor (CNI) therapy to an mTOR inhibitor requires clarification. Following completion of the 12-month, open-label, multicenter ZEUS study, in which 300 kidney transplant recipients were randomized to continue cyclosporine (CsA) or convert to everolimus at 4.5 months posttransplant, outcomes were assessed at month 36 (n = 284; 94.7%). CNI therapy was reintroduced in 28.4% of everolimus patients by month 36. The primary efficacy endpoint, estimated glomerular filtration rate (Nankivell, ANCOVA) was significantly higher with everolimus versus the CsA group at month 24 (7.6 mL/min/1.73 m(2) , 95%CI 4.3, 11.0 mL/min/1.73 m(2) ; p < 0.001) and month 36 (7.5 mL/min/1.73 m(2) , 95%CI 3.6, 11.4 mL/min/1.73 m(2) ; p < 0.001). The incidence of biopsy-proven acute rejection from randomization to month 36 was 13.0% in the everolimus arm and 4.8% in the CsA arm (p = 0.015). Patient and graft survival, as well as incidences of malignancy, severe infections and hospitalization, were similar between groups. Kidney transplant patients who are converted from CsA to everolimus at month 4.5 and who remain on everolimus thereafter may achieve a significant improvement in renal function that is maintained to 3 years. There was a significantly higher rate of rejection in the everolimus arm but this did not exert a deleterious effect by 3 years posttransplant.

[New radiological techniques to investigate patients suffering from chronic kidney disease]. / Nouvelles techniques radiologiques pour les patients insuffisants rénaux.

Radiological investigations using gadolinium or intravenous iodinated contrast products are used cautiously in patients suffering from chronic kidney disease because of their risk of acute kidney injury and systemic nephrogenic fibrosis. In this article, we review several radiological alternatives that can be useful to obtain renal anatomical and/or functional information in this patient population. The basic principles, indications, and advantages and limitations of Doppler ultrasound with measurement of the resistance index, contrast-enhanced ultrasound, and a technique called BOLD-MRI (blood-oxygenation level dependent-MRI) are discussed.

Meta-analyses qualify metzincins and related genes as acute rejection markers in renal transplant patients.

Definition of acute renal allograft rejection (AR) markers remains clinically relevant. Features of T-cell-mediated AR are tubulointerstitial and vascular inflammation associated with excessive extracellular matrix (ECM) remodeling, regulated by metzincins, including matrix metalloproteases (MMP). Our study focused on expression of metzincins (METS), and metzincins and related genes (MARGS) in renal allograft biopsies using four independent microarray data sets. Our own cases included normal histology (N, n = 20), borderline changes (BL, n = 4), AR (n = 10) and AR + IF/TA (n = 7). MARGS enriched in all data sets were further examined on mRNA and/or protein level in additional patients. METS and MARGS differentiated AR from BL, AR + IF/TA and N in a principal component analysis. Their expression changes correlated to Banff t- and i-scores. Two AR classifiers, based on METS (including MMP7, TIMP1), or on MARGS were established in our own and validated in the three additional data sets. Thirteen MARGS were significantly enriched in AR patients of all data sets comprising MMP7, -9, TIMP1, -2, thrombospondin2 (THBS2) and fibrillin1. RT-PCR using microdissected glomeruli/tubuli confirmed MMP7, -9 and THBS2 microarray results; immunohistochemistry showed augmentation of MMP2, -9 and TIMP1 in AR. TIMP1 and THBS2 were enriched in AR patient serum. Therefore, differentially expressed METS and MARGS especially TIMP1, MMP7/-9 represent potential molecular AR markers.

FTY720 versus MMF with cyclosporine in de novo renal transplantation: a 1-year, randomized controlled trial in Europe and Australasia.

FTY720 is a novel immunomodulator investigated in de novo renal transplantation and other therapeutic areas including multiple sclerosis. This 1-year multicenter, randomized, phase III study in 668 de novo renal transplant patients compared FTY720 2.5 mg plus full-dose cyclosporine (FDC) or FTY720 5.0 mg plus reduced-dose cyclosporine (RDC), with mycophenolate mofetil (MMF) plus FDC. The primary efficacy endpoint was the composite incidence of first treated biopsy-proven acute rejection (BPAR), graft loss, death or premature study discontinuation at month 12. Primary efficacy with FTY720 2.5 mg and MMF (32.4% and 30.2%; p = NS), plus mortality and BPAR incidence, were comparable. Patients receiving FTY720 5.0 mg plus RDC were discontinued from treatment due to increased risk of acute rejection (primary endpoint incidence 47.3%). FTY720 was associated with lower creatinine clearance (month 12: 53.1, 56.0 vs. 65.1 mL/min; p < 0.001) and more macular edema cases (2.2% and 1.3% vs. 0%), whereas cytomegalovirus infections were higher with MMF (6.2% and 10.6% vs. 18.1% p < 0.0001 and p = 0.0139, respectively). FTY720 2.5 mg provided comparable rejection prophylaxis over 12 months versus MMF; however, FTY720 5.0 mg did not support a 50% reduction in cyclosporine exposure. The cause of macular edema cases and lower creatinine clearance with FTY720 in de novo transplantation needs further investigation.

[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.

Antiproteinuric efficacy of fosinopril after renal transplantation is determined by the extent of vascular and tubulointerstitial damage.

BACKGROUND: Angiotensin converting enzyme (ACE) inhibitors have been successfully used for treatment of proteinuria after renal transplantation (RTx). Factors possibly responsible for the great inter-patient variance of the antiproteinuric effect (APE) have not yet been investigated in renal-transplanted patients. METHODS: 28 patients after RTx with a persistent proteinuria of more than 1.25 g/d were treated prospectively with does of fosinopril (10-15 mg/d) which were not effective on systemic arterial blood pressure. Prior to initiation of fosinopril, renal graft biopsy was performed in all patients and renal graft artery stenosis was excluded by duplex ultrasound. Serum creatinine and proteinuria were measured prior to, as well as 3 and 8 months after initiation of ACE inhibition, mean arterial pressure was controlled via 24-h measurement and repeated spot measurements. Reduction of proteinuria was correlated with renal histology, serum creatinine, creatinine clearance, mean arterial blood pressure, sodium excretion before therapy and the relative changes of these parameters during therapy respectively. RESULTS: Therapy had to be stopped in 8/28 patients due to side effects including rise of serum creatinine (n = 4). Three patients were excluded due to non-compliance. In the remaining patients (n = 17) proteinuria was reduced from 2.94 +/- 1.66 to 1.82 +/- 1.39 and 2.48 +/- 3.05 g/d after 3 and 8 months respectively, in the mean +/- SD. There was a significant inverse correlation between the APE and the extent of benign nephrosclerosis, interstitial fibrosis and tubular atrophy. No correlation of the APE to any of the other parameters could be demonstrated. CONCLUSIONS: Fosinopril can be administered effectively in a subgroup of proteinuric renal transplant recipients. However, because of a high proportion of patients developing side effects, careful monitoring is obligatory. Our results show that the lesser the degree of chronic morphological injury, the greater is the antiproteinuric effect. Thus, the degree of pre-existing histologically proven damage of the graft may serve as an indicator for the antiproteinuric efficacy of ACE inhibitor therapy after RTx.

The assessment of biomarkers to detect nephrotoxicity using an integrated database.

Groups of industrial workers exposed to heavy metals (cadmium, mercury, and lead) or solvents were studied together with corresponding control groups. The cohorts were collected from several European centers (countries). Eighty-one measurements were carried out on urine, blood, and serum samples and the results of these analyses together with questionnaire information on each individual were entered into a central database using the relational database package Rbase. After the completion of the database construction phase, the data were exported in a format suitable for analysis by the statistical package SAS. The potential value of each test as an indicator of nephrotoxicity was then assessed. Rigorous exclusion criteria were applied which resulted in the elimination of some tests and samples from the dataset. The measurable contributions of smoking, gender, metal exposure, and site were either singly or in combination assessed by biomarkers for nephrotoxicity. The parameters measured included three urinary enzymes, six specific proteins, total protein, two extracellular matrix markers, four prostaglandins and anti-GBM antibodies, and beta 2-microglobulin in serum. The most sensitive renal tests included the urinary enzymes N-acetyl-beta-D-glucosaminidase (NAG) and intestinal alkaline phosphatase (IAP), brush border antigens, and urinary low-molecular-weight proteins. Of the newer tests investigated the prostaglandins were the most promising. Different patterns of biomarker excretion were observed following exposure to lead, cadmium, or mercury. The dataset provides a unique repository of data which could provide the basis of an enlarging source of information on normal human reference ranges and on the effects of exposure to toxins and the use of biomarkers for monitoring nephrotoxicity.

Cathepsin B and L in isolated proximal tubular segments during acute and chronic proteinuria.

Acute and chronic proteinuria were studied in rats, using lysosomal cathepsin B and L as marker enzymes for tubular protein degradation. The activity of cathepsin B and L has been determined in microdissected segments S1, S2 and S3 of the proximal tubule by an ultramicroassay. Z-Phenylalanyl-arginine-7-amido-4-methylcoumarin served as a substrate. In normoproteinuric Sprague-Dawley rats, induction of acute unselective glomerular proteinuria with Adriamycin (5 mg/kg body weight) revealed a moderate activity increase of cathepsin B and L in the S2 segment, reaching 12.6 +/- 5.6 versus 8.6 +/- 4.2 pmol.mm-1.min-1 in controls. In contrast, Munich Wistar Frömter (MWF) rats, that are characterized by a genetically determined, chronically elevated glomerular protein excretion, showed a very high activity of cathepsin selectively in S2 of 25.0 +/- 12.1 pmol.mm-1.min-1. Acute proteinuria induced by Adriamycin in chronic proteinuric MWF rats could increase cathepsin activity in the S3 segment only, showing 12.0 +/- 8.3 versus 6.8 +/- 4.0 pmol.mm-1.min-1 in MWF control rats. In conclusion, chronically increased protein filtration changes the functional reserve capacity of the proximal tubule. While acutely induced glomerular proteinuria in normoproteinuric rats stimulates lysosomal proteolytic activity mainly in S2 segment, chronic proteinuric MWF rats may display already a maximally stimulated cathepsin activity in this segment probably due to long-term increased tubular protein load. In case of acute elevation of chronic proteinuria, the consecutive S3 segment shows increased lysosomal function for protein conservation.