Development of a practical prediction score for chronic kidney disease after cardiac surgery.

BACKGROUND: Chronic kidney disease (CKD) is a frequent and serious complication of cardiac surgery. This study was designed to establish a scoring system, calculated in the immediate postoperative period, to assess the risk of CKD at 1 yr in patients undergoing cardiac surgery with cardiopulmonary bypass. METHODS: We conducted a cohort study including patients with preoperative estimated glomerular filtration rate above 60 ml min-1 (1.73 m)-2 who underwent cardiac surgery with cardiopulmonary bypass. We identified risk factors for de novo CKD at 1 yr using logistic regression. We derived a risk score for CKD, and externally validated this score in a second cohort. RESULTS: The incidence of CKD was 18% and 23% in the derivation and validation cohorts, respectively. We developed a scoring system that included (i) the occurrence of postoperative acute kidney injury according to the Kidney Disease: Improving Global Outcomes criteria, (ii) age older than 65 yr, (iii) preoperative glomerular filtration rate <80 ml min-1 (1.73 m)-2, (iv) aortic cross-clamping time longer than 50 min, and (v) the type of surgery (aortic or cardiac transplantation). This score predicted CKD with good accuracy (area under the receiver operating characteristic curve: 0.81; 95% confidence interval: 0.77-0.86 in the derivation cohort), and with fair accuracy in the validation cohort (area under the receiver operating characteristic curve: 0.78; 95% confidence interval: 0.72-0.83). CONCLUSIONS: We provide an easy-to-calculate scoring system to identify patients at high risk of developing CKD after cardiac surgery with cardiopulmonary bypass. This system might help clinicians to target more accurately patients requiring monitoring of renal function after cardiac surgery, and to design appropriate interventional trials aimed at preventing CKD or mitigating its consequences.

Urinary mRNA for the Diagnosis of Renal Allograft Rejection: The Issue of Normalization.

Urinary messenger RNA (mRNA) quantification is a promising method for noninvasive diagnosis of renal allograft rejection (AR), but the quantification of mRNAs in urine remains challenging due to degradation. RNA normalization may be warranted to overcome these issues, but the strategies of gene normalization have been poorly evaluated. Herein, we address this issue in a case-control study of 108 urine samples collected at time of allograft biopsy in kidney recipients with (n = 52) or without (n = 56) AR by comparing the diagnostic value of IP-10 and CD3ε mRNAs-two biomarkers of AR-after normalization by the total amount of RNA, normalization by one of the three widely used reference RNAs-18S, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and Hypoxanthine-guanine phosphoribosyltransferase (HPRT)-or normalization using uroplakin 1A (UPK) mRNA as a possible urine-specific reference mRNA. Our results show that normalization based on the total quantity of RNA is not substantially improved by additional normalization and may even be worsened with some classical reference genes that are overexpressed during rejection. However, considering that normalization by a reference gene is necessary to ensure polymerase chain reaction (PCR) quality and reproducibility and to suppress the effect of RNA degradation, we suggest that GAPDH and UPK1A are preferable to 18S or HPRT RNA.

Fibrosis progression according to epithelial-mesenchymal transition profile: a randomized trial of everolimus versus CsA.

Markers of epithelial-mesenchymal transition (EMT) may identify patients at high risk of graft fibrogenesis who could benefit from early calcineurin inhibitor (CNI) withdrawal. In a randomized, open-label, 12-month trial, de novo kidney transplant patients received cyclosporine, enteric-coated mycophenolate sodium (EC-MPS) and steroids to month 3. Patients were stratified as EMT+ or EMT- based on month 3 biopsy, then randomized to start everolimus with half-dose EC-MPS (720 mg/day) and cyclosporine withdrawal (CNI-free) or continue cyclosporine with standard EC-MPS (CNI). The primary endpoint was progression of graft fibrosis (interstitial fibrosis/tubular atrophy [IF/TA] grade increase ≥1 between months 3-12) in EMT+ patients. 194 patients were randomized (96 CNI-free, 98 CNI); 153 (69 CNI-free, 84 CNI) were included in histological analyses. Fibrosis progression occurred in 46.2% (12/26) CNI-free EMT+ patients versus 51.6% (16/31) CNI EMT+ patients (p = 0.68). Biopsy-proven acute rejection (BPAR, including subclinical events) occurred in 25.0% and 5.1% of CNI-free and CNI patients, respectively (p < 0.001). In conclusion, early CNI withdrawal with everolimus initiation does not prevent interstitial fibrosis. Using this CNI-free protocol, in which everolimus exposure was relatively low and administered with half-dose EC-MPS, CNI-free patients were overwhelmingly under-immunosuppressed and experienced an increased risk of BPAR.

A model of hemodialysis after acute kidney injury in rats.

BACKGROUND: Acute kidney injury (AKI) is frequent among critically ill patients. Renal replacement therapy (RRT) is often required to deal with severe complications of AKI. This technique is however associated with side effects such as hemodynamic instability and delayed renal recovery. In this study, we aimed to describe a novel model of hemodialysis in rats with AKI and depict a dialysis membrane performance. METHODS: Eighteen Sprague-Dawley rats received 0.75% adenine-rich diet to induce AKI. After 2 weeks, nine underwent an arterio-venous extracorporeal circulation (ECC) (ECC group) for 2 h without a dialysis membrane on the circuit and nine received a hemodialysis session (HD group) for 2 h with an ECC circuit. All rats were hemodynamically monitored, and glomerular filtration rate (GFR) was measured by transcutaneous fluorescence after the injection of FITC-Sinistrin. Blood samples were collected at different time points to assess serum creatinine and serum urea concentrations and to determine the Kt/V. Sinistrin concentration was also quantified in both plasma and dialysis effluent. RESULTS: After 2 weeks of adenine-rich diet, rats exhibited a decrease in GFR. Both serum urea and serum creatinine concentrations increased in the ECC group but remained stable in the HD group. We found no significant difference in serum creatinine and serum urea concentrations between groups. At the end of experiments, mean serum urea was 36.7 mmol/l (95%CI 19.7-46.9 mmol/l) and 23.6 mmol/l (95%CI 15.2-33.5 mmol/l) in the ECC and HD groups, respectively (p = 0.15), and mean serum creatinine concentration was 158.0 µmol/l (95%CI 108.1-191.9 µmol/l) and 114.0 µmol/l (95%CI 90.2-140.9 µmol/l) in the ECC and HD groups, respectively (p = 0.11). The Kt/V of the model was estimated at 0.23. Sinistrin quantity in the ultrafiltrate raised steadily during the dialysis session. After 2 h, the median quantity was 149.2 µg (95% CI 99.7-250.3 µg). CONCLUSIONS: This hemodialysis model is an acceptable compromise between the requirement of hemodynamic tolerance which implies reducing extracorporeal blood volume (using a small dialyzer) and the demonstration that diffusion of molecules through the membrane is achieved.

Ofloxacin: new applications for the prevention of urinary tract infections in renal graft recipients.

BACKGROUND: Urinary tract infections (UTIs), the most common form of bacterial infection in kidney transplant recipients, recently have been demonstrated to be detrimental for long-term graft outcome. Therefore, reinforcing antibiotic prophylaxis might be vital, in addition to basic hygiene recommendations, surgical care, and prophylaxis by trimethoprim-sulfamethoxazole. METHODS: In 2006, a Legionella pneumophila contamination of our department's water pipes meant that all the patients undergoing renal transplantation underwent a 1-month regimen of ofloxacin (OFLO) (200 mg every other day). We took this opportunity to measure the incidence of UTI, including acute pyelonephritis (APN), in 100 consecutive patients transplanted before (n = 50) and after (n = 50) this treatment decision was reached. We also studied the antimicrobial resistance profiles in our department and in the rest of the hospital. RESULTS: No patient developed Legionnaire's disease. A dramatic decrease in the incidence of UTI (-63%) was also seen in patients undergoing OFLO treatment. Logistic regression analysis demonstrated that the use of OFLO was independently associated with a reduction in UTI (odd ratio [OR] = 0.31%, 95% confidence interval [CI] 0.11-0.84, P = 0.02) and APN (OR = 0.21%, 95% CI 0.07-0.98, P = 0.045). This protection was sustained during the whole first year post transplantation. As for resistance rates, we observed a decrease in the susceptibility of Pseudomonas aeruginosa to ciprofloxacin in our nephrology department, compared with that observed in the rest of the hospital. The incidence of multi-resistant bacteria was stable. DISCUSSION: Our unintentional extension of prophylactic antibiotherapy with OFLO gave rise to a dramatic decrease in the 1-year incidence of UTI and APN in kidney recipients. Emergence of resistant strains is, however, a major concern.

Are script concordance tests suitable for the assessment of undergraduate students? A multicenter comparative study.

INTRODUCTION: Script concordance tests (SCTs) have been developed to assess clinical reasoning in uncertain situations. Their reliability for the evaluation of undergraduate medical students has not been evaluated. METHODS: Twenty internal medicine SCT cases were implemented in undergraduate students of two programs. The results obtained on the SCTs were compared to those obtained by the same students on clinical-based classical multiple-choice questions (MCQs). RESULTS: A total of 551/883 students (62%) answered the SCTs. The mean aggregate score (based on a total 20 points) was 11.54 (3.29). The success rate and mean score for each question did not differ depending on the modal response but the discrimination rate did. The results obtained by the students on the SCT test correlated with their scores on the MCQ tests. Among students, 446/517 (86%) considered the SCTs to be more difficult than classical MCQs, although the mean score did not differ between the SCT and MCQ tests. CONCLUSION: The use of SCTs is a feasible option for the evaluation of undergraduate students. The SCT scores correlated with those obtained on classical MCQ tests.

Progressive clinical case-based multiple-choice questions: An innovative way to evaluate and rank undergraduate medical students.

INTRODUCTION: In France, at the end of the sixth year of medical studies, students take a national ranking examination including progressive clinical case-based multiple-choice questions (MCQs). We aimed to evaluate the ability of these MCQs for testing higher-order thinking more than knowledge recall, and to identify their characteristics associated with success and discrimination. METHODS: We analysed the 72 progressive clinical cases taken by the students in the years 2016-2019, through an online platform. RESULTS: A total of 72 progressive clinical cases (18 for each of the 4 studied years), corresponding to 1059 questions, were analysed. Most of the clinical cases (n=43, 60%) had 15 questions. Clinical questions represented 89% of all questions, whereas basic sciences questions accounted for 9%. The most frequent medical subspecialties were internal medicine (n=90, 8%) and infectious diseases (n=88, 8%). The most frequent question types concerned therapeutics (26%), exams (19%), diagnosis (14%), and semiology (13%). Level 2 questions ("understand and apply") accounted for 59% of all questions according to the Bloom's taxonomy. The level of Bloom's taxonomy significantly changed over time with a decreasing number of level 1 questions ("remember") (P=0.04). We also analysed the results of the students among 853 questions of training ECNi. Success and discrimination significantly decreased when the number of correct answers increased (P<0.0001 both). The success, discrimination, mean score, and mean number of discrepancies did not differ according to the diagnosis, exam, imaging, semiology, or therapeutic type of questions. CONCLUSION: Progressive clinical case-based MCQs represent an innovative way to evaluate undergraduate students.

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.

Renal allografts with IF/TA display distinct expression profiles of metzincins and related genes.

Chronic renal allograft injury is often reflected by interstitial fibrosis (IF) and tubular atrophy (TA) without evidence of specific etiology. In most instances, IF/TA remains an irreversible disorder, representing a major cause of long-term allograft loss. As members of the protease family metzincins and functionally related genes are involved in fibrotic and sclerotic processes of the extracellular matrix (ECM), we hypothesized their deregulation in IF/TA. Gene expression and protein level analyses using allograft biopsies with and without Banff'05 classified IF/TA illustrated their deregulation. Expression profiles of these genes differentiated IF/TA from Banff'05 classified Normal biopsies in three independent microarray studies and demonstrated histological progression of IF/TA I to III. Significant upregulation of matrix metalloprotease-7 (MMP-7) and thrombospondin-2 (THBS-2) in IF/TA biopsies and sera was revealed in two independent patient sets. Furthermore, elevated THBS-2, osteopontin (SPP1) and beta-catenin may play regulatory roles on MMP. Our findings further suggest that deregulated ECM remodeling and possibly epithelial to mesenchymal transition (EMT) are implicated in IF/TA of kidney transplants, and that metzincins and related genes play an important role in these processes. Profiling of these genes may be used to complement IF/TA diagnosis and to disclose IF/TA progression in kidney transplant recipients.

Studies on the human corpus luteum. II. Observations on the ultrastructure of luteal cells during pregnancy.

The ultrastructure of human corpora lutea obtained during the 6th, 10th, 16th, and 35th week of pregnancy is reported. Differences between the established luteal cell of pregnancy and the transitory luteal cell of the menstrual cycle are noted. In pregnancy the luteal cell is more compartmentalized into a peripheral mass of ER (endoplasmic reticulum) and a central area where mitochondria and Golgi complexes are concentrated. The latter area extends to a cell surface where microvilli face on a perivascular space. Long bundles of filaments are prominent within the luteal cell cytoplasm and, in contiguous cells, appear to arise from adjacent desmosomal regions. Bilateral subsurface cisternae of granular ER at lateral cell borders appear to be areas of specialized junctional surfaces. Certain luteal cells with irregular nuclear membranes are also characterized by vesicular aggregates enclosed within a single membrane. These aggregates are found within the peripheral nucleoplasm or the perinuclear cytoplasm. Their single limiting membrane often appears continuous with either the inner or outer leaflet of the nuclear membrane.

Studies on the human corpus luteum. I. Observations on the ultrastructure of development and regression of the luteal cells during the menstrual cycle.

The ultrastructure of huma corpora luntea obtained approximately 2, 3, 5, 11, and 15 days after ovulation is reported. All specimens were fixed in Karnovsky's formaldehyde-glutaral-dehyde solution. The 5-day corpus luteum is presumed to represent, in terms of fine structure, the ultrastructural aspects of high progesterone production and is compared to younger differentiating and older regressing specimens. A distinct topographic relationship of cytoplasmic organelles is noted in the mature 5-day luteal cell. It consists of a peripheral cupshaped mass of tubular ER (endoplasmic reticulum), associated with granular ER, lipid droplets, and mitochondria, which merges with a large paranuclear Golgi area extending to a cell surface bordering a perivascular space. The plasma membrane of active luteal cells is described and its variations suggest areas of specialized surface activities. The prevalence and ultrastructure of more electron-opaque stellate cells, of phagocytes, and of thecal cells are reported.

Studies on the human oocyte and its follicle. I. Ultrastructural and histochemical observations on the primordial follicle stage.

Oocytes in primordial ("resting") follicles in adult human ovaries contain a complex paranuclear structure identified by light microscopists as Balbiani's vitelline body. By electron microscopy this structure is composed of a mass of mitochondria with associated endoplasmic reticulum, multiple compound aggregates which form a ring around the cytocentrum, and a single stack or coil of annulate lamellae either attached to the nuclear membrane or free in the cytoplasm. The compound aggregates contain vacuoles and finely divided electron-opaque material. Evidence is presented for the probable transport of this material between the oocyte and its environment. The cytocentrum contains a central aggregate of amorphous electron-opaque deposits which appear to become periodically aligned on fine fibrils to form the long coarse fibers at the periphery of the cytocentrum. The apparent prevalence of annulate lamellae attached or adjacent to the nuclear membrane of oocytes in ovaries removed during the mid-follicular (estrogenic) phase of the cycle indicates the need for further study of a possible hormonal influence on the resting oocyte. By light microscopy phosphatases were not found within the oocyte, but adenosine-monophosphatase activity is present in the cortical cells surrounding primordial follicles, and also at the periphery of each primitive follicle cell, most prominently at the oocyte side. Glucose-6-phosphate dehydrogenase activity is present within the oocyte cytoplasm.

Advanced glycation end products regulate extracellular matrix protein and protease expression by human glomerular mesangial cells.

Advanced glycation end products (AGEs) may play a role in the pathogenesis of diabetic nephropathy, by modulating extracellular matrix turnover. AGEs are known to activate specific membrane receptors, including the receptor for AGE (RAGE). In the present study, we analyzed the various receptors for AGEs expressed by human mesangial cells and we studied the effects of glycated albumin and of carboxymethyl lysine on matrix protein and remodelling enzyme synthesis. Membrane RAGE expression was confirmed by FACS analysis. Microarray methods, RT-PCR, and Northern blot analysis were used to detect and confirm specific gene induction. Zymographic analysis and ELISA were used to measure the induction of tPA and PAI-1. We show herein that cultured human mesangial cells express AGE receptor type 1, type 2 and type 3 and RAGE. AGEs (200 microg/ml) induced at least a 2-fold increase in mRNA for 10 genes involved in ECM remodelling, including tPA, PAI-1 and TIMP-3. The increase in tPA synthesis was confirmed by fibrin zymography. The stimulation of PAI-1 synthesis was confirmed by ELISA. AGEs increased PAI-1 mRNA through a signalling pathway involving reactive oxygen species, the MAP kinases ERK-1/ERK-2 and the nuclear transcription factor NF-kappaB, but not AP-1. Carboxymethyl lysine (CML, 5 microM), which is a RAGE ligand, also stimulated PAI-1 synthesis by mesangial cells. In addition, a blocking anti-RAGE antibody partially inhibited the AGE-stimulated gene expression and decreased the PAI-1 accumulation induced by AGEs and by CML. Inhibition of AGE receptors or neutralization of the protease inhibitors TIMP-3 and PAI-1 could represent an important new therapeutic strategy for diabetic nephropathy.

[Coronary involvement and nephrotic syndrome in systemic lupus: A case report]. / Atteinte coronarienne et syndrome néphrotique au cours du lupus systémique : à propos d'une observation.

INTRODUCTION: Heart failure during systemic lupus erythematosus has various causes. CASE REPORT: A 29-year-old female presented with a systemic lupus flare and a nephrotic syndrome, followed by cardiogenic shock requiring extra-corporeal membranous oxygenation. Ventricular dysfunction was related to massive myocardial infarction due to an anterior interventricular artery thrombosis and an underlying atheroma. The young age and the absence of chest pain were not suggestive of coronary artery disease initially. Coronary thrombosis was probably favored by the nephrotic syndrome, in which the arterial thrombotic risk is increased. CONCLUSION: Coronary artery disease should be systematically evoked in the presence of ventricular dysfunction in patients with systemic lupus, including when they are young and in the absence of chest pain. Nephrotic syndrome should be identified as a risk factor for arterial thrombosis.

Chronic lymphocytic leukemia: a hazardous condition before kidney transplantation.

Long-term survival of patients with chronic lymphocytic leukemia (CLL) is over 10 years, and such patients are thus potential kidney recipients in the case of superimposed end-stage renal disease. However, the renal and patient outcome in this condition is unknown. We report the charts of four patients with CLL who were engrafted in France with a deceased-donor kidney and underwent routine triple immunosuppressive therapy. The results show that these patients developed severe infectious episodes (fatal in one case) and tumoral complications including rapid progression of CLL in two cases. Moreover, the graft may be infiltrated and damaged by monoclonal B cells: one patient lost his graft 14 months after transplantation. Various therapeutic options (modifications of the immunosuppressive regimen, anti-CD20 antibodies, irradiation of the graft) showed little (if any) efficacy. Therefore, we believe that CLL is a too hazardous condition to envisage solid organ transplantation with a routine immunosuppressive regimen, and we propose a more appropriate approach.

Cyclosporine-induced endoplasmic reticulum stress triggers tubular phenotypic changes and death.

The molecular mechanisms by which cyclosporine induces chronic nephrotoxicity remain poorly understood. A previous transcriptomic study suggested that cyclosporine might induce endoplasmic reticulum (ER) stress in human tubular cells. The aim of the present study was to characterize the features of tubular ER stress induced by cyclosporine and to investigate its effects on cell differentiation and viability. Using primary cultures of human tubular cells, we confirmed that cyclosporine is responsible for ER stress in vitro. This was also confirmed in vivo in the rat. In vitro, cyclosporine and other ER stress inducers were responsible for epithelial phenotypic changes leading to the generation of protomyofibroblasts, independent of transforming growth factor-beta signaling. RNA interference directed against cyclophilin A supported the role of its inhibition in triggering ER stress as well as epithelial phenotypic changes induced by cyclosporine. Salubrinal, which is known to protect cells from ER stress, significantly reduced epithelial phenotypic changes and cytotoxicity induced by cyclosporine in vitro. Salubrinal also reduced cyclosporine nephrotoxicity in rat kidneys. Thus, we describe a novel mechanism that initiates dedifferentiation and tubular cell death upon cyclosporine treatment. These results provide an interesting framework for further nephroprotective therapies by targeting ER stress.

[Epithelial-mesenchymal transition of the renal graft]. / La Transition Epithélio-Mésenthymateuse (TEM), marqueur prédictif d'évolution de NCA ?

About 40 % of renal graft losses over 10 years in Europe are caused by fibrosis. To explain the origin of interstitial fibroblasts, the epithelial-mesenchymal transition (EMT) theory has been recently ventured : under the effect of an aggression, tubular epithelial cells may change into fibroblasts, cross over the basal membrane, and join interstitium. This innovative hypothesis has been confirmed by the finding of a "fibroblast-specific" protein FSP-1 in the tubular epithelium, then by the detection of fibroblast-like FSP-1 expressing cells in the proximal tubule by confocal microscopy in a transgenic murine model in which fibrosis has been induced. In the renal graft, EMT markers such as FSP-1 and vimentin, have been detected in tubular epithelium in case of chronic allograft nephropathy, correlatively to the loss of expression of epithelial markers. The expression of EMT markers takes place very early, in the first months post-transplantation, in transplant patients whose renal function is not yet impaired, suggesting the existence of a patho-physiological link between EMT markers expression and graft fibrosis development.

[Delayed graft function]. / Reprise retardée de fonction rénale.

Delayed return to kidney function after transplantation is characterized essentially by acute ischemic tubular necrosis. It remains frequent and has no curative treatment. However, an induction treatment of antilymphocyte serum may reduce the delay in recuperation. In patients with delayed function, the maintenance immunosuppressive treatment should take into account the excessive risk of acute rejection over the short term and the more rapid deterioration of renal function over the long term. This means that biopsies to screen for acute rejection should be done systematically before the end of the 3rd month and anticalcineurin toxicity-sparing treatment should be considered, replacing anticalcineurins immediately with belatacept or after the 3-month acute period with proliferation signal inhibitors, if the kidney histology tests permit. In all cases, the classical measures of kidney protection remain indispensable.

[Massive rhabdomyolysis revealing a McArdle disease]. / Rhabdomyolyse massive révélant une maladie de McArdle.

INTRODUCTION: McArdle's disease is an autosomal recessive glycogenosis caused by deficiency of muscle glycogen phosphorylase resulting in glycogen accumulation in the skeletal muscle. Typically, McArdle's disease is characterized by exercise intolerance with muscle cramps and myoglobinuria. CASE REPORT: We report a 20-year-old woman with massive rhabdomyolysis and acute renal failure revealing a McArdle's disease. DISCUSSION: Although muscle impairment is constant in McArdle's disease, massive rhabdomyolysis with severe acute renal failure has been rarely reported as a presenting feature. The mechanisms and therapeutic implications of renal injury are discussed.