Ifosfamide nephrotoxicity in adult patients.

BACKGROUND: Ifosfamide, a widely prescribed antineoplasic agent, is frequently associated with kidney dysfunction. Its nephrotoxicity is well documented in children, but data are lacking in adult patients. METHODS: The aim of this retrospective study was to describe the clinical, biological and histological characteristics of ifosfamide nephrotoxicity. RESULTS: We report 34 patients (median age: 41 years) admitted in six French nephrology departments for kidney failure and/or tubular dysfunction. Fifteen patients (44.1%) received cisplatin as part of their chemotherapy. In 6 patients (17.7%), ifosfamide nephrotoxicity was revealed by a proximal tubular dysfunction (PTD), in 5 patients (14.4%) by an acute kidney injury (AKI), in 6 patients (17.7%) by a chronic kidney disease (CKD) and in 17 patients (49.7%) by an association of PTD and AKI. Fourteen renal biopsies (41.2%) were performed and revealed acute tubular necrosis (85.7%), vacuolation (78.6%) and nuclear atypias (71.4%) of renal epithelial cells, interstitial inflammation (71.4%) and fibrosis (57.1%). Electron microscopy showed mitochondrial enlargement and dysmorphic changes suggestive of mitochondrial toxicity. Ten patients (29.4%) progressed to Stage 5 CKD, six (17.6%) required haemodialysis and six patients died during a median follow-up period of 31 months. Risk factors for Stage 5 CKD were age and cisplatin co-administration.

Infectious complications of a rituximab-based immunosuppressive regimen in patients with glomerular disease.

BACKGROUND: Recent years have seen increasing use of rituximab (RTX) for various types of primary and secondary glomerulopathies. However, there are no studies that specifically address the risk of infection related to this agent in patients with these conditions. METHODS: We reviewed the outcomes of all patients who received RTX therapy for glomerular disease between June 2000 and October 2011 in eight French nephrology departments. Each case was analysed for survival, cause of death if a non-survivor and/or the presence of infectious complications, including severe or opportunistic infection occurring within the 12 months following RTX infusion. RESULTS: Among 98 patients treated with RTX, 25 presented with at least one infection. We report an infection rate of 21.6 per 100 patient-years. Five patients died within 12 months following an RTX infusion, of whom four also presented with an infection. The median interval between the last RTX infusion and the first infectious episode was 2.1 months (interquartile range 0.5-5.1). Most infections were bacterial (79%) and pneumonia was the most frequent infection reported (27%). The presence of diabetes mellitus (P = 0.006), the cumulative RTX dose (P = 0.01) and the concomitant use of azathioprine (P = 0.03) were identified as independent risk factors. Renal failure was significantly associated with an increased infection risk by bivariate analysis (P = 0.03) and was almost significant by multivariate analysis (P = 0.05). Nephrotic syndrome did not further increase the risk of infection and/or death. CONCLUSION: The risk of infection after RTX-based immunosuppression among patients with glomerulopathy must be considered and patients should receive close monitoring and appropriate infection prophylaxis, especially in those with diabetes and high-dose RTX regimens.

Detection of Drug-Drug Interactions Inducing Acute Kidney Injury by Electronic Health Records Mining.

BACKGROUND AND OBJECTIVE: While risk of acute kidney injury (AKI) is a well documented adverse effect of some drugs, few studies have assessed the relationship between drug-drug interactions (DDIs) and AKI. Our objective was to develop an algorithm capable of detecting potential signals on this relationship by retrospectively mining data from electronic health records. MATERIAL AND METHODS: Data were extracted from the clinical data warehouse (CDW) of the Hôpital Européen Georges Pompidou (HEGP). AKI was defined as the first level of the RIFLE criteria, that is, an increase ≥50 % of creatinine basis. Algorithm accuracy was tested on 20 single drugs, 10 nephrotoxic and 10 non-nephrotoxic. We then tested 45 pairs of non-nephrotoxic drugs, among the most prescribed at our hospital and representing distinct pharmacological classes for DDIs. RESULTS: Sensitivity and specificity were 50 % [95 % confidence interval (CI) 23.66-76.34] and 90 % (95 % CI 59.58-98.21), respectively, for single drugs. Our algorithm confirmed a previously identified signal concerning clarithromycin and calcium-channel blockers (unadjusted odds ratio (ORu) 2.92; 95 % CI 1.11-7.69, p = 0.04). Among the 45 drug pairs investigated, we identified a signal concerning 55 patients in association with bromazepam and hydroxyzine (ORu 1.66; 95 % CI 1.23-2.23). This signal was not confirmed after a chart review. Even so, AKI and co-prescription were confirmed for 96 % (95 % CI 88-99) and 88 % (95 % CI 76-94) of these patients, respectively. CONCLUSION: Data mining techniques on CDW can foster the detection of adverse drug reactions when drugs are used alone or in combination.

Glycated Hemoglobin Level and Mortality in a Nondiabetic Population with CKD.

BACKGROUND AND OBJECTIVES: Glycated hemoglobin (HbA1c) is used to diagnose diabetes mellitus (DM) and guide its management. The association between higher HbA1c and progression to ESRD and mortality has been demonstrated in populations with DM. This study examined the association between HbA1c and these end points in a population with CKD and without DM. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In the hospital-based NephroTest cohort study, measured GFR (mGFR) was taken by (51)Cr-EDTA renal clearance and HbA1c in 1165 adults with nondialysis CKD stages 1-5 and without DM between January 2000 and December 2010. The median follow-up was 3.48 years (interquartile range, 1.94-5.82) for the competing events of ESRD and pre-ESRD mortality. Time-fixed and time-dependent Cox models were used to estimate hazard ratios (HRs) for ESRD and mortality according to HbA1c, treated continuously or in tertiles. RESULTS: At inclusion, the mean mGFR was 42.2±19.9 ml/min per 1.73 m(2), and the mean HbA1c value was 5.5%±0.5%. During follow-up, 109 patients died, and 162 patients reached ESRD. Pre-ESRD mortality was significantly associated with HbA1c treated continuously: for every 1% higher HbA1c, the crude HR was 2.16 (95% confidence interval [95% CI], 1.27 to 3.68), and it was 1.85 (95% CI, 1.05 to 3.24) after adjustment for mGFR and other risk factors of death. After excluding incident diabetes over time, the updated mean of HbA1c remained significantly associated with higher mortality risk: adjusted HR for the highest (5.7%-6.4%) versus the lowest tertile (<5.3%) was 2.62 (95% CI, 1.16 to 5.91). There was no association with ESRD risk after adjustment for risk factors of CKD progression. CONCLUSIONS: In a CKD cohort, HbA1c values in the prediabetes range are associated with mortality. Such values should be therefore included among the risk factors for negative outcomes in CKD populations.

The consequences of sudden fluid shifts on body composition in critically ill patients.

INTRODUCTION: Estimation of body composition as fat-free mass (FFM) is subjected to many variations caused by injury and stress conditions in the intensive care unit (ICU). Body cell mass (BCM), the metabolically active part of FFM, is reported to be more specifically correlated to changes in nutritional status. Bedside estimation of BCM could help to provide more valuable markers of nutritional status and may promote understanding of metabolic consequences of energy deficit in the ICU patients. We aimed to quantify BCM, water compartments and FFM by methods usable at the bedside for evaluating the impact of sudden and massive fluid shifts on body composition in ICU patients. METHODS: We conducted a prospective experimental study over an 6 month-period in a 18-bed ICU. Body composition of 31 consecutive hemodynamically stable patients requiring acute renal replacement therapy for fluid overload (ultrafiltration ≥5% body weight) was investigated before and after the hemodialysis session. Intra-(ICW) and extracellular (ECW) water volumes were calculated from the raw values of the low- and high-frequency resistances measured by multi-frequency bioelectrical impedance. BCM was assessed by a calculated method recently developed for ICU patients. FFM was derived from BCM and ECW. RESULTS: Intradialytic weight loss was 3.8 ± 0.8 kg. Percentage changes of ECW (-7.99 ± 4.60%) and of ICW (-7.63 ± 5.11%) were similar, resulting ECW/ICW ratio constant (1.26 ± 0.20). The fall of FFM (-2.24 ± 1.56 kg, -4.43 ± 2.65%) was less pronounced than the decrease of ECW (P < 0.001) or ICW (P < 0.001). Intradialytic variation of BCM was clinically negligible (-0.38 ± 0.93 kg, -1.56 ± 3.94%) and was significantly less than FFM (P < 0.001). CONCLUSIONS: BCM estimation is less driven by sudden massive fluid shifts than FMM. Assessment of BCM should be preferred to FFM when severe hydration disturbances are present in ICU patients.

Discoidin domain receptor 1 is a major mediator of inflammation and fibrosis in obstructive nephropathy.

The interactions between tubulointerstitial infiltrating cells and the extracellular matrix play an important role in regulating renal fibrosis. Discoidin domain receptor 1 (DDR1) is a nonintegrin tyrosine kinase receptor for collagen implicated in cell adhesion, proliferation, and extracellular matrix remodeling. We have previously demonstrated that transgenic mice lacking DDR1 are protected from hypertension-associated renal fibrosis. The purpose of this study was to determine the role of DDR1 in renal inflammation and fibrosis related to primitive tubulointerstitial injury. After 12 days of unilateral ureteral obstruction (UUO), kidney histopathologic and real-time quantitative PCR analyses were performed in DDR1(-/-) and wild-type mice. DDR1 expression was strongly increased in the obstructed kidney. Wild-type mice developed important perivascular and interstitial inflammation and fibrosis. In comparison, DDR1(-/-) mice displayed reduced accumulation of fibrillar collagen and transforming growth factor ß expression. F4/80(+) cell count and proinflammatory cytokines were remarkably blunted in DDR1(-/-) obstructed kidneys. Leukocyte rolling and adhesion evaluated by intravital microscopy were not different between DDR1(-/-) and wild-type mice. Importantly, macrophages isolated from DDR1(-/-) mice presented similar M1/M2 polarization but displayed impaired migration in response to monocyte chemoattractant protein-1. Together, these data suggest that DDR1 plays an important role in the pathogenesis of renal disease via enhanced inflammation. Inhibition of DDR1 expression or activity may represent a novel therapeutic target against the progression of renal diseases.