[Epidemiology of acute renal failure]. / Épidémiologie de l'insuffisance rénale aiguë.

The acute renal failure is common in the hospitalized patients with the incidence is increasing. This results from the aging of the population and the widespread use of nephrotoxic therapies or diagnostic techniques. The acute renal failure is associated with an increased length of stay in hospital and the short and long-term mortality. The most common histological injury is the acute tubular necrosis. Although the most of acute renal failure is recovering, recent works have shown that there is a strong association between an acute renal failure and the increased risk of developing a chronic kidney disease.

Predictors of Autogenous Arteriovenous Hemodialysis Access Thrombosis after Renal Transplantation.

BACKGROUND: The fate of autogenous arteriovenous fistula (aAVF) after renal transplantation (RT) remains variable. The aim of this study was to determine the predictors for their thrombosis after RT. METHODS: We conducted a monocentric retrospective review of prospective clinical records of 145 patients with a functional aAVF who had an RT between January 2004 and December 2009 in the University Hospital of Clermont-Ferrand. Our primary end point was the thrombosis of the aAVF. Univariate and multiple logistic regression analyses were used to identify risk factors associated to aAVF thrombosis after RT. RESULTS: There were 105 men (72%) and 40 women (28%), mean age 52 years (range: 18.4-74.7 years). The aAVF was created on average 40 months (range: 2-169) before the RT. The aAVF was distal in 96 cases (66%) and proximal in 49 cases (34%). Nineteen aAVF (13.1%) were complicated and required an endovascular or surgical repair before RT. Forty-nine patients (34%) required multiple aAVF (>2). Mean follow-up from RT was 58 months (range: 1 day-123 months) and from aAVF creation 97 months (range: 5-262 months). At the end of the follow-up, 81 aAVFs (59%) were patent, 42 (29%) were thrombosed, and 22 (15%) were surgically closed. Patients that had multiple fistulas before RT and active smokers were significantly at risk to thrombose their aAVF after the RT in univariate (P = 0.03 and P = 0.02, respectively) and multiple logistic regression analyses (P = 0.03 and P = 0.047, respectively). CONCLUSIONS: Thrombosis is a part of the natural history of the aAVF after RT. A history of multiple aAVF creations before RT and active smoking were associated to significant increased risk for fistula thrombosis. Because hemodialysis may be needed after RT, the aAVF patency should be preserved, excepted when the aAVF resulted in complications. Follow-up of the aAVF after RT is important to detect and treat complications before thrombosis occurs.

Energy expenditure, spontaneous physical activity and with weight gain in kidney transplant recipients.

BACKGROUND & AIMS: Alterations in energy metabolism could trigger weight gain after renal transplantation. METHODS: Nineteen transplanted non-diabetic men, 53 ± 1.6 years old, receiving calcineurin inhibitors but no corticosteroids were studied. They were compared with nine healthy men matched for height, age and lean body mass. Daily energy expenditure and its components (sleeping, basal and absorptive metabolic rates) were analyzed for 24 h in calorimetric chambers and for 4 days in free living conditions using calibrated accelerometry. Other variables known to influence energy expenditure were assessed: body composition, physical activity, 4-day food intake, drug consumption, serum C-reactive protein, interleukin-6, thyroid and parathyroid hormones, and epinephrine. Transplant recipients who gained more than 5% body weight after transplantation (n = 11, +11.0 ± 1.5 kg) were compared with those who did not (n = 8) and with the controls. RESULTS: Weight gain compared with non-weight gain patients and controls exhibited higher fat mass without change in lean body mass. Daily, sleeping and resting energy expenditure adjusted for lean body mass was significantly higher in non-weight gain (167.1 ± 4.2 kJ/kg/lean body mass/24 h, P < 0.05) compared with weight gain patients (147.4 ± 3.6) and controls (146.1 ± 4.6). Weight gain compared with controls and non-weight gain subjects had lower free living physical activity and a higher consumption of antihypertensive drugs and ß-blockers. CONCLUSIONS: After kidney transplantation, weight gain patients were characterized by lower adjusted energy expenditure, reduced spontaneous physical activity but a more sedentary life style and a trend toward a higher energy intake explaining the reason they gained weight. The nWG KTR had increased resting and sleeping EE which protected them from weight gain. Such hypermetabolism was also observed in 24-h EE measurements. By comparison with the nWG patients, the WG transplant recipients were characterized by higher ß-blocker consumption. These data could be helpful in the prevention of weight gain in kidney transplant recipients.

Impact of prior CKD management in a renal care network on early outcomes in incident dialysis patients: a prospective observational study.

BACKGROUND: Effective therapeutic strategies are available to prevent adverse outcomes in patients with chronic kidney disease (CKD) but their clinical results are hindered by unplanned implementation. Coordination of care emerges as a suitable way to improve patient outcomes. In this study, we evaluated the effect of planned and coordinated patient management within a dedicated renal care network comparatively to standard renal care delivered in nephrology departments of teaching hospitals. METHODS: This observational matched cohort study included 40 patients with CKD stage 4-5 in the network group as compared with a control group of 120 patients matched for age, sex and diabetic status. Main outcome was a composite endpoint of death from cardiovascular cause and cardiovascular events during the first year after dialysis initiation. RESULTS: There was no difference between the two groups neither for the primary outcome (40% vs 41%) nor for the occurrence of death from cardiovascular cause or cardiovascular events. Whereas the proportion of patients requiring at least one hospitalization was identical (83.3% vs 75%), network patients experienced less individual hospitalizations than control patients (2.3 ± 2.0 vs 1.6 ± 1.7) during the year before dialysis start. Patients of the network group had a slower renal function decline (7.7 ± 2.5 vs 4.9 ± 1.1 ml/min/1,73 m(2) per year; p=0.04). CONCLUSIONS: In this limited series of patients, we were unable to demonstrate a significant impact of the coordinated renal care provided in the network on early cardiovascular events in incident dialysis patients. However, during the predialysis period, there were less hospitalizations and a slower slope of renal function decrease.

[Renal biopsy practice: results of a French study and recommendations]. / Pratique de la biopsie rénale: résultat d'une enquête en France, revue de la littérature et recommandations.

BACKGROUND: Although several risk factors associated with complications after renal biopsy (RB) have been identified, recommendations for RB procedures are still lacking. Our working group, appointed by the scientific commission of the Société de néphrologie in France, aimed to depict the main aspects of the practice of RB in adults in France, before establishing some guidelines. METHODS: Members of the Société de néphrologie in France were asked to participate to a questionnaire survey on RB procedures. RESULTS: Eighty-eight nephrologists from 74 units (27 in teaching hospitals, 35 in public general hospitals, and 12 in private centers) participated in our study. Native kidney and graft biopsies were performed in 73 and 35 units, respectively. RB activity was highly variable among units, ranging from several hundred to less than ten per year. Transjugular RB was judged to be smoothly accessible in 28 out of 73 units (38.4%). Significant variations in practices were observed regarding patient information before RB, assessment of hemorrhagic risk factors, care of patients with antiplatelet agents and hemorrhagic risk factors, and radiological guidance. Early discharge (<12 hours) was the rule in three (4.1%) units for native kidney biopsies and in ten (28.6%) units for graft biopsies. CONCLUSIONS: Our study is the first to provide a representative picture of "everyday" RB practices in a country. Consensual recommendations on all points mentioned are provided here.

[Acute renal failure in the elderly]. / Insuffisance rénale aiguë du sujet âgé

Acute renal failure in elderly patients is common and likely to become more so as life expectancy in France continues to grow. The chances of acute renal failure occurring in the elderly are increased by changes in renal function and the effects of various chronic diseases such as diabetes, hypertension and obstructive urological disorders, all of which increase in incidence with age. The elderly may develop all types of the disease but are most prone to drug-related acute renal failure. The diagnostic and therapeutic strategies adopted are the same as those for adult patients but should take into account the potential risks and benefits in this specific age group. However, age should no longer be considered as the sole determining factor in diagnostic and therapeutic decisions. The elderly are among those who benefit most from preventive measures against acute renal failure.

INF2 mutations in Charcot-Marie-Tooth disease with glomerulopathy.

BACKGROUND: Charcot-Marie-Tooth neuropathy has been reported to be associated with renal diseases, mostly focal segmental glomerulosclerosis (FSGS). However, the common mechanisms underlying the neuropathy and FSGS remain unknown. Mutations in INF2 were recently identified in patients with autosomal dominant FSGS. INF2 encodes a formin protein that interacts with the Rho-GTPase CDC42 and myelin and lymphocyte protein (MAL) that are implicated in essential steps of myelination and myelin maintenance. We therefore hypothesized that INF2 may be responsible for cases of Charcot-Marie-Tooth neuropathy associated with FSGS. METHODS: We performed direct genotyping of INF2 in 16 index patients with Charcot-Marie-Tooth neuropathy and FSGS who did not have a mutation in PMP22 or MPZ, encoding peripheral myelin protein 22 and myelin protein zero, respectively. Histologic and functional studies were also conducted. RESULTS: We identified nine new heterozygous mutations in 12 of the 16 index patients (75%), all located in exons 2 and 3, encoding the diaphanous-inhibitory domain of INF2. Patients presented with an intermediate form of Charcot-Marie-Tooth neuropathy as well as a glomerulopathy with FSGS on kidney biopsy. Immunohistochemical analysis revealed strong INF2 expression in Schwann-cell cytoplasm and podocytes. Moreover, we demonstrated that INF2 colocalizes and interacts with MAL in Schwann cells. The INF2 mutants perturbed the INF2-MAL-CDC42 pathway, resulting in cytoskeleton disorganization, enhanced INF2 binding to CDC42 and mislocalization of INF2, MAL, and CDC42. CONCLUSIONS: INF2 mutations appear to cause many cases of FSGS-associated Charcot-Marie-Tooth neuropathy, showing that INF2 is involved in a disease affecting both the kidney glomerulus and the peripheral nervous system. These findings provide new insights into the pathophysiological mechanisms linking formin proteins to podocyte and Schwann-cell function. (Funded by the Agence Nationale de la Recherche and others.).

Renal biopsy practice in France: results of a nationwide study.

BACKGROUND: Although several risk factors associated with complications after renal biopsy (RB) have been identified, the gold standard for RB procedures remains to be defined. Practices vary widely among nephrologists, depending on personal experience and the availability of particular techniques. The purpose of our study was to depict the main aspects of the practice of RB in adults in France. METHODS: Members of the Société de Néphrologie in France were asked to participate in a questionnaire survey on RB procedures. RESULTS: Eighty-eight nephrologists from 74 units (27 in teaching hospitals, 35 in public general hospitals and 12 in private centres) participated in our study. Native kidney and graft biopsies were performed in 73 and 35 units, respectively. RB activity was highly variable among units, ranging from several hundred to <10 per year. Transjugular renal biopsy was judged to be smoothly accessible in 28 out of 73 units (38.4%). Significant variations in practices were observed regarding patient information before RB, assessment of haemorrhagic risk factors, management of patients with antiplatelet agents and haemorrhagic risk factors, and radiological guidance. Early discharge (<12 h) was the rule in 3 (4.1%) units for native kidney biopsies and in 10 (28.6%) units for graft biopsies. CONCLUSIONS: Our study is the first to provide a representative picture of 'everyday' RB practices in a country. Important variations in procedures were observed. Our study may represent a preliminary step for the elaboration of guidelines for all aspects of RB practices.

Hemolysis in a patient with alkaptonuria and chronic kidney failure.

In alkaptonuria, the absence of homogentisic acid oxidase results in the accumulation of homogentisic acid (HGA) in the body. Fatal disease cases are infrequent, and death often results from kidney or cardiac complications. We report a 24-year-old alkaptonuric man with severe decreased kidney function who developed fatal metabolic acidosis and intravascular hemolysis. Hemolysis may have been caused by rapid and extensive accumulation of HGA and subsequent accumulation of plasma soluble melanins. Toxic effects of plasma soluble melanins, their intermediates, and reactive oxygen side products are increased when antioxidant mechanisms are overwhelmed. A decrease in serum antioxidative activity has been reported in patients with chronic decreased kidney function. However, despite administration of large doses of an antioxidant agent and ascorbic acid and intensive kidney support, hemolysis and acidosis could not be brought under control and hemolysis led to the death of the patient.