Magnetic Resonance Imaging Assessment of Kidney Oxygenation and Perfusion During Sickle Cell Vaso-occlusive Crises.

BACKGROUND: Our understanding of the pathophysiologic processes underlying sickle cell nephropathy remains incomplete. We performed a pilot study to investigate the potential value of magnetic resonance imaging (MRI) for the assessment of kidney oxygenation and detection of potential changes to tissue perfusion and cellular integrity during a vaso-occlusive crisis. STUDY DESIGN: A case-control study. SETTING & PARTICIPANTS: 10 homozygous patients with sickle cell disease (SCD), without kidney disease (based on estimated glomerular filtration rate and albuminuria), underwent renal MRI during a vaso-occlusive crisis episode. The imaging data obtained were compared with those for a second MRI performed at steady state (median, 56 [IQR, 37-72] days after the vaso-occlusive crisis MRI). The control group consisted of 10 apparently healthy individuals. MEASUREMENTS: Deoxyhemoglobin level assessed by R2* value was calculated using the blood oxygen level-dependent technique. The intravoxel incoherent motion diffusion-weighted imaging technique was used to calculate D, D*, and F parameters. RESULTS: Median medullary R2* values on steady-state MRI were significantly higher for patients with SCD than for controls (P=0.01) and did not change significantly during the vaso-occlusive crisis. No significant differences in median cortical R2* values were observed. Both cellular integrity (D) and local perfusion (D* and F) were significantly altered in medullary and cortical areas during vaso-occlusive crises in comparison to steady state in patients with SCD. These parameters did not differ significantly between patients with SCD assessed at steady state and the control group. LIMITATIONS: Small sample size, estimation of glomerular filtration rate according to CKD-EPI creatinine equation without adjustment for race. CONCLUSIONS: Deoxyhemoglobin levels in the medullary area are higher in patients with SCD, during vaso-occlusive crises and at steady state, than in controls. Alterations to the tissue perfusion and cellular integrity of renal parenchyma are a common finding during vaso-occlusive crises that provide additional evidence that a vaso-occlusive crisis may be associated with subclinical kidney injury detectable on MRI.

[Incidence and management of anemia in renal transplantation: an observational-French study]. / Incidence et prise en charge de l'anémie en transplantation rénale: une étude observationnelle française.

The management of anemia after kidney transplantation remains poorly explored. The Management of Anemia in French Kidney Transplant Patients (MATRIX) study is an observational study conducted in 10 academic hospitals among kidney-transplant patients designed to evaluate the prevalence, associated factors and management of post-transplant anemia. Over two consecutive weeks, 418 recipients (males: 248; age: 50.8+/-12.7 years) were included, all were transplanted for more than six months. Mean serum creatinine (Scr) was 152+/-67 micromol/l and mean hemoglobin (Hb) was 12.4+/-1.8 g/dl (males: 12.8+/-1.9 g/dl; females 11.9+/-1.6 g/dl). Irrespective of the delay following transplantation, 23% of patients (n=95) were severely anemic (Hb < or = 11 g/dl). Eighteen percent of the patients received an antianemic treatment (10% oral iron, 7% erythropoiesis stimulating agents (ESA), 4% folic acid) and only 35% of the severely anemic patients were actually treated (n=33). A significantly-negative correlation was observed between eGFR and Hb levels (R= -0.347, p<0.02). Ninety-six percent of the 193 patients transplanted for more than six months and a Scr greater than 150 micromol/l (n=185) suffered at least one comorbidity (89% hypertension, 32% hypercholesterolemia, 13% diabetes); this group represent the second cohort. Seventy-four percent of them were treated with mycophenolate mofetil, 16% with azathioprine, and 62% with an ACEI or angiotensin II receptor antagonists. Since the transplantation, 127 patients (66%) have been anemic (Hb < or = 11 g/dl) and 58% (n=112) were treated (iron and/or ESA, respectively 81 and 55%). Among the patients not treated for anemia, 74% had an Hb level below 12g/dl. ESA-treated patients received a mean dose of 8500 UI+/-2800 per week. Anemia is under-diagnosed and under-treated in renal-transplant recipients, despite its high prevalence. As expected, a correlation between renal function and Hb levels was observed, as in CKD patients. Prospective studies are underway to assess the consequences of postkidney transplant anemia on quality of life, cardiovascular morbidity and chronic allograft nephropathy and to define the benefit of the treatment.

International Study of Health Care Organization and Financing for end-stage renal disease in France.

The major features of ESRD management in France include the predominance of hemodialysis and the resulting competition for dialysis stations. In 2003, the prevalence of ESRD in France was 0.087%. Of the 52,000 ESRD patients, 30,882 were receiving dialysis and 21,233 had functioning renal transplants. The annual expenditure per ESRD patient in 2003 was estimated at euro40,975. Autodialysis, at euro49,133 per patient per year, was much less expensive than dialyzing in-center at either a public or private facility (euro111,006 and euro75,125, respectively). Transplant activity in France has rapidly increased in recent years, reaching 22 donors per million population in 2005.

[Renal and urinary tract disease national research program]. / Programme national de recherche sur les maladies du rein et des voies urinaires.

The National Institute of Health and Medical Research (Inserm), the Society of Nephrology, and the French Kidney Foundation recognized the need to create a National Research Program for kidney and urinary tract diseases. They organized a conference gathering 80 researchers to discuss the state-of-the art and evaluate the strengths and weaknesses of kidney and urinary tract disease research in France, and to identify research priorities. From these priorities emerged 11 of common interest: 1) conducting epidemiologic studies; 2) conducting large multicenter cohorts of well-phenotyped patients with blood, urine and biopsy biobanks; 3) developing large scale approach: transcriptomics, proteomics, metabolomics; 4) developing human and animal functional imaging techniques; 5) strengthening the expertise in renal pathology and electrophysiology; 6) developing animal models of kidney injury; 7) identifying nontraumatic diagnostic and prognostic biomarkers; 8) increasing research on the fetal programming of adult kidney diseases; 9) encouraging translational research from bench to bedside and to population; 10) creating centers grouping basic and clinical research workforces with critical mass and adequate logistic support; 11) integrating and developing european research programs.