Relationship between renal function and blood pressure dipping status in renal transplant recipients: a longitudinal study.

BACKGROUND: Hypertension (HT) is associated with adverse outcomes in kidney transplant (KTX) recipients. Blunting of physiological decrease in nighttime compared to daytime blood pressure (non-dipping status) is frequent in this setting. However, weather non-dipping is independently associated with renal function decline in KTX patients is unknown. METHODS: We retrospectively screened KTX outpatients attending for a routine ambulatory blood pressure monitoring (ABPM) (T1) at a single tertiary hospital. Patients had two successive follow-up visits, 1 (T2) and 2 (T3) years later respectively. Routine clinical and laboratory data were collected at each visit. Mixed linear regression models were used with estimated glomerular filtration rate (eGFR) as the dependent variable. RESULTS: A total of 123 patients were included with a mean follow-up of 2.12 ± 0.45 years after ABPM. Mean age and eGFR at T1 were 56.0 ± 15.1 and 54.9 ± 20.0 mL/min/1.73m2 respectively. 61 patients (50.4%) had sustained HT and 81 (65.8%) were non-dippers. In multivariate analysis, systolic dipping status was positively associated with eGFR (p = 0.009) and compared to non-dippers, dippers had a 10.4 mL/min/1.73m2 higher eGFR. HT was negatively associated with eGFR (p = 0.003). CONCLUSIONS: We confirm a high prevalence of non-dippers in KTX recipients. We suggest that preserved systolic dipping is associated with improved renal function in this setting independently of potential confounders, including HT and proteinuria. Whether modification of dipping status by chronotherapy would preserve renal function remains to be tested in clinical trials.

[Nephrology : what's new in 2018 ?] / Néphrologie.

Major advances in the treatment of ANCA associated-renal vasculitides, IGA nephropathy and renal autosomal dominant polycystic disease were published within the past year. There is neither clear benefit of early initiation of renal replacement therapy in the intensive care unit nor with the use of chloride-poor solutions to prevent kidney failure. Maintenance parenteral iron supplementation in hemodialysis patients is neither associated with infectious nor cardiovascular risks. Cognitive decline may be more associated with hemodialysis than peritoneal dialysis. In transplantation, the persistence of complement-binding donor-specific antibodies after treatment is predictor of graft loss. Tocilizumab is a promising treatment for chronic antibody-mediated rejection.

Des progrès importants ont été effectués cette année dans le traitement des vascularites rénales à ANCA (anticorps anti-cytoplasme des polynucléaires neutrophiles), de la néphropathie à IgA et de la polykystose rénale. Il n'y a pas d'avantage clair à l'initiation précoce de la dialyse en cas d'insuffisance rénale sévère et à l'utilisation des solutions pauvres en chlore dans le remplissage volémique. En hémodialyse chronique, une supplémentation en fer parentéral jusqu'à 400 mg par mois n'est pas associée à un risque infectieux ou cardiovasculaire augmenté. L'hémodialyse pourrait être associée à un déclin cognitif plus important que la dialyse péritonéale. En transplantation, la persistance d'anticorps dirigés contre le greffon et liant le complément après traitement du rejet, est prédicteur de perte du greffon. Le tocilizumab serait un traitement prometteur du rejet chronique médié par les anticorps.

N-acetylcysteine does not prevent contrast nephropathy in patients with renal impairment undergoing emergency CT: a randomized study.

BACKGROUND: Patients admitted to the emergency room with renal impairment and undergoing a contrast computed tomography (CT) are at high risk of developing contrast nephropathy as emergency precludes sufficient hydration prior to contrast use. The value of an ultra-high dose of intravenous N-acetylcysteine in this setting is unknown. METHODS: From 2008 to 2010, we randomized 120 consecutive patients admitted to the emergency room with an estimated clearance lower than 60 ml/min/1.73 m2 by MDRD (mean GFR 42 ml/min/1.73 m2) to either placebo or 6000 mg N-acetylcysteine iv one hour before contrast CT in addition to iv saline. Serum cystatin C and creatinine were measured one hour prior to and at day 2, 4 and 10 after contrast injection. Nephrotoxicity was defined either as 25% or 44 µmol/l increase in serum creatinine or cystatin C levels compared to baseline values. RESULTS: Contrast nephrotoxicity occurred in 22% of patients who received placebo (13/58) and 27% of patients who received N-acetylcysteine (14/52, p = 0.66). Ultra-high dose intravenous N-acetylcysteine did not alter creatinine or cystatin C levels. No secondary effects were noted within the 2 groups during follow-up. CONCLUSIONS: An ultra-high dose of intravenous N-acetylcysteine is ineffective at preventing nephrotoxicity in patients with renal impairment undergoing emergency contrast CT. TRIAL REGISTRATION: The study was registered as Clinical trial (NCT01467154).

Renin-angiotensin system blockade and contrast-induced renal toxicity.

BACKGROUND: The influence of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) on contrast-induced renal toxicity has been poorly studied. Nevertheless, it is a common practice in many centers to stop these drugs before coronarography. Our goal was to study whether renal function was affected in patients taking ACEIs or ARBs and undergoing a coronary angiogram. METHODS: Patients on ACEIs or ARBs (n=17) and those not on ACEIs or ARBs (n=18) admitted for a coronary angiogram underwent glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) assessment either by isotopic clearances (51Cr-EDTA and MAG3) or inulin and paraimmuno-hippurate clearances 24 hours prior to and immediately after coronary angiogram. RESULTS: Median percentage GFR changes induced by the injection of contrast medium during coronary angiogram were -9% (interquartile range -19% to +3%) in the control group and -1% (interquartile range -9% to +39%) in the ACEI/ARB group. Mean ERPF remained stable after coronarography in the control group (median change -8%; interquartile range -18% to +6%) and increased slightly in the ACEI/ARB group (median change +9%; interquartile range -17% to +60%). The median percentage difference in EPRF change was not statistically significant between the 2 groups (p=0.18). CONCLUSIONS: Inhibition of the renin-angiotensin system is not associated with a decline in renal function in patients receiving contrast media, and there is no need to interrupt this treatment prior to coronary angiogram.