[Hyperthyroidism-induced calciphylaxis: A case report]. / Calciphylaxie dans un contexte de maladie de Basedow : à propos d'un cas.

BACKGROUND: Calciphylaxis or calcific uremic arteriolopathy (CUA) is a cutaneous disease with ulcerations secondary to calcification of cutaneous and subcutaneous small arteries and arterioles. It is a rare but severe disease with significant morbidity and mortality affecting 1 to 4% of dialysis patients. The circumstances of occurrence are multiple. CASE: We report the case of a severe bilateral lower limb calciphylaxis in a 69-year-old, obese, hemodialysis patient with a recent diagnosis of Graves' disease complicated with hypercalcemia and cardiac arrhythmia requiring the use of vitamin K antagonist. Complex and multidisciplinary therapeutic management (daily hemodialysis, sodium thiosulfate therapy, treatment of hypercalcemia by denosumab, hyperbaric oxygen therapy, meshed skin autograft) allowed complete healing of the lesions. CONCLUSION: This is the first description of AUC secondary to hyperthyroidism in a dialysis patient. Multidisciplinary care is essential to achieve clinical improvement in those critical situations.

Iron deficiency: an emerging therapeutic target in heart failure.

In patients with heart failure, iron deficiency is frequent but overlooked, with a prevalence of 30%-50%. Since it contributes to cardiac and peripheral muscle dysfunction, iron deficiency is associated with poorer clinical outcomes and a greater risk of death, independent of haemoglobin level. Therefore, iron deficiency emerges as a new comorbidity and a therapeutic target of chronic heart failure in addition to chronic renal insufficiency, anaemia and diabetes. In a series of placebo-controlled, randomised studies in patients with heart failure and iron deficiency, intravenous iron had a favourable effect on exercise capacity, functional class, LVEF, renal function and quality of life. These clinical studies were performed in the context of a renewed interest in iron metabolism. During the past 10 years, knowledge about the transport, storage and homeostasis of iron has improved dramatically, and new molecules involved in iron metabolism have been described (eg, hepcidin, ferroportin, divalent metal transporter 1). Recent European guidelines recommend the monitoring of iron parameters (ie, serum ferritin, transferrin saturation) for all patients with heart failure. Ongoing clinical trials will explore the benefits of iron deficiency correction on various heart failure parameters.

L-carnitine treatment in incident hemodialysis patients: the multicenter, randomized, double-blinded, placebo-controlled CARNIDIAL trial.

BACKGROUND: L-carnitine levels decrease rapidly and steadily with duration of hemodialysis, and carnitine depletion can impair response to recombinant human erythropoietin (rHuEPO). The study hypothesis was that L-carnitine supplementation during the first year of hemodialysis would improve this response. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: From October 2006 through March 2010, this multicenter, randomized, double-blinded study assigned 92 incident hemodialysis patients to receive placebo or 1 g of intravenous L-carnitine after each dialysis session for 1 year. The primary outcome measure compared the groups for rHuEPO resistance index (EPO-RI), defined as weekly rHuEPO doses (IU/kg body weight divided by hemoglobin level) (g/dl). RESULTS: In the L-carnitine group, carnitine concentration increased from a mean ± SD of 79 ± 51 µmol/L to 258 ± 137 µmol/L; in the placebo group, it declined from 68 ± 25 µmol/L to 53 ± 24 µmol/L (interaction group × time, P<0.001). Carnitine deficiency affected about 30% of the patients in the placebo group during the study period. EPO-RI varied from 15.8 ± 11.3 to 9.5 ± 5.8 IU/kg per g/dl in the placebo group and from 20.6 ± 12.8 to 15.6 ± 15.9 IU/kg per g/dl in the L-carnitine group, for a mean variation of -3.94 ± 12.5 IU/kg per g/dl and -2.98 ± 15.5 IU/kg per g/dl, respectively (P=0.7). After adjustment for baseline characteristics, the EPO-RI course was similar in each group (difference between groups, P=0.10; interaction group × time, P=0.9). CONCLUSIONS: Carnitine levels decrease by about 11% ± 33% during the first year of hemodialysis. Treatment of incident hemodialysis patients with L-carnitine does not improve their response to rHuEPO.

Isonatric dialysis biofeedback in hemodiafiltration with online regeneration of ultrafiltrate (HFR): rationale and study protocol for a randomized controlled study.

Dialysate sodium prescription has major implications for hemodialysis tolerance but also for dialyzed patients' cardiovascular morbidity as a determinant factor of blood pressure. Biofeedback systems have been developed to drive dialysate conductivity in order to reach a prescribed serum sodium concentration, indirectly evaluated by a dialysate or an ultrafiltrate conductivity measurement. A biofeedback system using hemodiafiltration with online regeneration of ultrafiltrate (HFR) has been specially developed with an isonatric mode maintaining an equal serum sodium concentration between start and end of the dialysis session, combined with ultrafiltration and conductivity profiles. We hypothesized that using this biofeedback in an isonatric mode would have a beneficial effect on blood pressure and dialysis tolerance. The study protocol has been approved by our ethics committee and is presented herein.

[Renal physiology]. / Physiologie rénale.

The kidneys are responsible for the urinary excretion of uremic toxins and the regulation of several body systems such as intra and extracellular volume status, acid-base status, calcium and phosphate metabolism or erythropoiesis. They adapt quantitative and qualitative composition of the urine to keep these systems in balance. The flow of plasma is filtered in the range of 120 mL/min, and depends on the systemic and renal hemodynamics which is subject to self-regulation. The original urine will then be modified in successive segments of the nephron. The proximal nephron is to lead the massive reabsorption of water and essential elements such as sodium, bicarbonates, amino-acids and glucose. The distal nephron includes the distal convoluted tubule, the connector tube and the collecting duct. Its role is to adapt the quality composition of urine to the needs of the body.

Evolution of renal function in patients treated with antiangiogenics after nephrectomy for renal cell carcinoma.

PURPOSE: Side effects of antiangiogenic agents are moderate compared with other therapies. The most frequent adverse events are of a renovascular origin and manifest as hypertension (HTN) and thrombotic microangiopathy. To date, data are scanty on the renal tolerance of such drugs regarding renal function as itself, i.e., glomerular filtration rate (GFR). We report on the evolution of GFR in patients receiving antiangiogenic therapy after unilateral nephrectomy for kidney cancer. PATIENTS AND METHODS: Data from 73 patients followed in our oncology department for kidney cancer, who had undergone unilateral nephrectomy, and received any antiangiogenic therapy were reviewed. Their GFR was calculated using the aMDRD formula. RESULTS: All patients showed a declining renal function over time (-1.23 and -2.51 mL/min/1.73 m(2) using the slope of the curve or the difference between GFR at baseline and that at the end of treatment, respectively). Among them, patients who were recorded as having HTN before initiation of antiangiogenic therapy showed a higher decrease in their GFR of -13.28 and -12.06 mL/min/1.73 m(2). CONCLUSION: We recommend that blood pressure should be measured closely in those patients before initiation of antiangiogenic therapy. When HTN is diagnosed, it should be treated and renal function should be monitored since those patients may be at risk for rapidly decreasing renal function under therapy.

[Vascular and renal effects of anti-angiogenic therapy]. / Effets vasculaires et rénaux des médicaments anti-angiogéniques: recommandations françaises pour la pratique (SN, SFHTA, APNET, FFCD).

Angiogenesis inhibitor drugs (bevacizumab, sunitinib, sorafénib...) are now widely used for treatment of cancers, including colorectal, advanced renal cell and hepatocellular carcinomas, breast cancer). Vascular and renal side-effects of these drugs are not well known. Hypertension is one of the most common side effects. Incidence of hypertension may be different among angiogenis inhibitors and seems dose-depend. Arterial pressure can usually be controlled with anti-hypertensive medications, and treatment with angiogenesis inhibitors can be continued in most cases; however, serious hypertension-induced side effects were reported included malignant hypertension, stroke and reversible posterior leucoencephalopathy. Renal damage is infrequently reported: usually reversible mild or moderate proteinuria and in some rare cases nephritic syndrome, acute renal dysfunction, proliferative or collapsing glomerulonephritis, interstitial nephritis and thrombotic microangiopathy. Prolongation of the QT interval, congestive heart failure and left ventricular dysfunction have been reported in patients using tinibs. In the present guidelines, we recommend: (1) before the first administration of angiogenesis inhibitors: acute IV or oral antihypertensive medications should not be administered in a patient regardless of arterial pressure levels with postponing the administration because of hypertension is not recommended; (2) initial work-up should include ambulatory measurement of arterial pressure (by the general practitioner or by the patient using home blood pressure (three times in the morning and in the evening during three consecutive days) with a validated (cf: http://afssaps.sante.fr/) upper arm device: ideally, this device should be financed and provided by the pharmaceutical companies marketing the angiogenesis inhibitor drugs. Using 24-hour ambulatory blood pressure measurement is optional; (3) urine dipstick (and quantification if positive) and estimated glomerular filtration rate (using abbreviated MDRD rather than Cockcroft-Gault formula) must be performed before treatment and regularly during follow-up; (4) therapeutic management must be done in accordance with national or international guidelines (in France: http://www.has-sante.fr/); (5) optimal care is best achieved within a network of professionals including general practitioners, oncologists, cardiologists and nephrologists.

[Is dialysis efficient in the prevention of ionic contrast agent-induced nephropathy?]. / Néphropathie induite par les produits de contraste iodés, l'epuration extrarénale est-elle efficace en prévention?

UNLABELLED: A FREQUENT AND EXPENSIVE PROBLEM: Ninety percent of contrast media nephrotoxicity (CMN) occur in patients with pre-existing kidney failure. Its aggravation may require early chronic dialysis. PREVENTIVE MEASURES: CMN prophylaxis is important in these patients. Pre- and post-hydration, with infusion of isotonic saline solution or sodium bicarbonate, and reduction of contrast medium (CM) volume to the strict minimum are essential for preventing CM-induced kidney failure. THE INTEREST OF PROPHYLACTIC HEMODIALYSIS AND HEMOFILTRATION: An interesting approach in preventing CMN is the early elimination of the CM with dialysis techniques. Preventive hemodialysis does not reduce the risk of CMN, but hemofiltration has shown significant efficacy in a population of patients with kidney failure. THE INTEREST OF IMMEDIATE HEMODIALYSIS IN CHRONIC HEMODIALYSIS PATIENTS: Although nephrotoxicity is no longer a problem in patients undergoing chronic hemodialysis, CM, especially in high-dose injections, may be responsible for fluid and electrolyte abnormalities and/or volemic expansion. No data yet justify a conclusion that a hemodialysis session immediately after injection of a CM in chronic dialysis patients might be helpful.

Renal safety of adefovir dipivoxil in patients with chronic hepatitis B: two double-blind, randomized, placebo-controlled studies.

BACKGROUND: The incidence of adefovir dipivoxil (ADV) nephrotoxicity has been previously reported with the 60 and 120 mg daily dose in human immunodeficiency virus (HIV). We report a complete analysis on the renal tolerance of ADV at the currently approved dose of 10 mg daily for the treatment of chronic hepatitis B. METHODS: To investigate the efficacy, safety, and the tolerability of two dosing regimens of ADV (10 mg daily or 30 mg daily), two double-blind, placebo-controlled studies were performed in patients with chronic hepatitis B and compensated liver disease who were not undergoing current treatment and who had evidence of hepatitis B virus (HBV) replication. RESULTS: There was no overall median change from baseline at week 48 in serum creatinine or serum phosphorus levels in the ADV 10 mg group. In the ADV 30 mg group there was a slight increase of 0.2 mg/dL in median serum creatinine levels, and decrease of 0.1 mg/dL in serum phosphorus levels at week 48. Serum creatinine increase and hypophosphatemia were more frequently observed in patients receiving ADV 30 mg daily compared with ADV 10 mg and placebo. There were no grade 4 proteinuria, hematuria, or glycosuria events. CONCLUSION: Mild nephrotoxicity was demonstrated with the dose of 30 mg daily. Nephrotoxicity, as defined by an increase >/=0.5 mg/dL from baseline in serum creatinine or a serum phosphorus value of <1.5 mg/dL on two consecutive occasions, was not observed in patients treated with ADV 10 mg for a median follow-up period of approximately 64 weeks.

Herbs and the kidney.

The use of herbal therapy has increased dramatically in past years and may lead to renal injury or various toxic insults, especially in renal patients. In most countries, herbal products are not regulated as medicines. Herbal poisoning may be secondary to the presence of undisclosed drugs or heavy metals, interaction with the pharmacokinetic profile of concomitantly administered drugs, or association with a misidentified herbal species. Various renal syndromes were reported after the use of medicinal plants, including tubular necrosis, acute interstitial nephritis, Fanconi's syndrome, hypokalemia or hyperkalemia, hypertension, papillary necrosis, chronic interstitial nephritis, nephrolithiasis, urinary retention, and cancer of the urinary tract. It seems critical that caregivers be aware of the potential risk of such often underreported therapy and carefully question their patients about their use of this popular branch of alternative medicine.