Carlo Alberto Ricciardi

Renal biopsy: Still a landmark for the nephrologist

Renal biopsy was performed for the first time more than one century ago, but its clinical use was routinely introduced in the 1950s. It is still an essential tool for diagnosis and choice of treatment of several primary or secondary kidney diseases. Moreover, it may help to know the expected time of end stage renal disease. The indications are represented by nephritic and/or nephrotic syndrome and rapidly progressive acute renal failure of unknown origin. Nowadays, it is performed mainly by nephrologists and radiologists using a 14-18 gauges needle with automated spring-loaded biopsy device, under real-time ultrasound guidance. Bleeding is the major primary complication that in rare cases may lead to retroperitoneal haemorrhage and need for surgical intervention and/or death. For this reason, careful evaluation of risks and benefits must be taken into account, and all procedures to minimize the risk of complications must be observed. After biopsy, an observation time of 12-24 h is necessary, whilst a prolonged observation may be needed rarely. In some cases it could be safer to use different techniques to reduce the risk of complications, such as laparoscopic or transjugular renal biopsy in patients with coagulopathy or alternative approaches in obese patients. Despite progress in medicine over the years with the introduction of more advanced molecular biology techniques, renal biopsy is still an irreplaceable tool for nephrologists.

Sclerostin levels in uremic patients: a link between bone and vascular disease.

Abstract Sclerostin is a marker of low-turnover bone disease in end stage renal disease patients. The aim of this study was to evaluate serum sclerostin in uremic patients, analyzing its behavior during a single hemodialysis session. Twenty-one adult patients on intermittent hemodialysis treatment were enrolled. Acetate Free Bio-filtration (AFB) was the technique employed. Uremic patients were characterized by higher levels of serum sclerostin when compared with values observed in healthy subjects. Sclerostin assessed in pre-dialysis samples was 1.4 ± 1.02 ng/mL, whereas, in post dialysis samples, a reduction of sclerostin values was observed (0.8 ± 0.6 ng/mL; p: 0.008). Sclerostin correlated with parameters of dialysis adequacy, such as creatinine levels and Kt/V values, and it was significantly associated with atherosclerotic disease. Receiver operating characteristics analysis revealed a good diagnostic profile in identifying atherosclerotic disease. Sclerostin, a full dialyzable substance during AFB dialysis, is closely associated with atherosclerotic disease. Its reduction obtained through AFB could represent a defensive mechanism, improving vascular disease and renal osteodystrophy.

Higher serum sclerostin levels and insufficiency of vitamin D are strongly associated with vertebral fractures in hemodialysis patients: a case control study

SummaryIn hemodialysis patients, vertebral fractures were associated with elevated sclerostin levels, suggesting that sclerostin could reflect bone fragility in these patients.IntroductionFragility fractures are common in hemodialysis patients. The aims of our study were to determine the prevalence of vertebral fracture and analyze associations between sclerostin serum levels and vertebral fractures in hemodialysis patients.MethodsNinety-two hemodialysis patients and 100 controls matched for age and sex were studied. Bone mineral density was measured by ultrasonography at non-dominant heel. The markers of bone turnover included serum osteocalcin, C-terminal telopeptide, and sclerostin. All participants underwent radiography of the thoracic and lumbar spine to ascertain the presence of vertebral fractures.ResultsBone ultrasound parameters at calcaneus were significantly lower in hemodialysis patients compared with controls; bone turnover markers and parathyroid hormone level were significantly higher, while serum of 25-OH-D3 was significantly lower in hemodialysis group. One or more moderate or severe vertebral fractures were found in 38 hemodialysis patients, whereas in control group, 10 patients had a vertebral fracture. In hemodialysis group, the comparison between patients with and without vertebral fractures showed that the patients with vertebral fractures had the serum sclerostin levels statistically higher than patients without vertebral, while serum levels of 25-OH-D3 was significantly lower in patients with vertebral fractures compared to the patients without vertebral fractures. Multivariate analysis disclosed that sclerostin levels were associated with an increased risk of vertebral fractures in hemodialysis patients after adjusting for multiple variables.ConclusionsOur data shows high prevalence of vertebral fractures in hemodialysis patients and that it is associated with elevated sclerostin levels, reflecting bone fragility in these patients.

TO044SOLUBLE NOGO-B AMELIORATES DIABETIC GLOMERULOPATHY

Carlo Alberto Ricciardi, Jiaqi Pan, Ivan Hernandez, Xiaoyan Bai, Kathryn White, Jianting Ke, Maria Flaquer Rife, Anthea Hayward, Fan Fan Hou, David Long, Luigi Gnudi Cardiovascular Division King’s College London London United Kingdom, Electron Microscopy Services Newcastle University Newcastle United Kingdom, Nanfang Hospital Southern Medical University Guangzhou China, 5th Affiliated HospitalNephrology Sun Yat-Sen University Zhuhai China and Institute of Child Health University College London London United Kingdom

Persistent left superior vena cava and partially left inferior vena cava: a case report of a dangerous central venous catheterization

Background The coexistence of a double superior vena cava (SVC) and a partially left inferior vena cava (PLIVC) with a circumaortic collar, associated with other congenital malformations, was not described previously. Case Description We present a 33-year-old woman in hemodialysis with complete exhaustion of the brachial routes for vascular access, admitted to our Nephrology Unit for a long-term central venous catheter (CVC) implant, usually by us performed under EchoScopic Technique (EST), an echographic venipuncture followed by continuous radioscopic control of guidewire and catheter in all the steps of implant. An intraoperative venography showed a complete stop of right internal jugular vein, a right SVC, a persistent left SVC, a left inferior vena cava in the iliac and subrenal tracts, a circumaortic venous collar in the renal tract, and normal right suprarenal and hepatic tracts. Conclusions The double SVC was related to the persistence of the caudal part of the anterior cardinal veins. As to the PLIVC, the iliac and subrenal parts of the inferior vena cava can be related to the persistent left supracardinal vein, while the circumaortic venous collar to the persistent intersupracardinal and left subsupracardinal anastomoses. All invasive procedures, and particularly those potentially complicated, must be performed under EST, now considered a mandatory tool for CVC implants, owing to the hypothesis of possible venous congenital anomalies.

The Myth of Water and Salt: From Aquaretics to Tenapanor

The impact of water intake has been studied in several renal diseases. For example, increasing water intake is useful to prevent primary and secondary nephrolithiasis. In autosomal dominant polycystic kidney disease, arginine vasopressin (AVP) is involved in the progression of the disease, and water intake could play a therapeutic role by inhibiting the synthesis of AVP, but its efficacy is still controversial. Conversely, the use of aquaretics, which are antagonists of AVP V2 receptors, results in the reduction of the increase rate of total kidney volume with a slower decline of glomerular filtration rate. In chronic kidney disease, AVP contributes to glomerular hyperfiltration, arterial hypertension, and synthesis of renin, resulting in renal sclerosis. Increased water intake could reduce AVP activation determining a potential protective effect on the kidney, but its efficacy has not yet been clearly demonstrated. On the other side, sodium and potassium play an important role in the control of arterial blood pressure and are involved in the development and progression of chronic kidney disease. Reduction of sodium intake and increase of potassium intake determine a decrease of arterial blood pressure with a beneficial effect on the kidney; however, adherence to sodium restriction is very poor. Regarding this, sodium-hydrogen exchanger isoform 3 inhibitors may reduce sodium absorption in the gut. The most recent sodium-hydrogen exchanger isoform 3 inhibitor, known as tenapanor, reduces extracellular fluid volume, left ventricular hypertrophy, albuminuria, and blood pressure in experimental studies and increases fecal loss of sodium in humans.