Yuk Lun Cheng

Increasing home based dialysis therapies to tackle dialysis burden around the world: a position statement on dialysis economics from the 2nd Congress of the International Society for Hemodialysis

PHILIP KAM-TAO LI, WAI LUN CHEUNG, SING LEUNG LUI, CHRISTOPHER BLAGG, ALAN CASS, LAI SEONG HOOI, HO YUNG LEE, FRANCESCO LOCATELLI, TAO WANG, CHIH-WEI YANG, BERNARD CANAUD, YUK LUN CHENG, HUI LIN CHOONG, ANGEL L DE FRANCISCO, VICTOR GURA, KAZO KAIZU, PETER G KERR, UN I KUOK, CHI BON LEUNG, WAI-KEI LO, MADHUKAR MISRA, CHEUK CHUN SZETO, KWOK LUNG TONG, KRIANG TUNGSANGA, ROBERT WALKER, ANDREW KUI-MAN WONG, ALEX WAI-YIN YU, on behalf of the participants of THE ROUNDTABLE DISCUSSION ON DIALYSIS ECONOMICS in the SECOND CONGRESS OF THE INTERNATIONAL SOCIETY FOR HEMODIALYSIS (ISHD 2009)*

Phosphorus-Enriched Hemodialysates: Formulations and Clinical Use

Although hyperphosphatemia is a cardinal feature of renal failure, the occasional patient suffering from end‐stage renal disease (ESRD) may present with hypophosphatemia. For example, hypophosphatemia can develop in ESRD patients if they suffer from malnutrition or if they are aggressively dialyzed. Hypophosphatemia is commonly prevented or treated with the oral or the intravenous administration of soluble phosphate salts; however, determination of the required oral or intravenous dose is difficult. Under appropriate circumstances, phosphorus‐enriched dialysates can also be employed for the purpose of phosphorus administration. Various preparations of soluble phosphate salts can be used to enrich hemodialysates.

Effect of membrane permeability on inflammation and arterial stiffness: a randomized trial.

BACKGROUND AND OBJECTIVES Both larger molecule removal and dialyzer biocompatibility have been implicated in the high-flux hemodialysis (HD)-associated favorable outcome. In an attempt to delineate the effect of membrane permeability, we performed a randomized, crossover study to compare the inflammatory biomarkers, lipid profile, and aortic pulse wave velocity (PWV) of two dialyzers that are composed of identical membranes but with different flux characteristics. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Stable patients who had anuria and were on low-flux polysulfone membrane were randomly allocated either to HD with high-flux polyamide membrane (group A; 22 patients) or to HD with low-flux polyamide membrane (group B; 24 patients) for 24 weeks, then they were started on 24 weeks of the alternative HD treatment. Apart from the dialyzer, the dialysis prescription remained unchanged. RESULTS Nineteen patients from group A and 23 patients from group B completed the study. Predialysis beta(2)-microglobulin levels decreased significantly when using the high-flux polyamide membrane. No difference between membranes was observed for serum albumin, high-sensitivity C-reactive protein, fibrinogen, IL-6, triglycerides, HDL cholesterol, LDL cholesterol, and lipoprotein(a) during the study. A significant increase in aortic PWV, a marker of aortic stiffness, was noted after patients switched from high-flux to low-flux polyamide membranes. Similarly, the rate of change in aortic PWV was significantly decreased with the use of the high-flux polyamide membrane. CONCLUSIONS Our findings suggest that dialysis with polyamide membranes with different flux characteristics did not modify the inflammatory indices and lipid profile in stable HD patients; however, a seemingly beneficial effect on aortic stiffness was noted for patients who were maintained on high-flux polyamide membrane.

Gonadal Mosaicism of Frasier Syndrome in 3 Chinese Siblings with Donor Splice Site Mutation of Wilms’ Tumour Gene

Frasier syndrome is a rare human developmental disorder classically affecting 46,XY females and leading to male pseudohermaphroditism and chronic renal failure. We describe a family with both 46,XX and 46,XY females affected by the syndrome due to WT1 splice site mutations. The diagnosis of Frasier syndrome in 1 of the children led to the discovery of the syndrome in 2 other siblings, of whom 1 is asymptomatic. Since the mutation was not found in either parents, gonadal mosaicism was suggested. The implication of family screening for WT1 gene mutation in asymptomatic members is also discussed.

Increasing home-based dialysis therapies to tackle dialysis burden around the world: A position statement on dialysis economics from the 2nd Congress of the International Society for Hemodialysis.

Philip Kam-Tao LI, Wai Lun CHEUNG, Sing Leung LUI, Christopher BLAGG, Alan CASS, Lai Seong HOOI, Ho Yung LEE, Francesco LOCATELLI, Tao WANG, Chih-Wei YANG, Bernard CANAUD, Yuk Lun CHENG, Hui Lin CHOONG, Angel L. de FRANCISCO, Victor GURA, Kazo KAIZU, Peter G. KERR, Un I. KUOK, Chi Bon LEUNG, Wai-Kei LO, Madhukar MISRA, Cheuk Chun SZETO, Kwok Lung TONG, Kriang TUNGSANGA, Robert WALKER, Andrew Kui-Man WONG, Alex Wai-Yin YU, On Behalf of the participants of the Roundtable Discussion on Dialysis Economics in the 2nd Congress of the International Society for Hemodialysis held in Hong Kong in August 2009

Hepatocellular carcinoma after kidney transplantation: analysis of Hong Kong Renal Registry

Abstract Kidney transplant recipients have increased risk of cancers when compared with the general population. Hepatocellular carcinoma (HCC) is extremely important in Asia where hepatitis B virus (HBV) infection is endemic. The aim is to study the epidemiological and clinical aspects of all de novo HCC in our kidney transplant recipients. Moreover, various preventive strategies which may help to optimize the outcome will also be discussed. A retrospective review of all patients who developed HCC after kidney transplantation between May 1972 and December 2011 in Hong Kong, based on the data from Hong Kong Renal Registry. After a follow-up period of 40,246 person-years, 20 patients (males 15: females 5) developed HCC. The annual incidence was 49.7/100,000 persons per year. Among them, 16 were HBV carriers, 2 were hepatitis C (HCV) carriers and 2 had HBV and HCV co-infection. Presence of HBV infection was associated with 78-fold higher risk for HCC development. Majority (85%) were asymptomatic when HCC was diagnosed by ultrasound or alpha-fetoprotein surveillance. All patients diagnosed by surveillance received active treatment while 2/3 of symptomatic patients could only receive symptomatic care and died rapidly. In conclusion, HBV infection is the major etiological factor for HCC development in kidney transplant recipients in HBV endemic areas. Regular HCC surveillance appeared to be able to detect early stage cancers which are amenable to treatment and offer the best hope of cure.

Severe acute respiratory syndrome in haemodialysis patients: a report of two cases

In March 2003, an outbreak of severe acute respiratory syndrome (SARS) occurred in Hong Kong. As of July 10, 2003, the World Health Organization has reported 1755 cases of SARS in Hong Kong and 8437 cases worldwide [1]. Outbreaks and case clusters have been reported in the literature in recentmonths [2–5]. The first known case of SARS in Hong Kong was a physician working in a hospital in Guangdong Province who travelled to Hong Kong on February 21, 2003 [3]. A novel coronavirus has been identified as a possible cause of SARS [6,7]. SARS can occur in both healthy individuals and those with chronic illness including endstage renal failure. Clinical information of SARS on renal dialysis patients is lacking. We describe here two end-stage renal failure patients, both receiving chronic haemodialysis, who acquired the disease after contact with SARS patients and had different outcomes.

Preparation of a Phosphorus-Enriched Hemodialysate Using an ‘Acid Concentrate’ Soluti on and a Sodium Bicarbonate Powder

This article is also accessible online at: http://BioMedNet.com/karger Dear Sir, Enrichment of the ‘acid concentrate’ of a dual-concentrate, bicarbonate-buffered hemodialysate generating system has been described previously [1, 2]. However, the enrichment in that instance involved the variety of generating system championed by Sargent et al. [3] in which the liquid ‘acid concentrate’ was diluted 1:35.83. In the present study, we determined the feasibility of enriching with phosphorus the ‘acid concentrate’ of another type of dual-concentrate, bicarbonate-buffered dialysate generating system (Gambro Healthcare®, Lakewood, Colo., USA) pioneered by Delin et al. [4] in which the liquid ‘acid concentrate’ was diluted 1:44. This concentrate had a pH in the neighborhood of 2.5 and contained (in mmol/l): 4,496 sodium chloride, 90 potassium chloride, 67 calcium chloride, 17 magnesium chloride, 180 acetic acid, and 500 D-glucose [5]. In order to produce a phosphorus-enriched dialysate using the above Gambro Healthcare dual-concentrate system, 54 or 108 ml of a Phospho-soda®-buffered saline laxative containing 4.15 mmol/ml of phosphorus and 4.82 mmol/ml of sodium [6] (obtained from C.B. Fleet Co., Inc., Lynchburg, Va., USA) was added to 3.78 liters of the system’s ‘acid concentrate’. The phosphorus level achieved in these modified ‘acid concentrates’ amounted to 58.5 or 117 mmol/l, respectively. After the addition of phosphorus, the resultant mixture was vigorously shaken to ensure thorough mixing. No precipitation of insoluble divalent cation salts was evident in either of these phosphorusenriched ‘acid concentrates’. With the aid of a conventional Centry 3® dual-concentrate dialysis machine (Gambro Healthcare), each of the above modified ‘acid concentrates’ and the accompanying ‘sodium bicarbonate concentrate’ powder (BiCart® column, Gambro Healthcare) were used to produce a final dialysate. The final dialysate so produced contained (in mmol/l): sodium 140.5 (or 142), potassium 2, calcium 1.5, magnesium 0.38, bicarbonate 35, chloride 106, acetate 4, glucose 11, and phosphorus 1.3 (or 2.6) [i.e., 4 (or 8) mg/dl]. No precipitation of insoluble divalent cation salts was noted in the final dialysate. The final dialysate enriched with 1.3 mmol/l phosphorus in the above manner was used to dialyze 6 hypophosphatemic maintenance hemodialysis patients for 3.5– 4 h using Hemophan® dialyzers (model 500HG, Gambro Healthcare), modified cellulose dialyzers having an in vitro phosphorus clearance of 172 ml/min (at a dialyzer blood flow of 300 ml/min). The dialyzer blood flow was maintained at 300 ml/min and the dialysate flow rate at 500 ml/min. The resultant changes in plasma chemistry previously described [7] are depicted in table 1. It can be seen that it is feasible to raise the plasma phosphorus levels in hypophosphatemic hemodialysis patients by dialysis against a phosphorus-enriched dialysate using the Gambro Healthcare system of generating bicarbonate-buffered dialysates. The ability of the divalent cations and the phosphate ions to remain in solution in the phosphorus-enriched ‘acid concentrates’ of the present study is related to the high acidity of the concentrates; as a result, the solubility product constants of these ions are not exceeded.

Relatives in silent kidney disease screening (RISKS) study: A Chinese cohort study

Family members of patients with end‐stage renal disease (ESRD) have higher risk for chronic kidney disease (CKD). Limited study has examined the risk of developing CKD in relatives of patients in earlier stages of CKD.

Hong Kong study using valsartan in IgA nephropathy (HKVIN): a double-blind randomized placebo-controlled study

BACKGROUND Previous studies showed that angiotensin-receptor blocker (ARB) therapy decreased proteinuria and possibly slowed the rate of renal function decline in patients with chronic proteinuric nephropathies. We performed a double-blind, randomized, placebo-controlled, multicenter study on the ARB valsartan in the treatment of patients with immunoglobulin A (IgA) nephropathy. METHODS From 6 centers, we recruited 109 patients with IgA nephropathy who had either: (1) proteinuria with protein greater than 1 g/d and serum creatinine level less than 2.8 mg/dL (< 250 micromol/L), or (2) serum creatinine level of 1.4 to 2.8 mg/dL (120 to 250 micromol/L) regardless of degree of proteinuria. Patients were randomly assigned to administration of either valsartan, 80 mg/d (titrated up to 160 mg/d for blood pressure control), or placebo for 104 weeks. Additional antihypertensive therapy was allowed to achieve a target blood pressure of 140/90 mm Hg. The primary end point was doubling of serum creatinine level or dialysis-dependent renal failure. Secondary outcomes included change in proteinuria and decrease in glomerular filtration rate (GFR). RESULTS There were 54 patients in the treatment group and 55 patients in the placebo group. Baseline clinical characteristics were similar between groups, although the treatment group had a marginally greater baseline GFR (87 +/- 36 versus 78 +/- 38 mL/min/1.73 m2 [1.45 +/- 0.60 versus 1.30 +/- 0.63 mL/s/1.73 m2];P = 0.29) and less proteinuria (protein, 1.8 +/- 1.2 versus 2.3 +/- 1.7 g/d; P = 0.21) than the placebo group. Average blood pressures during the study were 92.7 +/- 10.6 mm Hg in the treatment group and 100.9 +/- 9.1 mm Hg in the placebo group (P < 0.001). During the study period, 4 patients in the placebo group and 1 patient in the treatment group reached the primary end point (log-rank test, P = 0.18). Proteinuria decreased significantly in the treatment group (protein, 1.8 +/- 1.2 to 1.2 +/- 1.2 g/d; P = 0.03), but did not change in the placebo group. With multiple linear regression models, valsartan treatment resulted in a 33.0% decrease in proteinuria (95% confidence interval, 10.9 to 55.1) after adjusting for other confounding factors. There was a significant decrease in mean rate of GFR decrease in the valsartan-treated group (-5.62 +/- 6.79 mL/min/y [-0.09 +/- 0.11 mL/s/y]) compared with the placebo group (-6.98 +/- 6.17 mL/min/y [-0.12 +/- 0.10 mL/s/y]) throughout the study period after adjustment for average blood pressure and proteinuria (P = 0.014). CONCLUSION Valsartan significantly decreases proteinuria and slows renal deterioration in patients with IgA nephropathy after adjustment for confounding factors, notably blood pressure. The long-term benefit of valsartan needs to be confirmed with additional studies.