Dae-Suk Han

Frequencies of hepatitis B and C infections among haemodialysis and peritoneal dialysis patients in Asia-Pacific countries: analysis of registry data

BACKGROUNDnThe impact of dialysis modality on the rates and types of infectious complications has not been well studied. The aim of the present investigation was to evaluate the rates of hepatitis C virus (HCV) and hepatitis B virus (HBV) infections in peritoneal dialysis (PD) and haemodialysis (HD) patients in the Asia-Pacific region.nnnMETHODSnThe study included the most recent period-prevalent data recorded in the national or regional dialysis registries of the 10 Asia-Pacific countries/areas (Australia, New Zealand, Japan, China, Taiwan, Korea, Thailand, Hong Kong, Malaysia and India), where such data were available. Longitudinal data were also available for all incident Australian and New Zealand patients commencing dialysis between 1 April 1995 and 31 December 2005. Rates of HCV and HBV infections were compared by chi-square, Poisson regression and Kaplan-Meier survival analyses, as appropriate.nnnRESULTSnData were obtained on 201,590 patients (HD 173,788; PD 27,802). HCV seroprevalences ranged between 0.7% and 18.1% across different countries and were generally higher in HD versus PD populations (7.9% +/- 5.5% versus 3.0% +/- 2.0%, P = 0.01). Seroconversion rates on dialysis were also significantly higher in HD patients (incidence rate ratio PD versus HD 0.33, 95% CI 0.13-0.75). HCV infection was highly predictive of mortality in Japan (relative risk 1.37, 95% CI 1.15-1.62, P = 0.003) and in Australia and New Zealand (adjusted hazards ratio 1.29, 95% CI 1.05-1.58). HBV infection data were limited, but less clearly influenced by dialysis modality.nnnCONCLUSIONSnDialysis modality selection significantly influences the risk of HCV infection experienced by end-stage renal failure patients in the Asia-Pacific region. No such association could be identified for HBV infection.

Changing prevalence of glomerular diseases in Korean adults: a review of 20 years of experience

BACKGROUNDnThe prevalence of glomerular diseases differs according to geographic area, race, age and indications for a renal biopsy. This study was conducted to evaluate the distribution and changing patterns of renal diseases during the past 20 years in a large patient population in Korea.nnnMETHODSnPatients aged 16 years or older who underwent a renal biopsy at Severance Hospital in the Yonsei University Health System from 1987 to 2006 were enrolled. All medical records were reviewed retrospectively.nnnRESULTSnIn total, 1818 patients (M:F = 1.02:1) were reviewed. Glomerulonephritis (GN) comprised 85.9% of the total biopsied cases. The most common primary GN was IgA nephropathy (IgAN) (28.3%), which was followed by minimal change disease (MCD) (15.5%), membranous nephropathy (MN) (12.3%), focal segmental glomerulosclerosis (FSGS) (5.6%) and membranoproliferative GN (MPGN) (4.0%). The most common secondary GN was lupus nephritis (8.7%). The most common idiopathic nephrotic syndrome was MCD (38.5%), which was followed by MN and IgAN. Among 128 (7.4%) patients who were HBsAg-positive, MN (30.5%) and MPGN (21.1%) were the most common GN. When the incidence rates between 1987-91 and 2002-06 were compared, IgAN increased from 25.6 to 34.5%, while MCD (from 23.2 to 7.0%) and MPGN (from 6.7 to 1.7%) decreased significantly (P < 0.01).nnnCONCLUSIONSnIgAN was the most common primary GN, and MCD was the most common cause of nephrotic syndrome. In the 5-year quartile comparison, the relative frequency of IgAN increased, while the relative frequency of MCD and MPGN decreased significantly during the past 20 years.

Purification, characterization, and primary structure of a chitinase from Pseudomonas sp. YHS-A2

Abstract A chitinase gene (chiA) from Pseudomonas sp. YHS-A2 was cloned into Escherichia coli using pUC19. The nucleotide sequence determination revealed a single open reading frame of chiA comprised of 1902u2009nucleotide base pairs and 633u2009deduced amino acids with a molecular weight of 67,452u2009Da. Amino acid sequence alignment showed that ChiA contains two putative chitin-binding domains and a single catalytic domain. Two proline-threonine repeat regions, which are linkers between catalytic and substrate-binding domains in some cellulases and xylanases, were also found. From E. coli, ChiA was purified 12.8-fold relative to the periplasmic fraction. The Michaelis constant and maximum initial velocity for p-nitrophenyl-N,N′-diacetylchitobiose were 1.06u2009mM and 44.4u2009μmol/h per mg protein, respectively. The purified ChiA binds not only to colloidal chitin but also to other substrates (avicel, chitosan, and xylan), but the binding affinity of avicel, chitosan, and xylan is around 10u2009times lower than that of colloidal chitin. The reaction of ChiA with colloidal chitin and chitooligosaccharides (trimer-hexamer) produced an end product of N,N′-diacetylchitobiose, indicating that ChiA is a chitobiosidase.

Uric acid is associated with the rate of residual renal function decline in peritoneal dialysis patients

BACKGROUNDnUric acid (UA) is known to play a pathogenic role in chronic kidney disease (CKD). However, its effect in end-stage renal disease (ESRD) has not yet been elucidated. We explored the prevalence of hyperuricaemia and the relationship between UA and residual renal function (RRF) in peritoneal dialysis (PD) patients.nnnMETHODSnThe subjects of this study were 134 PD patients who started dialysis at the Yonsei University Health System between January 2000 and December 2005. Timed urine collections were performed within 1 month of PD commencement and at 6-month intervals thereafter. The slope of decline of RRF over time was calculated by linear regression analysis of serial urinary urea and creatinine clearances for each patient. Biochemical and clinical data at the time of initial urine collection were considered as baseline.nnnRESULTSnAt baseline, 32.8% of the PD patients had hyperuricaemia (UA >or=7.0 mg/dl). A significant majority of patients with hyperuricaemia were diabetic (P = 0.02). Hypertensive patients had a higher UA level (P = 0.002) compared to normotensive patients. The overall reduction rate of RRF in hyperuricaemic patients was significantly higher than in the normouricaemic group (P = 0.001). In the multiple linear regression analysis, hyperuricaemia and history of DM showed a significant negative correlation with the reduction rate of RRF after adjusting for demographic data, comorbid conditions, body mass index, baseline RRF and medications (P = 0.001).nnnCONCLUSIONSnHyperuricaemia is common among PD patients and is significantly associated with the rate of decline of RRF.

Clinical implications of subclinical hypothyroidism in continuous ambulatory peritoneal dialysis patients.

BACKGROUNDnDespite the high prevalence of subclinical hypothyroidism in patients with chronic kidney disease, little is known about the clinical features and implications of this disorder in end-stage renal disease patients. This study aimed to investigate the clinical implications of subclinical hypothyroidism in continuous ambulatory peritoneal dialysis (CAPD) patients.nnnMETHODSnThis is a cross-sectional study with 51 stable patients who were maintained on CAPD for more than 3 months. A thyroid function test with blood sampling and echocardiography were conducted. Subclinical hypothyroidism was defined as a thyrotropin (TSH) level over 5 mIU/l and normal free T(4).nnnRESULTSnOf the 51 patients, subclinical hypothyroidism was detected in 14 (27.5%). Among those with subclinical hypothyroidism, only 4 (28.6%) patients had autoimmune thyroiditis. Patients with subclinical hypothyroidism had lower left ventricular ejection fractions (LVEF; 61.5 vs. 70.0%, p = 0.002) and lower fractional shortening at endocardial levels (endoFS; 33.9 vs. 40.0%, p = 0.009) compared to those with normal TSH levels. In addition, logTSH was inversely associated with LVEF (r = -0.361, p = 0.009) and endoFS (r = -0.320, p = 0.022). In a multivariate linear regression, adjusted for age, diabetes, previous coronary artery disease and logCRP (C-reactive protein), logTSH was an independent correlate with LVEF (beta = -0.388, p < 0.001).nnnCONCLUSIONnThis study suggests that subclinical hypothyroidism is common and might be implicated in cardiac dysfunction in CAPD patients.

Therapeutic Approach to Hyponatremia

Hyponatremia is a relatively common disorder occurring in up to 6% of hospitalized patients and can occur through any mechanism that produces a relative excess of body water to body sodium. Although most hyponatremia patients are asymptomatic, severe symptomatic hyponatremia is a medical emergency that may lead to cerebral edema, tentorial herniation and death. More aggressive therapy is indicated in these patients. However, in some patients, the treatment itself may result in central nervous system demyelination that may be associated with permanent neurologic sequelae. The therapeutic strategy that should guide optimal treatment of hyponatremia requires attention to the following four factors: the patient’s volume status, the presence or absence of symptoms, duration of hypo-osmolality, and the presence or absence of risk factors for the development of neurologic complication. An initial categorization according to the clinical ECF volume status of the patient will allow a determination of the appropriate initial therapy in the majority of cases. The importance of duration of hyponatremia and the presence or absence of symptoms relates to how well the brain has adapted to the hyponatremia. The severity of hyponatremia is also an important consideration because osmotic demyelination is rarely seen in patients with the initial serum sodium greater than 120 mEq/l. Clinical surveys have identified subgroups of patients at greatest risk for developing neurologic complication of hyponatremia. Optimal therapy of these patients must consider balancing the risks of hyponatremia against the risks of correction for each patient individually. Although individual variability in response to treatment is considerable, consensus guidelines for treating hyponatremic patients allow a rational and safe therapeutic approach to minimize the neurologic complications.

Effects of icodextrin on patient survival and technique success in patients undergoing peritoneal dialysis

BACKGROUNDnMany studies have suggested clinical benefits of icodextrin in peritoneal dialysis (PD) patients regarding fluid management, glycaemic control and metabolic improvement. However, reports on whether icodextrin can improve patient and technique survival is sparse.nnnMETHODSnA total of 2163 patients from 54 centres in Korea who initiated PD from July 2003 to December 2006 were enrolled. Outcomes data were retrieved retrospectively from the Baxter Korea database. Among these patients, 641 patients who had been prescribed icodextrin for >50% of their PD duration were defined as the icodextrin group and the remaining 1522 patients as the non-icodextrin group. Propensity score matching yielded 640 matched pairs of patients. We compared all-cause mortality and technique failure rates between the two groups.nnnRESULTSnThere were no significant differences in age, gender, diabetes, cardiovascular comorbidity, socioeconomic status, biocompatible solution use in short dwells or centre experience between the two groups. Death occurred in 92 (14.4%) patients in the icodextrin group compared with 128 (20.0%) in the non-icodextrin group [hazard ratio (HR), 0.69; 95% confidence interval (CI), 0.53-0.90; P = 0.006]. In addition, icodextrin use was associated with a significantly lower risk of technique failure (HR, 0.60; 95% CI, 0.40-0.92; P = 0.018). The icodextrin group had fewer technique failures due to non-compliance compared with the non-icodextrin group whereas peritonitis- or ultrafiltration failure-related technique failure was not different between the two groups.nnnCONCLUSIONnThis study further supports previous findings of long-term utilization of icodextrin solution improving patient and technique survival in PD patients. To confirm these results, a large randomized prospective study is warranted.

Nutrition in patients on peritoneal dialysis.

Protein–energy wasting (PEW) is prevalent among patients on dialysis and has emerged as an important risk factor for morbidity and mortality in these patients. Numerous factors, including inflammation, inadequate dialysis, insufficient nutrient intake, loss of protein during dialysis, chronic acidosis, hypercatabolic illness and comorbid conditions, are involved in the development of PEW. The causes and clinical features of PEW in patients on peritoneal dialysis and hemodialysis are comparable; assessment of the factors that lead to PEW in patients receiving peritoneal dialysis is important to ensure that PEW is managed correctly in these patients. For the past 20 years, much progress has been made in the prevention and treatment of PEW. However, the results of most nutritional intervention studies are inconclusive. In addition, the multifactorial and complicated pathogenesis of PEW makes it difficult to assess and treat. This Review summarizes the nutritional issues regarding the causes, assessment and treatment of PEW, with a focus on patients receiving peritoneal dialysis. In addition, an in-depth overview of the results of nutritional intervention studies is provided.

Influence of ketoanalogs supplementation on the progression in chronic kidney disease patients who had training on low-protein diet.

Aim:u2003 A low‐protein diet (LPD) is a conservative treatment in patients with chronic kidney disease (CKD) to improve uremic symptoms and slow the progression of renal dysfunction. However, the deleterious effects of protein restriction on nutritional status have raised concern. We investigated whether ketoanalogs supplementation in CKD patients who had training on LPD retards the progression of CKD and maintains nutritional status.

DECREASED CIRCULATING KLOTHO LEVELS IN PATIENTS UNDERGOING DIALYSIS AND RELATIONSHIP TO OXIDATIVE STRESS AND INFLAMMATION

♦ Introduction: It has been reported that klotho deficiency is associated with oxidative stress and inflammation in experimental kidney disease models. Patients with endstage renal disease (ESRD) are particularly characterized by increased oxidative stress and inflammation. However, little is known about the relationship between these features and klotho in patients with ESRD. ♦ Methods: We conducted a single-center, cross-sectional study of 78 patients receiving peritoneal dialysis (PD). Serum concentrations of klotho, high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), and 8-isoprostane were measured by enzyme-linked immunosorbent assay. To define factors independently associated with klotho, we determined Spearman’s correlation coefficients for between co-variates and conducted multiple linear regression analyses. ♦ Results: Patients were classified by median concentration of klotho. In patients with klotho levels > 329.6 pg/mL, serum 8-isoprostane and IL-6 levels were significantly higher than in those with klotho levels < 329.6 pg/mL. In correlation analyses, log 8-isoprostane (γ = –0.310, p = 0.006) and log IL-6 (γ = –0.343, p = 0.002) were inversely correlated with log klotho. After adjustment for age, gender, mean arterial pressure, log intact parathyroid hormone, and log IL-6, log 8-isoprostane was independently associated with log klotho (β = –0.158, p = 0.040). However, the significant relationship between klotho and IL-6 was not seen in an adjusted model. ♦ Conclusions: This study showed that circulating klotho levels were significantly associated with 8-isoprostane levels in patients undergoing PD, suggesting a potential link between klotho deficiency and enhanced oxidative stress in ESRD patients.