Chih-Yu Yang

Mapping of psoriasis to 17q terminus

Psoriasis is a chronic, inflammatory, hyperproliferative disease of the skin, scalp, nails, and joints, with a prevalence of up to 2% in Caucasians1,2 but well under 1% in the Mongoloid races of the Far East.3 The disease varies in severity. Some patients display mild disease with isolated scaling erythematous plaques on the elbows or knees, whereas for others most of their cutaneous surface can be affected. At the cellular level, psoriasis is characterised by markedly increased epidermal proliferation and incomplete differentiation, elongation, dilation, and leakiness of the superficial plexus of dermal capillaries, and by a mixed inflammatory and immune cell infiltrate of the epidermis and papillary dermis.1,2 Dermal infiltrates comprised of T cells and macrophages typically appear in early lesions before epidermal changes.4 The therapeutic effect of immunosuppressive agents suggests psoriasis has a primary immune pathogenic basis.5 Susceptibility to the development of psoriasis is likely to have a significant genetic component. Accumulating evidence is consistent with the idea that psoriasis is a multifactorial disorder caused by the concerted action of multiple disease genes in a single individual and triggered by environmental factors.6 Some of these genes control the severity of a variety of diseases, via their regulation of the inflammatory and immune processes (severity genes), whereas others are unique to psoriasis (specific genes). A number of genetic studies have sought to identify the psoriasis susceptibility loci. Associations between psoriasis and human lymphocyte antigen alleles were first described in 1990.7 Subsequently, genome-wide linkage scans have mapped psoriasis to several chromosomal regions including PSORS1 at 6p21,8,9 PSORS2 at 17q,8–10 PSORS3 at 4q,11 PSORS4 at 1q,12 PSORS5 at 3q,13 PSORS6 at 19p,14 and PSORS7 at 1p.15 Recently, the International Psoriasis Genetics Consortium reassessed these candidate …

Risks of Death and Stroke in Patients Undergoing Hemodialysis With New-Onset Atrial Fibrillation A Competing-Risk Analysis of a Nationwide Cohort

Background— Whether oral anticoagulant use should be considered in patients undergoing hemodialysis with atrial fibrillation (AF) remains controversial because of the uncertainty regarding risk-benefit assessments. The purpose of this study was to investigate the risk of ischemic stroke in patients undergoing hemodialysis with new-onset AF, in comparison with those without arrhythmia. Methods and Results— This nationwide, population-based, propensity score–matched cohort study used data from Taiwan’s National Health Insurance Research Database during 1998 to 2011 for patients on hemodialysis with new-onset nonvalvular AF and matched subjects without arrhythmia. The clinical end points were ischemic stroke (fatal or nonfatal), all-cause death, and other serious adverse cardiovascular events. In comparison with the matched cohort, patients with AF (n=6772) had higher risks of ischemic stroke (adjusted hazard ratio [aHR], 1.27; 95% confidence interval [CI], 1.13–1.43), all-cause death (aHR, 1.59; 95% CI, 1.52–1.67), in-hospital cardiovascular death (aHR, 1.83; 95% CI, 1.71–1.94), myocardial infarction (aHR, 1.33; 95% CI, 1.17–1.51), and hospitalization for heart failure (aHR, 1.90; 95% CI, 1.76–2.05). After considering in-hospital death as a competing risk, AF significantly increased the risk of heart failure (HR, 1.56; 95% CI, 1.45–1.68), but not those of ischemic stroke and myocardial infarction. Additionally, the predictive value of the CHA2DS2–VASc score for ischemic stroke was diminished in the competing-risk model. Conclusions— The risk of stroke was only modestly higher in patients undergoing hemodialysis with new-onset AF than in those without AF, and it became insignificant when accounting for the competing risk of in-hospital death.

Effect of Far Infrared Therapy on Arteriovenous Fistula Maturation: An Open-Label Randomized Controlled Trial

BACKGROUND Malfunction of the arteriovenous fistula (AVF) is an important cause of morbidity and hospitalization in hemodialysis (HD) patients. The aim of this study is to evaluate the effect of far infrared therapy on the maturation and patency of newly created AVFs in patients with chronic kidney disease stage 4 or 5. STUDY DESIGN Randomized controlled study. SETTING & PARTICIPANTS Patients with estimated glomerular filtration rate of 5-20 mL/min/1.73 m². INTERVENTION 40 minutes of far infrared therapy 3 times weekly for a year. OUTCOMES The primary outcome is the rate of AVF malfunction within 12 months, with malfunction defined as either: (1) thrombosis without thrill for AVFs not undergoing HD or (2) receiving any type of interventional procedure due to a lower Kt/V (<1.2) for patients undergoing HD. Secondary outcomes include: (1) cumulative primary unassisted AVF patency, defined as time from creation of the AVF to the first episode of AVF malfunction; (2) physiologic maturation of the AVF by the definition of AVF access blood flow (Qa) ≥500 mL/min and AVF diameter ≥4 mm at 3 months; and (3) clinical maturation of the AVF suitable for HD at 1 year. MEASUREMENTS AVF Qa was measured by Doppler ultrasonography at 2 days and 1, 2, 3, and 12 months. RESULTS We enrolled 122 patients who were randomly allocated to the intervention (n = 60) and control (n = 62) groups. In comparison to controls, patients in the intervention group had higher Qa values at 1, 2, 3, and 12 months; a higher rate of physiologic maturation (90% vs 76%; P = 0.04) at 3 months; and a lower rate of AVF malfunction (12% vs 29%; P = 0.02) but higher rates of AVF cumulative unassisted patency (87% vs 70%; P = 0.01) and clinical maturation (82% vs 60%; P = 0.008) within 12 months. LIMITATIONS This is a single-center nonblinded study. CONCLUSIONS Far infrared therapy improves the access flow, maturation, and patency of newly created AVFs in patients with chronic kidney disease stages 4 and 5.

Postdialysis blood pressure rise predicts long-term outcomes in chronic hemodialysis patients: a four-year prospective observational cohort study

BackgroundThe blood pressure (BP) of a proportion of chronic hemodialysis (HD) patients rises after HD. We investigated the influence of postdialysis BP rise on long-term outcomes.MethodsA total of 115 prevalent HD patients were enrolled. Because of the fluctuating nature of predialysis and postdialysis BP, systolic BP (SBP) and diastolic BP before and after HD were recorded from 25 consecutive HD sessions during a 2-month period. Patients were followed for 4 years or until death or withdrawal.ResultsKaplan-Meier estimates revealed that patients with average postdialysis SBP rise of more than 5 mmHg were at the highest risk of both cardiovascular and all-cause mortality as compared to those with an average postdialysis SBP change between -5 to 5 mmHg and those with an average postdialysis SBP drop of more than 5 mmHg. Furthermore, multivariate Cox regression analysis indicated that both postdialysis SBP rise of more than 5 mmHg (HR, 3.925 [95% CI, 1.410-10.846], p = 0.008) and high cardiothoracic (CT) ratio of more than 50% (HR, 7.560 [95% CI, 2.048-27.912], p = 0.002) independently predicted all-cause mortality. We also found that patients with an average postdialysis SBP rise were associated with subclinical volume overload, as evidenced by the significantly higher CT ratio (p = 0.008).ConclusionsA postdialysis SBP rise in HD patients independently predicted 4-year cardiovascular and all-cause mortality. Considering postdialysis SBP rise was associated with higher CT ratio, intensive evaluation of cardiac and volume status should be performed in patients with postdialysis SBP rise.

Essential trace element status and clinical outcomes in long-term dialysis patients: A two-year prospective observational cohort study

BACKGROUND & AIMS Essential trace elements are involved in many biological processes for normal cell function including immunological defense against oxidation and infection. Deficiency of these elements generally leads to illness or even death in the general population. Therefore, we investigated the predictive values of trace element status on clinical outcomes in dialysis patients, who are more prone to trace element deficiency. METHODS We enrolled 111 prevalent patients on maintenance dialysis from a Taipei tertiary-care referral hospital and measured serum levels of selenium, copper, and zinc. Patients were followed for 2 years or until death or withdrawal. RESULTS Multivariate Cox regression analysis indicated that patients with diabetes mellitus (HR, 2.162 [95% CI, 1.105-4.232], p=0.024), prior stroke (HR, 3.876 [95% CI, 1.136-13.221], p=0.030), and zinc deficiency (HR, 0.979 [95% CI, 0.966-0.992], p=0.002) were more likely to be hospitalized for infectious diseases. Furthermore, beyond traditional risk factors, such as old age and hypoalbuminemia, multivariate Cox regression also indicated that lower serum level of zinc independently predicts overall mortality (HR, 0.973 [95% CI, 0.948-0.999], p=0.046). CONCLUSIONS In long-term dialysis patients, the serum level of zinc was an independent predictor of future hospitalization due to infectious diseases and of overall mortality.

Circulating Wnt/β-catenin signalling inhibitors and uraemic vascular calcifications

BACKGROUND The process of vascular calcification has been associated with the canonical Wnt/β-catenin signalling pathway in cell cultures and animal studies. The relationship between circulating Wnt/β-catenin inhibitors and vascular calcification in dialysis patients is unknown. The aim of this study was to investigate the associations between serum dickkopf-1 (Dkk-1) and sclerostin, two circulating inhibitors of the Wnt/β-catenin signalling pathway, and the severity of aortic calcification (AoC) and cardiovascular outcomes in dialysis patients. METHODS This was a prospective observational cohort study. One hundred and twenty-five patients on maintenance haemodialysis participated in the study. Serum levels of Dkk-1 and sclerostin were measured. AoC scores were calculated from plain films of both posterior-anterior and lateral views. The patients were followed up for 2 years or until death or withdrawal. RESULTS The circulating sclerostin level was inversely associated with the severity of AoC (P = 0.035) and indicators of the bone turnover rate including serum alkaline phosphatase (ALP) (r = -0.235, P = 0.008) and intact parathyroid hormone (r = -0.523, P < 0.001). Furthermore, Cox regression analysis indicated that the patients with high circulating sclerostin levels were less likely to experience future cardiovascular events [1 pmol/L sclerostin increase, hazard ratio 0.982 (95% CI, 0.967-0.996), P = 0.015] after adjusting for a propensity score. In contrast, serum Dkk-1 was not associated with AoC and clinical outcomes. CONCLUSIONS In long-term haemodialysis patients, circulating sclerostin but not Dkk-1 is inversely associated with AoCs and future cardiovascular events. Our findings suggest that sclerostin, as a bone-related protein, might act as a communicator between uraemic bone and vasculature.

Prevalence of the JAK2‐V617F mutation in Taiwanese patients with chronic myeloproliferative disorders

Background:  The Janus kinase‐2 (JAK‐2) V617F mutation has been recently reported in patients with myeloproliferative disorders (MPD), which is believed to underlie growth factor hypersensitivity displayed by haematopoietic progenitors in these disorders. However, its frequency has been rarely determined in Taiwanese patients.

THE RISK FACTORS AND THE IMPACT OF HERNIA DEVELOPMENT ON TECHNIQUE SURVIVAL IN PERITONEAL DIALYSIS PATIENTS: A POPULATION-BASED COHORT STUDY

♦ Objectives: There is a lack of consensus on the risk factors for hernia formation, and the impact on peritoneal dialysis (PD) survival has seldom been studied. ♦ Methods: This was a population-based study and all collected data were retrieved from the National Health Insurance Research Database of Taiwan. Patients who commenced PD between January 1998 and December 2006 were screened for inclusion. Multiple logistic regression and Cox proportional hazards models were applied to estimate the predictors for hernia formation and determine the predictors of PD withdrawal. ♦ Results: A total of 6,928 PD patients were enrolled and followed until December 2009, with 631 hernia events and 391 hernioplasties being registered in 530 patients (7.7%). The incidence rate was 0.04 hernias/patient/year. Longer PD duration (per 1 month increase, hazard ratio (HR) 1.019) and history of mitral valve prolapse (MVP) (HR 1.584) were independent risk factors for hernia formation during PD, and female gender (HR 0.617) was a protective factor. On the other hand, there were 4,468 PD withdrawals, with cumulative incidence rates of 41% at 1 year, 66% at 3 years, and 82% at 5 years. Independent determinants for cumulative PD withdrawal included hernia formation during PD (HR 1.154), age (per 1 year increase, HR 1.014), larger dialysate volume (per 1 liter increase, HR 0.496), female gender (HR 0.763), heart failure (HR 1.092), hypertension (HR 1.207), myocardial infarction (HR 1.292), chronic obstructive pulmonary disease (COPD) (HR 1.227), cerebrovascular accident (CVA) (HR 1.364), and history of MVP (HR 0.712) ♦ Conclusions: Prolonged PD duration was a risk factor for hernia formation, and female gender was protective. Hernia formation during PD therapy may increase the risk of PD withdrawal.

Plasma Protein Characteristics of Long-Term Hemodialysis Survivors

Hemodialysis (HD) patients are under recurrent circulatory stress, and hemodialysis has a high mortality rate. The characteristics of plasma proteomes in patients surviving long-term HD remain obscure, as well as the potential biomarkers in predicting prognoses. This study reports the proteome analyses of patient plasma from non-diabetic long-term HD (LHD, dialysis vintage 14.9±4.1 years, n = 6) and the age/sex/uremic etiology-comparable short-term HD (SHD, dialysis vintage 5.3±2.9 years, n = 6) using 2-DE and mass spectrometry. In addition, a 4-year longitudinal follow-up of 60 non-diabetic HD patients was subsequently conducted to analyze the baseline plasma proteins by ELISA in predicting prognosis. Compared to the SHD, the LHD survivors had increased plasma vitamin D binding proteins (DBP) and decreased clusterin, apolipoprotein A-IV, haptoglobin, hemopexin, complement factors B and H, and altered isoforms of α1-antitrypsin and fibrinogen gamma. During the 45.7±15 months for follow-up of the 60 HD patient cases, 16 patients died. Kaplan-Meier analysis demonstrated that HD patients with the lowest tertile of the baseline plasma DBP level have a significantly higher mortality rate. Multivariate Cox regression analysis further indicated that DBP is an independent predictor of mortality. In summary, the altered plasma proteins in LHD implicated accelerated atherosclerosis, defective antioxidative activity, increased inflammation/infection, and organ dysfunction. Furthermore, lower baseline plasma DBP in HD patients is related to mortality. The results suggest that the proteomic approach could help discover the potential biomarker in HD prognoses.

Effect of add-on direct renin inhibitor aliskiren in patients with non-diabetes related chronic kidney disease

BackgroundThe renin-angiotensin-aldosterone system (RAAS) plays an important role in the progression of chronic kidney disease (CKD). Although dual RAAS inhibition results in worse renal outcomes than monotherapy in high risk type 2 diabetes patients, the effect of dual RAAS inhibition in patients with non-DM CKD is unclear. The aim of this study was to evaluate the potential renoprotective effect of add-on direct renin inhibitor in non-DM CKD patients.MethodsWe retrospectively enrolled 189 non-DM CKD patients who had been taking angiotensin II receptor blockers (ARBs) for more than six months. Patients were divided into an add-on aliskiren group and an ARB monotherapy group. The primary outcomes were a decline in glomerular filtration rate (GFR) and a reduction in urinary protein-to-creatinine ratio at six months.ResultsThe baseline characteristics of the two groups were similar. Aliskiren 150 mg daily reduced the urinary protein-to-creatinine ratio by 26% (95% confidence interval, 15 to 37%; p < 0.001). The decline in GFR was smaller in the add-on aliskiren group (−2.1 vs. -4.0 ml/min, p = 0.038). Add-on aliskiren had a neutral effect on serum potassium in the non-DM CKD patients. In subgroup analysis, the proteinuria-reducing effect of aliskiren was more prominent in patients with a GFR less than 60 ml/min, and in patients with a urinary protein-to-creatinine ratio greater than 1.8. The effect of aliskiren in retarding the decline in GFR was more prominent in patients with hypertensive nephropathy than in those with glomerulonephritis.ConclusionAdd-on direct renin inhibitor aliskiren (150 mg daily) safely reduced proteinuria and attenuated the decline in GFR in the non-DM CKD patients who were receiving ARBs.