Eve Chowaniec

Hepatitis C virus infection in dialysis patients.

Hepatitis C virus (HCV) infection is a global health problem, common worldwide, leading to acute and chronic hepatitis and its consequences of hepatocirrhosis and hepatocellular carcinoma. Patients on hemodialysis belong to the high‐risk group of HCV infection. The prevalence of HCV infection in dialysis patients ranges from 4% to more than 70% in some countries. The main reasons for such a high incidence of infections are a high prevalence of HCV infection in the general population, lack of standard infection precautions and effective vaccination, inadequate disinfection procedures of dialysis machines and other medical equipment, as well as spread of infection from patient to patient, especially in dialytic centers with a high percentage of infected patients. The diagnostic procedures useful in the evaluation of HCV infection are detection of anti‐HCV antibodies, identification of HCV RNA, counts of virus copies, and identification of its genome. From the 6 major genotypes and multiple subtypes of the HCV, genotypes 1a and 1b are the most common in Europe and Japan, and 1b is responsible for more severe liver disease and aggressive course leading to liver fibrosis. Antiviral therapy of HCV+ dialysis patients with interferon‐α (INF‐α) gives slightly better results than in the general population, but is poorly tolerated and associated with side effects. Although ribavirin in not recommended for dialysis patients, the addition of small doses of this compound to pegylated INF is discussed, especially for patients in whom previous infection treatment failed.

Carpal tunnel syndrome in hemodialysis patients as a dialysis-related amyloidosis manifestation--incidence, risk factors and results of surgical treatment.

Summary Background Carpal tunnel syndrome (CTS) is the most common complication of dialysis-related amyloidosis (DRA) developing in patients on long-term dialysis therapy. The aim of this study was to evaluate the incidence of CTS and identify factors influencing the development of CTS in patients on maintenance hemodialysis, as well as results of its surgical treatment. Material/Methods The study included 386 patients, among whom CTS was diagnosed in 40 patients (10.4%) on the basis of signs and physical symptoms, as well as by nerve conduction. The group of patients with CTS and the group of patients without CTS were compared according to age (mean 54.50 vs. 56.48 years) and duration of dialysis treatment. Initial analysis of CTS incidence by sex, presence of anti-HCV antibodies, and location of arterio-venous fistula (AV fistula) was undertaken. Results Duration of dialysis treatment was the statistically significant risk factor for the development of CTS (16.05 vs. 4.51 years; p<0.0001). Among patients treated for a long period on hemodialysis (20–30 years), 100% required surgical release procedures, while 66.66% of those treated for 15–19 years, 42.1% of those treated for 10–14 years, and 1.6% of those treated for less than 10 years. CTS was diagnosed more often in anti-HCV-positive patients as compared with anti-HCV-negative patients (47.5 vs. 6.9%; p<0.0001). No significant differences were found when comparing CTS incidence by sex or between the development of CTS requiring surgical release intervention and location of the AV fistula. Conclusions Surgical release procedure of the carpal tunnel gave good treatment results in patients with CTS.

Risk Stratification in Dialysis Patients: Coronary Artery Calcification Score Combined with High Sensitive C-Reactive Protein and Framingham Score for Cardiovascular Risk Prediction in Asymptomatic Subjects

Introduction: Vascular calcification independently predicts cardiovascular disease, the major cause of death in Chronic Kidney Disease (CKD) patients. Coronary Artery Calcium Score (CACS) is a marker for atherosclerotic plaque burden, vascular calcification and has been shown to be a predictor of incidence of myocardial infarction and death from Cardiovascular (CV) disease. Objectives: The aim of the study was to evaluate factors influencing CV mortality in a group of Peritoneal Dialysis (PD) patients during a six year observation period. Patients and methods: The study included 53 patients with no symptoms of CV disease (25 women, 28 men; mean age of 52 ± 12 years) treated with PD for a median period of 24 months. Baseline Framingham Risk Score (FRS) was assessed and CACS was measured using Multi-Row Spiral Computed Tomography (MSCT). Laboratory measurements included high sensitive C-reactive protein (hsCRP), osteoprotegerin (OPG), fibroblast growth factor 23 (FGF23), osteopontin (OPN), osteocalcin (OC), intact parathyroid hormone (iPTH), total calcium (Ca) and phosphates (Pi). The data concerning mortality was collected over a 6 year period. Results: During the six year observation period, 24 (45%) patients died, including 19 due to CV causes. Median overall survival was 72 months (lower quartile, 17 months). CACS was a significant predictor of all-cause and CV mortality both in simple analysis (HR=1.03 per 100 Agatston units, p=0.02 and HR=1.05, p=0.003), as well as in a multiple model adjusted for age of patients, dialysis duration, weekly creatinine clearance, Ca x Pi, iPTH, OPG, hsCRP and FRS (HR=1.04, p=0.02 and HR=1.05, p=0.01). The value of 800 Agatston units significantly differentiated the group into those with higher and lower risk for CV death (p=0.04). Age and FGF23 concentration were independent predictors of CACS. Also, hsCRP and FRS significantly predicted all-cause and CV mortality in simple Cox regression (HR=1.04, p=0.002 and HR=1.04, p=0.003; HR=1.14, p=0.047 and HR=1.23, p=0.01) as well as in a multiple model (HR=1.05, p=0.002 and HR=1.05, p=0.01; HR=1.23, p=0.01 and HR=1.33, p=0.004). Adding CACS to FRS and hsCRP significantly improved the prediction of cardiovascular mortality (p=0.02). Conclusions: Coronary calcium imaging is a non-invasive method of CV risk stratification that can accurately identify high-risk asymptomatic dialysis patients at the start of dialysis. The assessment of CACS together with inflammatory markers and conventional CV risk factors (FRS) may contribute to early diagnosis, prevention and reduction of deaths from CV disease in dialysis patients. Among the markers of bone disease, FGF-23 (a regulator of phosphorus metabolism) may be an early predictor of vascular calcification among dialysis patients.