Urinary Extracellular Vesicles for Non-Invasive Quantification of Principal Cell Damage in Kidney Transplant Recipients.

The objective of the present study was to compare principal cell-specific aquaporin-2 (AQP2) abundances in urinary extracellular vesicles (uEVs) on the first postoperative day in deceased-donor kidney transplant recipients without and with acute kidney injury. We measured uEV markers (CD9 and CD63) and the abundances of proximal tubular sodium-glucose transporter 2, distal tubular sodium/chloride cotransporter, and principal cell-specific aquaporin-2 using Western blotting of urine. uEV-AQP2 levels were normalized to living donor controls. The validation cohort consisted of 82 deceased-donor kidney transplant recipients who had a median age of 50 years (IQR 43 to 57 years). A total of 32% of recipients had acute kidney injury. The median uEV-AQP2 was significantly higher in recipients with acute kidney injury compared to immediate allograft function (2.05; IQR 0.87 to 2.83; vs. 0.81; IQR 0.44 to 1.78; p < 0.01). The Youden index indicated a uEV-AQP2 threshold of 2.00. Stratifying uEV-AQP2 into quartiles showed that recipients with higher uEV-AQP2 levels had higher rates of acute kidney injury (Cochran-Armitage, p = 0.001). The discovery cohort showed elevated CD9, CD63, and uEV-AQP2 levels in urine from recipients with acute kidney injury compared to immediate allograft function. We were able to quantify the damage of principal cells after kidney transplant to predict acute kidney injury using uEV-AQP2.

A roadmap for optimizing chronic kidney disease patient care and patient-oriented research in the Eastern European nephrology community.

Chronic kidney disease (CKD) is a major health problem because of its high prevalence, associated complications and high treatment costs. Several aspects of CKD differ significantly in the Eastern European nephrology community compared with Western Europe because of different geographic, socio-economic, infrastructure, cultural and educational features. The two most frequent aetiologies of CKD, DM and hypertension, and many other predisposing factors, are more frequent in the Eastern region, resulting in more prevalent CKD Stages 3-5. Interventions may minimize the potential drawbacks of the high prevalence of CKD in Eastern Europe, which include several options at various stages of the disease, such as raising public, medical personnel and healthcare authorities awareness; early detection by screening high-risk populations; preventing progression and CKD-related complications by training health professionals and patients; promoting transplantation or home dialysis as the preferred modality; disseminating and implementing guidelines and guided therapy and encouraging/supporting country-specific observational research as well as international collaborative projects. Specific ways to significantly impact CKD-related problems in every region of Europe through education, science and networking are collaboration with non-nephrology European societies who have a common interest in CKD and its associated complications, representation through an advisory role within nephrology via national nephrology societies, contributing to the training of local nephrologists and stimulating patient-oriented research. The latter is mandatory to identify country-specific kidney disease-related priorities. Active involvement of patients in this research via collaboration with the European Kidney Patient Federation or national patient federations is imperative to ensure that projects reflect specific patient needs.

Adherence to treatment and hospitalization risk in hemodialysis patients.

BACKGROUND: The aim of this study was to evaluate whether adherence to treatment is associated with hospitalization risk in hemodialysis patients. METHODS: We completed a cohort analysis of risk factors during 1 census month (November) and 1 year of follow-up during 5 consecutive years (2002-2006) in all end-stage renal disease patients hemodialyzed in the Kaunas region. During the census month, we collected data on noncompliance defined as (i) skipping of a hemodialysis (HD) session, (ii) shortening of 1 or more HD sessions, (iii) presence of hyperkalemia, (iv) presence of hyperphosphatemia, or (v) interdialytic weight gain (IDWG). In addition, data on age, sex, disability status, comorbidities, anemia control, malnutrition and inflammation, calcium-phosphorus metabolism and hospitalization rate were collected. Relative risk of hospitalization was estimated using Cox regression evaluating time to first hospitalization. RESULTS: We analyzed 559 patients for a total of 1,163 patient-years during the 5 years of the study. On multivariate analysis, adjusting for ischemic heart disease, diabetes mellitus, higher number of comorbid conditions, higher systolic blood pressure before dialysis, worse disability status, lower hemoglobin, albumin and urea before dialysis, the relative risk for hospitalization increased by 1.1 for every additional percentage point of IDWG and by 1.19 with each 1 mmol/L rise of serum phosphorus level. Skipping or shortening of hemodialysis sessions and serum potassium level were not associated with hospitalization. CONCLUSIONS: Higher IDWG and higher serum levels of phosphorus independently increased the relative risk of hospitalizations in hemodialysis patients. With skipped and shortened dialysis sessions, higher serum potassium level was not associated with hospitalization risk.