Mechanisms Involved in Hypersensitivity Reactions to Polysulfone Hemodialysis Membranes.

Several cases of patients with anaphylactic or systemic hypersensitivity reactions to polysulfone (PS) hemodialysis (HD) membranes and tolerance to cellulose triacetate (CTA) membranes have recently been reported. To investigate the mechanisms involved in PS hypersensitivity, basophil, T cell, and complement activation were analyzed in acute-phase samples from two patients with systemic reactions to PS-based membranes. Basophil and T cell activation, as well as higher serum tryptase levels were detected in acute-phase samples compared with basal levels. Complement levels (C3 and C4) were decreased in acute-phase samples from PS-allergic patients to a higher extent than in samples from control donors taken at the same time points, indicating complement activation during the acute reactions. An experimental external circuit was established on pediatric membranes after rinsing with low or high priming volumes of saline solution, to analyze basophils, T cells, and complement activation in blood samples from 10 PS-allergic and 8 nonallergic HD patients upon contact with PS-based or CTA membranes. Predialysis and postdialysis samples were collected. Basophils from PS-allergic patients exhibited increased degranulation, and T cells showed significantly increased activation after contact with PS-based membranes primed with low volumes of saline. No activation was detected in leukocytes from nonallergic patients under the same experimental conditions. Membrane priming with high volumes of saline abrogated activation of basophils and T cells. However, basophils from allergic donors showed significantly higher responses to Fcεc stimulation after contact with PS membranes. Basophil degranulation and elevated serum tryptase levels in allergic patients during acute reactions support the systemic activation of mast cells and basophils during hypersensitivity reactions to PS-based membranes. A leachable component of the membranes might be responsible for cell activation in some patients.

Clinical evolution of chronic renal patients with HIV infection in replacement therapy.

Patients on renal replacement therapy (RRT) infected with the human immunodeficiency virus (HIV) are a special group with growing interest. In order to study the epidemiological data of HIV+ patients on RRT in Spain, we collected individual information from 2004-2011 (period of use of highly active antiretroviral therapy [HAART] in the Autonomous Communities of Andalusia, Aragon, Asturias, Catalonia, Valencia, Castilla la Mancha, Castilla León, Galicia, Madrid, La Rioja and the Basque Country, comprising 85% of the Spanish population. A total of 271 incident and 209 prevalent patients were analysed. They were compared with the remaining patients on RRT during the same period. The annual incidence was 0.8 patients per one million inhabitants, with a significant increase during the follow-up period. The proportion of prevalent HIV+ patients was 5.1 per 1,000 patients on RRT (95% confidence interval [CI] 4.4-5.8. Although glomerular diseases constituted the majority of cases (42%), diabetic nephropathy was the cause in 14% of patients. The nation-wide totals for these percentages were 13 and 25%, respectively. Compared to the total of patients in treatment, the risk of death was significantly higher in the HIV+ group: hazard ratio (HR) adjusted for age, sex and diabetes was 2.26 (95% CI 1.74 - 2.91). Hepatitis C coinfection increased the risk of death in the HIV+ group (HR 1.77; 95% CI 1.10 - 2.85). The probability of kidney transplantation in HIV+ was only 17% after 7 years, comparing with total RTT patients (HR 0.15; 95% CI: 0.10-0.24). Despite the use of HAART, the incidence of HIV+ patients on dialysis has increased; their mortality still exceeds non-HIV patients, and they have a very low rate of transplantation. It is necessary to further our knowledge of this disease in order to improve results.

Renal replacement therapy in Europe: a summary of the 2011 ERA-EDTA Registry Annual Report.

BACKGROUND: This article provides a summary of the 2011 ERA-EDTA Registry Annual Report (available at www.era-edta-reg.org). METHODS: Data on renal replacement therapy (RRT) for end-stage renal disease (ESRD) from national and regional renal registries in 30 countries in Europe and bordering the Mediterranean Sea were used. From 27 registries, individual patient data were received, whereas 17 registries contributed data in aggregated form. We present the incidence and prevalence of RRT, and renal transplant rates in 2011. In addition, survival probabilities and expected remaining lifetimes were calculated for those registries providing individual patient data. RESULTS: The overall unadjusted incidence rate of RRT in 2011 among all registries reporting to the ERA-EDTA Registry was 117 per million population (pmp) (n = 71.631). Incidence rates varied from 24 pmp in Ukraine to 238 pmp in Turkey. The overall unadjusted prevalence of RRT for ESRD on 31 December 2011 was 692 pmp (n = 425 824). The highest prevalence was reported by Portugal (1662 pmp) and the lowest by Ukraine (131 pmp). Among all registries, a total of 22 814 renal transplantations were performed (37 pmp). The highest overall transplant rate was reported from Spain, Cantabria (81 pmp), whereas the highest rate of living donor transplants was reported from Turkey (39 pmp). For patients who started RRT between 2002 and 2006, the unadjusted 5-year patient survival on RRT was 46.8% [95% confidence interval (CI) 46.6-47.0], and on dialysis 39.3% (95% CI 39.2-39.4). The unadjusted 5-year patient survival after the first renal transplantation performed between 2002 and 2006 was 86.7% (95% CI 86.2-87.2) for kidneys from deceased donors and 94.3% (95% CI 93.6-95.0) for kidneys from living donors.

Disease progression in the contralateral carotid artery after endarterectomy.

Our objectives were to establish the incidence and progression of stenotic lesions in the contralateral carotid artery (CCA) after endarterectomy, to identify subpopulations of patients at risk of contralateral disease progression, and to evaluate the efficacy of duplex scanning surveillance at detecting these lesions. We performed a prospective study on 180 patients in whom the CCA to the operated artery was healthy or showed <70% stenosis. All patients had completed a clinical and hemodynamic follow-up program, including duplex scanning of both carotids, with sessions 3 and 6 months after surgery and then every semester until 2 years. Thereafter, examinations were scheduled according to the severity of stenosis. Mean follow-up time was 26.2 months (range 1.6-67.6). Disease progression was observed in 26 lesions (15%), nine of which (5.5%) progressed to severe stenosis (SS). Kaplan-Meier event-free rates of any disease progression were 89%, 88%, 82%, and 79% for 1, 2, 3, and 4 years, respectively. Event-free rates of progression to SS were 98%, 96%, 93%, and 90.6%, respectively, for 1, 2, 3, and 4 years. The risk of progression to SS was five times higher for stenoses that were moderate at the start of the study (p = 0.025). Severe contralateral stenoses were more common and appeared later during follow-up than ipsilateral restenoses. Progression of contralateral stenotic lesions is not uncommon and is essentially related to the presence of a moderate lesion at the start of follow-up. Indeed, moderate stenosis is a risk factor for progression to SS, which appears later and more frequently than ipsilateral restenosis. It therefore seems that patients with a moderate contralateral lesion would benefit from long-term duplex ultrasound surveillance.