Nitrosative stress and corneal transplant endothelial cell death during acute graft rejection.

BACKGROUND: Nitrosative stress takes place in endothelial cells (EC) during corneal acute graft rejection. The purpose of this study was to evaluate the potential role of peroxynitrite on corneal EC death. METHODS: The effect of peroxynitrite was evaluated in vivo. Fifty, 250, and 500 microM in 1.5 microL of the natural or denatured peroxynitrite in 50 microM NaOH, 50 microM NaOH alone, or balanced salt solution were injected into the anterior chamber of rat eyes (n=3/group). Corneal toxic signs after injection were assessed by slit-lamp, in vivo confocal imaging, pachymetry, and EC count. The effect of peroxynitrite was also evaluated on nitrotyrosine and leucocyte elastase inhibitor/LDNase II immunohistochemistry. Human corneas were incubated with peroxynitrite and the effect on EC viability was evaluated. A specific inducible nitric oxide synthase inhibitor (iNOS) was administered systemically in rats undergoing allogeneic corneal graft rejection and the effect on EC was evaluated by EC count. RESULTS: Rat eyes receiving as little as 50 microM peroxynitrite showed a specific dose-dependent toxicity on EC. We observed an intense nitrotyrosine staining of human and rat EC exposed to peroxynitrite associated with leucocyte elastase inhibitor nuclear translocation, a noncaspase dependent apoptosis reaction. Specific inhibition of iNOS generation prevented EC death and enhanced EC survival of the grafted corneas. However, inhibition of iNOS did not have a significant influence on the incidence of graft rejection. CONCLUSION: Nitrosative stress during acute corneal graft rejection in rat eyes induces a noncaspase dependent apoptotic death in EC. Inhibition of nitric oxide production during the corneal graft rejection has protective effects on the corneal EC survival.

Research needs in allergy: an EAACI position paper, in collaboration with EFA.

In less than half a century, allergy, originally perceived as a rare disease, has become a major public health threat, today affecting the lives of more than 60 million people in Europe, and probably close to one billion worldwide, thereby heavily impacting the budgets of public health systems. More disturbingly, its prevalence and impact are on the rise, a development that has been associated with environmental and lifestyle changes accompanying the continuous process of urbanization and globalization. Therefore, there is an urgent need to prioritize and concert research efforts in the field of allergy, in order to achieve sustainable results on prevention, diagnosis and treatment of this most prevalent chronic disease of the 21st century.The European Academy of Allergy and Clinical Immunology (EAACI) is the leading professional organization in the field of allergy, promoting excellence in clinical care, education, training and basic and translational research, all with the ultimate goal of improving the health of allergic patients. The European Federation of Allergy and Airways Diseases Patients' Associations (EFA) is a non-profit network of allergy, asthma and Chronic Obstructive Pulmonary Disorder (COPD) patients' organizations. In support of their missions, the present EAACI Position Paper, in collaboration with EFA, highlights the most important research needs in the field of allergy to serve as key recommendations for future research funding at the national and European levels.Although allergies may involve almost every organ of the body and an array of diverse external factors act as triggers, there are several common themes that need to be prioritized in research efforts. As in many other chronic diseases, effective prevention, curative treatment and accurate, rapid diagnosis represent major unmet needs. Detailed phenotyping/endotyping stands out as widely required in order to arrange or re-categorize clinical syndromes into more coherent, uniform and treatment-responsive groups. Research efforts to unveil the basic pathophysiologic pathways and mechanisms, thus leading to the comprehension and resolution of the pathophysiologic complexity of allergies will allow for the design of novel patient-oriented diagnostic and treatment protocols. Several allergic diseases require well-controlled epidemiological description and surveillance, using disease registries, pharmacoeconomic evaluation, as well as large biobanks. Additionally, there is a need for extensive studies to bring promising new biotechnological innovations, such as biological agents, vaccines of modified allergen molecules and engineered components for allergy diagnosis, closer to clinical practice. Finally, particular attention should be paid to the difficult-to-manage, precarious and costly severe disease forms and/or exacerbations. Nonetheless, currently arising treatments, mainly in the fields of immunotherapy and biologicals, hold great promise for targeted and causal management of allergic conditions. Active involvement of all stakeholders, including Patient Organizations and policy makers are necessary to achieve the aims emphasized herein.

Partir de soi, rencontrer l'autre--quelques réflexions sur la formation de psychiatre [The self and the other: a few comments on psychiatric education].

This manuscript has served for an oral presentation in honour of Professor Pierre Bovet who retired from his position as head physician at the Department of Psychiatry of the Lausanne University Hospital, Switzerland. Pierre Bovet has focused his clinical and scientific interest and his teaching activities on the schizophrenic spectrum disorders. The author tries to describe the essential elements of a clinical attitude which allows to really encounter the patient.

Time-Course In Vivo Trafficking Pattern and Effector Function of Donor-Specific Regulatory T Cells in Response to an Allograft.

Background: Experimental data have suggested that adoptive transfer of CD4+CD25+Foxp3+ regulatory T cells (Tregs), capable of controlling immune responses to specifi c auto- or alloantigens, could be used as a therapeutic strategy to promote specifi c tolerance in T-cell mediated diseases and in organ transplantation (Tx). However, before advocating the application of immunotherapy with Tregs in Tx, we need to improve our understanding of their in vivo homeostasis, traffi cking pattern and effector function in response to alloantigens. Methods : Donor-antigen specifi c murine Tregs were generated and characterized in vitro following our described protocols. Using an adoptive transfer and skin allotransplantation model, we have analyzed the in vivo expansion and homing of fl uorescent-labeled effector T cells (Teff) and Tregs, at different time-points after Tx, using fl ow-cytometry as well as fl uorescence microscopy techniques. Results: Tregs expressed CD62L, CCR7 and CD103 allowing their homing into lymphoid and non-lymphoid tissues (gut, skin) after intravenous injection. While hyporesponsive to TCR stimulation in vitro, transferred Tregs survived, migrated to secondary lymphoid organs and preferentially expanded within the allograft draining lymph nodes. Furthermore, Foxp3+ cells could be detected inside the allograft as early as day 3-5 after Tx. At a much later time-point (day 60 after Tx), graft-infi ltrating Foxp3+ cells were also detectable in tolerant recipients. When transferred alone, CD4+CD25- Teff cells expanded within secondary lymphoid organs and infi ltrated the allograft by day 3-5 after Tx. The co-transfer of Tregs limited the expansion of alloreactive Teff cells as well as their recruitment into the allograft. The promotion of graft survival observed in the presence of Tregs was in part mediated by the inhibition of the production of effector cytokines by CD4+CD25- T cells. Conclusion: Taken together, our results suggest that the suppression of allograft rejection and the induction of Tx tolerance are in part dependant on the alloantigendriven homing and expansion of Tregs. Thus, the appropriate localization of Tregs may be critical for their suppressive function in vivo.

Respiratory viruses in lung transplant recipients: a critical review and pooled analysis of clinical studies.

Lung transplant recipients present an increased risk for severe complications associated with respiratory infections. We conducted a review of the literature examining the clinical relationship between viral respiratory infection and graft complications. Thirty-four studies describing the clinical impact of influenza, respiratory syncytial virus, parainfluenza, human metapneumovirus, rhinovirus, enterovirus, coronavirus, bocavirus or adenovirus were identified. The detection rate of respiratory viral infection ranged from 1.4% to 60%. Viruses were detected five times more frequently when respiratory symptoms were present [odds ratio (OR) = 4.97; 95% CI = 2.11-11.68]. Based on available observations, we could not observe an association between respiratory viral infection and acute rejection (OR = 1.35; 95% CI = 0.41-4.43). We found a pooled incidence of 18% (9/50) of bronchiolitis obliterans syndrome (BOS) in virus-positive cases compared to 11.6% (37/319) in virus-negative cases; however, limited number of BOS events did not allow to confirm the association. Our review confirms a causal relationship between respiratory viruses and respiratory symptoms, but cannot confirm a link between respiratory viruses and acute lung rejection. This is related in part to the heterogeneity and limitations of available studies. The link with BOS needs also to be reassessed in appropriate prospective studies.

Ganciclovir Exposure under a 450 mg Daily Dosage of Valganciclovir for the Prevention of Cytomegalovirus Disease in Kidney Transplant Recipients.

Background: It is suggested that a low dose of valganciclovir can be equally effective than a standard dose for cytomegalovirus (CMV) prophylaxis after kidney transplantation. The aim of our study was to determine the ganciclovir exposure observed under a routine daily dosage of 450 mg valganciclovir in kidney transplant recipients with a wide range of renal function. Methods: In this prospective study, kidney transplant recipients with a GFR MDRD above 25 mL/min at risk for CMV (donor or recipient seropositive for CMV) received a dose of valganciclovir (450 mg daily) prophylaxis for 3 months. Ganciclovir levels at trough (Ctrough) and at peak (C3h) were measured monthly. Ganciclovir exposure (AUC0-24) was estimated using Bayesian non-linear mixed-effect modelling (NONMEM) and compared between 3 groups of patients according to their kidney function: GFRMDRD 26-39 mL/min (Group 1), GFRMDRD 40-59 mL/min (Group 2) and GFRMDRD 60-90 mL/min (Group 3). CMV DNAemia was assessed during and after prophylaxis using PCR. Results: Thirty-six patients received 450 mg daily of valganciclovir for 3 months. Median ganciclovir C3h was 3.9 mg/L (range: 1.3-7.1) and Ctrough was 0.4 mg/L (range 0.1-2.7). Median (range) AUC0-24 of ganciclovir was 59.3 mg.h/L (39.0-85.3) in Group 1 patients, 35.8 mg.h/L (24.9-55.8) in Group 2 patients and 29.6 mg.h/L (22.0- 43.2) in Group 3 patients (p<0.001). Anemia was more common in Group 1 patients compared to patients on the other groups (p=0.01). No differences in other adverse events according to ganciclovir exposure were observed. CMV DNAemia was not detected during prophylaxis. After discontinuing prophylaxis, CMV DNAemia was seen in 8/34 patients (23.5%) and 4/36 patients (11%) developed CMV disease. Conclusion: A routine dosage of valganciclovir achieved plasma levels of ganciclovir in patients with GFR>60 mL/min similar to those previously reported using oral ganciclovir. A daily dose of 450 mg valganciclovir appears to be acceptable for CMV prophylaxis in most kidney transplant recipients.

Interim analysis of the Reitan Catheter Pump (RCP) heart failure efficacy study: RCP improves cardiovascular and renal function in acute decompensated heart failure (ADHF)

Background: The RCP is a 14 French collapsable percutaneous cardiovascular support device positioned in the descending part of the thoracic aorta via the femoral artery. A 10 patient first in man study demonstrated device safety and significant improvement in renal function among high risk PCI patients. We now report haemodynamic and renal efficacy in patients with ADHF.Methods: Prospective non randomised study seeking to recruit 20 patients with ADHF with a need for inotropic or mechanical circulatory support with: i) EF < 30% ii)Cardiac index(CI) < 2.2 L / min / m2 Outcome measures included: 1) Cardiac index (CI) 2) Pulmonary Capillary Wedge Pressure (PCWP) 3) Urine output / serum creatinine 4) Vascular / device complications 5) 30 day mortalityResults: INTERIM ANALYSIS (n=12) The mean age of the study group was 64 years, with a mean baseline creatinine of 193 umol/L, eGFR 38 ml/min. The intended RCP treatment period was 24 hours. During RCP treatment there was a significant mean reduction of PCWP at 4 hours of 17% (25 to 21 mmHg p=0.04). Mean CI increased at 12 hours by 11%, though not reaching significance (1.78 to 1.96 L/min/m2 p=0.08). RCP insertion prompted substantial diuresis. Urine output tripled over the first 12 hours compared to baseline (55 ml/hr vs 213 ml/hr p=0.03). This was associated with significantly improved renal function, a 28% reduction in serum creatinine at 12 hours (193 to 151 umol/L p=0.003), and a increase in eGFR from 38 ml/min to 50 ml/min (p=0.0007). 2 patients previously refused cardiac transplantation were reassessed and successfully transplanted within 9 months of RCP treatment on the basis of demonstrable renal reversibility. There were no vascular or device complications. There were 2 deaths at 30 days, one from multi-organ failure and sepsis, and one from intractable heart failure - neither were device related.Conclusion: RCP support in ADHF patients was associated with improved haemodynamics, and an improvement in renal function. The Reitan Catheter Pump may have a role in providing percutaneous cardiovascular and renal support in the acutely decompensated cardiac patient, and may have a role in suggesting renal reversibility in potential cardiac transplant patients. Further data will be reported at recruitment completion.