Parvovirus 4 in French in-patients: a study of haemodialysis and lung transplant cohorts

International audienceThe epidemiology and the clinical implication of human parvovirus 4 (PARV4) in human populations is still under evaluation. The distribution of PARV4 DNA was determined in cohorts of French haemodialysis and lung transplant patients. Plasma samples (n=289) were tested for PARV4 by real-time PCR assay (ORF2), and amplification products selected at random were sequenced. Analysis of available serological and biological markers was also undertaken. Fifty-seven samples out of 185 (30.8%) were positive for PARV4 DNA in the cohort of haemodialysis patients. A higher prevalence of the virus was identified in individuals with markers of HBV infection. PARV4 was also identified in 14 out of 104 samples (13.5%) from lung transplant recipients, with no clear-cut association with available clinical markers. Point mutations located on the zone of real-time detection were identified for some amplification products. This study describes the detection of PARV4 in the blood of haemodialysis and lung transplanted patients with significant difference in prevalence in these two cohorts. Further studies will be needed in order to understand better both the potential implication in host health and the natural history of this virus

Clinical relevance of cell-free DNA quantification and qualification during the first month after lung transplantation

BackgroundMany studies have reported the relevance of donor-derived cfDNA (dd-cfDNA) after lung transplantation (LTx) to diagnose and monitor acute rejection (AR) or chronic rejection or infection (INF). However, the analysis of cfDNA fragment size has not been studied. The aim of this study was to determine the clinical relevance of dd-cfDNA and cfDNA size profiles in events (AR and INF) during the first month after LTx.MethodsThis prospective, single-center study includes 62 LTx recipients at the Marseille Nord Hospital, France. Total cfDNA quantification was performed by fluorimetry and digital PCR, dd-cfDNA by NGS (AlloSeq cfDNA-CareDX®), and the size profile by BIABooster (Adelis®). A bronchoalveolar lavage and transbronchial biopsies at D30 established the following groups: not-injured and injured graft (AR, INF, or AR+INF).ResultsQuantification of total cfDNA was not correlated with the patient’s status at D30. The percentage of dd-cfDNA was significantly higher for injured graft patients at D30 (p=0.0004). A threshold of 1.72% of dd-cfDNA correctly classified the not-injured graft patients (negative predictive value of 91.4%). Among recipients with dd-cfDNA >1.72%, the quantification of small sizes (80-120bp) >3.70% identified the INF with high performance (specificity and positive predictive value of 100%).ConclusionWith the aim of considering cfDNA as a polyvalent non-invasive biomarker in transplantation, an algorithm combining the quantification of dd-cfDNA and small sizes of DNA may significantly classify the different types of allograft injuries

Entropic Lower Bound of Cardinality for Sparse Optimization

We introduce a family of cardinality's lower bounds, defined as ratios of norms. We prove that the tightest bound of the family is obtained as a limit case, and involves a Shannon entropy. We then use this entropic lower bound in sparse optimization problems to approximate cardinality requirements. This provides a nonlinear nonconvex relaxed problem, which can be efficiently solved by off-the-shelf nonlinear solvers. In the numerical study, we focus on the case where the optimization is performed on the simplex, and where the classical l1 penalization does not yield sparse solution. The Finance Index Tracking problem is taken as an example and illustrates the efficiency of the proposed approach

De Novo persistent post-lung transplantation HLA donor-specific antibodies (DSA) but not performed DSA are associated with worse survival and a higher risk of developing chronic lung allograft dysfunction

International audienc

De Novo Persistent Post-Lung Transplantation HLA Donor-Specific Antibodies (DSA) but not Preformed DSA are Associated with Worse Survival and a Higher Risk of Developing Chronic Lung Allograft Dysfunction

International audienc

De Novo persistent post-lung transplantation HLA donor-specific antibodies (DSA) but not performed DSA are associated with worse survival and a higher risk of developing chronic lung allograft dysfunction

International audienc

De Novo Persistent Post-Lung Transplantation HLA Donor-Specific Antibodies (DSA) but not Preformed DSA are Associated with Worse Survival and a Higher Risk of Developing Chronic Lung Allograft Dysfunction

International audienc

De Novo Persistent Post-Lung Transplantation HLA Donor-Specific Antibodies (DSA) but not Preformed DSA are Associated with Worse Survival and a Higher Risk of Developing Chronic Lung Allograft Dysfunction

International audienc

IMPACT OF FC-GAMMA RECEPTORS IIIA [158F/V] POLYMORPHISMS ON CHRONIC LUNG ALLOGRAFT DYSFUNCTION (CLAD) AND PATIENTS SURVIVAL AFTER LUNG TRANSPLANTATION

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