23 research outputs found
Post-viral idiopathic purpura fulminans is associated with inherited thrombophilia and anti-cardiolipin antibodies
IntroductionIdiopathic purpura fulminans (IPF) is a rare and severe coagulation disorder, associated with transient anti-protein S (anti-PS) antibodies in the context of post-viral infection such as varicella. Anti-protein S antibodies are frequently found in the context of varicella, in contrast with the rarity of IPF. Other factors such as anti-phospholipid antibodies (APL) and inherited thrombophilia may be associated with severe vascular complication.MethodThis is an ancillary study of a French multicenter retrospective series and systematic review of literature. We analyzed patients who were tested for inherited thrombophilia, namely antithrombin, protein C, protein S deficiency; prothrombin gene G20210A polymorphism (FII:G20210A),Factor V R506Q polymorphism (FV:R506Q); and/or for APL (lupus anticoagulant (LA), anti-cardiolipin antibodies (ACL), or anti-beta 2-GPI antibodies (AÎČ2GP1).ResultsAmong the 25 patients tested for inherited thrombophilia, 7 (28%) had positive results. Three had FV R506Q, two FII:G20210A, one compound heterozygote FV:R506Q associated to FII:G20210A, and one protein C deficiency. APL testing was performed in 32 patients. It was positive in 19 patients (59%): 17 ACL (53%), 5 LA (16%), 4 AÎČ2GP1 (13%). The risk of severe complications was not associated with presence of inherited thrombophilia or APL presence, with RR: 0.8 [95% CI: 0.37â1.71], pâ=â1 and RR: 0.7 [95% CI: 0.33â1.51], pâ=â0.39, respectively. We found a high prevalence of inherited thrombophilia or APL in a population of patients with IPF. However, we do not find an association with the occurrence of severe vascular complications or venous thromboembolism
Cold-preservation of human adult hepatocytes for liver cell therapy
Hepatocyte transplantation is a promising alternative therapy for the treatment of hepatic failure, hepatocellular deficiency, and genetic metabolic disorders. Hypothermic preservation of isolated human hepatocytes is potentially a simple and convenient strategy to provide on-demand hepatocytes in sufficient quantity and of the quality required for biotherapy. In this study, first we assessed how cold storage in three clinically safe preservative solutions (UW, HTS-FRS, and IGL-1) affects the viability and in vitro functionality of human hepatocytes. Then we evaluated whether such cold-preserved human hepatocytes could engraft and repopulate damaged livers in a mouse model of liver failure. Human hepatocytes showed comparable viabilities after cold preservation in the three solutions. The ability of fresh and cold-stored hepatocytes to attach to a collagen substratum and to synthesize and secrete albumin, coagulation factor VII, and urea in the medium after 3 days in culture was also equally preserved. Cold-stored hepatocytes were then transplanted in the spleen of immunodeficient mice previously infected with adenoviruses containing a thymidine kinase construct and treated with a single dose of ganciclovir to induce liver injury. Engraftment and liver repopulation were monitored over time by measuring the blood level of human albumin and by assessing the expression of specific human hepatic mRNAs and proteins in the recipient livers by RT-PCR and immunohistochemistry, respectively. Our findings show that cold-stored human hepatocytes in IGL-1 and HTS-FRS preservative solutions can survive, engraft, and proliferate in a damaged mouse liver. These results demonstrate the usefulness of human hepatocyte hypothermic preservation for cell transplantation
Hepatitis C Virus Reveals a Novel Early Control in Acute Immune Response
Recognition of viral RNA structures by the intracytosolic RNA helicase RIG-I triggers induction of innate immunity. Efficient induction requires RIG-I ubiquitination by the E3 ligase TRIM25, its interaction with the mitochondria-bound MAVS protein, recruitment of TRAF3, IRF3- and NF-ÎșB-kinases and transcription of Interferon (IFN). In addition, IRF3 alone induces some of the Interferon-Stimulated Genes (ISGs), referred to as early ISGs. Infection of hepatocytes with Hepatitis C virus (HCV) results in poor production of IFN despite recognition of the viral RNA by RIG-I but can lead to induction of early ISGs. HCV was shown to inhibit IFN production by cleaving MAVS through its NS3/4A protease and by controlling cellular translation through activation of PKR, an eIF2α-kinase containing dsRNA-binding domains (DRBD). Here, we have identified a third mode of control of IFN induction by HCV. Using HCVcc and the Huh7.25.CD81 cells, we found that HCV controls RIG-I ubiquitination through the di-ubiquitine-like protein ISG15, one of the early ISGs. A transcriptome analysis performed on Huh7.25.CD81 cells silenced or not for PKR and infected with JFH1 revealed that HCV infection leads to induction of 49 PKR-dependent genes, including ISG15 and several early ISGs. Silencing experiments revealed that this novel PKR-dependent pathway involves MAVS, TRAF3 and IRF3 but not RIG-I, and that it does not induce IFN. Use of PKR inhibitors showed that this pathway requires the DRBD but not the kinase activity of PKR. We then demonstrated that PKR interacts with HCV RNA and MAVS prior to RIG-I. In conclusion, HCV recruits PKR early in infection as a sensor to trigger induction of several IRF3-dependent genes. Among those, ISG15 acts to negatively control the RIG-I/MAVS pathway, at the level of RIG-I ubiquitination.These data give novel insights in the machinery involved in the early events of innate immune response
Are low-density lipoprotein receptor-related protein 1 or non-neutralizing antibodies predictors of FVIII in vivo recovery in haemophilia A patients?
International audienc
Conductrices dâhĂ©mophilie : expĂ©rience dâun CHRU en France
International audienceOBJECTIVES:To report the management of carriers of haemophilia in a French university hospital and assess different issues of these patients.PATIENTS AND METHODS:Retrospective study of the carriers of haemophilia who consulted at the university hospital of Montpellier, France, between 1995 and 2011. Information were obtained from medical records and from a questionnaire sent to carriers. We recorded data about biological characteristics, bleeding tendency and management of pregnancies.RESULTS:Sixty-four carriers of haemophilia A or B were included. Their median FVIII or FIX level was 52 % (range, 15-137 %). Menstrual bleeding lasted more than 7 days in 31 % of carriers. A total of 142 pregnancies started in 54 carriers, and 101 resulted in live births with 26 boys with haemophilia. Sixty-two prenatal diagnoses carried out, 15 have terminated their pregnancy because of a hemophiliac male fetus. Seventy-six percent of deliveries were vaginal delivery and 49 % took place in a level-3 maternity. There were 10.8 % and 8.5 % primary and secondary post-partum hemorrhage, respectively.CONCLUSION:The risk of bleeding among carriers of haemophilia is associated with their antihemophilic factor level. To improve the management of carriers, a multidisciplinary and standardized medical record, with a specific questionnaire to evaluate bleedings, could be considered. A regional register that lists all carriers, regardless of their antihemophilic factor level, would also be useful
Recommendations on testing for thrombophilia in venous thromboembolic disease: a French consensus guideline.
International audienc
Treatment of girls and women with haemophilia A and haemophilia B: a retrospective study in the francecoag cohort
International audienc