Béatrice Poirier

Spontaneous dissecting aneurysm of the extracranial vertebral artery (20 cases)

SummarySpontaneous dissecting aneurysm of the vertebral artery is an infrequent cause of vertebro basilar ischemic strokes. Previously reported cases concern essentially occlusion of the basilar artery. Only 14 cases of spontaneous dissecting aneurysm concern the extracranial vertebral artery among these eight were angiographically documented. In this study based upon 15 patients (20 dissecting aneurysms), the authors discuss etiological factors, such as hypertension or fibromuscular dysplasia: on clinical findings they insist upon the diagnostic value of preliminary symptoms, cervical pain or posterior headaches; the most frequent angiographic appearance was a long and irregular stenosis of one or two segments of the vertebral artery. The prognosis of these aneurysms most often appears favourable in this group.

Viral inactivation of human bone tissue using supercritical fluid extraction

A new bone tissue process using supercritical carbon dioxide fluid extraction (SFE) has been evaluated for its ability to inactivate or eliminate viruses. Four viruses, human immunodeficiency virus type 1 (HIV-1), Sindbis virus, polio Sabin type I virus, and pseudorabtes virus (PRV), were exposed to four different processing steps. In addition to supercritical CO2, hydrogen peroxide, sodium hydroxide, and ethanol treatments were evaluated. The mean cumulated reduction factors (log10) for the four viruses exposed to these four steps were > 14.2 for HIV-1, > 18.2 for Sindbis virus, > 24.4 for poliovirus, and > 17.6 for PRV. The mean reduction factors obtained by the supercritical fluid extraction alone were > 4.0, > 4.3, > 6.6, and > 4.0, respectively. These results demonstrate that the SFE process is effective in inactivating viruses on human femoral heads, and provides a level of inactivation similar to that obtained by traditional cleaning methods. It is proposed that CO2 SFE be incorporated as a routine step in the processing of bone allografts for transplantation either to replace or supplement existing procedures. ASAIO Journal 1998; 44:289–293.

Safety and immunogenicity of SC599, an oral live attenuated Shigella dysenteriae type-1 vaccine in healthy volunteers: results of a Phase 2, randomized, double-blind placebo-controlled trial.

SC599 vaccine is a live Shigella dysenteriae 1 strain attenuated by deletion of invasion [icsA], iron chelation [ent, fep] and shiga toxin A subunit [stxA] genes. In a preliminary Phase 1 single dose prospective study, we showed that SC599 vaccine was well tolerated, and the maximum tolerable dose was greater than 10(8) CFU [Sadorge C, Ndiaye A, Beveridge N, Frazer S, Giemza R, Jolly N, et al. Phase 1 clinical trial of live attenuated Shigella dysenteriae type-1 DeltaicsA Deltaent Deltafep DeltastxA:HgR oral vaccine SC599 in healthy human adult volunteers. Vaccine 2008; 26(7):978-8]. In this Phase 2 trial, three groups of volunteers ingested a single dose of SC599 [10(5) CFU, n=38; 10(7) CFU, n=36] or placebo [n=37]. Both 10(5) and 10(7) CFU doses were immunogenic, inducing significant IgA and IgG LPS-specific ASCs and antibody responses, comparable in magnitude to those of other strains that prevented illness following experimental challenge. In the intention to treat analysis, 34.2% and 44.4% IgA ASC responders were detected in the 10(5) and 10(7) CFU groups respectively (p<0001 vs placebo for both groups), as well as 31.6% and 33.3% serum IgA responders (p<001 and p<0.001 vs placebo for 10(5) and 10(7) CFU groups, respectively). No difference between the two vaccine groups was observed. No stxB-specific antibody response was detected in the vaccines. SC599 excretion occurred in 23.7 and 30.6% of subjects in the 10(5) and 10(7) CFU groups, respectively. SC599 vaccine was well tolerated, and the reported adverse events were mainly digestive. These results indicate that a single oral immunization of SC599 vaccine elicits a significant circulating IgA ASC and serum antibody response that may confer protection against the most severe symptoms of Shigellosis in responders to the vaccine.

Intracerebral gene therapy in children with mucopolysaccharidosis type IIIB syndrome: an uncontrolled phase 1/2 clinical trial

BACKGROUND Mucopolysaccharidosis type IIIB syndrome (also known as Sanfilippo type B syndrome) is a lysosomal storage disease resulting in progressive deterioration of cognitive acquisition after age 2-4 years. No treatment is available for the neurological manifestations of the disease. We sought to assess the safety and efficacy of a novel intracerebral gene therapy. METHODS Local regulatory authorities in France allowed inclusion of up to four children in this phase 1/2 study. Treatment was 16 intraparenchymal deposits (four in the cerebellum) of a recombinant adenoassociated viral vector serotype 2/5 (rAAV2/5) encoding human α-N-acetylglucosaminidase (NAGLU) plus immunosuppressive therapy. We assessed tolerance, neurocognitive progression, brain growth, NAGLU enzymatic activity in CSF, and specific anti-NAGLU immune response for 30 months after surgery. This trial is registered with EudraCT, number 2012-000856-33, and the International Standard Clinical Trial Registry, number ISRCTN19853672. FINDINGS Of seven eligible children, the four youngest, from France (n=2), Italy (n=1), and Greece (n=1), aged 20, 26, 30, and 53 months, were included between February, 2012, and February, 2014. 125 adverse events were recorded, of which 117 were treatment emergent and included six classified as severe, but no suspected unexpected serious adverse drug reactions were seen. Vector genomes were detected in blood for 2 days after surgery. Compared with the natural history of mucopolysaccharidosis type III syndromes, neurocognitive progression was improved in all patients, with the youngest patient having function close to that in healthy children. Decrease in developmental quotient was -11·0 points in patient one, -23·0 in patient two, -29·0 in patient three, and -17·0 in patient four, compared with -37·7 in the natural history of the disease. NAGLU activity was detected in lumbar CSF and was 15-20% of that in unaffected children. Circulating T lymphocytes that proliferated and produced tumour necrosis factor α upon ex-vivo exposure to NAGLU antigens were detectable at 1-12 months and 3-12 months, respectively, but not at 30 months in three of four patients. INTERPRETATION Intracerebral rAVV2/5 was well tolerated and induced sustained enzyme production in the brain. The initial specific anti-NAGLU immune response that later subsided suggested acquired immunological tolerance. The best results being obtained in the youngest patient implies a potential window of opportunity. Longer follow-up is needed to further assess safety outcomes and persistence of improved cognitive development. FUNDING Association Française Contre les Myopathies, Vaincre les Maladies Lysosomales, Institut Pasteur, and UniQure.

Bone allografts and supercritical processing: effects on osteointegration and viral safety

Abstract A new bone tissue process using supercritical carbon dioxide extraction was evaluated for viral inactivation and the allografts produced by this process were tested in an in vivo implantation experiment. Four viruses, human immunodeficiency virus type I (HIV-1), Sindbis virus, Polio Sabin type I virus and Pseudorabies virus (PRV) were assayed. Four processing stages, supercritical CO2, hydrogen peroxide, sodium hydroxide and ethanol treatments were also tested. The efficiency of the process was assessed in terms of reduction factors which are the log10 of the ratio of the virus load before and after the stage to be evaluated. The cumulated reduction factors were the following: >18.2 for Sindbis virus, >24.4 for Poliovirus, >17.6 for PRV and >14.2 for HIV-1. Such allografts processed in this way were implanted into sheep leading to a much faster osseointegration in comparison with non-treated allografts. The combination of better graft incorporation and viral safety suggest that this process could become a new way for processing bank bones, alternatively or additionally, to the procedures presently used.

Effect of intermittent interleukin-2 therapy on CD4+ T-cell counts following antiretroviral cessation in patients with HIV.

Background:Interleukin (IL)-2 therapy impacts T-cell homeostasis. Whether IL-2 expanded CD4+ T cells may persist following viral rebound has not been fully investigated. Methods:Patients with CD4+ T cells 500/&mgr;l or more and HIV RNA less than 50 copies/ml were randomized to continue antiretroviral therapy (ART) either alone (n = 67) or combined with three IL-2 cycles (n = 81; 6 million units) twice daily for 5 days at weeks 0, 8, and 16 before stopping ART (week 24). Patients were followed up to 168 weeks. Results:At week 24, median CD4+ T-cell counts were 1198 and 703 cells/&mgr;l in the IL-2 and control groups, respectively (P < 0.001). At week 72, 27% (IL-2 group) and 45% (control group; P = 0.03) of patients were in failure (defined as no interruption of ART at week 24, CD4 drop below 350 cells/&mgr;l or ART resumption). After week 24, a biphasic decline (before and after week 32) of CD4 was noted −106 and −7 cells/&mgr;l per month in controls and −234 and −17 in IL-2 group (all P ⩽ 0.0001). At week 96, IL-2-expanded CD4+CD25+ T cells remained higher than in the control group (26 vs. 16%, P = 0.006). Conclusion:In IL-2-treated patients, CD4+CD25+ T cells persisting despite viral replication allow a longer period of ART interruption.

Dengue virus induced polypeptide synthesis

SummaryDengue 2 virus polypeptide synthesis was investigated in BHK21 cells. Nine or ten virus induced polypeptides were identified, three of which are glycoproteins as demonstrated by tunicamycin treatment of infected cells. We performed pulse chase experiments, experiments with amino-acid analogs, protease inhibitors or pactamycin treatment of infected cells, to determine whether or not large polypeptide processing occurs. In some of these experiments a large polypeptide (P130) was immunoprecipitated by an anti-dengue 2 serum. We observed a transfer of label between small molecular weight polypeptides which might be the result of restricted proteolytic cleavage.

Peripheral and local human papillomavirus 16-specific CD8+ T-cell expansions characterize erosive oral lichen planus.

Erosive oral lichen planus (OLP) is a chronic, disabling mucocutaneous dysimmune rare disease characterized by mucosal inflammatory erosive lesions with pathological evidence for a marked CD8+ cytotoxic T-lymphocyte (CTL) infiltration. However, the specificity of lesional CTL in OLP has never been analyzed. To investigate the molecular mechanisms underlying dysregulation of T-cell immune responses in patients with OLP, we studied the diversity and antigen specificity of the TCR expressed by CD8+ T cells using dextramer staining, spectratyping, and TCR sequencing in 10 OLP patients undergoing extracorporeal photochemotherapy. Expansions of TCRVβ3-bearing CD8+ T cells were found in peripheral blood and in lesional tissues of OLP patients. Spectratyping and sequencing studies identified specific clonotypes in each patient. These expansions were enriched with human papillomavirus 16 (HPV16)-specific CD8+ T cells in HLA-A*0201+ patients as shown by their immune recognition of the E711-20 immunodominant epitope. Under treatment with extracorporeal photochemotherapy, clonotypic CD8+ T-cell expansions decreased in parallel with clinical remission. Altogether, these data establish a link between HPV infection and OLP pathogenesis by identifying a massive clonal expansion of CD8+ T cells with increased frequency of HPV 16-specific CD8+ T cells in OLP patients.

CHRONOVAC VOYAGEUR: A study of the immune response to yellow fever vaccine among infants previously immunized against measles

For administration of multiple live attenuated vaccines, the Advisory Committee on Immunization Practices recommends either simultaneous immunization or period of at least 28days between vaccines, due to a possible reduction in the immune response to either vaccine. The main objective of this study was to compare the immune response to measles (alone or combined with mumps and rubella) and yellow fever vaccines among infants aged 6-24months living in a yellow fever non-endemic country who had receivedmeasles and yellow fever vaccines before travelling to a yellow fever endemic area. SUBJECTS AND METHODS A retrospective, multicenter case-control study was carried out in 7 travel clinics in the Paris area from February 1st 2011 to march 31, 2015. Cases were defined as infants immunized with the yellow fever vaccine and with the measles vaccine, either alone or in combination with mumps and rubella vaccine, with a period of 1-27days between each immunization. For each case, two controls were matched based on sex and age: a first control group (control 1) was defined as infants having received the measles vaccine and the yellow fever vaccine simultaneously; a second control group (control 2) was defined as infants who had a period of more than 27days between receiving the measles vaccine and yellow fever vaccine. The primary endpoint of the study was the percentage of infants with protective immunity against yellow fever, measured by the titer of neutralizing antibodies in a venous blood sample. RESULTS One hundred and thirty-one infants were included in the study (62 cases, 50 infants in control 1 and 19 infants in control 2). Of these, 127 (96%) were shown to have a protective titer of yellow fever antibodies. All 4 infants without a protective titer of yellow fever antibodies were part of control group 1. DISCUSSION The measles vaccine, alone or combined with mumps and rubella vaccines, appears to have no influence on humoral immune response to the yellow fever vaccine when administered between 1 and 27days. The absence of protective antibodies against yellow fever was observed only among infants who received both vaccines simultaneously. CONCLUSION These results may support a revision of current vaccination recommendations concerning the administration of these two live attenuated vaccines either on the same day or at least 28days apart. Our findings show no statistically significant difference if the interval between both vaccines is more than 24 h, but the immune response seems to be reduced when the two vaccines are given at the same time.

Le lichen plan buccal érosif est caractérisé par l’expansion locale et périphérique de lymphocytes T CD8+ spécifiques de HPV16

Le lichen plan buccal erosif (LPBE) est une maladie chronique dysimmunitaire rare et invalidante caracterisee par des lesions muqueuses inflammatoires erosives, avec une infiltration de lymphocytes cytotoxiques CD8+. La specificite de ces lymphocytes dans le LPBE n’a toutefois jamais ete analysee. Dans le but d’identifier les mecanismes moleculaires sous-jacents, nous avons etudie la diversite et la specificite du recepteur (TCR) exprime par les lymphocytes CD8+ par analyse en spectratyping, sequencage du TCR et marquage par dextrameres, chez 10 patients atteints de LPBE et traites par photochimiotherapie extracorporelle. Une expansion des lymphocytes CD8+ portant le TCR Vβ3 a ete retrouvee dans le sang peripherique et les lesions tissulaires. Les etudes de sequences ont permis d’identifier des clonotypes specifiques chez chaque patient. Ces expansions etaient enrichies en lymphocytes CD8+ specifiques de HPV16 chez les patients HLA-A*0201+ comme le demontrait la reconnaissance de l’epitope immunodominant E711-20. Sous traitement par photochimiotherapie extracorporelle, les expansions clonotypiques des CD8+ diminuaient parallelement a une remission clinique. Ces resultats permettent d’etablir un lien entre l’infection HPV et la pathogenese du LPBE en mettant en evidence une expansion clonale de lymphocytes CD8+ specifiques de HPV16 dans cette affection.