[Tropism of hepatitis C virus for leukocytes-- importance of the analysis of viral E1 and E2 envelope glycoprotein genes by sequencing]. / Tropisme leucocytaire du virus de l'hépatite C - intérêt de l'analyse des séquences des gènes des glycoprotéines d'enveloppe virales E1 et E2.

The ability of hepatitis C virus (HCV) to infect leukocytes could favour HCV pathogenesis. Although viral infection of these immunocompetent cells is poorly (or not) productive, the impact on their immunomodulatory functions could be important. Viral envelope glycoproteins E1 and E2, because of their crucial role in the recognition of viral receptors on permissive cells, could contribute to viral leukocytic tropism and, as a consequence, to the pathophysiology of HCV chronic infection.

[Study of hepatitis C virus leukotropism by characterization of viral quasispecies in the liver transplantation setting]. / Etude du leucotropisme du virus de l'hépatite C par analyse des quasi-espèces virales dans le contexte de la transplantation hépatique.

Besides hepatocytes, representing the main replication site of hepatitis C virus, peripheral blood mononuclear cells also represent a crucial target for viral infection. Hepatitis C virus compartmentalization (i.e., non-random distribution) of viral variants between plasma and peripheral blood mononuclear cells, more frequently observed in liver transplant patients compared to non-transplanted patients, makes liver transplantation an interesting model for the analysis of hepatitis C leukotropism. This article aims to present, firstly, in clinical and biological features arguing favour of hepatitis C virus infection leukotropism and, secondly, to review current knowledge about compartmentalization between plasma and peripheral blood mononuclear cells, especially in the liver transplantation setting.

Atypical symptoms in patients with herpesvirus DNA detected by PCR in cerebrospinal fluid.

BACKGROUND: Polymerase chain reaction (PCR) detection of herpesvirus DNA in cerebrospinal fluid (CSF) is an important tool in the diagnosis of central nervous system (CNS) syndromes. The corresponding viral infections present with diverse clinical signs, which are often classical although no sign can be considered as specific. This retrospective study aims to describe atypical symptoms in patients with herpesvirus DNA detected in CSF by PCR. A total of 3452 cerebrospinal fluid samples from patients with suspected herpesvirus infection of the CNS were investigated between 1998 and 2003 in our clinical virology laboratory. "In-house" PCRs for each herpesvirus [herpes simplex virus (HSV), varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein Barr virus (EBV), or human herpes virus 6 (HHV6)] were used until 2001 and a commercially available "Herpes Consensus PCR" was used thereafter. One of the five herpesviruses investigated in this study was found in 71 (2.1%) of CSF samples (37 HSV, 14 VZV, 1 CMV, 9 EBV and 10 HHV6). These samples were obtained from 62 patients whose clinical findings were generally consistent with the PCR data. However, some little known features of herpesvirus-related symptoms, such as partial seizure associated with HSV infection, and unusual VZV or HHV6-related myelitis were also observed.

[Rational use of viral serology in the child]. / Utilisation rationnelle des sérologies virales chez l'enfant.

Very sensitive and allowing discrimination between IgG and IgM, the enzyme immunoassays are the most commonly used to carry out viral serologies. The presence of IgG corresponding to a natural or postvaccination immune status or to a latent or occult infection is a reliable information to assess the protection against some opportunistic or teratogenic infections respectively in children or pregnant women. The search of IgM by immunocapture is suitable to early diagnose the majority of common viral diseases in childhood, specially when presenting in an atypical form, and to attest a congenital rubella infection. Moreover, IgG avidity proved to be useful in dating an infection and confirming positive IgM results. However, viral infections localized at an entry site of the host, such as respiratory and enteric diseases, as well as syndromes of herpes simplex and enteroviral origin, do not represent indications of serological diagnosis. Provided its use with discernment, the serological diagnosis of viral infections have to be considered as a high performance and of low cost biological tool.

[Evaluation of two commercial enzyme immunoassays for diagnosis of hepatitis C in the conditions of a virology laboratory]. / Evaluation de deux trousses commerciales EIA pour le diagnostic de l'hépatite C dans les conditions d'un laboratoire de virologie.

BACKGROUND: Most studies which evaluate antibody detection assays are conducted on blood donors specimens, i.e healthy individuals. Sera collected in patients, vs healthy individuals, can make serological tests difficult because of possible non specific reactions interfering with serological tests. The aim of this work was to compare the specificity and the sensitivity of two commercial automated assays for the detection of hepatitis C virus antibody, Monolisa anti-HCV Plus on the Evolis automate (Biorad) and Axsym anti-HCV 3.0 (Abbott). PATIENTS AND METHOD: The prospective study of specificity included 2020 routine serum samples sent to our virology laboratory. The sensitivity was established with eight commercially available HCV seroconversion panels. RESULTS: The Monolisa and the Axsym assays showed a specificity of 99.64 and 99.12%, respectively. Of 49 specimens from eight commercially available HCV seroconversion panels, the number of positive results was 21 and 24 for the two tests, respectively. CONCLUSION: A statistical analysis of specificity and sensitivity results proved no significant difference between the two tests. Nevertheless, the Monolisa kits could be preferred for its more homogeneous sensitivity than the Axsym test and for its apparent better specificity. The final choice of a kit should also take into account the easiness to perform and an optimal integration in the usual practice of the concerned laboratory.

[Immunoblot in the serological diagnosis of hepatitis C virus infection]. / Intérêt de l'immunoblot dans l'évaluation du statut sérologique vis-à-vis de l'hépatite C.

The objective of the study was to assess three immunoblot assays, the Deciscan HCV Plus, the Riba and the Inno-Lia, on 44 discordant samples with three EIA kits. These immunoblots were considered as confirmation reagents. A result was considered as a false positive by anti-HCV antibody assay if the three immunoblots were negative or if two immunoblots were negative with the third being indeterminate and a negative virological genomic diagnosis observed on all the samples. The result was positive if at least two immunoblots out of three were positive. Thus, 34 samples were considered as false positive and ten samples were excluded because it was impossible to conclude between true or false positive result. The 44 discordant results were never confirmed as positive by the use immunoblot or PCR. The three immunoblots were negative for half of the samples and two immunoblots and one indeterminate were observed for 77% of the samples. The false positive results by the Monolisa assay were more often found indeterminate with the Deciscan assay than with the other immunoblots. That was also checked for Vitros/Riba pair. One of the explanations could be the use of common antigens for the reagents from the same manufacturer. The Inno-Lia test is the most specific immunoblot according to the results obtained in our study.

Properties of a chimeric simian-human immunodeficiency virus expressing an hybrid HIV-1 Nef/SIVmac Nef protein.

The nef genes of human and simian immunodeficiency viruses code for a membrane associated protein critical for AIDS development. SIVmac Nef presents C-terminal a 27 amino acid extension absent of HIV-1 Nef. To estimate the influence of this C-terminal domain on virus properties, we constructed viruses derived from SIVmac239 by replacing SIV nef with HIV-1 Lai nef gene (SHIV NefLai4) or with a sequence encoding a Nef fusion protein: HIV-1 Lai Nef/SIV Nef-Cterm (SHIV-Cterm). The recombinant viruses replicated efficiently in vitro in CEMx174 cells and in activated macaque PBMCs. The addition of SIV Nef C-terminal domain to HIV-1 Nef in SHIVNefLai4 did not change the in vitro properties of the chimeric virus, both viruses being more infectious than a nef deleted virus. Although the half-life of Nef fusion protein was augmented, SHIV-Cterm remained slightly less infectious than SIVmac239.

One-round determination of seven leukocyte subsets in rhesus macaque blood by flow cytometry.

BACKGROUND: Rhesus macaques are frequently used in biomedical research as experimental models for studying infectious diseases and for preclinical vaccination trials. The infection of these monkeys with simian immunodeficiency viruses (SIV) or simian-human immunodeficiency viruses (SHIV) reproduces the clinical and immunological characteristics of human infection by human immunodeficiency virus (HIV). Evolution of the immune response in the infected animals is generally analyzed by determining the lymphocyte subsets on blood samples using flow cytometry but requiring multiple, blood consuming, determinations. METHODS: Cell subsets present in whole-blood samples were labeled with a combination of anti-human monoclonal antibodies to CD2, CD20, CD4, CD8, and CD14 coupled to FITC or PE and analyzed by flow cytometry. RESULTS: In one round, we obtained the precise determination of macaque blood cell composition by flow cytometry. Monocytes, granulocytes, eosinophils, B lymphocytes, helper, and cytotoxic T lymphocytes were distinguished. Results obtained correlated strongly with those obtained with conventional blood cell differential systems and with separate staining of lymphocytes. The analysis of blood from healthy rhesus macaques and SHIV-infected animals demonstrated the accuracy of the determination even in very pathological situations such as macaques with simian AIDS. CONCLUSIONS: Our method allows fast determination of the blood cell composition and will be particularly useful to evaluate the cell subset evolution of macaques involved in large-scale experimental trials.

Ultrastructural and molecular characterization of Pneumocystis carinii isolated from a rhesus monkey (Macaca mulatta).

High levels of heterogeneity have been observed among isolates of Pneumocystis carinii derived from different mammalian host species. We report the characterization of P. carinii isolated from a rhesus monkey (Macaca mulatta), which was immunosuppressed as a result of infection with a chimeric simian-human immunodeficiency virus (SHIVsbg). Histopathological examination showed evidence of severe P. carinii pneumonia with a large predominance of trophozoite forms. Alveolitis consisted of typical foamy, honeycomb exudate, with only a few alveolar macrophages. The lung inflammatory response was rather moderate without type-2 pneumocyte hyperplasia or collagenosis. P. carinii organisms were sometimes observed in the bronchiolar lumen. Ultrastructurally, macaque-derived P. carinii was more similar to human- or rabbit-derived parasites than to mouse-derived P. carinii. Molecular studies were carried out on the macaque-derived P. carinii DNA at two genetic loci: the genes encoding the mitochondrial large subunit ribosomal RNA (mt LSU rRNA) and the mitochondrial small subunit ribosomal RNA (mt SSU rRNA). Comparison of the DNA sequences with those from P. carinii isolated from eight other host species demonstrated that the macaque-derived P. carinii was genetically distinct at both loci, and was more closely related to human-derived P. carinii than to P. carinii derived from non-primate sources. We propose that macaque-derived P. carinii be named Pneumocystis carinii f.sp. macacae.

[Retrospective study of the value of the RIBA-3 test in 68 patients with discordant serologies with regard to hepatitis C obtained with third generation ELISA tests. Is there still a value in RIBA-3?]. / Etude rétrospective de l'intérêt du test RIBA-3 pour 68 cas de sérologies discordantes vis-à-vis du virus de l'hépatite C obtenues avec des tests ELISA de 3e génération. Reste-t-il un intérêt au RIBA-3?

The aim of the present study is to evaluate the ability of RIBA-3 to resolve cases with controversial ELISA results, since modifications have been introduced by the manufacturer in July 1997 to analyse immunoblot patterns. Sera from 68 patients are studied: 49 controversial cases Ortho/Murex, 17 Ortho/Abbott and 2 cases tested by the three ELISA kits. Indeterminate patterns by ELISA assays remain unresolved in 65% of the samples. RIBA analysis performed in patients with controversial results Ortho/Murex seems to reveal a lack in sensitivity of the Murex kit, but does not show differences in the specificity between these two immunoassays. The RIBA patterns among the samples with Ortho/Abbott controversial results do not demonstrate any discrepancy in the sensitivity of these ELISA tests but it appears that Ortho could be less specific. Our data need to be further confirmed by the analysis of more samples. At last, when the ELISA result is included in the grayzone, the RIBA pattern is generally indeterminate and it is negative in other cases. Finally, the controversial ELISA results, that are mainly found in patients with severe immunosuppression, remain indeterminate depending on the RIBA test. Moreover, the immunoblot is less sensitive and more expensive than any other HCV ELISA test, so there is no convenience to use it for confirmation of a preliminary positive or indeterminate screening.

[Prenatal diagnosis of viral infections. A two year study in Strasbourg]. / Diagnostic prénatal des infections virales. Bilan de deux années d'activité à Strasbourg.

We report here the results of a 2-year study on the prenatal diagnosis of viral infections in Strasbourg. This screening was carried out by virus isolation, by PCR assay, or by detection of IgM fetal antibody for 98 pregnant women at risk of transmitting one of the viruses that causes fetal disease such as parvovirus B19 (B19), Herpesviruses [cytomegalovirus (CMV), varicella-zoster virus, herpes simplex virus] and rubella virus. A viral etiology was proven in 7 out 98 cases: PCR applied to B19 DNA detection was positive in 5 amniotic fluids (AF), 2 fetal serums and one ascitic liquid. The diagnosis of 2 cases of CMV infection was obtained by both PCR and virus isolation in AF from twins fetuses. The detection of specific IgM in maternal serum or fetal serum is useful to achieve the diagnosis but serological tests on other samples have no efficiency. No virus was found in any other specimen, but the genome of Toxoplasma gondii was detected by PCR in 1 of 17 AF samples analyzed at the Institut de Parasitologie. These findings show that PCR assay is a sensitive method for the positive diagnosis of intrauterine infection and promises to careful follow-up of the pregnancy.

[A case report of post-rubella myelitis in an adult]. / A propos d'un cas de myélite post-rubéolique chez l'adulte.

Neurological complications following rubella are only rarely encountered. We report a case of isolated myelitis. A 44-year-old healthy female suffered from an erythematous macular rash which rapidly cleared. However, the following days, dysuria initiated hospitalization. On admission, she was febrile but alert and in normal mental status. General physical examination was quite unremarkable. Four days later, she suffered from acute urinary retention, fecal retention and vaginal hypoesthesia. Routine laboratory data, chest skull and spinal column X-rays were unremarkable. The sterile cerebrospinal fluid contained 30 lymphocytes/mm3, 0.48 g/ml of protein but normal amount of glucose. Rubella antibody titers showed a significant elevation and specific IgM were detected by immunocapture. Improvement was rapid and recovery was uneventful except a mild vaginal hypoesthesia that persisted 5 weeks later. Diffuse myelitis occurring shortly after rubella vaccination have also been described. The immunopathological mechanisms by which involvement of the nervous system occurs is far from clear. Little is known about the pathogenesis of post-vaccination myelitis and although the mecanism of sensitization and the specific neural antigens are not known, post-infectious and post-vaccinal myelitis are thought to share a common pathogenic basis.

Molecular epidemiology of ocular isolates of adenovirus 8 obtained over nine years.

Twenty nine strains of adenovirus 8 have been isolated over nine years in Strasbourg, France, 22 of which were from one private ophthalmologist. To assess a possible relation between these strains, the DNA of adenovirus was analysed by restriction fragment length polymorphism using eight different enzymes. Among these, three proved discriminant (Xba I, Bgl II, Eco RI) and made it possible to define 13 genotypes differing from each other by one to three DNA bands. Seven genotypes were unique isolates, while three, representing 16 strains, were isolated over five to eight years. All the genotypes but one were closely related, with 87% homology. All 13 differed from an adenovirus 8 strain from Lyon (homology 68-76%). This study confirmed the stability of adenovirus 8 in a given population.

Aspirin and heparin prevent hepatic blood stasis and thrombosis induced by the toxic glycoprotein Bolesatine in mice.

Bolesatine is a toxic glycoprotein isolated from Boletus satanas Lenz, which inhibits protein synthesis in vivo and in vitro. The LD50 (24 h) is 1 mg /kg bw (i.p.), in mice and rats. When given i.p. to mice (0.1 - 1.0 mg/kg bw) bolesatine induced thrombi and blood stasis in the liver, 5 - 21 h after injection, and modifications of the number of blood corpuscles in peripheral blood. These effects were efficiently reversed by aspirin, ticlopidin and heparin (as attested by histology and electron microscopy) which however failed to prevent death in animals given lethal doses. Together, these results showed that the death of bolesatine poisoned animals given high doses, was rather due to a combination of thrombosis and other toxic effects. In addition, they suggest that these antithrombotic drugs may overcome cases of human poisoning, with low exposures of this boletus, showing a hypertension probably due to mechanical obstruction which resists normal therapy.

Protection of SIVmac-infected macaque monkeys against superinfection by a simian immunodeficiency virus expressing envelope glycoproteins of HIV type 1.

The infection of macaque monkeys by attenuated simian immunodeficiency virus can vaccinate against pathogenic molecular clones and isolates of the same virus. The correlates of this potent protective immunity are not fully understood but may be the key to an effective AIDS vaccine for humans. Aiming to determine whether host immune responses to envelope glycoprotein are an essential component of the immunity to primate lentiviruses, we have tried to superinfect SIVmac-infected macaque monkeys with SHIVsbg, a chimeric primate lentivirus constructed from the SIVmac239 genome with the env, rev, tat, and vpu genes from HIV-1 Lai. After inoculation of a large dose of SHIVsbg, the chimeric virus was isolated by coculture of mononuclear blood cells from four of five SIV-infected monkeys, but three animals were protected from extracellular SHIV viremia and did not seroconvert to HIV-1 glycoproteins. In the two SIV-infected monkeys that did develop SHIV viremia, cell-associated viral load was reduced at least 100-fold. These data indicate that an antiviral response capable of effectively controlling primate lentivirus replication might not necessarily involve the envelope glycoprotein.

[Comparison of immunogenicity of vaccination and serovaccination against hepatitis B virus in patients with alcoholic cirrhosis]. / Comparaison de l'immunogénicité de la vaccination et de la sérovaccination contre le virus de l'hépatite B chez les malades atteints de cirrhose alcoolique.

OBJECTIVES: The association of anti-HBs immunoglobulins and anti-HBV vaccine could increase the immunogenicity of the latter. The aim of this prospective randomized trial was to compare the immunogenicity of anti-HBs vaccination and serovaccination in alcoholic patients with cirrhosis. METHODS: Alcoholic patients with cirrhosis were randomized in 2 groups: a) Vaccination group: 3 i.m. injections of GenHevac B followed by one booster at month 9; b) Serovaccination group: same vaccination schedule followed by one i.m. injection of anti-HBs immunoglobulins (500 IU). RESULTS: Twenty-five patients (17 males and 8 females, mean age 56 years) were included in the study: 13 received a vaccination and 12 received a serovaccination. After 12 months, the seroconversion rates were 69% and 67% in vaccination and in serovaccination groups, respectively. The predictive factors of non responsiveness were as following: Child B cirrhosis, low number of CD8, a high CD4/CD8 rate, the existence of HLA DR7 antigen, and the absence of HLA DR1 antigen. CONCLUSION: In alcoholic patients with cirrhosis, serovaccination does not increase the immunogenicity of anti-HBs vaccination and should not be recommended.

High viral load and CD4 lymphopenia in rhesus and cynomolgus macaques infected by a chimeric primate lentivirus constructed using the env, rev, tat, and vpu genes from HIV-1 Lai.

Chimeric primate lentiviruses composed of SIV and HIV genes may allow the analysis of the role of these discrete HIV genes in viral pathogenesis in macaque monkeys. We have constructed a chimeric virus in which the env, rev, tat, and vpu genes of HIV-1 Lai replace the env, rev, and tat genes of the SIVmac239 genome. This virus, SHIVsbg, replicates efficiently in rhesus (Indian and Chinese subspecies) and cynomolgus monkeys with viral loads in PBMC and lymph nodes of up to one infected cell per 30 cells during the acute phase of the infection. Sera from all monkeys recognize specific HIV-1 glycoproteins. The onset of lymphadenopathy in all animals was concurrent with a depletion of CD4 lymphocytes in peripheral blood. The virulence of this SHIV for rhesus and cynomolgus monkeys therefore closely parallels that of HIV-1 for human in the acute phase of the infection. Changes in the env and vpu genes of a molecular clone of HIV-1 can now be analyzed after passage in nonhuman primate species as the SHIVsbg replicates efficiently. The SHIVsbg-macaque model is an important step in the development of a readily available animal model for HIV-1 vaccine studies.

Productive infection of primary cultures of endothelial cells from the cat liver sinusoid with the feline immunodeficiency virus.

Given the similarities between the two viruses, the feline immunodeficiency virus (FIV) is becoming an interesting animal model for human immunodeficiency virus (HIV) studies. To explore the still controversial role of the liver in the development of HIV infection, sinusoidal endothelial cells (SEC) were isolated, and primary cultures were infected with the FIV Villefranche IFFA strain. The isolated cells were characterized by their typical fenestrations, the presence of von Willebrand factor (vWf), and their ability to take up acetylated low-density lipoproteins and denatured collagen. Two weeks after infection, significant amounts of FIV p24 antigen were detected by immunofluorescence in both multinucleated giant and single cells and by enzyme-linked immunosorbent assay in the culture medium. High amounts of viral particles were observed together with different steps of budding at the plasma membrane or at the membrane of intracytoplasmic vacuoles. The released viral particles were shown to be infectious for a permissive cell line. During the first 3 weeks of infection, the only cytopathic effect of FIV was syncytia formation. No noticeable impairment of the pattern of fenestrations and the modulation of their number by a cytoskeleton-mediated process occurred. The productive infection of SEC may contribute to the progression of the infection.

Enterovirus in sudden unexpected deaths in infants.

BACKGROUND: Conventional approaches to virus detection failed to provide convincing evidence of a viral etiology in sudden unexplained deaths in infants (SUDI). Many viruses may not have been detected by the routinely used methods; among them enteroviruses (EV) have seldom been found in SUDI. METHODS: In this study EV were sought directly in stools, in pharyngeal and tracheal samples and in myocardial and lung tissues, by using a nested PCR; they were also sought indirectly by detecting IgM antibodies with a new capture immunoassay. Twenty-four SUDI cases were divided into two groups: Group I, certainly associated with; or Group II, not associated with clinical, biologic or histologic signs of viral infection. RESULTS: EV were found in stools but their prevalence was not significantly different between Group I and Group II (20 and 22.2%, respectively). On the contrary EV were detected in respiratory tract and/or lung samples in 53.8% of infants of Group I and in none of Group II. Anti-EV IgM antibodies were detected in 55.5% of infants of Group I and in none of Group II. CONCLUSIONS: These results indicate that EV infection may be specifically associated with the subgroup of SUDI with viral signs, raising the question of its role in this condition.