Genetic subtyping and V3 serotyping of HIV type 1 isolates in Congo.
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Amino Acid Sequence↗
Biomedical subjects
J M Huraux
Publications and source records attributed to J M Huraux.
Comparative evaluation of hepatitis C virus RNA quantitation by branched DNA, NASBA, and monitor assays.
Several studies have shown a relationship between pretreatment hepatitis C virus (HCV) viral load and the response to interferon (IFN) therapy, creating a need for quantitative HCV-RNA assays. Here, we compared three commercial methods: nucleic acid sequence-based amplification NASBA (Organon), branched DNA 2.0 (bDNA) (Chiron), and Monitor (Roche), with reverse-transcription polymerase chain reaction (RT-PCR) as the reference. We assessed sensitivity and reproducibility on a well-characterized panel of sera (EUROHEP), a Chimp Rodney plasma pool, and samples from IFN-treated and -untreated patients with chronic hepatitis C caused by different HCV genotypes. The reproducibility of the NASBA and bDNA methods was slightly better than that of Monitor, especially for genotypes 2 and 4. NASBA had the highest sensitivity (99% vs. 94% and 88% with Monitor and bDNA, respectively), especially for the follow-up of patients on IFN. NASBA gave the highest HCV-RNA concentrations, which were approximately 10-fold more than with the bDNA assay and 100-fold more than with the Monitor kit. The linearity, tested on the chimp Rodney plasma pool, was better with bDNA for high viral load than with NASBA and Monitor, although for low concentration of HCV RNA, bDNA was negative. Pretreatment viral load was lower in patients who had a sustained virological response to IFN, although the bDNA method was not sensitive enough to quantify all pretreatment samples. This study indicates that gene amplification methods (NASBA or Monitor) have better sensitivity than bDNA assays for quantification of HCV RNA in patients with chronic HCV infection, although the bDNA and NASBA methods are more likely to quantify all genotypes. Prospective studies are needed to demonstrate the usefulness of quantitative assays for the follow-up of patients with chronic hepatitis C.
Base Sequence↗
Three cases of severe subfulminant hepatitis in heart-transplanted patients after nosocomial transmission of a mutant hepatitis B virus.
Fulminant and severe viral hepatitis are frequently associated with mutant hepatitis B virus (HBV) strains. In this study, the genetic background of a viral strain causing severe subfulminant outcome in heart-transplanted patients was studied and compared with viral hepatitis B strains that were not linked to severe liver disease in the same setting. A total of 46 patients infected nosocomially with HBV genotype A were studied. Five different viral strains were detected, infecting 3, 9, 5, 24, and 5 patients, respectively. Only one viral strain was found to be associated with the subfulminant outcome and 3 patient deaths as a consequence of severe liver disease. The remaining 43 patients with posttransplantation HBV infection did not show this fatal outcome. Instead, symptoms of hepatitis were generally mild or clinically undiagnosed. Comparison of this virus genome with the four other strains showed an accumulation of mutations in the basic core promoter, a region that influences viral replication, but also in hepatitis B X protein (HBX) (7 mutant motifs), core (10 mutant motifs), the preS1 region (5 mutant motifs), and the HBpolymerase open reading frame (17 motifs). Some of these variations, such as those in the core region, were located on the tip of the protruding spike of the viral capsid (codons 60 to 90), also known in part as an important HLA class II-restricted epitope region. These mutations might therefore influence the immune-mediated response. The viral strain causing subfulminant hepatitis was, in addition, the only strain with a preCore stop codon mutation and, thus, hepatitis B e antigen (HBeAg) expression was never observed. The combination of these specific viral factors is thought to be responsible for the fatal outcome in these immune-suppressed heart-transplant recipients.
Base Sequence↗
[Maternal-fetal viral infections: preventive treatment of maternal-fetal transmission during pregnancy, delivery and after birth].
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Acquired Immunodeficiency Syndrome↗
The influence of highly active antiretroviral therapy on AIDS-associated Kaposi's sarcoma.
To assess the clinical and biological benefit of highly active antiretroviral therapy on AIDS-associated Kaposi's sarcoma (KS), 13 patients with AIDS-associated Kaposi's sarcoma (five pulmonary KS and eight cutaneous KS) were prospectively followed for a mean duration of 12 months. Six patients were treated with specific anti-KS chemotherapy before or simultaneously with the introduction of antiretroviral therapy. Clinical response was assessed according to the AIDS Clinical Trial Group (ACTG) criteria. CD4 cell counts, plasma HIV-1 RNA and human herpesvirus 8 (HHV-8) viraemia were measured at baseline and at different points. Among patients with pulmonary KS, we observed three complete responses (CR), one partial response (PR) and one progression. The median survival time after the diagnosis of pulmonary KS was 15 months with a median duration of the response after the discontinuation of specific chemotherapy for KS of 8 months. Among patients with cutaneous KS, we observed four CR, three PR and one stable response. A complete response was significantly associated with a reversal in HHV-8 viraemia (five of six vs. one of six; P = 0.02, Mann-Whitney test).
Acquired Immunodeficiency Syndrome↗
Human herpesvirus 8 infection, Castleman's disease and POEMS syndrome.
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Antibodies, Viral↗
Polymorphism of the human immunodeficiency virus type 1 (HIV-1) protease gene and response of HIV-1-infected patients to a protease inhibitor.
In order to analyze the impact of protease gene polymorphism on response to regimens containing a protease inhibitor, the entire protease coding domain from 58 human immunodeficiency virus type 1 (HIV-1)-infected patients who were protease inhibitor naive was sequenced before therapy was started. Plasma HIV-1 RNA levels were measured at baseline and at month 3 and month 6 after treatment. All patients were treated with a combination of two reverse transcriptase inhibitors and a protease inhibitor (saquinavir EOF [n = 28], ritonavir [n = 16], or indinavir [n = 14]). Before treatment, 30 different positions whose codons differed from the subtype B consensus sequence were observed. Major mutations associated with protease inhibitor resistance were not observed. No statistical correlation between the number of amino acid differences and the treatment efficacy at month 3 (-2.4 log) or month 6 (-2.7 log) was observed. At baseline, genotypic analysis of the HIV-1 protease gene of patients who have never received a protease inhibitor does not allow prediction of the efficacy of regimens containing a protease inhibitor.
Acquired Immunodeficiency Syndrome↗
Preferential associations of alleles of three distinct genes argue for the existence of two prototype variants of human herpesvirus 7.
We had previously described six distinct alleles of the glycoprotein B (gB) gene of human herpesvirus 7 (HHV-7). The genetic changes corresponding to these alleles did not affect gB gene transcription or translation in in vitro assays. The study of distinct HHV-7-positive human samples showed preferential associations of some gB alleles with some alleles of two other genes, distantly located on the HHV-7 genome, coding for the phosphoprotein p100 (p100) and the major capsid protein (MCP). Two allele combinations, corresponding to 44 and 31% of the samples studied, respectively, were interpreted as the genetic signatures of two major prototype HHV-7 variants.
Alleles↗
Response to interferon alpha treatment and disappearance of cryoglobulinaemia in patients infected by hepatitis C virus.
BACKGROUND: Mixed cryoglobulinaemia is closely associated with hepatitis C virus (HCV) infection. AIM: To assess in a prospective open study the efficiency of interferon alpha treatment of cryoglobulinaemia, as reflected by the disappearance of cryoglobulins and clinical manifestations of the disease, and to analyse the factors predictive of a response to interferon. METHOD: Eighty seven consecutive patients with chronic hepatitis C treated for the first time with interferon at a dose of 3 x 10(6) international units three times a week for six months were studied. Forty three patients had cryoglobulins, which were responsible for clinical manifestations in 12. RESULTS: At the end of interferon treatment, cryoglobulins had disappeared in 39% of the patients. A clinical improvement (except for neuropathies) was observed in all patients. Six months after interferon treatment was stopped, the same rate of response (normal alanine aminotransferase values and undectable HCV RNA) was observed in patients with or without cryoglobulins. Only 14% of patients still had undetectable cryoglobulins, and all of them also had undetectable serum HCV RNA. The disappearance of cryoglobulins was found less frequently in patients with clinical symptoms than in asymptomatic ones, but the difference was not significant. Sustained responders were more often men, infected by genotype 2 or 3, with a lower pretreatment viral load. CONCLUSION: The presence of cryoglobulins does not seem to affect the response to interferon in HCV infected patients. The improvement in cryoglobulinaemia is strongly associated with a virological response, reinforcing the hypothesis of a direct role for HCV in the pathogenesis of this disease.
Adult↗
[Polymorphism of protease genes in patients infected with HIV-1 and response to therapy including a protease inhibitor].
Protease inhibitors (PIs) are recently introduced drugs that have improved the survival of HIV-infected patients when given in combination with two reverse transcriptase inhibitors. The HIV-1 protease gene is naturally highly polymorphic. Selection pressure due to IP use can result in major or minor resistance-associated mutations (RAMs). This study investigated whether presence before IP therapy of minor RAMs on the protease gene predicts the virological response. Of the 58 PI-naive patients included in the study, 12 had received two nucleoside reverse transcriptor inhibitors, 14 had received indinavir, 16 ritonavir, and 28 saquinavir-SGC. Viral load was measured on D0 (prior to PI initiation) and at M3 and M6 (Roche Monitor 1.5 with 200 and 20 copies/ml as the thresholds). The protease gene was fully sequenced on D0 using the ABI 377 automatic sequencer after RNA amplification by nested RT-PCR. None of the viral strains exhibited major mutations, but 57 of 58 (98%) had at least one minor mutation (median number of substitutions, 4), 60% had 1 to 4 substitutions, and 40% had 5 to 9 substitutions. Substitutions seen with a prevalence > 20% were located at codons 15, 35, 37, 41, 63, and 77. Numbers of substitutions at M3 and M6 were not correlated with viral load or the nature of the PI used, and neither were they significantly different between patients with more or fewer than 20 copies/ml. These data suggest that the protease genotype at PI initiation does not predict the efficacy of a regimen including a PI and is of no assistance in deciding whether or not to include a PI in a triple combination regimen.
Acquired Immunodeficiency Syndrome↗
Point mutations in the varicella-zoster virus DNA polymerase gene confers resistance to foscarnet and slow growth phenotype.
Seven independent laboratory mutants were derived from seven distinct wild-type varicella-zoster virus (VZV) isolates after exposure to increasing concentrations of foscarnet (PFA) and were found to be resistant to this drug. Single base changes resulting in amino acid substitutions were observed in the nucleotide sequence of the DNA polymerase gene of each PFA-resistant mutant. The mutations were found to occur within the domain II (Arg-665 --> Gly for strains vrMOR and vrVER; Val-666 --> Leu for vrLEB; Gln-692 --> Arg for vrOLI) and domain III (Arg-806 --> Ser for vrABD; Leu-809 --> Ser for vrALI and vrCHA) of DNA polymerase gene. In addition, the PFA-resistant mutants exhibited a phenotype characterized by slow growth, the strains showing a marked delay in immediate-early antigen plaque formation compared with the wild-type VZV from which they were derived. These results may have implications for successful isolation and characterization of PFA-resistant strains from clinical samples containing mixed viral populations.
Amino Acid Sequence↗
Yellow fever 5' noncoding region as a potential element to improve hepatitis C virus production through modification of translational control.
The lengthy 5' noncoding region (5' NCR) of hepatitis C virus (HCV) RNA forms a highly ordered secondary structure, very conserved among different strains. It includes an internal ribosome entry site (IRES) element, responsible for the cap-independent translation initiation of HCV RNA. Similarly to the IRES of hepatitis A virus (HAV), another human hepatitis virus, HCV IRES, activity in internal initiation of translation is weak. Furthermore, both viruses exhibit a poor growth phenotype that may result at least partially from an inhibitory control of translation. To enhance HCV translation, as a preliminary step in designing constructs for improvement in viral production, we sought to evaluate a chimeric construct containing the yellow fever virus (YFV) 5' NCR fused to the initiation codon of the HCV coding sequence. YF viral RNA, as the majority of eukaryotic messenger RNAs, is translated by a ribosome scanning mechanism in a cap-dependent manner. The efficiency of translation initiation of the parental HCV construct was compared in vitro in rabbit reticulocyte lysates with that of the chimeric construct containing YFV 5' NCR. Surprisingly, the related distanced YFV 5' NCR was fivefold more active than was the wild-type HCV IRES in directing that function. Furthermore, chimeric transcripts were shown to be effective in vivo after transfection of eukaryotic cells. Taken together, these results raise the following question: why has the HCV genus evolved to the acquisition of an IRES element within its 5' NCR among the Flaviviridae family?
5' Untranslated Regions↗
Prevalence of human herpesvirus 8 infection measured by antibodies to a latent nuclear antigen in patients with various dermatologic diseases.
BACKGROUND: Human herpesvirus 8 (HHV-8) has been detected in all epidemiological forms of Kaposi sarcoma (KS). The role of HHV-8 in dermatologic diseases other than KS is controversial. Some studies based on polymerase chain reaction findings suggest an association between HHV-8 and epithelial tumors of the skin, lymphoproliferative disorders, or pemphigus. OBJECTIVE: To assess the prevalence of antibodies against a latent nuclear antigen of HHV-8 in patients with various dermatologic diseases. DESIGN: An indirect immunofluorescence assay was used to search for HHV-8 antibodies. SETTING: Ambulatory or hospitalized patients from a university hospital associated with a research laboratory. PATIENTS: Eighty-three patients with various non-KS dermatologic diseases and 16 patients with KS who were seronegative for the human immunodeficiency virus. Controls were 100 healthy subjects living in the same area. RESULTS: Antibodies to HHV-8 were found in 100% (16/16) of the patients with KS and 3.6% (3/83) of the patients with non-KS dermatologic diseases: 1 patient with pemphigus vulgaris, 1 with discoid lupus erythematosus, and 1 with bullous pemphigoid. The prevalence of antibodies to HHV-8 in controls was 2% (2/100) and was not significantly different than the prevalence in patients with dermatologic diseases other than KS (P =.28). CONCLUSIONS: Our serologic study confirms the higher prevalence of HHV-8 antibodies in patients with KS and demonstrates that contrary to other human herpesviruses, HHV-8 is not a ubiquitous virus in France. We could not determine any causal association between HHV-8 and pemphigus or lymphoproliferative disorders of the skin.
Adult↗
Slow progression rate of fibrosis in hepatitis C virus patients with persistently normal alanine transaminase activity.
In hepatitis C virus (HCV) patients with persistently normal alanine transaminase (ALT), the progression rate of fibrosis is unknown. The aims of this study were: 1) to compare HCV patients with normal ALT (group I) with HCV patients with elevated ALT (group II) matched on independent factors associated with fibrosis; and 2) to assess the progression rate of fibrosis. One hundred two HCV patients were included in each group. Histological lesions were staged using the METAVIR score. We defined fibrosis progression per year as the ratio of the fibrosis stage in METAVIR units to the duration of infection. In group I, ALT values were normal, and lower than in group II (25 vs. 127 IU/L; P < .0001). HCV RNA was present less frequently in group I (66% vs. 97%; P < .0001). There were no significant differences for viremia and genotypes. Histological activities were lower in group I (0.6 vs. 1.38; P < .0001). The stage of fibrosis was lower in group I (0.95 vs. 1.8; P < .001). The median progression rate of fibrosis was lower in group I (0.05 vs. 0.13; P < .001). In group I, after exclusion of negative HCV-RNA patients, the median progression rate of positives remained lower (0.05 vs. 0.13; P < .001). In group I, all cirrhotic patients (n = 3) were heavy drinkers. HCV patients with normal ALT showed weaker histological activity and lower fibrosis scores, and the progression rate of fibrosis was twice as slow as in HCV patients with elevated ALT. In these patients, severe fibrosis was associated with high alcohol consumption.
Adolescent↗
Mutations in NS5A region of hepatitis C virus genome correlate with presence of NS5A antibodies and response to interferon therapy for most common European hepatitis C virus genotypes.
A part of the hepatitis C virus (HCV) nonstructural protein 5A (NS5A) amino acid sequence, designated as an interferon (IFN)-sensitive determining region (ISDR), has been shown to be correlated with a response to IFN in Japanese patients. We have shown previously that the presence of NS5A antibodies (Abs) detected by the INNOLIA test (IL-NS5A Ab) is also correlated with a response to IFN. The aim of this study was to investigate, in a wide range of patients, the possible relationship within the NS5A protein between the sequence of ISDR and that used in the INNOLIA test designated as IL3R. Serum samples from 52 patients infected by HCV genotypes 1, 2, and 3 were analyzed before and after treatment. The patients were classified as nonresponders (NRs), responder-relapsers (RRs), or long-term responders (LTRs). We amplified the NS5A region for 42 patients using polymerase chain reaction (PCR), and these amplicons were sequenced directly. The 10 remaining patients were analyzed using PCR with mutation-specific primers. No correlation was found between the IL3R sequence of the HCV strains and the presence of the IL-NS5A Ab for all genotypes. However, for the subtype 1b, only 2 of 11 NR patients tested had an arginin in position 2218 within the ISDR versus 3 of 3 LTR and 10 of 13 RR patients. All patients with R-2218 had IL-NS5A Ab. For the genotype 1a, 2 of 2 LTR and 1 of 3 RR were mutated in position 2216-2218 in comparison to three NR sequences. For the genotype 3, no mutations were found in the region homologous to 1b-ISDR, but 4 of 5 LTR and RR patients had a mutation T-2161 to A or V versus 0 of 3 NR patients. A close correlation was found between arginin in position 2218 in ISDR, the presence of IL-NS5A Ab, and the response to IFN therapy for genotype 1b, but this association did not predict a long-term response. For genotype 3, a potential ISD mutation could be located at the codon 2161.
Amino Acid Sequence↗
Pattern of HCV antibodies with special reference to NS5A reactivity in HCV-infected patients: relation to viral genotype, cryoglobulinemia and response to interferon.
BACKGROUND/AIMS: We aimed to compare the anti-hepatitis C virus reactivity in confirmatory assays (RIBA 3.0 Ortho Diagnostic and INNO-LIA HCV Ab III Innogenetics) among patients infected with different hepatitis C virus genotypes, with or without cryoglobulinemia, and in patients treated with interferon. METHODS: One hundred and three patients followed in our hepatogastroenterology unit were included in the study and compared to 320 consecutive patients tested using RIBA 3.0. Seventy-nine of the 103 patients were treated with interferon. Long-term responders to interferon were defined as having normal alanine aminotransferase levels and being HCV RNA negative 6 months after the end of treatment. Initial responders were defined as having normal alanine aminotransferase levels at the end of interferon therapy but abnormal alanine aminotransferase levels and/or detectable HCV RNA during the following 6 months. Non-responders were defined as still having elevated alanine aminotransferase during and after interferon. Serological tests (RIBA and INNO-LIA) were performed according to the manufacturers' instructions. HCV RNA was detected by nested polymerase chain reaction. Hepatitis C virus genotype was determined by using a Line Probe Assay (Innogenetics). RESULTS: There was no significant difference in the pattern of hepatitis C virus reactivity according to the hepatitis C virus genotype or presence of cryoglobulinemia. Twenty-three patients were classified as non-responders, 35 as initial responders, 21 as long-term responders. NS5 reactivity was significantly different (p<0.01) between these three groups: 34% of non-responders (8/23) had RIBA 3.0 NS5 reactivity and 13% (3/23) were reactive in the INNO-LIA III. Almost all long-term responders (95%) had NS5 reactivity by both RIBA 3.0 and INNO-LIA III. CONCLUSION: We conclude that patients who respond to interferon have stronger reactivity against NS5 antigens than non-responders. Molecular changes in the NS5A region may be responsible for such differences, as recently suggested.
Antiviral Agents↗
Single amino acid change in DNA polymerase is associated with foscarnet resistance in a varicella-zoster virus strain recovered from a patient with AIDS.
The genetic characterization of a foscarnet-resistant strain of varicella-zoster virus (VZV) that was isolated from a patient with AIDS is reported. Compared with the sequence of the Dumas reference strain, this strain, which was isolated from a patient in whom foscarnet treatment failed, had two point mutations. The emergence of one of the mutations, which includes a change from a glutamic acid to a lysine at position 512 in the DNA polymerase, suggests that this mutation is implicated in the VZV foscarnet resistance. The other mutation, which replaces serine 863 by a glycine, is also present in 2 susceptible strains--Oka and a wild-type isolate.
AIDS-Related Opportunistic Infections↗
Line probe assay for detection of human immunodeficiency virus type 1 mutations conferring resistance to nucleoside inhibitors of reverse transcriptase: comparison with sequence analysis.
We compared the line probe assay (LiPA) to sequence analysis for the detection of mutations conferring resistance to nucleoside inhibitors of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT). Plasma samples from 40 patients who had received zidovudine, dideoxyinosine, and dideoxycytosine, alone or in combination, and who were enrolled in the ALTIS 2 clinical trial (lamivudine [3TC] plus stavudine) were tested at enrollment and at week 24. RT PCR products from plasma were used for LiPA, and DNA was used for sequence analysis. LiPA gave uninterpretable results for 8.5% of the analyzed codons corresponding to 63 samples, mainly for codons 41, 69, and 70. Several minor discrepancies between the two methods occurred, mainly due to the ability of LiPA to detect mixed populations while sequence analyses detect a single homogeneous population. LiPA is suitable for detecting mixed populations and easy to implement in clinical laboratories and might be useful for epidemiological surveys of primary HIV-1 resistance.
Anti-HIV Agents↗