Elyanne Gault

Molecular Phylogenetic Analyses Indicate a Wide and Ancient Radiation of African Hepatitis Delta Virus, Suggesting a Deltavirus Genus of at Least Seven Major Clades

ABSTRACT Hepatitis D virus (HDV) is a satellite of hepatitis B virus (HBV) for transmission and propagation and infects nearly 20 million people worldwide. The HDV genome is a compact circular single-stranded RNA genome with extensive intramolecular complementarity. Despite its different epidemiological and pathological patterns, the variability and geographical distribution of HDV are limited to three genotypes and two subtypes that have been characterized to date. Phylogenetic reconstructions based on the delta antigen gene and full-length genome sequence data show an extensive and probably ancient radiation of African lineages, suggesting that the genetic variability of HDV is much more complex than was previously thought, with evidence of additional clades. These results relate the geographic distribution of HDV more closely to the genetic variability of its helper HBV.

Efficacy of peginterferon alpha-2b in chronic hepatitis delta: relevance of quantitative RT-PCR for follow-up.

Hepatitis delta virus (HDV) can cause severe acute and chronic liver disease in patients infected by hepatitis B virus. Interferon alpha at high doses, although poorly efficient, is the only treatment reported to provide some benefit in chronic hepatitis delta. Pegylated interferon alpha (PEG‐IFN) has not yet been evaluated. Treatment is usually monitored by the qualitative detection of HDV‐RNA in serum. In this study, safety and efficacy of PEG‐IFN were assessed in chronic hepatitis delta, and serum HDV‐RNA kinetics were determined using quantitative RT‐PCR. Fourteen patients with chronic hepatitis delta received subcutaneous PEG‐IFN alpha‐2b during 12 months (1.5 μg/kg per week). Serum HDV‐RNA was quantified at initiation and during the course of therapy, and during the posttreatment follow‐up period, which ranged from 6 to 42 months (median 16 months). PEG‐IFN alpha‐2b was well tolerated, inducing no serious adverse effect. Sustained biochemical response was obtained in 8 patients (57%). At the end of treatment, 8 patients (57%) had achieved virological response (undetectable HDV‐RNA). Sustained virological response throughout the posttreatment follow‐up period was observed in 6 patients (43%). HDV‐RNA kinetics were predictive of the response: after 3 months of PEG‐IFN, HDV‐RNA levels were significantly lower in the responders than in the nonresponders group (P = .018). After 6 months of therapy, a negative HDV‐RNA was predictive of sustained response (P = .021). In conclusion, this preliminary study indicates that PEG‐IFN alpha‐2b is safe and efficient for treatment of chronic hepatitis delta. The follow‐up of HDV‐RNA levels during therapy, which allows the differentiation of various profiles of virological responses, improves treatment monitoring. (HEPATOLOGY 2006;44:728–735.)

Eighth major clade for hepatitis delta virus.

Hepatitis delta virus is the only representative of the Deltavirus genus, which consists of 7 differentiated major clades. In this study, an eighth clade was identified from 3 distinct strains. Deltavirus genetic variability should be considered for diagnostic purposes. Clinical consequences of the diversity have yet to be evaluated.

Real-Time PCR Quantification of Human Cytomegalovirus DNA in Amniotic Fluid Samples from Mothers with Primary Infection

ABSTRACT A real-time PCR assay was developed to quantify human cytomegalovirus (HCMV) DNA in amniotic fluid (AF) samples collected from 30 pregnant women with primary HCMV infection as detected either from HCMV-immunoglobulin G (IgG) seroconversion or by the presence of HCMV-specific IgG and IgM associated with a low IgG avidity. Clinical information available for each case included ultrasonographic examination and fetal or newborn outcome. HCMV infection of fetuses or newborns was confirmed for the 30 studied cases. AF samples were subdivided into three groups. In group A (n = 13), fetuses presented major ultrasound abnormalities, and pregnancy was terminated. In group B (n = 13), fetuses had normal ultrasound findings, the pregnancy went to term, and the newborns were asymptomatic at birth. In group C (n = 4), fetuses had no or minor ultrasonographic signs, and pregnancy was terminated. The HCMV DNA load values in AF samples were significantly higher in group A (median, 2.8 × 105 genome equivalents [GE]/ml) than in group B (median, 8 × 103 GE/ml) (P = 0.014). Our findings suggest that HCMV load level in AF samples correlates with fetal clinical outcome but might also be dependent on other factors, such as the gestational age at the time of AF sampling and the time elapsed since maternal infection.

Quantification of Hepatitis Delta Virus RNA in Serum by Consensus Real-Time PCR Indicates Different Patterns of Virological Response to Interferon Therapy in Chronically Infected Patients

ABSTRACT Hepatitis delta virus (HDV), in association with hepatitis B virus, is responsible for severe acute and chronic hepatitis. Treatment of the infection relies on the long-term administration of high doses of alpha interferon (IFN), and the treatment efficiency is monitored by the detection of anti-HDV immunoglobulin M and HDV genome in serum. Like the case for other chronic viral infections, HDV genome quantification in serum should be useful for the follow-up of infected patients. The aims of this study were to develop a quantitative assay for the detection of any type of HDV in serum and to evaluate the benefit of HDV RNA quantification for the follow-up of chronically infected patients receiving IFN. A real-time reverse transcription-PCR assay was developed to quantify the HDV RNA load in serum. Its efficacy was evaluated with 160 serum samples, 76 of which were collected from 11 chronically infected patients who were treated with pegylated IFN. The assay was sensitive (100 copies/ml of serum) and efficient for all HDV types, including type 3 and the recently described types 5, 6, and 7. The viral load determinations for treated patients allowed us to identify different profiles of virological responses to IFN therapy with more accuracy than that attainable with the qualitative approach. In conclusion, we have developed a quantitative HDV RNA assay for serum which is adapted to the follow-up of antiviral treatment for patients infected with any HDV type. The assay will help us to understand the natural history of HDV infection and to define guidelines for the management of chronic delta hepatitis.

Guillain–Barré Syndrome following Primary Cytomegalovirus Infection: A Prospective Cohort Study

BACKGROUND Little is known about the epidemiology and the prognostic factors of Guillain-Barré syndrome (GBS) following primary infection with cytomegalovirus (CMV-GBS). METHODS We prospectively followed up 506 patients with cases of GBS who were admitted to our center from 1996 through 2006. We diagnosed 63 (12.4%) CMV-GBS cases by immunoglobulin (Ig) M detection and IgG avidity. Plasma CMV DNA was detected at hospital admission. Patient subgroups were compared using Fishers exact test and the Wilcoxon rank-sum test. Temporal variations were analyzed with time series methods. RESULTS Patients with CMV-GBS were mostly young (median age, 32 years; sex ratio, 0.85), but we also identified a subpopulation of patients consisting of women aged >50 years. Sensory defects (in 72% of cases) and facial palsy (49%) were frequent, and test results positive for CMV DNA in plasma at hospital admission (found in 62% of cases) tended to be associated with objective sensory defect (P=.052). The main factors associated with long-term neurological sequelae (21%) were older age (P<.001) and assisted ventilation during hospitalization (P=.005). The number of CMV-GBS cases decreased between 1996 and 2006 (P=.019) and displayed an annual periodicity between the months of July and October. The incidence of CMV-GBS was estimated to be between 0.6 and 2.2 cases per 1000 cases of primary CMV infection (versus 0.25 to 0.65 cases per 1000 cases of Campylobacter jejuni infection). CONCLUSIONS This study provides new insights about the epidemiology of CMV-GBS and shows that the risk of developing GBS is similar following primary CMV infection or C. jejuni infection. Our results also suggest a direct or indirect involvement of viral replication in the neuropathological processes of CMV-GBS.

A Human Rotavirus with Rearranged Genes 7 and 11 Encodes a Modified NSP3 Protein and Suggests an Additional Mechanism for Gene Rearrangement

ABSTRACT A human rotavirus (isolate M) with an atypical electropherotype with 14 apparent bands of double-stranded RNA was isolated from a chronically infected immunodeficient child. MA-104 cell culture adaptation showed that the M isolate was a mixture of viruses containing standard genes (M0) or rearranged genes: M1 (containing a rearranged gene 7) and M2 (containing rearranged genes 7 and 11). The rearranged gene 7 of virus M1 (gene 7R) was very unusual because it contained two complete open reading frames (ORF). Moreover, serial propagation of virus M1 in cell culture indicated that gene 7R rapidly evolved, leading to a virus with a deleted gene 7R (gene 7RΔ). Gene 7RΔ coded for a modified NSP3 protein (NSP3m) of 599 amino acids (aa) containing a repetition of aa 8 to 296. The virus M3 (containing gene 7RΔ) was not defective in cell culture and actually produced NSP3m. The rearranged gene 11 (gene 11R) had a more usual pattern, with a partial duplication leading to a normal ORF followed by a long 3′ untranslated region. The rearrangement in gene 11R was almost identical to some of those previously described, suggesting that there is a hot spot for gene rearrangements at a specific location on the sequence. It has been suggested that in some cases the existence of short direct repeats could favor the occurrence of rearrangement at a specific site. The computer modeling of gene 7 and 11 mRNAs led us to propose a new mechanism for gene rearrangements in which secondary structures, besides short direct repeats, might facilitate and direct the transfer of the RNA polymerase from the 5′ to the 3′ end of the plus-strand RNA template during the replication step.

Rearrangements of Rotavirus Genomic Segment 11 Are Generated during Acute Infection of Immunocompetent Children and Do Not Occur at Random

ABSTRACT Group A rotaviruses are the main cause of viral gastroenteritis in infants. The viral genome consists of 11 double-stranded RNA (dsRNA) segments. Dysfunction of the viral RNA polymerase can lead to gene rearrangements, which most often consist of partial sequence duplication of a dsRNA segment. Gene rearrangements have been detected in vivo during chronic infection in immunodeficient children or in vitro during passages at a high multiplicity of infection in cell culture, suggesting that these replication conditions lead to selective advantages favoring the recovery of viruses with rearranged genes. During acute rotavirus infection, the replication level is high, but the occurrence of rearrangement events has never been reported. By the use of a reverse transcription-PCR assay specifically designed to detect small numbers of copies of rearranged forms of segment 11 in a high background of its standard counterpart, we detected 12 rearrangement events among 161 cases (7.5%) of acute rotavirus infection in immunocompetent children. Strikingly, in all but one case, rearrangement took place at the same location within the short direct repeat AUGU sequence. For the unique case with a different rearrangement pattern, the rearrangement occurred within the direct repeat ACAAGUC that was specific for this isolate. In conclusion, we report the occurrence of segment 11 rearrangements during acute rotavirus infection in immunocompetent children. We show that under such conditions of infection, the viral RNA polymerase generates rearrangements which occur not at random but within direct repeats which might constitute hot spots for RNA recombination.

Monitoring epidemic viral respiratory infections using one‐step real‐Time Triplex RT‐PCR targeting influenza A and B viruses and respiratory syncytial virus

Rapid and specific diagnosis of influenza A/B and respiratory syncytial virus (RSV) viruses is needed for optimal management of patients with acute respiratory infections. In this study, a one‐step triplex real‐time RT‐PCR assay was developed for rapid diagnosis of influenza A/B and RSV infections to optimize diagnosis efficiency of acute respiratory infections. Cell‐culture supernatants and clinical samples were used to evaluate specificity and sensitivity of the assay. The assay was used routinely during two winter epidemics for testing respiratory specimens from 2,417 patients. The limit of detection in cell‐culture supernatant was 1–10 plaque forming units/input (influenza A/B) and 2 × 10−2 50% tissue culture infectious dose/input (RSV). In clinical samples, the assay was as sensitive as commercial molecular assays for the detection of each influenza A/B and RSV (Flu‐A/B and RSV‐A/B r‐gene™) individually, and far more sensitive than antigen detection. During the winter 2008–2009, the assay identified 145 RSV, 42 influenza A, and one mixed RSV‐influenza A infections among 298 patients. The next winter, the assay was used in two independent hospital laboratory settings. 776 patients were tested in one hospital and 1,343 in the other, resulting in 184 and 501 RSV, 133 and 150 influenza A, and 1 and 11 mixed RSV‐influenza A infections, respectively, being detected. This new user‐friendly assay allows rapid (within hours), effective molecular diagnosis of single or mixed infections involving influenza A (including seasonal A H1N1 and H3N2, and A(H1N1) 2009), influenza B, and RSV(A/B). The assay is very valuable for managing patients during winter epidemics when influenza and respiratory syncytial viruses co‐circulate. J. Med. Virol. 83:695–701, 2011.

Multicenter Trials Need To Use the Same Assay for Hepatitis C Virus Viral Load Determination

ABSTRACT This study, involving 20 laboratories and using currently available assays for hepatitis C virus RNA quantification, demonstrated that differences in viral load values are due not to interlaboratory variations but rather to the nature of the assay itself. This underlines the importance of using the same assay in multicenter studies or when monitoring antiviral therapy.