Journal of Clinical Virology

Editorial Board

2012-02-01

An adolescent with fever, headache, and myalgias

Virginia M. Pierce, Richard L. Hodinka — 2011-12-21

A 17-year-old male presented to the Emergency Department in February 2011 with a five day history of fever (maximum temperature of 104°F [40°C]) and malaise, diffuse myalgias, frontal headache, and progressive fatigue that had started two weeks earlier. He reported no weight loss, rhinorrhea, sore throat, cough, dysuria, or rash, but complained of photophobia, nausea, daily episodes of vomiting and right lower quadrant abdominal pain, and nonbloody diarrhea that began on the day of presentation.

Ten years of human metapneumovirus research

F. Feuillet, B. Lina, M. Rosa-Calatrava, G. Boivin — 2011-11-10

Abstract: Described for the first time in 2001, human metapneumovirus (hMPV) has become one of the main viral pathogens responsible for acute respiratory tract infections in children but also in the elderly and immuno-compromised patients. The pathogen most closely related to hMPV is human respiratory syncytial virus (hRSV), the most common cause of bronchiolitis and pneumonia in young children. hMPV has been classified into two main viral groups A and B and has a seasonal distribution in temperate countries with most cases occurring in winter and spring. Given the difficulties encountered in culturing hMPV in vitro, diagnosis is generally achieved using real-time polymerase chain reaction.Like other Paramyxoviridae, hMPV has a negative-sense single-stranded RNA genome that includes 8 genes coding for 9 different proteins. The genomic organization and functions of surface attachment and fusion glycoproteins are relatively similar to those of hRSV. Although many groups have studied the viral life cycle of hMPV, many questions remain unanswered concerning the exact roles of the viral proteins in the attachment, fusion and replication of hMPV.To date, there remains no approved modality to combat hMPV infections. The majority of treatments that have been tested on hMPV have already demonstrated activity against hRSV infections. Some innovative approaches based on RNA interference and on fusion inhibitors have shown efficacy in vitro and in animal studies and could be beneficial in treating human hMPV disease. Difficulties faced inducing a durable immune response represent the biggest challenge in the development of an effective hMPV vaccine. Several strategies, such as the use of live-attenuated viruses generated by reverse genetics or recombinant proteins, have been tested in animals with encouraging results.

Establishing diagnostic cut-off criteria for the COBAS AmpliPrep/COBAS TaqMan HIV-1 Qualitative test through validation against the Amplicor DNA test v1.5 for infant diagnosis using dried blood spots

Jean Maritz, Wolfgang Preiser, Gert U. van Zyl — 2011-12-23

Abstract: Background: As antibody testing cannot confirm HIV-1 infection in children less than 18 months of age, diagnosis in these children depends on nucleic acid testing. The COBAS® AmpliPrep/COBAS® TaqMan® (CAP/CTM, Roche® Molecular Systems, Inc., Branchburg, NJ) HIV-1 Qualitative test is a total nucleic acid real-time PCR assay utilising whole EDTA blood or dried blood spots (DBS), which recently replaced the Roche® AMPLICOR® DNA test v1.5 (Amplicor) as the diagnostic HIV PCR assay in many South African laboratories. For the Amplicor assay, stringent diagnostic criteria were previously formulated for the local population, and a comparison reported the CAP/CTM's sensitivity at 99.7% and specificity at 100% for both sample types compared to these Amplicor criteria.Objectives: To validate the assay prior to introduction in our laboratory and to define stringent diagnostic cut-off criteria.Study design: Whole EDTA blood samples from patients younger than 18 months sent for routine HIV-1 diagnosis were tested by Amplicor, and positive results were confirmed from DBS. CAP/CTM assays were subsequently performed from DBS.Results: The CAP/CTM had a sensitivity of 98.8% and a specificity of 97.1%, but a positive predictive value (PPV) of only 78.7% compared to the Amplicor assay. Samples positive by CAP/CTM but negative by Amplicor displayed poor amplification curves compared to concordant positive samples. Upon re-testing those with sufficient material available by CAP/CTM, all showed negative results.Conclusions: The decreased PPV may either be due to false positive CAP/CTM results, or increased sensitivity compared to the Amplicor assay. Criteria were formulated for defining presumed false-positive results.

HCV core antigen testing in HIV- and HBV-coinfected patients, and in HCV-infected patients on hemodialysis

2011-12-16

Abstract: Background: A quantitative HCV core antigen (HCVcoreAg) immunoassay has been developed for the confirmation of viremia in patients with hepatitis C.Objectives: We evaluated the correlation of HCV RNA and HCVcoreAg in different patient populations without HCV-specific treatment: HIV/HCV-coinfection, HBV/HCV-coinfection, and patients with end-stage renal disease.Study design: HCVcoreAg was quantified by a fully-automated immunoassay. Correlation of HCVcoreAg with HCV RNA was studied cross-sectionally in HIV/HCV- and HBV/HCV-coinfected patients, as well as before and after hemodialysis in patients with end-stage renal disease.Results: A concordant positive or negative test result for both HCV RNA and HCVcoreAg was observed in 68 of 71 (96%), 55 of 57 (96%), and in 109 of 109 (100%) samples of patients with HIV- or HBV/HCV-coinfection, and patients undergoing hemodialysis, respectively. HCVcoreAg showed high correlation with HCV RNA in samples from HIV/HCV-coinfected patients and HCV-infected patients undergoing hemodialysis (r=0.97 and r=0.94, p<0.001). There was no overall correlation between HCVcoreAg and HCV RNA in HBV/HCV-coinfected individuals (r=0.04, p=0.822). Excluding patients with HCV RNA to HCVcoreAg ratios below 100 and above 10,000kIU/fmol led to improved correlation (r=0.53; p=0.02), but remained worse than for the other cohorts. Overall, HCV RNA to HCVcoreAg ratios did not differ significantly between the different patient populations, though variation tended to be higher in HBV/HCV-coinfected patients. Patients with lower HCV RNA levels tend to have lower HCV RNA/HCVcoreAg ratios.Conclusions: HCVcoreAg represents a reliable marker of viral replication showing a good correlation with HCV RNA in various patient populations, with some limitations in HBV/HCV-coinfection.

HPV genotypes and their prognostic significance in head and neck squamous cell carcinomas

Jaana Rautava, Jonna Kuuskoski, Kari Syrjänen, Reidar Grenman, Stina Syrjänen — 2011-12-16

Abstract: Background: Human papillomavirus (HPV) has been reported in up to 50% of head and neck squamous cell carcinomas (HNSCCs). Presence of HPV in HNSCC has been associated with more favorable prognosis.Objectives: This study was designed to disclose HPV genotype distribution in head and neck squamous cell carcinomas (HNSCC) and their role in disease outcome. In addition, role of herpesviruses 1 and 2 (HSV-1 and -2) and cytomegalovirus (CMV) as co-factors was elucidated.Study design: HPV-genotyping of 106 HNSCC was done with Multimetrix®-kit. Luminex-based-method was used to detect HSV-1 and -2 and CMV.Results: In males, 50% of HNSCC were HPV DNA positive and 25% of these were multiple HPV-types infections and in women, 72% and 31%, respectively. Low-risk (LR) HPV-types were found in 20.5% and co-infection with HSV-1 in 6.6%. Patients with HPV-positive and -negative HNSCC had similar survival. Patients not treated with chemoradiotherapy and co-infected with HSV-1 and HPV had a worse outcome. Similarly patients with LR-HPVs treated with radiotherapy had a poor prognosis.Discussion: Radiotherapy for HNSCC in patients with either the presence of LR-HPV-types or a co-infection with HPV and HSV-1 may result in poor outcome.

Comparison of Abbott RealTime High Risk HPV and Hybrid Capture 2 for the detection of high-risk HPV DNA in a referral population setting

2011-11-24

Abstract: Background: The Abbott RealTime High Risk HPV assay (ART) is an automated multiplex real-time PCR test for detection of DNA from 14 high risk (HR) HPV types in cervical specimens and simultaneous distinction of HPV16 and HPV18 from other HR-HPV.Objectives: To evaluate the performance of the ART assay in specimens referred for HPV testing to our laboratory (referral population) by comparison with historical data from HC2 and INNO-LiPA as well as histological status, if available.Study design: 412 cervical specimens were collected from women between 18 and 70 years of age: 301 previously tested by HC2 without clinical data and 111 previously tested by HC2 and INNO-LiPA with histological diagnosis of CIN3+.Results: Our study demonstrated good overall agreement between ART, HC2 and INNO-LiPA. In the group of the CIN3+ specimens HR-HPV was detected by ART in 93.07% (95% CI: 88.12–98.02), while HR-HPV detection rates with HC2 and INNO-LiPA were 91.09% (95% CI: 85.53–96.65) and 95.05% (95% CI: 90.82–99.28), respectively. The typing capability of ART for HPV16, HPV18 and a pool of twelve other HR-HPV types was investigated by comparison with INNO-LiPA demonstrating high overall assay concordance (89.81%; k 0.87).Conclusions: The Abbott RealTime assay showed similar clinical performance for detection of CIN3+ compared with HC2. The high level of automation and ability to identify HPV16, HPV18 and other HR-HPV make this assay a very attractive option for HR-HPV testing, potentially improving patient management by risk stratification of cytological abnormal populations.

Molecular epidemiology of a large community-based outbreak of hepatitis B in Bristol, UK

2011-11-14

Abstract: Background: A large outbreak of hepatitis B virus (HBV) infection in the UK occurred between 2001 and 2005 in Bristol, UK.Objectives: To identify HBV strains circulating amongst risk groups in the HBV outbreak cohort.Study design: Cross-sectional study of acute HBV outbreak cases in Bristol.Results: HBV sequences from sera of 95 of the 237 cases (40%) were characterised. The majority of cases (77%) were found to carry an HBV variant belonging to genotype D, designated HBVBV. Eighty-eight percent (36/41) of sequences from injection drug users were HBVBV as were 70% (19/27) from those with heterosexual intercourse as the primary identified risk factor. Of 15 sequences characterised from cases of pre-outbreak acute or chronic hepatitis B residing in Bristol, 40% also carried HBVBV; the earliest was from a case identified in 1994.Conclusion: The findings from this study link the spread of HBVBV from injecting drug users to the general population through heterosexual intercourse during the outbreak. The molecular sequencing of specimens from this outbreak reports the emergence of HBVBV, a HBV strain circulating in Bristol and South West England, as the cause of one of the largest outbreaks of acute hepatitis B in the UK.

Molecular characterization of a novel entecavir mutation pattern isolated from a multi-drug refractory patient with chronic hepatitis B infection

2011-11-11

Abstract: Background: Prolonged antiviral treatment results in selection and accumulation of resistant strains in quasispecies pool in hepatitis B virus (HBV) infection.Objectives: The aim of this study was to characterise a novel HBV pattern which shows resistance to lamivudine, adefovir dipivoxil and entecavir using in vitro phenoyping assay.Study design: A male 36 years old patient diagnosed with anti HBe-positive chronic hepatitis B (CHB) had received lamivudine treatment for 7 years following an initial unsuccessfull interferon treatment. The therapy had been switched to adefovir and then to entecavir when breakthrough occcured during each treatment. This led only to a temporary HBV DNA decline which soon was followed by viral breakthrough despite the lack of known entecavir resistance mutations. Patient died after 9 months of entecavir treatment from liver failure. A total of 434 clones from 6 different serum samples were analysed retrospectively. HBV genomes bearing mutation patterns suggestive of antiviral resistance were analysed by in vitro phenotyping assay.Results: Dominance of a clone carrying L80LV, L91I, M204I, S219A, N238D, Y245H changes was detected in the last serum sample of the patient just before his death. This pattern displayed 30.4 fold resistance to entecavir when compared with the wild type HBV by in vitro phenotyping assay.Conclusion: A novel mutation pattern showing a high degree of resistance to entecavir was documented. In this pattern, the S219A and Y245H mutations mainly seem to contribute to the emergence of ETV resistance.

The dominance of human coronavirus OC43 and NL63 infections in infants

2011-12-21

Abstract: Background: It is unknown to what extent the human coronaviruses (HCoVs) OC43, HKU1, 229E and NL63 infect healthy children. Frequencies of infections are only known for hospitalized children.Objectives: Comparing infection frequencies in children who have mild infections with frequencies in children needing hospital uptake will determine whether infection by one of the four HCoVs leads to more severe disease. In addition, the sequence of seroconversions can reveal whether infection by one HCoV protects from infection by other HCoVs.Study design: Two distinct study groups were monitored: healthy children and children hospitalized due to respiratory infection. HCoV natural infection rates in healthy children were obtained by serology in 25 newborns (followed 0–20months). The frequencies of severe HCoVs infection was determined by real time RT-PCR among 1471 hospitalized infants (<2-years old) with acute respiratory tract disease.Results: The majority of healthy children seroconverted for HCoV-OC43 (n=19) and HCoV-NL63 (n=17), less for HCoV-HKU1 (n=9) and HCoV-229E (n=5). Notably, HCoV-HKU1 seroconversion was absent after HCoV-OC43 infection. Also HCoV-229E infection was rarely observed after HCoV-NL63 infection (1 out of 5). In the hospital 207 (14%) out of 1471 children were HCoV positive. Again we observed most infection by HCoV-OC43 (n=85) and HCoV-NL63 (n=60), followed by HCoV-HKU1 (n=47) and HCoV-229E (n=15).Conclusions: HCoV-NL63 and HCoV-OC43 infections occur frequently in early childhood, more often than HCoV-HKU1 or HCoV-229E infections. HCoV-OC43 and HCoV-NL63 may elicit immunity that protects from subsequent HCoV-HKU1 and HCoV-229E infection, respectively, which would explain why HCoV-OC43 and HCoV-NL63 are the most frequently infecting HCoVs. There are no indications that infection by one of the HCoVs is more pathogenic than others.

Genomic signatures and antiviral drug susceptibility profile of A(H1N1)pdm09

2011-12-16

Abstract: Background: Genetic changes in influenza surface and internal genes can alter viral fitness and virulence. Mutation trend analysis and antiviral drug susceptibility profiling of A(H1N1)pdm09 viruses is essential for risk assessment of emergent strains and disease management.Objective: To profile genomic signatures and antiviral drug resistance of A(H1N1)pdm09 viruses and to discuss the potential role of mutated residues in human host adaptation and virulence.Study design: A(H1N1)pdm09 viruses circulating in Portugal during pandemic and post-pandemic periods and 2009/2010 season. Viruses were isolated in MDCK-SIAT1 cell culture and subjected to mutation analysis of surface and internal proteins, and to antiviral drug susceptibility profiling.Results: The A(H1N1)pdm09 strains circulating during the epidemic period in Portugal were resistant to amantadine. The majority of the strains were found to be susceptible to oseltamivir and zanamivir, with five outliers to neuraminidase inhibitors (NAIs) identified. Specific mutation patterns were detected within the functional domains of internal proteins PB2, PB1, PA, NP, NS1, M1 and NS2/NEP, which were common to all isolates and also some cluster-specific.Discussion: Modification of viral genome transcription, replication and apoptosis kinetics, changes in antigenicity and antiviral drug susceptibility are known determinants of virulence. We report several point mutations with putative roles in viral fitness and virulence, and discuss their potential to result in more virulent phenotypes. Monitoring of specific mutations and genetic patterns in influenza viral genes is essential for risk assessing emergent strains, disease epidemiology and public health implications.

Molecular typing of adenoviruses in pediatric respiratory infections in Buenos Aires, Argentina (1999–2010)

P.R. Barrero, L.E. Valinotto, E. Tittarelli, A.S. Mistchenko — 2011-12-05

Abstract: Background: The human adenovirus (HAdV) types most commonly found in respiratory samples belong to HAdV species C (HAdV-C1, -C2, -C5, and -C6) and to HAdV species B (HAdV-B3 and -B7). Several studies in South America have shown the association between severe respiratory infections and subspecies B1.Objectives: The aim of this study was to identify the adenovirus types associated with acute lower respiratory tract infections in children, found as single or coinfections, throughout a 12-year period.Study design: All samples that tested positive for adenovirus by immunofluorescence assay from January 1999 to December 2010 were typed by evaluating a set of four viral genes (E1A, VA, hexon and fiber). Quantitative PCRs for HAdV-B and HAdV-C species were performed to compare the viral load found in single infections and coinfections.Results: From a total of 743 HAdV, 654 (88%) were single infections and 89 (12%) coinfections. From the 654 single HAdV infections, members of four species were present: species B (n=492, 75.23%), species C (n=138, 21.1%), species E (n=19, 2.91%), and species D (n=5, 0.76%). Only members of species B (n=109, 57.67%) and species C (n=80, 42.33%) were detected in coinfections. HAdV-B7 and HAdV-B3 were the most prevalent types (n=308, 36.54%; n=230, 27.28% respectively) and HAdV-C1, -C2, -E4, -C5, -C6, -D8, -B11, -B14 and -B21 were also detected. Viral loads for species C viruses were higher in single infections than in coinfections (p<0.01), whereas the opposite was observed for species B viruses (p<0.0001).Conclusions: This study provides a thorough description of adenovirus circulation and diversity in Buenos Aires in a 12-year period. The high proportion of coinfections found in this work shows that this phenomenom might be more common than expected.

Quantitation of human herpesvirus-6A, -6B and -7 DNAs in whole blood, mononuclear and polymorphonuclear cell fractions from healthy blood donors

2011-12-02

Abstract: Background: Diagnosis of human herpesvirus-6A (HHV-6A), -6B (HHV-6B) or -7 (HHV-7) infections is often based on the measure of viral load in blood.Objectives: The aim of this study was to define usual values of HHV-6A, HHV-6B and HHV-7 loads in blood fractions (whole blood [WB], mononuclear cells [PBMCs], polymorphonuclear leukocytes [PMNLs]) of blood donors.Study design: HHV-6A, HHV-6B and -7 DNAs were quantitated using real-time PCR assays in WB, PBMCs and PMNLs separated on Ficoll or dextran gradients, respectively, for 200 blood donors. Viral loads were expressed as the number of viral genomic copies per million cells (Cop/M) for all fractions, and also per milliliter for WB.Results: HHV-6B DNA was rarely detected in WB (8%), PBMCs (16.5%), and PMNLs (10.5%), HHV-6A was never detected, whereas HHV-7 DNA was often present in WB (51.5%), PBMCs (62%) and PMNLs (51.5%). Median loads were low with 81 Cop/M in WB, 62 Cop/M in PBMCs and 34.5 Cop/M in PMNLs for HHV-6B, and 129 Cop/M in WB, 225 Cop/M in PBMCs and 62 Cop/M in PMNLs for HHV-7. Viral load expression per million cells and per mL were equivalent. One subject had chromosomally integrated HHV-6 with high viral loads ranging from 2.23×106 to 3.21×106 Cop/M in all compartments and plasma.Conclusions: These results allow to propose viral load in WB as a sensitive and suitable marker, with values for healthy subjects at approximately 100 Cop/M for both viruses. The prevalence of chromosomally integrated HHV-6 was 0.5%.

Hantavirus and acute appendicitis—The diagnosis behind the diagnosis?

2011-12-12

Abstract: A 33-year-old man with a history of acute lower abdominal pain was admitted to the emergency room. After laparoscopic appendectomy and pathological confirmed acute appendicitis the patient developed thrombocytopenia and acute renal failure. Serological testing for hantaviruses revealed a positive result for PUUV IgG and IgM. Immunohistochemical work-up detected PUUV antigen in endothelial cells of capillaries and larger vessels. The high percentage of patients with hantavirus infection and severe abdominal pain is remarkable and, up to now, unexplained. To our knowledge this is the first report demonstrating PUUV antigen in the human intestine. Further studies are warranted whether hantaviruses are setting the stage for a secondary bacterial infection or cause an inflammation itself.

Parotitis associated with Crimean Congo hemorrhagic fever virus

Selçuk Kaya, Gurdal Yilmaz, Barış Ertunç, Iftihar Koksal — 2011-11-14

Abstract: Background: Crimean Congo Hemorrhagic Fever (CCHF) is a potentially fatal tick-borne viral disease, the course of which may accompanied by various clinical findings.Objectives: We describe a picture of non-suppurative parotitis developing in association with CCHF virus.Study design: A 48-year-old patient presenting to our hospital with lethargy, hemorrhage and pain and swelling below the left ear was diagnosed with CCHF through IgM antibody and polymerase chain reaction positivity in serum investigated for CCHF virus. A picture of non-suppurative parotitis developed on the 3rd day of admission.Results: Other causes of parotitis were excluded with the help of serological tests, and the case was regarded as one of CCHF-associated parotitis. The patient was put on adjuvant therapy, an improvement in clinical findings was observed and he was discharged in a healthy condition on the 8th day.Conclusions: Ours is the first case in the literature of parotitis seen during CCHF. CCHF should be considered in differential diagnosis in addition to other frequently encountered viral agents in patients from endemic regions presenting with a picture of non-suppurative parotitis.

Hepatitis E in three immunocompromized children in southeastern France

2011-12-19

Abstract: Hepatitis E virus (HEV) causes an emerging autochthonous disease in developed countries where links with a viral porcine reservoir have been evidenced. Moreover, chronic HEV infection and associated-cirrhosis have been described in severely immunocompromized patients. Nonetheless, only few studies have focused on pediatric HEV infections worldwide and only four autochthonous cases have been reported in children in developed countries. We describe here acute hepatitis E in three immunocompromized children. Case no. 1 was a 9-year-old liver transplant recipient girl in whom H1N1 2009 flu infection was diagnosed concurrently with hepatitis E. Case no. 2 was a 12-year-old boy presenting early medullar relapse of lymphoblastic leukemia of type B and in whom HEV RNA was detected over a 29-week period. Case no. 3 was a 9-year-old boy with a rare primary immunodeficiency due to XIAP deficiency. HEV infections were all autochthonously acquired and involved different viruses classified as subtype f, c, and e of genotype 3, which are those described in autochthonous cases in Europe. These three observations prompt to consider HEV as a causative agent of hepatitis in children in developed countries, and to perform particularly HEV testing in those severely immunocompromized who may develop chronic hepatitis E.

Real-time PCR versus viral culture on urine as a gold standard in the diagnosis of congenital cytomegalovirus infection

2011-12-16

Abstract: Background: Cytomegalovirus (CMV) infection is the most common cause of congenital infection. Whereas CMV PCR has replaced viral culture and antigen detection in immunocompromised patients because of higher sensitivity, viral culture of neonatal urine is still referred to as the gold standard in the diagnosis of congenital CMV infection.Objective: To compare real-time CMV PCR with shell vial culture on urine in the diagnosis of congenital CMV, in a multicenter design.Study design: A series of neonatal urines (n=340), received for congenital CMV diagnostics and routinely assessed with shell vial CMV culture, was retrospectively tested by real-time CMV PCR.Results: The proportion of newborns found to be congenitally infected by real-time CMV PCR was 8.2% (28/340, 95%CI 5.6–11.8%), and 7.4% (25/340, 95%CI 4.9–10.8%) by rapid culture. When considering rapid culture as reference, real-time PCR was highly sensitive (100%), whereas sensitivity of rapid culture was 89.3% when considering real-time PCR as reference.Conclusions: Our results, supported by analytical and clinical data on CMV DNA detection in neonatal urine, suggest enhanced sensitivity of recent PCR techniques when compared to viral culture. There is considerable rationale to favor real-time CMV PCR as a gold standard in the diagnosis of congenital CMV infection. A large-scale study combining both laboratory and clinical data is required to determine the exact time frame for sampling of neonatal urine when using real-time PCR.

An outbreak of severe respiratory tract infection due to human metapneumovirus in a long-term care facility for the elderly in Oregon

Robert S. Liao, Dianna M. Appelgate, Robert K. Pelz — 2011-11-11

Abstract: Human metapneumovirus (hMPV) was demonstrated to be responsible for an outbreak of acute respiratory tract infection with high morbidity and mortality among residents of a long-term care facility for the elderly during the late spring–summer in Oregon. Respiratory virus infections are a common cause of death in the elderly and the burden of human metapneumovirus may be underestimated. This case report stresses the importance of hMPV in causing outbreaks in long-term care facilities for the elderly. Cough and elevated temperature were common to all the resident patient cases. Six resident patient cases had hMPV laboratory confirmation of which 5 had the diagnosis of pneumonia and 4 were hospitalized. The fatality rate was 33.3% among laboratory confirmed cases and 31.3.0% among probable resident patient cases. The signs and symptoms observed in the elderly with acute respiratory infection caused by hMPV are difficult to distinguish from those associated with other respiratory viruses and direct testing for hMPV with molecular methods should be routinely pursued to prevent nosocomial infections.

Dynamic changes in HCV RNA levels and viral quasispecies in a patient with chronic hepatitis C after telaprevir-based treatment

2011-12-06

Abstract: Background: Telaprevir is a selective inhibitor of the hepatitis C virus NS3·4A serine protease. Treatment with telaprevir resulted in a rapid HCV-RNA decline in chronic hepatitis C genotype 1 patients.Objectives: To report the clinical and viral course of a patient treated with telaprevir in combination with pegylated interferon-alpha-2a and ribavirin in a Phase 2 clinical trial (PROVE3).Study design: This previous non-responder to interferon based therapy was treated for 40 weeks with a telaprevir, pegylated interferon alpha-2a, and ribavirin regimen. Viral sequencing and phylogenetic analysis were performed before, during and after therapy.Results: The patient, a 54 years old male patient, experienced a viral relapse 4 weeks post-treatment and HCV-RNA levels continued to increase 14 weeks post-treatment (150,000IU/mL). The viral population, which was wild type at baseline, consisted of only V36A variants at both of these post-treatment timepoints. Subsequently, this patient had a transient disappearance of HCV-RNA for more than 1 year in the absence of antiviral therapy. Thereafter, HCV-RNA reappeared again with a viral population consisting of only wild type virus. Phylogenetic analysis of NS3·4A corresponded with a viral population bottleneck resulting in changes in viral quasispecies.Conclusion: In this case report, significant viral load reductions resulted in a genetic bottleneck leading to a reduction of variability in the hepatitis C viral population. We hypothesize that the reduction in viral heterogeneity potentially led to a reduced viral capacity to adapt to a host immune response leading to a transient loss of detectable HCV-RNA.

Natural presence of NS3 protease R155K hepatitis C virus variants with decreased sensitivity to protease inhibitors

Philippe Colson, Raj Purgus, Patrick Borentain, René Gérolami — 2011-11-14

Hepatitis C virus NS3/4A serine protease inhibitors (HCV-PIs) increase substantially the rates of sustained virological response in HCV genotype 1 infections in association with the current standard of care (SOC) treatment by pegylated-interferon and ribavirine. Nonetheless, the high levels of diversity and variability of HCV promote the emergence of various genotypic patterns conferring resistance to HCV-PIs under the selective pressure of therapy, as early as 4 days after treatment initiation. Moreover, they make possible the occurrence of viral strains naturally resistant to HCV-PIs. Indeed, 0.2–2.2% of persons infected with HCV genotype 1 and never exposed to HCV-PIs were found to harbor viral strains with clinically-relevant HCV-PI resistance mutations, as assessed by population sequencing. Amino acid substitution R155K within HCV NS3 protease is among those known to confer resistance to the two currently available HCV-PIs, telaprevir and boceprevir. The natural presence of HCV 155K mutants as the majority quasi-species was previously described by population sequencing in two case reports and from 8/1,352 (0.6%) patients in three different prevalence studies of HCV-PIs resistance mutations. Overall, majority R155K HCV were recovered from 0.8 to 1.0% of patients infected with HCV genotype 1a, and in none of those infected with other HCV genotypes/subtypes. Such specific association with HCV-1a was related to the requirement for one single nucleotide substitution for HCV-1a instead of two for HCV-1b. Noteworthy, HCV-1a is responsible for >25% of hepatitis C worldwide and in North America and Europe (http://hcv.lanl.gov/components/sequence/HCV/geo/geo.comp). In January 2011, we identified another case of infection with NS3 protease 155K HCV in a patient never exposed to any anti-HCV drug, while genotyping HCV in view of SOC therapy. This patient is a 50-year-old man undergoing hemodialysis for chronic kidney disease and in whom chronic hepatitis C was diagnosed in 2003 when he presented with nephrotic syndrome. HCV genotype was 1a, based on phylogenetic analysis of HCV NS3 protease sequence recovered by population sequencing as described previously ().

Erratum to “Standardization and performance evaluation of “modified” and “ultrasensitive” versions of the Abbott RealTime HIV-1 assay, adapted to quantify minimal residual viremia” [J. Clin. Virol. 52 (2011) 17–22]

2011-12-16

The publisher regrets a typesetter error that resulted in the introduction in page 21, second column, lines 2, 4 and 5 of the numbers 252, 255 and 256 in the text. These numbers are not part of the text of the article.

ESCV Membership

2012-02-01