BACKGROUND: Human herpesvirus 6 (HHV-6) isolates are classified into two variants, termed HHV-6A and HHV-6B, on the basis of distinct genetic, antigenic and biological characteristics, but the specific pathogenicity of each variant remains poorly understood. OBJECTIVES: To design a rapid, sensitive and specific real-time variant-specific PCR (VS-PCR) method to differentiate both variants in biological specimens. STUDY DESIGN: The VS-PCR was adapted from a real-time PCR assay, based on TaqMan technology, previously developed for the genome quantitation of both HHV-6 variants [Gautheret-Dejean A, Manichanh C, Thien-Ah-Koon F, Fillet AM, Mangeney N, Vidaud M, et al. Development of a real-time polymerase chain reaction assay for the diagnosis of human herpesvirus-6 infection and application to bone marrow transplant patients. J Virol Meth 2002;100:27-35], a consensual reverse primer (Taq2) being changed into two variant-specific primers named H6A and H6B. This method was applied to a large set of biological specimens obtained in different pathological contexts. RESULTS: The sensitivity threshold was about 10 copies/well for HHV-6A-specific PCR (PCR-A) and 1 copy/well for HHV-6B-specific PCR (PCR-B). Both assays showed a linear dynamic range from 10 to 100,000 copies of HHV-6 DNA. Regarding the specificity and the capacity of discrimination of each assay, one variant could be detected and identified in the presence of more than 1000 times higher concentrations of the other variant in virus mixtures. The comparison of the results obtained with this VS-PCR with those previously obtained with a classic PCR method allowed us to validate our new technique on a wide panel of biological samples, including numerous patients with severe HHV-6-related symptoms. The high prevalence of HHV-6B was confirmed in healthy individuals and immunocompromised patients. HHV-6A was identified in distinct samples from several patients exhibiting neurological disorders. CONCLUSIONS: We developed a new VS-PCR assay, able to differentiate HHV-6A and HHV-6B in biological samples, even in the case of mixed infections. Our study confirms the wide prevalence of HHV-6B and highlights the potential greater neuropathogenic role of HHV-6A in immunocompromised patients and young infants.
BACKGROUND:Human herpesvirus 6 (HHV-6) isolates are classified into two variants, termed HHV-6A and HHV-6B, on the basis of distinct genetic, antigenic and biological characteristics, but the specific pathogenicity of each variant remains poorly understood. OBJECTIVES: To design a rapid, sensitive and specific real-time variant-specific PCR (VS-PCR) method to differentiate both variants in biological specimens. STUDY DESIGN: The VS-PCR was adapted from a real-time PCR assay, based on TaqMan technology, previously developed for the genome quantitation of both HHV-6 variants [Gautheret-Dejean A, Manichanh C, Thien-Ah-Koon F, Fillet AM, Mangeney N, Vidaud M, et al. Development of a real-time polymerase chain reaction assay for the diagnosis of human herpesvirus-6 infection and application to bone marrow transplant patients. J Virol Meth 2002;100:27-35], a consensual reverse primer (Taq2) being changed into two variant-specific primers named H6A and H6B. This method was applied to a large set of biological specimens obtained in different pathological contexts. RESULTS: The sensitivity threshold was about 10 copies/well for HHV-6A-specific PCR (PCR-A) and 1 copy/well for HHV-6B-specific PCR (PCR-B). Both assays showed a linear dynamic range from 10 to 100,000 copies of HHV-6 DNA. Regarding the specificity and the capacity of discrimination of each assay, one variant could be detected and identified in the presence of more than 1000 times higher concentrations of the other variant in virus mixtures. The comparison of the results obtained with this VS-PCR with those previously obtained with a classic PCR method allowed us to validate our new technique on a wide panel of biological samples, including numerous patients with severe HHV-6-related symptoms. The high prevalence of HHV-6B was confirmed in healthy individuals and immunocompromised patients. HHV-6A was identified in distinct samples from several patients exhibiting neurological disorders. CONCLUSIONS: We developed a new VS-PCR assay, able to differentiate HHV-6A and HHV-6B in biological samples, even in the case of mixed infections. Our study confirms the wide prevalence of HHV-6B and highlights the potential greater neuropathogenic role of HHV-6A in immunocompromised patients and young infants.
Authors: Petr Hubacek; Alena Hrdlickova; Martin Spacek; Miroslav Zajac; Katerina Muzikova; Petr Sedlacek; Petr Cetkovsky Journal: Folia Microbiol (Praha) Date: 2012-07-15 Impact factor: 2.099
Authors: Peter D Burbelo; Ahmad Bayat; Jason Wagner; Thomas B Nutman; James N Baraniuk; Michael J Iadarola Journal: Am J Transl Res Date: 2012-10-10 Impact factor: 4.060
Authors: Dharam Ablashi; Henri Agut; Roberto Alvarez-Lafuente; Duncan A Clark; Stephen Dewhurst; Dario DiLuca; Louis Flamand; Niza Frenkel; Robert Gallo; Ursula A Gompels; Per Höllsberg; Steven Jacobson; Mario Luppi; Paolo Lusso; Mauro Malnati; Peter Medveczky; Yasuko Mori; Philip E Pellett; Joshua C Pritchett; Koichi Yamanishi; Tetsushi Yoshikawa Journal: Arch Virol Date: 2013-11-06 Impact factor: 2.574
Authors: Kristen M Tamburro; Dongmei Yang; Jessica Poisson; Yuri Fedoriw; Debasmita Roy; Amy Lucas; Sang-Hoon Sin; Nadia Malouf; Vincent Moylan; Blossom Damania; Stephan Moll; Charles van der Horst; Dirk P Dittmer Journal: Virology Date: 2012-08-24 Impact factor: 3.616
Authors: Joshua A Hill; Sophia Koo; Belisa B Guzman Suarez; Vincent T Ho; Corey Cutler; John Koreth; Philippe Armand; Edwin P Alyea; Lindsey R Baden; Joseph H Antin; Robert J Soiffer; Francisco M Marty Journal: Biol Blood Marrow Transplant Date: 2012-05-04 Impact factor: 5.742