Molecular Testing

HHV-6 or HHV-7 can be cultured from clinical specimens using coculture with stimulated lymphoblasts. Use of cord blood lymphocytes limits the chance of measuring replication of endogenous virus from the lymphoblasts. Demonstration of cytopathic effect or of viral antigen supports the diagnosis. Viral culture is, however, time-consuming. Serologic diagnosis is of greatest use in seroprevalence studies. An immunofluorescence assay or an enzyme immunoassay is most commonly employed. Appropriate controls are essential to exclude cross-reactions between Betaherpesviridae and should include a preadsorption step with appropriate antigens. An immunoblot assay has been described for detection of HHV-7 using the p89 tegument protein. Immunohisto-chemistry often uses antibodies against gp82 (HHV-6A), p101 (HHV-6B), or pp85 (HHV-7). In situ hybridization using HHV-7 plasmid clone (pH7SB-268) has also been described.

The most sensitive diagnostic technique is quantitative PCR that is rapid and can be performed on samples obtained by noninvasive means. Real-time PCR using TaqMan reaction combines single-step amplification with computer-based analysis. Detection of viral DNA in whole blood does not distinguish acute from previous infection but a high viral copy number, DNA in the absence of antibody, or DNA in plasma can suggest acute infection. Quantitative PCR is also of use in diagnosing reactivation in immunocompromised hosts, but HHV-6A DNA may not be identified in peripheral blood lymphocytes. Nested or multiplex PCR methodologies are also described. Published primers include a 240-bp amplicon of HHV-6 major antigen's structural protein, 5'-ATCTC-GATTCCGTTCAGTCT-3' and 5'-TGAGACACCTGAA-GAAAAAG-3', and a 186-bp amplicon corresponding to the U10 encoded structural protein of HHV-7, 5'-TATCCCAGCTGTTTTCATATAGTAAC-3' and 5'-CAAAAAATCTAGTGCTACCGCAAGGC-3'.[11] For discrimination of HHV-6A and HHV-6B, primers that amplify an IE target have been described; a 278-bp amplicon of HHV-6A is generated with primers H6fA 5'-CATGAAGATGATGACAA-TAAAATG-3', H6bA 5'-TGGAACCATCTTGTTCTGTCC-3', and exonuclease probe H6tmA 5'-FAM-CCGCCCAGA[TAMRA]TCTGT-CACTGAGGCTG-3'p and a 145-bp amplicon of HHV-6B with primers H6fB 5'-GAGACCGGGTCTGGACAACA-3', H6bB 5'-GAGTTGCTGAGTTGGTAAAGG-3', and exonuclease probe H6tmB 5'-FAM-CTCCAAGTG-TACCGAAACGC[TAMRA]TTCCTGG-3'p.[12]

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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