High prevalence of HHV‐6 DNA in peripheral blood mononuclear cells of healthy individuals detected by nested‐PCR

Abstract

The aim of the study was the evaluation of human herpesvirus-6 (HHV-6) infection rate and semiquantification of viremia in healthy people. Healthy blood donors were studied. Human herpesvirus-6 IgG and IgM antibody titers were measured by indirect immunofluorescence assay. Human herpesvirus-6 DNA amplification (nested-PCR) was performed in peripheral blood mononuclear cells (PBMC) and in serum. Seventeen of 50 (34 percent) individuals were positive for IgG anti-HHV-6 and the titers ranged from 1:40 to 1:160. None of 30 individuals was positive for IgM anti-HHV-6, suggesting no recent infection nor reactivation. Human herpesvirus-6 DNA was detected by nested-PCR amplification in peripheral blood mononuclear cells but not in sera. When 1 microgram DNA was amplified, HHV-6 DNA was detected in 8 of 20 individual (40%), but in 18 of 20 (90%) when 5 micrograms DNA were amplified. It is concluded that HHV-6 is present in a high proportion of the healthy population but in minimal amounts, and although it can be detected in 1.4 x 10(5) PBMC, 7 x 10(5) cells are necessary to detect most cases. No reactivation was observed in healthy people.

U94 of human herpesvirus 6 is expressed in latently infected peripheral blood mononuclear cells and blocks viral gene expression in transformed lymphocytes in culture

“…Viral replication was assessed by immunofluorescence and by RT-PCR detection of viral transcripts. In addition, the presence of viral genomic DNA was investigated by PCR for the HHV-6 U31 ORF, and a semi- (2,3,4). RNA (no initial reverse transcription step) and cDNA (ϩRT) were amplified by PCR and analyzed by agarose gel.…”

“…Primary infection is associated with exanthem subitum (2) and nonspecific febrile illness in infants (3). After primary infection, the virus persists in the host and up to 90% of healthy adult blood donors harbor HHV-6 DNA in peripheral blood mononuclear cells (PBMCs) (4). More than 90% of healthy adults also show serologic evidence of past infection (5), and approximately 5% of the healthy adult population has anti-HHV-6 IgM antibody, suggesting that the virus may periodically reactivate, without clinically apparent sequelae (6).…”

Infection with AIDS-related herpesviruses in human immunodeficiency virus-negative infants and endemic childhood Kaposi's sarcoma in Africa.

“…The levels detected for both viruses were between 300 to 18 000 copies per cell (Tables 2 and 3). This contrasts with levels detected in normal adults, which average only 1 copy per 10& to 10' cells, presumably representing latent infection (Cone et al, 1993 b ;Cuende et al, 1994 ;Bigoni et al, 1996). Thus, in order to detect latent adult DNA between 10& to 10' cells would need to be sampled to detect one genome copy of DNA (Cone et al, 1993 b ;Cuende et al, 1994).…”

Predictive Value of Quantitative PCR-Based Viral Burden Analysis for Eight Human Herpesviruses in Pediatric Solid Organ Transplant Patients

“…Although seroprevalence of these two viruses approaches 100% in most adult populations, a wide range of values for detection of DNA in blood has been reported in the literature, with the most sensitive techniques reporting the highest values. [62][63][64][65] From the data in this current study, the es- *A sample was considered to be a true positive for a CMV-related disease if it gave a positive result or a value above the cutoff and was harvested within 5 weeks of evidence of CMV etiology by histology, serology, and/or non-immune-mediated tissue destruction.…”