cytomegalovirus in healthy individuals

Polymorphonuclear leukocytes (PMNL) have been shown to harbour human cytomegalovirus (HCMV) in viraemic patients, but to date PMNL of asymptomatic healthy subjects have not been examined directly to determine whether this is a normal site of HCMV persistence. Using the polymerase chain reaction (PCR), paired DNA samples prepared from adherent peripheral blood mononuclear cells (PBMC), which are known to be a site of persistence of HCMV, and PMNL of 10 healthy adults were analysed. All of seven individuals who were HCMV seropositive, and one of three who were seronegative gave a reproducible signal for HCMV DNA in their adherent PBMC, whereas none of the paired PMNL DNA samples gave a positive result. The remaining two seronegative subjects showed no HCMV DNA in either the PBMC or PMNL samples. In every case where PCR for HCMV was negative, PCR amplification of a control human gene was used to show there was no inability to amplify the DNA. We conclude that within the leukocyte population of ormal asympto-matic HCMV carders, PMNL do not appear to harbour persistent HCMV whereas adherent PBMC in the same subjects are a site of persistence. We and others have previously used the polymerase chain reaction (PCR) to demonstrate he presence of human cytomegalovirus (HCMV) in leukocytes of seropositive and some seronegative healthy carriers (Taylor-Wiedeman et al., 1991; Stainer et al., 1989). In these normal subjects, peripheral blood monocytes (PBMC) were the principal site of persistence (Taylor-Wiedeman et al., 1991). However, only PBMC were studied and analysis of polymorphonuclear leukocytes (PMNL) from healthy carriers was not addressed. Detection of HCMV in the PMNL fraction of peripheral blood has been reported in patients infected with human immunodeficiency virus (HIV), other im-munocompromised patients and immunocompeten