Dharam Ablashi on HHV-6 and AIDS
HHV-6 infection in HIV-infected asymptomatic and AIDS patients.
http://www.ncbi.nlm.nih.gov/pubmed/9705559
Abstract
In
order to investigate the levels of HHV-6 infection and elevated
antibodies to HHV-6 in HIV-1-infected asymptomatic and symptomatic
patients, peripheral blood mononuclear cells were (PBMC) cultured. As
patients progressed from asymptomatic HIV infection to AIDS, there was a
concurrent increase in replicating HHV-6. Plasma obtained from several
of these patients showed the presence of IgM antibody and a
significantly elevated level of HHV-6 IgG antibody. Serial samples of
plasma from 10 AIDS patients collected over a period of 4 years were
assayed for the detection of HHV-6 core protein (gp116/64/54) by antigen
capture ELISA. The results demonstrated that either a persistent
infection or reactivation can occur based on the degree of fluctuation
in HHV-6 antigen detected. ELISA to HHV-6 purified viral proteins, i.e.,
early (p41/38) and late (gp110), demonstrated that IgG antibody to
gp110 did not differentiate between HIV-1-infected and healthy donors.
IgG and IgM antibody to p41/38, however, showed a significantly higher
prevalence in HIV-1-infected individuals (56.7-85.3%) than in normal
healthy donors (19.0%), suggesting virus activation. PBMC culture from
the AIDS patients expressing significant peaks of HHV-6 core antigen
(gp116/64/54) in their plasma showed that in most cases, HHV-6 early and
late antigens were detectable; however, those patients with
consistently low antigen peaks had no detectable antigens in their PBMC.
Only 55% of PBMC cultures established from IgM antibody-positive
HIV-1-infected asymptomatic and AIDS patients expressed HHV-6 antigens
in the short-term cultures, but HHV-6 antigens could not be demonstrated
in PBMC culture from 4 IgM-antibody-positive healthy donors. HHV-6
isolates obtained from the HIV-1-positive patients were predominantly
HHV-6 variant A, compared to healthy donors. Based on the data presented
here, it is evident that the levels of HHV-6 infection increased in
HIV-1-infected asymptomatic individuals as they progressed to AIDS. Our
immunovirological data on HHV-6-infected individuals with HIV infection
support a role for HHV-6 in the pathogenesis of AIDS. We believe that
simultaneous active infection with HIV-1 and HHV-6 may contribute to
enhanced immune suppression perhaps leading to disease manifestations.