Reuters Health Information (2006-12-29): Progression toward AIDS associated with increased teno virus titers
Progression toward AIDS associated with increased teno virus titers
Last Updated: 2006-12-29 12:15:20 -0400 (Reuters Health)
NEW YORK (Reuters Health) - Titers of Torque teno virus (TTV) and Torque teno minivirus (TTMV) are elevated in HIV patients progressing toward AIDS, Scottish researchers report in the January issue of the Journal of Medical Virology.
Dr. Juraj Petrik, of the University of Edinburgh, and Dr. Katrina Thom, of the Scottish National Blood Transfusion Service, note that although these anelloviruses have not been associated with any disease, they are highly prevalent in the general population. More than 90% of adults are infected and co-infections with other pathological viruses are frequent.
The role of the immune system in controlling the infections has yet to be established, the team adds, and they have not been studied in patients with HIV.
To investigate further, the researchers studied bone marrow and spleen tissues taken at autopsy from 13 subjects with AIDS, 6 pre-AIDS HIV-positive subjects and 7 HIV-negative subjects.
All were positive for the viruses and the AIDS group had significantly higher titers of TTV and TTMV in both the bone marrow and spleen than was the case in the HIV positive and negative groups.
Although there appeared to be no association with hepatitis C virus co-infection or type of anellovirus infection, analysis of TTV/TTMV titer and CD4 T lymphocyte count demonstrated a significant inverse correlation.
"There are several hematological complications of AIDS, such as thrombocytopenia and neutropenia, whose underlying cause remains somewhat of a mystery and it is possible that high levels of TTV and TTMV could be contributing to these conditions," Dr. Thom told Reuters Health. "Although attempts have been made to correlate TTV/TTMV infection with disease processes, a causal role has yet to be conclusively established."
"The ubiquity of these viruses supports the hypothesis that anelloviruses are not pathogenic per se," Dr. Thom said.
However, she concluded, "comparison with parvovirus B19 and the human papillomaviruses shows that high prevalence in the general population does not necessarily preclude a pathogenic role."
J Med Virol 2007;79:1-7.