Human endogenous retroviruses may provide insight evidence to HIV diagnosis

Sep 4 2010

Why is it so hard to isolate and purify human immunodeficiency virus (HIV)? Why has no one been able to see, by electron microscopy, a single HIV particle in the blood of AIDS patients, even those who have a "high viral load"? Why does HIV seem to mutate with startling rapidity? AIDS researchers have not been able to come up with answers to these questions.

HERVs—human endogenous retroviruses—might provide explanations that have been overlooked for 20 years, writes Professor Etienne de Harven, M.D., in the fall 2010 issue of the Journal of American Physicians and Surgeons. HERVs are present in all of us, and fragments of their DNA may be confused with HIV in the polymerase chain reaction (PCR) tests used to estimate viral load.

The beautiful photographs of HIV published in both lay and scientific journals are embellished with special effects from computerized image reconstruction. Since they come from cell cultures, which are likely to be contaminated, the particles may be "elegant artifacts" rather than the exogenous virus—a virus of external origin—believed to cause AIDS, de Harven states.

About 8 percent of the human genome consists of sequences incorporated from retroviruses. When cells break down, DNA fragments are released into the circulation—including these viral sequences. Patients with clinical AIDS carry a large spectrum of infectious diseases, so a high level of circulating DNA is expected.

While "AIDS Rethinkers" may challenge the role of HIV in AIDS, or even its existence, they are obligated to explain the observations of clinicians and researchers. HERVs are, at a minimum, a confounding variable that needs to be investigated, de Harven notes.

Puzzles involving the interpretation of diagnostic tests for HIV, the epidemiology and transmission patterns of AIDS, and strategies for prevention and treatment cannot be solved without broadening AIDS research beyond the narrow confines accepted by the "Orthodoxers," de Harven believes. Alternate hypotheses need to be objectively assessed, and conclusions must be based on scientific evidence rather than consensus.