New research suggests that a noninvasive technique called antibody-targeted positron emission tomography (immunoPET) can be used visualize HIV reservoirs more effectively than tissue biopsies, the currently employed method. Identifying HIV reservoirs is important not only in understanding the disease, but also in creating targeted treatments that rid the virus in hard-to-detect areas.
In the context of HIV, the immunoPET technique tags specific antibodies with positron emitting radionuclides that react to gp120 - the envelope protein of HIV. These tagged antibodies can later be observed on a screen and pinned to a specific location in the body. In macaques, the immunoPET technique was able to identify where latent HIV resided in antiretroviral treated specimens. In contrast to tissue biopsies that may require samples from areas of the body that are hard or impossible to reach (e.g. gastrointestinal tract), the immunoPET can visualize the virus' location without any physical sample. An additional benefit of the immunoPET technique is that it is an in vivo technique that is capable of revealing trends over time, for example, the path that HIV takes to establish reservoirs in certain areas of the body.
ImmunoPET is already used as in vivo method used in the diagnosis and prognosis of certain cancers and cardiovascular conditions. However, it has not been used commonly in the field of infectious disease. Such a technique is promising for a virus whose evasive mechanisms have eluded researchers for years.