Imaging technique illuminates immune status of monkeys with HIV-like virus

Thursday, July 12, 2018

Approach could improve understanding of immune system recovery in people treated for HIV infection

Findings from an animal study suggest that a non-invasive imaging technique could, with further development, become a useful tool to assess immune system recovery in people receiving treatment for HIV infection. Researchers used single-photon emission computed tomography (SPECT) and a CD4-specific imaging probe to assess immune system changes throughout the bodies of macaques infected with SIV, a simian form of HIV, following initiation and interruption of antiretroviral therapy (ART). They evaluated pools of CD4⁺T cells, the main cell type that HIV infects and destroys, in tissues such as lymph nodes, spleen and gut.

Their findings illustrate that CD4⁺ T-cell levels in the blood — a measure of immune system health in people living with HIV — often fail to fully reflect the situation in tissues. A low blood CD4⁺ T-cell level indicates an immune system weakened by HIV, and the level generally increases when ART is started and the immune system begins to recover. The new research, led by scientists at the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, delineates the complexity of the immune recovery process at the level of different tissues.