The use of SPECT to evaluate the immune system in macaque monkeys infected with a simian form of HIV someday could help HIV-positive humans, according to a preclinical study published online July 12 in JCI Insight.
The imaging technique targets CD4+ T-cells that have been infected by HIV. A low level of CD4+ T-cells in the blood is a sign that the virus has weakened the immune system. With antiretroviral therapy (ART), CD4+ T-cell levels generally increase.
This research, led by scientists at the U.S. National Institute of Allergy and Infectious Diseases, used SPECT to see how CD4+ T-cell levels responded in seven monkeys with simian immunodeficiency virus (SIV) months after treatment with ART. The group found that responses varied among animals and among clusters of lymph nodes within the same animal.
The researchers also analyzed changes in CD4+ T-cell pools in the gut. In this case, there were fewer differences in gut CD4+ T-cell pools between healthy and SIV-infected animals, which potentially contradicts conventional wisdom that the gut is the major target of SIV infection.