SPECT imaging finds a new role in HIV research

An imaging technique that can assess immune system recovery in macaque monkeys with an HIV-like infection could have similar future applications for evaluating recovery in humans after HIV treatment, the National Institutes of Health has announced.

In the simian study, recently published in JIC Insight, researchers were able to use single-photon emission computed tomography and a CD4-specific imaging probe to evaluate immune system changes throughout the bodies of the monkeys, all of whom had been injected with SIV and treated with antiretroviral therapy. They tracked the process through CD4+ T cells in various tissues.

SPECT imaging from seven monkeys was able to offer some insight into how CD4+ T-cells reconstitute themselves after HIV takes hold, according to an NIH release. While T-cells are a common measure of progress in patients being treated with antiretroviral therapy, blood levels “often fail to fully reflect the situation in tissues.” Results also varied among animals and even among lymph nodes, though CD4+ cell pools in the spleen appeared similar in both healthy and infected animals.

The authors also found that the reconstruction process for CD4+ T-cell pools in the lymph nodes of monkeys receiving long-term therapy were “suboptimal.” As time continued, the researchers said, they remained smaller than pools seen in the healthy control animals.

According to the release, the study’s authors think the tech could be applied to future HIV trials and used to help scientists evaluate immune reconstruction after HIV treatment.