Researchers have identified five individuals with HIV who, despite being on ARVs and maintaining a fully suppressed viral load, experienced rapid decline in their CD4 counts.

Publishing their findings in JCI Insight, these investigators studied five individuals with HIV who experienced extreme immune decline (EXID) despite more than three years of fully suppressive ARV treatment. They compared this cohort with a group of immunological nonresponders (INRs), whose immune systems failed to robustly rebound despite long-term suppressive ARV treatment, as well as immunological responders (IRs).

During four years of ARV treatment, the INRs experienced an average increase of 193 CD4s, compared with 427 CD4s among IRs. The five people with EXID, meanwhile, experienced an average decline of 157 CD4s over three years.

The study authors did not identify a single driving factor behind EXID among these five people. It appeared that genes that influenced the activity of immune cells as well as autoimmune reactions (in which the immune system attacks healthy tissue) may contribute to the condition.

Two of the people with EXID developed antibodies that attacked their own CD4 cells. Two others’ immune systems were overly active on a cellular level, which caused harmful inflammation.

All five of those with EXID had a strain of HIV other than clade B, which is the most common strain in North America and Europe. This finding suggests that an individual’s genes may interact with non–clade B strains of HIV in a way that gives rise to EXID.

The investigators hope that ongoing research into these cases of EXID will help them develop new treatment strategies for those with the condition.  

To read a press release about the study, click here.

To read the study, click here.