Hope as DRC group shows rare HIV immune response

A team of researchers has found in the Democratic Republic of Congo a high number of people who appear to be able to fight HIV without using antiretroviral treatment.

These findings published Tuesday in EBioMedicine may help researchers uncover biological trends within this population that could lead to advancements in HIV treatments — and potentially vaccines.

Abbott Laboratories researchers said this group of people test positive for HIV antibodies, but have low to non-detectable viral load counts without using ARVs. They are referred to as HIV elite controllers.

Researchers from Abbott, the Johns Hopkins University, the National Institute of Allergy and Infectious Diseases, the University of Missouri-Kansas City and the Université Protestante au Congo found that the prevalence of HIV elite controllers was 2.7-4.3 per cent in the DRC – compared to a 0.1-2 per cent prevalence worldwide.

This new research will fuel additional studies that look to understand this unique immune response. Findings from the study could lead researchers closer to their goal of ending the HIV epidemic by uncovering links between natural virus suppression and future treatments.

"The finding of a large group of HIV elite controllers in the DRC is significant considering that HIV is a life-long, chronic condition that typically progresses over time," said Tom Quinn, director of Johns Hopkins Centre for Global Health, and chief of the International HIV/AIDS Research Section of the National Institute of Allergy and Infectious Diseases, National Institutes of Health, and one of the study authors.

"There have been rare instances of the infection not progressing in individuals prior to this study, but this high frequency is unusual and suggests there is something interesting happening at a physiological level in the DRC that's not random."

Since the beginning of the global HIV epidemic, 76 million people have been infected with HIV and 38 million people today are living with the virus.

 As the first company to develop an FDA-approved test for HIV more than 30 years ago, Abbott understands the importance of HIV research and established its Global Viral Surveillance Program to identify HIV and hepatitis mutations – ensuring its diagnostic tests remain up to date. With the origins of the HIV epidemic traced to sub-Saharan Africa, specifically the DRC, this region is of specific interest to the scientific community.

The new findings from Abbott researchers and partners are a continuation of virus hunting efforts that led to the identification of a new strain of HIV in 2019.

"Global surveillance work keeps us ahead of emerging infectious diseases – and in this instance, we realised we had found something that could be another step toward unlocking a cure for HIV," said Michael Berg, an associate research fellow in infectious disease research at Abbott, and lead author of the study.

"The global research community has more work to do – but harnessing what we learn from this study and sharing it with other researchers puts us closer to new treatments that could possibly eliminate HIV."

Plasma samples from surveillance efforts collected in 1987, 2001-03 and 2017-19 in the DRC – home to the oldest known HIV strains – allowed researchers to rule out false positives, collection site bias, high genetic diversity and antiretroviral treatment as the cause of non-detectable viral counts in 10,457 patients from 2017 to 2019.

"Every new HIV discovery is another piece in the evolutionary jigsaw puzzle that we're trying to understand," said Carole McArthur, professor of oral and cranio-facial sciences, University of Missouri-Kansas City, director of residency research in pathology, Truman Medical Centre, and one of the study authors.

"Each of these pieces helps us see a bit more clearly as to where we need to look next and contributes to the knowledge bank that all researchers will turn to in the next phase of our work."