08/09/2026
Researchers at the University of the Witwatersrand, the National Health Laboratory Service and University Medical Center Utrecht have developed a strategy to better identify who needs drug resistance testing when HIV treatment is not working as expected.
The ITREMA-2 study, led by virologists Professor Annemarie (Anne) Wensing of Ezintsha at the University of the Witwatersrand and University Medical Center Utrecht, and Dr Kim Steegen of the National Health Laboratory Service and the University of the Witwatersrand, was published online in The Lancet HIV (click here to view).
The strategy measures dolutegravir in the same blood sample already used for viral load testing. When dolutegravir was not detectable, integrase inhibitor resistance could be ruled out with a negative predictive value of almost 98%. When dolutegravir was present despite ongoing viral replication, resistance testing could be targeted to those most likely to benefit.
A total of 288 people with HIV participated in the study at Hillbrow Community Health Centre and Helen Joseph Hospital, two large public HIV clinics in Johannesburg.
“An increased viral load does not automatically mean that treatment is failing because of drug resistance,” says Professor Annemarie Wensing. “Measuring dolutegravir in the same sample helps identify who needs resistance testing and provides clinicians and nurses with objective information to better support medication intake.”
The multidisciplinary team also studied how the strategy could be integrated into routine care. When incorporated into the care pathway at confirmed virological failure, estimated monitoring costs were 23% lower than with the previous standard approach.
An adapted version of the reflex testing strategy has recently been implemented by the South African Department of Health in public HIV care. Dr Kim Steegen played a key role in supporting the Department of Health in translating the approach from research into routine practice.
The ITREMA-2 study was funded by the Amsterdam Dinner Foundation through Aidsfonds and the Dutch Research Council (NWO).
Laboratory-initiated reflex plasma dolutegravir exposure testing provides an objective, cost-efficient strategy to predict the absence of dolutegravir resistance and supports adherence management, enabling timely, individualised treatment decisions. Reflex dolutegravir exposure testing could enhance...
