Supersensitive Viral Load Assay in Predicting CD4-Guided Treatment Failure

Area of Science:

• Infectious Diseases
• Virology
• Clinical Medicine

Background:

• Highly active antiretroviral therapy (HAART) is crucial for managing HIV.
• Treatment interruptions (STI) are sometimes used in HIV management.
• Predicting the success of re-treatment after STI is important for patient outcomes.

Purpose of the Study:

• To investigate if HIV RNA suppression levels before STI predict virological failure during HAART re-treatment.
• To evaluate the utility of measuring low HIV RNA levels (<50 copies/ml) for predicting treatment outcomes.

Main Methods:

• A case-control substudy of the Staccato trial in Thailand.
• Included subjects undergoing CD4-guided STI with HIV RNA >50 copies/ml (cases) and <50 copies/ml (controls) after HAART re-treatment.
• Matched controls for age, gender, and pre-ART CD4 count.
• Measured HIV RNA with a 5 copies/ml detection limit on pre-virological failure samples.

Main Results:

• HIV RNA levels increased significantly in cases compared to controls across successive STI cycles (p-trend=0.004).
• The last recorded HIV RNA level below 50 copies/ml was significantly higher in cases than controls (p=0.004).

Conclusions:

• The degree of HIV RNA suppression at the time of treatment interruption may predict the success of subsequent re-treatment.
• Measuring HIV RNA below 50 copies/ml is a potentially useful biomarker for predicting virological failure after STI in HIV patients.