Multiple sites in HIV-1 reverse transcriptase associated with virological response to combination therapy

Area of Science:

• Virology
• Molecular Biology
• Pharmacogenomics

Background:

• Combination antiretroviral therapy (cART) is crucial for managing HIV.
• Understanding baseline genetic factors influencing treatment response is vital for personalized medicine.

Purpose of the Study:

• To investigate if baseline sequence variations in reverse transcriptase can predict virological response to cART.
• To identify specific mutations or combinations of mutations associated with treatment outcomes.

Main Methods:

• Analysis of reverse transcriptase amino acid sequences from baseline isolates of 55 patients in the ACTG241 trial.
• Application of simple and multiple linear regression to correlate baseline mutations with virological response at 8 and 48 weeks.

Main Results:

• Baseline zidovudine resistance mutations predicted short-term (week 8) virological response.
• Amino acid position 215 showed significant impact on week 8 response, with combinations like 215+44 and 41+202 explaining ~30% of variation.
• A model including amino acids 214+215+60+202 and baseline viral load explained >40% of week 48 response variation.
• An unexpected finding was a threefold better response with mutant combination 601+215Y/F compared to 60V+215Y/F over 48 weeks.

Conclusions:

• Baseline amino acid mutations at novel sites influence virological response to cART.
• Predictors for long-term treatment response differ from short-term predictors and may necessitate complex analytical models.
• This study highlights the potential of baseline genotypic analysis for optimizing cART strategies.