Measuring HIV Persistence on Antiretroviral Therapy

Area of Science:

• Virology
• Immunology
• Infectious Diseases

Background:

• Accurate measurement of persistent, replication-competent human immunodeficiency virus (HIV) is essential for evaluating eradication strategies and developing a cure.
• Various assays exist to quantify the viral reservoir, but each has limitations in detecting latent or intact proviruses.
• Understanding HIV persistence during antiretroviral therapy (ART) requires a combination of different assay approaches.

Purpose of the Study:

• To review existing and novel assays for measuring persistent replication-competent HIV.
• To highlight the advantages and disadvantages of different methods for quantifying the HIV reservoir.
• To discuss the implications of assay selection for the development of HIV curative therapies.

Main Methods:

• Review of current literature on assays for HIV persistence.
• Analysis of the strengths and weaknesses of quantitative viral outgrowth assay (QVOA) and its variants.
• Evaluation of methods quantifying or sequencing specific HIV genomic regions.
• Consideration of full-length integrated genome sequencing for intact provirus detection.

Main Results:

• Standard QVOA and its modifications may underestimate latent HIV by failing to detect non-induced, replication-competent proviruses.
• Assays quantifying or sequencing partial HIV genomes can overestimate reservoir size by including defective viral DNA.
• Full-length genome sequencing offers better discrimination of replication-competent proviruses but can be resource-intensive.

Conclusions:

• No single assay perfectly quantifies the HIV reservoir; a combination of methods is often necessary.
• Novel assay development and application are critical for advancing HIV cure research.
• Accurate measurement of the viral reservoir is a key hurdle to overcome for effective HIV eradication strategies.