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Updated: May 13, 2026
Prediction of HIV-1 Coreceptor Usage (Tropism) by Sequence Analysis using a Genotypic Approach
Published on: December 1, 2011
Trofile HIV co-receptor usage assay
Andrew J Low1, Rachel A McGovern, P Richard Harrigan
120/48 Nelson Street, Annandale, NSW 2038, Australia +0 450 010 207 ; +0 604 806 9044 andrewjohnlow@gmail.com.
Background:
The introduction of CCR5 antagonists increases the options available for constructing therapeutic drug regimens for HIV-positive patients. However, as these drugs do not inhibit HIV variants that use the CXCR4 co-receptor, a pretreatment test is required to determine accurately HIV co-receptor usage (tropism) before initiating CCR5 antagonist-based therapy.
Objective/Method:
To discuss the Monogram Trofile assay as a diagnostic tool for determining HIV tropism by critically reviewing reported literature and available data.
Conclusions:
Monogram Trofile has become, largely by default, the de facto standard for HIV tropism assay. However, there is significant room for improvement in the speed, cost and availability of the test. Furthermore, the test is not quantitative, requires high-input HIV RNA viral loads, and produces results that are less biologically stable than expected. These technical considerations may limit the use of CCR5 antagonists in therapy. Nevertheless, this test is likely to remain the most widely used tropism diagnostic for the short term. We expect that a more practical and possibly more accurate method for measuring HIV tropism can be developed.
Insights
The Monogram Trofile assay is the current standard for determining HIV tropism, essential for guiding CCR5 antagonist therapy. However, improvements in speed, cost, and test stability are needed for broader clinical application.
Area of Science:
- Virology
- Immunology
- Pharmacology
Background:
- CCR5 antagonists offer new HIV treatment options.
- These drugs are ineffective against HIV variants using the CXCR4 co-receptor.
- Accurate HIV co-receptor tropism testing is crucial before starting CCR5 antagonist therapy.
Purpose of the Study:
- To critically review the Monogram Trofile assay for HIV tropism determination.
- Evaluate the assay's performance based on available literature and data.
Main Methods:
- Literature review of published studies on the Monogram Trofile assay.
- Analysis of available data regarding assay performance and clinical utility.
Main Results:
- Monogram Trofile is the de facto standard HIV tropism assay.
- Significant limitations exist, including speed, cost, and availability.
- The assay is non-quantitative, requires high viral loads, and yields results with suboptimal biological stability.
Conclusions:
- Technical limitations of the Monogram Trofile assay may impact CCR5 antagonist therapy use.
- Despite limitations, it will likely remain the primary tropism diagnostic in the short term.
- Development of more practical and accurate HIV tropism assays is anticipated.
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