Use of a high resolution melting assay to analyze HIV diversity in HIV-infected Ugandan children

Abstract

Background: We used a novel high resolution melting (HRM) diversity assay to analyze HIV diversity in Ugandan children (age 0.6-12.4 years) who were enrolled in an observational study of antiretroviral treatment (ART). Children were maintained on ART if they were clinically and immunologically stable.

Methods: HIV diversity was measured before ART (baseline) in 76 children and after 48 or 96 weeks of ART in 14 children who were not virally suppressed. HIV diversity (expressed as HRM scores) was measured in 6 regions of the HIV genome (2 in gag, 1 in pol, 3 in env).

Results: Higher baseline HRM scores were significantly associated with older age (≥2 years, P ≤ 0.001 for all 6 regions). HRM scores from different regions were weakly correlated. Higher baseline HRM scores in 3 regions (1 in gag, 2 in env) were associated with ART failure. HIV diversity was lower in 4 regions (2 in gag, 1 in pol, 1 in env) after 48-96 weeks of nonsuppressive ART compared with baseline.

Conclusions: Higher levels of HIV diversity were observed in older children before ART, and higher levels of diversity in some regions of the HIV genome were associated with ART failure. Prolonged exposure to nonsuppressive ART was associated with a significant decrease in viral diversity in selected regions of the HIV genome.

Figure 1. Correlation of HRM scores in six regions of the HIV genome

The figure shows the results of correlation analyses for HRM scores in the six genomic regions analyzed (see text); 15 pairwise comparisons are shown. The correlation coefficients (r) and the P values for the pairwise comparisons are shown in the figure panels. Data for children < 2 years of age are shown with circles; data from children ≥ 2 years of age are shown with triangles.

Figure 2. Association of HRM scores with age

Plots of HRM score and age in years are shown for each of the six genomic regions analyzed. Data for children < 2 years of age are shown with circles; data from children ≥ 2 years of age are shown with triangles.