HIV-1 Genotypic Resistance Testing Using Sanger and Next-Generation Sequencing in Adults with Low-Level Viremia in China

OBJECTIVE

In this study, we aimed to determine drug-resistance mutations (DRMs) in HIV-1 patients with low-level viremia (LLV) and explored the performance of next-generation sequencing (NGS) in detecting HIV DRMs by using LLV samples.

METHODS

Overall, 80 samples with LLV were amplified and sequenced using a commercial Sanger sequencing (SS) genotyping kit. Furthermore, 51 samples successfully sequenced using SS were simultaneously subjected to NGS. Genotyping success rates of various viremia categories by two sequencing methods were calculated. Stanford HIV-1 drug-resistance database (HIVdb version 8.9) was used to analyze the DRMs. In the NGS assay, a threshold of 5% was considered for reporting low-frequency variants, and the DRMs detected using SS and NGS were compared.

RESULTS

The overall success rate of PR/RT regions was 88.1% (67/80) using SS and 86.3% (44/51) using NGS. Furthermore, a significant linear trend was noted between viral load and the genotyping success rate. A total of 38.8% (26/67) participants harbored at least one mutation, as revealed through SS. Moreover, the prevalence of DRMs in persistent LLV was significantly higher than that in intermittent LLV (62.1% vs. 21.1%; P < 0.05). A total of 69 DRMs were detected using the two sequencing methods at the threshold of 5%. Moreover, 10 DRMs missed by SS were detected using NGS, whereas 8 DRMs missed by NGS were detected by SS.

CONCLUSION

Our data suggested that the genotyping resistance testing is necessary to guide antiretroviral therapy optimization in LLV patients.

Effectiveness of first-line antiretroviral therapy in HIV/AIDS patients: A 5-year longitudinal evaluation in Fujian Province, Southeast China

The aim of this study was to evaluate the long-term effectiveness of first-line antiretroviral therapy in HIV/AIDS patients in Southeast China. A total of 450 eligible patients were selected to initiate first-line antiretroviral therapy from February 2005 through August 2009. During the study period from 2009 through 2013, each subject received clinical and laboratory monitoring for effectiveness, safety and toxicity once every 3 months in the first year, and once every 6 months in the following years. The response to first-line antiretroviral therapy was evaluated through body weight gain and immunological and virological outcomes. During the mean follow-up period of 70.86 ± 28.9 months, the overall mortality was 14.2%. The mean body weight and CD4(+) counts increased significantly following antiretroviral therapy as compared to baselines across the follow-up period, and the rate of immunological effectiveness was over 85% in all subjects at 2 to 5 years of treatment. The rate of inhibition of HIV virus was 87.67%, 89.32%, 91.73%, 92.8% and 91.63% across the study period. In addition, significant differences were detected after treatment as compared to baselines, and Pearson correlation analysis revealed a positive correlation between immunological effectiveness and viral inhibition. Forty-eight percent of the subjects changed antiretroviral drugs once, and 16.22% twice, and 31 patients switched from first-line to second-line antiretroviral therapy. Long-term antiretroviral therapy remains effective for treatment of HIV/AIDS, resulting in higher mean body weight, effective viral inhibition and a higher CD4 count. Immunological effectiveness of antiretroviral therapy positively correlates with HIV viral inhibition.

Japanese external quality assessment program to standardize HIV-1 drug-resistance testing (JEQS2010 program) using in vitro transcribed RNA as reference material

To design appropriate antiretroviral therapy regimens and avoid the emergence of human immunodeficiency virus (HIV)-1 variants with reduced susceptibility to antiretroviral drugs, genotypic drug-resistance testing (HIV genotyping) is strongly recommended. To monitor the quality of HIV genotyping in Japan, we performed an external quality assessment (EQA), named the Japanese external quality assessment program, to standardize HIV genotyping (JEQS). To accurately evaluate the quality of HIV genotyping, we employed as reference material (RM) a well-characterized sample, in vitro transcribed RNA (trRNA) that includes the HIV gag-pol sequence, and created a JEQS2010 panel consisting of three single variant and three mixed trRNA samples. All 11 participating laboratories showed high concordance rates (>96%) for the single variant samples. Eight laboratories also showed good rates of detecting minor variants, but three laboratories failed to detect the variants comprising one-half of the sample. These three laboratories used a common primer that had four internal mismatches to the minor trRNA clone. This program showed the usefulness of trRNA as RM, the high quality of HIV genotyping, and extensive interlaboratory variation in the ability to detect minor variants. These results suggest that improving the quality of HIV genotyping in Japan requires regularly implementing the EQA program and improving the HIV genotyping protocol in each laboratory.