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Published on: August 31, 2014
Virologic and immunologic response to cART by HIV-1 subtype in the CASCADE collaboration
Giota Touloumi1, Nikos Pantazis, Marie-Laure Chaix
1Athens University Medical School, Athens, Greece. gtouloum@med.uoa.gr
Insights
Combination antiretroviral therapy (cART) shows similar virologic and immunologic response across diverse HIV subtypes. Efficacy of current antiretroviral agents is comparable for subtype B and common non-B HIV infections.
Area of Science:
- Virology
- Immunology
- Infectious Diseases
- Public Health
Background:
- HIV infection is caused by various subtypes, with B being predominant in high-income countries.
- Understanding treatment response across different HIV subtypes is crucial for global health strategies.
Purpose of the Study:
- To compare virologic response and CD4 count changes after combination antiretroviral therapy (cART) initiation.
- To assess differences in treatment outcomes between HIV-1 subtype B and specific non-B subtypes.
Main Methods:
- Analysis of HIV-RNA and CD4 counts from the CASCADE database for individuals infected since 1996 and aged 15+.
- Utilized survival and longitudinal modeling to estimate probabilities of virologic response, failure, and CD4 increase post-cART initiation.
Main Results:
- No overall significant difference in virologic response or failure rates between HIV subtypes B and non-B.
- Subtypes CRF01_AE and A showed a trend towards faster initial virologic response compared to subtype B.
- CD4 count increases were similar across subtypes, with subtype A exhibiting lower initial but faster long-term increases.
Conclusions:
- Virologic and immunologic responses to cART are generally similar across studied HIV subtypes.
- The efficacy of current antiretroviral drugs appears comparable for subtype B and most common non-B HIV infections in high-income settings.
- Limited statistical power due to the rarity of some non-B subtypes necessitates further research.
Background:
We aimed to compare rates of virologic response and CD4 changes after combination antiretroviral (cART) initiation in individuals infected with B and specific non-B HIV subtypes.
Methods:
Using CASCADE data we analyzed HIV-RNA and CD4 counts for persons infected ≥1996, ≥15 years of age. We used survival and longitudinal modeling to estimate probabilities of virologic response (confirmed HIV-RNA <500 c/ml), and failure (HIV-RNA>500 c/ml at 6 months or ≥1000 c/ml following response) and CD4 increase after cART initiation.
Results:
2003 (1706 B, 142 CRF02_AG, 55 A, 53 C, 47 CRF01_AE) seroconverters were included in analysis. There was no evidence of subtype effect overall for response or failure (p = 0.075 and 0.317, respectively) although there was a suggestion that those infected with subtypes CRF01_AE and A responded sooner than those with subtype B infection [HR (95% CI):1.37 (1.01-1.86) and 1.29 (0.96-1.72), respectively]. Rates of CD4 increase were similar in all subtypes except subtype A, which tended to have lower initial, but faster long-term, increases.
Conclusions:
Virologic and immunologic response to cART was similar across all studied subtypes but statistical power was limited by the rarity of some non-B subtypes. Current antiretroviral agents seem to have similar efficacy in subtype B and most widely encountered non-B infections in high-income countries.
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