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What is Resistance?

Mutations & Resistance in HIV

Managing Resistance to HIV Therapy
Causes of Treatment Failure
- Rational Treatment Sequencing
- Treatment Choices
- Hidden Dangers?
- Resistance Studies
- Measuring Resistance

Resistance Quiz

References

Credits
blank_30.GIF (61 bytes)

blank_30.GIF (61 bytes)
Managing Resistance to HIV Therapy Next

The aim of antiretroviral therapy is to suppress viral replication for as long as possible, to keep mutations to a minimum and so limit the appearance of resistant variants. In practice, achieving a viral load below the level of detection appears to be associated with a durable treatment response (Figure 1).

Figure 1: Time to failure predicted by virological nadir
102 phase 2 RTV failures (>0.6log Virological load (VL) rise from nadir)
Kempf D, et al. HIV Drug Resistance Workshop, St Petersburg 1997: Abstract 62

This figure clearly shows how the level of treatment response achieved is related to the length of response to therapy. Individuals who have an optimum response to therapy ie. viral load falls below 200 viral copies/ml, generally demonstrate a longer treatment response than individuals who do not achieve such low viral loads following treatment.

The virological load nadir is the point at which an individual’s viral load is at its lowest, as established by sequential viral load testing.

 

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