Question
Please explain my resistance test results in non-technical language…
29 October 2010. Related: All topics, Resistance.
I’ve just had the results today of my drug resistance tests and have been told that I am unable to have any NNRTIs or abacavir, Trizivir and Atripla. This is the first resistance test I’ve ever had and I’ve been HIV-positive for 10 years now.
I did not see my usual doctor today and the doctor I saw didn’t really explain the consequences of this result. Are you able to give me a non clinical explanation of what this means to me please.
Many thanks.
Richard
Answer
Hi Richard
You didn’t say whether or not you are have been on treatment or not. This is important to know.
The resistance test results mean that your HIV has changed in small ways that meant the drugs listed will not work for you.
If you were on treatment and your viral load rebounded, then these results relate to those current drugs. But resistance to one type of drug often causes resistance to other similar drugs.
In terms of explaining the results, the most commonly used resistance tests (genotypic tests) look at the structure of a sample of your HIV to see whether there have been any changes. The results are reported as a serious of letters and numbers and these changes (or mutations) often reduce how well a drug can work, or can stop the drug working completely.
For example, a mutation called K103N will mean you are resistant to the NNRTI efavirenz, but also to the NNRTI nevirapine, and means that you cannot use Atripla because that 3-in-1 formulation includes efavirenz.
There are four main mutations are linked to abacavir resistance (usually M184V plus one or more from K65R, L74V and Y115F). Because abacavir is one of the drugs in Trizivir (and also in Kivexa), you couldn’t use these drugs if you have resistance to abacavir, as one of the active ingredients – the abacavir – would not be working.
You will still have other treatment options that will work for you. If you want to send me details of your treatment history I can send links to relevant information.
If you have used other combinations in several years ago, and developed resistance to those drug (for example to protease inhibitors), then you need to consider your whole treatment history when choosing new drugs now.
If you have never used HIV treatment, then these results suggest that either you were originally infected with an strain of HIV that was already resistant to these drugs, or you may have been reinfected more recently with a new strain of HIV that is resistant to these drugs.
PS: although the mutation names sound technical and difficult. the number just refers to the junction on the HIV structure where the mutation has been seen. The first letter refers to the amino acid that should be at that junction and the end letter refers to the amino acid that is now at that junction. So K103N means that at junction 103 there has been a change from K (lysine) to N (asparagine). Sorry if this is more info than you wanted, but sometimes it helps when this is explained.
Comment