文章导读：The reason why you would suspect resistance is in a patient who was placed on a given medicine or combination and the viral load started increasing on therapy in a compliant patient. A secondary place where you may think about resistance is in a patient who is being treated where the viral load doesn't decrease any further, it goes down but then stops decreasing and is at a plateau or flat response.
Robert G. Gish California Pacific Medical Center, San Francisco, United States
Hepatology Digest: With nucleoside antiviral drug treatment, what are the clinical criteria for diagnosis of antiviral resistance? How can we detect antiviral-resistant mutations?
Prof. Gish: The reason why you would suspect resistance is in a patient who was placed on a given medicine or combination and the viral load started increasing on therapy in a compliant patient. A secondary place where you may think about resistance is in a patient who is being treated where the viral load doesn’t decrease any further, it goes down but then stops decreasing and is at a plateau or flat response. Then what you need to do is a resistance test—what is called genotypic resistance testing. These are special tests that look for changes in the viral genome. They look for specific point mutations that are known to be associated with drug failure or drug resistance. There are two tests that are easily available worldwide commercially. One test is a sequencing assay and the other is a test called an INNO-LiPA. Once you have one of these tests completed and you have identified a point resistance mutation, then you need to inform the patient and change his therapy. If the patient has a flat response or a rising DNA level, then you have to go back to the patient and discuss adherence and compliance.