Besides I47A, mutation L76V at the HIV protease gene has recently been proposed to cause lopinavir resistance. This change was present in 37 (2.7%) out of 1376 patients failing protease inhibitor containing regimens. Although 26 (70%) were on lopinavir, most had previously failed other protease inhibitors and carried multiple protease inhibitor resistance mutations. Therefore, L76V does not appear to be a primary lopinavir resistance change when the drug is used in combination therapy.
Department of Infectious Diseases, Hospital Carlos III, Madrid, Spain.
Received 26 June, 2007
Revised 24 October, 2007
Accepted 2 November, 2007