Figure 6.

Drug-resistance amino-acid profiles of HIV-1 protease. Protease-inhibitor treatment leads to growth of viruses with changes in specific amino-acid positions. The numbers across the top designate amino-acid positions in HIV-1 protease; the solid line indicates the flap region. Filled boxes indicate mutations that occur in treated patients; red boxes indicate that mutation is seen in patients both before therapy starts (bottom panel) and in patients after therapy has begun (top panel); hatched boxes indicate mutations that occur during passage of virus cultured in the presence of a drug. The percentages in the bottom panel refer to the percentage of clones that contain the mutation indicated in the corresponding row. In the top panel, each row displays the profile of amino-acid changes related to high-level resistance to protease inhibitors that are approved by the US Food and Drugs Administration (FDA) for treatment of HIV-1-infected adults. Abbreviations: APV, amprenavir; IDV, indinavir; LPV, loprinavir; NFV, nelfinavir; RTV, ritonavir; SQV, saquinavir. Only RTV, NFV, and IDV have FDA approval for treatment of children and adolescents.