A 40-year-old man with HIV comes to the physician for a routine follow-up examination. He has been nonadherent with his antiretroviral medication regimen for several years. He appears chronically ill and fatigued. CD4+ T-lymphocyte count is 205/mm3. HIV genotypic analysis is performed. The viral isolates are found to have a mutation in the variable (V3) region of the env gene, which makes the virus capable of infecting T cells with a specific surface receptor, but infection of macrophages is inefficient. Which of the following antiretroviral medications is most likely to be ineffective in this patient?

Question

A 40-year-old man with HIV comes to the physician for a routine follow-up examination. He has been nonadherent with his antiretroviral medication regimen for several years. He appears chronically ill and fatigued. CD4+ T-lymphocyte count is 205/mm3. HIV genotypic analysis is performed.  The viral isolates are found to have a mutation in the variable (V3) region of the env gene, which makes the virus capable of infecting T cells with a specific surface receptor, but infection of macrophages is inefficient.  Which of the following antiretroviral medications is most likely to be ineffective in this patient?

Quizplus · Accepted Answer

Eductional Objective: R5 strains (macrophage-tropic) of HIV attach to the host CD4 receptor and CCR5 chemokine coreceptor; CCR5 inhibitors such as maraviroc can be used in the treatment of R5 virus.  X4 strains (T lymphotropic) of HIV bind to the CD4 receptor and CXCR4 chemokine receptor; X4 virus cannot be treated with CCR5 inhibitors.

A 40-Year-Old Man with HIV Comes to the Physician for a Routine