Impact of drug resistance genotypes on CD4+ counts and plasma viremia in heavily antiretroviral‐experienced HIV‐infected patients

A total of 273 HIV-infected patients with prior treatment failures were identified, with a mean viral load of 50,438 copies/ml.

• Ninety-seven percent of patients had at least one drug resistance mutation, with 87.2% for nucleoside reverse transcriptase inhibitors, 68.5% for non-nucleoside reverse transcriptase inhibitors, and 92.7% for protease inhibitors.
• Resistance to three or more drugs within each class was found in 45.8% of patients for nucleoside reverse transcriptase inhibitors, 40.7% for non-nucleoside reverse transcriptase inhibitors, and 44.7% for protease inhibitors.
• Cross-resistance to compounds from two or three drug families was observed in 41% and 19.4% of patients, respectively.
• Nearly half of the patients had plasma HIV-RNA below 10,000 copies/ml, associated with significantly higher CD4+ counts (408 versus 259 cells/mul; P < 0.001).
• Patients with higher plasma viremia had significantly more drug resistance mutations compared to those with lower viremia.
• No favorable effect on viral load was observed for specific drug resistance mutations known to reduce viral fitness in vitro.

AI simplified