Antiretroviral-naive and -treated HIV-1 patients can harbour more resistant viruses in CSF than in plasma

In most cases, resistance mutations were present and similar in both studied compartments. However, in 3.4% of ARV-naive and 8.8% of ARV-treated patients, the virus was more resistant in CSF than in plasma. These results support the need for genotypic resistance testing when lumbar puncture is performed.