Prevalence of Integrase Strand Inhibitor Resistance (INSTI)in New Orleans, Louisiana, 2012-2013

Integrase strand inhibitors (INSTI) are the newest class of antiretroviral (ARV) therapies available to patients. There is little surveillance data on INSTI resistance, particularly in the South. A retrospective review on all patients who underwent PhenoSense Integrase testing between January 1, 2012 and June 30, 2013 was performed to better identify who should be screened for integrase strand transfer inhibitor (INSTI) resistance at the Interim Louisiana State University Hospital (ILH). Fifty-three patients underwent PhenoSense testing for elvitegravir/raltegravir resistance during this time period. Resistance was significantly associated with INSTI experience but not with other characteristics including sex, age, race, CD4 cell count, or concurrent reverse transcriptase inhibitor or protease inhibitor mutations. The frequency of reduced elvitegravir/ raltegravir susceptibility among INSTI experienced patients with virologic failure at ILH was 14/41 (34%). Future surveillance monitoring will be useful for determining if baseline INSTI resistance testing needs to be performed for INSTI naïve patients in the future at ILH.