Incidence of HIV Resistance Mutations in Treatment Naïve Patients in the Greater Newark, New Jersey Area: A Prospective Observational Analysis

Background: Current guidelines recommend that all HIV positive patients that are treatment naïve be screened for genotypic mutations within the virus to determine whether or not specific anti-retroviral (ARV) drugs will be effective at the start of therapy. The aim of our study was to the determine the incidence of mutations and the identification of any potential risk factors for ARV resistance in treatment naïve patients in the Greater Newark, NJ.

Methods: A prospective observational study done in an outpatient setting at St Micheal’s Medical Center, Newark New Jersey between October 2009 to Febuary 2016. All patients included were treatment-naive with genotypic resistance tests performed at first visit into care. Medical records were reviewed to obtain clinical and demographic data including age, sex, race, risk factors for HIV, baseline HIV viral load (VL), CD4 count, and genotypic profile. Using Fisher exact test we analyzed the genotypic testing (GT) to determine the frequency of major drug resistance mutations associated with the various ARV agents.

Results: A total of 150 treatment naïve patients had genotypic testing prior to ARV and were included in the study. The majority of the patients, 107 (71.3%) were males, 110 (73.4%) were African American, and 49.3% MSM. The mean age at diagnosis was 37.63 (range 18-63) with a mean CD4 count of 354(range 6-1,610) and viral load of 129,272 (range 970-992,510).
Thirty two (21.3%) of patients had at least one resistance mutations. The most class with mutations was NNRTIs at 16% (24/150) and the most common mutation present was K103 in 10% of the patients.
Forty two (28%) patients had CD4 cell count <200, 72 (48%) were between 200-500 cell and 36 (24%) > 500 CD4 cells. Twelve (50%) of the patients with NNRTI resistance mutations had a CD4 cell count <200. Patients with CD4 cell count <200 at presentation were significantly more likely to have NNRTI mutation resistance (p=0.008).

Conclusion: Patients with lower CD4 cell counts on presentation are more likely to have NNRTI resistance mutations, probably indicating a longer duration of HIV infection. Resistance to NNRTIs is the most prevalent but appears to be decreasing.