TITLE:
HIV Drug Resistance Profiles and Clinical Outcomes in Patients with Viremia Maintained at Very Low Levels
AUTHORS:
Michael R. Jordan, Julie Winsett, Aileen Tiro, Vuth Bau, Rony S. Berbara, Christopher Rowley, Nobel Bellosillo, Christine Wanke, Eoin P. Coakley
KEYWORDS:
HIV; Low Level Viremia; Treatment Experienced Patients; HIV Drug Resistance
JOURNAL NAME:
World Journal of AIDS,
Vol.3 No.2,
May
30,
2013
ABSTRACT:
We describe an observational study of
clinical, virologic and drug resistance profiles in HIV-positive antiretroviral
adherent subjects with stable low level viremia (LLV) 50 - 1000 copies/mL for more than 12
months. Subjects were followed from time of first detectable viral load (VL).
In total, 102 episodes of LLV were detected among 80 individuals. The median
(mean, range) HIV copy number at genotyping was 250 (486, - 3900) copies/mL after 14 (17.9, 0 - 58) months of LLV. Few patients
maintained LLV for the entire 9 years period of observation, with half (52%) experiencing viremic progression following a
stable period of LLV either spontaneously or after treatment interruption or
failed regimen intensification. In the setting of prolonged periods of
sustained LLV, mean duration 22 (range 8 - 106) months, drug resistance (DR)
was almost universal. Resistance to ≥1 on-treatment drugs was defined in 97% of
specimens and DR to all drugs in the treatment regimen in over half of all
patients. Evolution of DR mutations during the period of LLV was observed in
20/28 (71%) subjects with specimens available for follow-up testing. This
evolution was associated with viremic progression to levels >1000 copies/mL (p = 0.03). Our data suggest that DR
present in patients with LLV is likely to impact long term clinical outcomes,
highlighting the importance of optimizing techniques to detect the presence of
drug resistant HIV in the setting of LLV and the need for larger prospective
studies to assess the emergence of DR in the setting of sustained LLV and the
impact of this DR on treatment outcomes.