Abstract

Suboptimal adherence associated with virologic failure and resistance mutations among patients on 1st line HAART in Bangalore, India

Presented by Maria Ekstrand (United States).

M. Ekstrand^1,2,3, A. Shet^2,4, S. Chandy⁵, G. Singh⁵, R. Shamsundar⁶, V. Madhavan⁷, S. Saravanan⁷, N. Kumarasamy<sup>7

1</sup>University of California, San Francisco, Medicine, San Francisco, United States, ²St John's Research Institute, Bangalore, India, ³University of California Berkeley, School of Public Health, Berkeley, United States, ⁴St John's National Academy of Health Sciences, Pediatrics, Bangalore, India, ⁵St John's National Academy of Health Sciences, Medicine, Bangalore, India, ⁶St John's National Academy of Health Sciences, Microbiology, Bangalore, India, ⁷YRGCARE, Chennai, India

Background: This study was conducted to examine the relationship between adherence, viral load (VL) and resistance mutations among public and private clinic outpatients receiving first-line HAART in Bangalore, India.
Methods: We recruited a cohort of 552 outpatients receiving HAART. Viral load testing was conducted for all study participants. HIV-1 genotypic resistance testing was performed for n=92 with VL>1,000 copies/mL. Interpretation of drug resistance mutations was performed according to the Stanford database (http://hivdb.stanford.edu/hiv). Past month adherence and treatment interruptions of >48 hours were assessed via self-report.
Results: 6% (n=34) of participants reported < 95% past month adherence and 20% (n=110) reported a history of >48 hr treatment interruptions. Combining the two adherence measures, 23% (n=123) were classified as “suboptimally-adherent”.
Overall, 24% (n=132) had detectable VL, (median =8,850 c/mL, IQR 1,175-147,688 c/mL). All adherence measures were significantly associated with VL, with 42% of suboptimally-adherent, and 19% of optimally-adherent patients showing virological failure (p< .0001).
Among the 92 samples with VL >1,000, 69% (n=63) had 1+ NRTI mutations, with M184V being the most common (62%, n=57) and 44% (n=40) having thymidine analogue mutations (TAMS). 72% (n=66) had 1+ NNRTI mutations and 23% (n=21) had 3+ NNRTI mutations. Adherence was significantly associated (p< .02) with mutations when treatment interruptions were included, with 87% of “suboptimally-adherent” patients having at least one mutation.
Conclusions: Our findings illustrate for the first time the strong association between suboptimal adherence, treatment failure and worsening drug resistance among patients on first-line HAART in India. The predictive value of standard adherence measures was improved by including data on treatment interruptions. The observed mutations can jeopardize future treatment options, especially in light of limited access to 2^nd line treatments. Research is needed to examine individual, family and structural reasons for treatment interruptions. Culturally-appropriate techniques are needed to improve both types of adherence in this setting.