Viremia and HIV-1 drug resistance mutations among patients receiving second-line highly active antiretroviral therapy in Chennai, Southern India.
BACKGROUND
A cross-sectional study among individuals receiving second-line antiretroviral treatment was conducted to report on the level of detectable viremia and the types of drug resistance mutations among those with detectable human immunodeficiency virus (HIV) type 1 plasma viral loads (PVLs).


METHODS
PVLs were measured using Abbott m2000rt real-time polymerase chain reaction, and genotyping was performed with the ViroSeq genotyping system, version 2.0, and ViroSeq analysis software, version 2.8.


RESULTS
Of 107 patient plasma specimens consecutively analyzed, 30 (28%) had undetectable PVLs (<150 copies/mL), and 77 (72%) were viremic with a median PVL of 5450 copies/mL (interquartile range, 169-1 997 967). Sequencing was done for 107 samples with PVLs >2000 copies/mL: 33 patients (73%) had 1 of the protease (PR) inhibitor mutations; 41 (91%) had nucleoside reverse-transcriptase inhibitor (NRTI) mutations; 33 (73%) had non-NRTI (NNRTI) mutations; and 30 (66.7%) had both NRTI and NNRTI mutations. Triple-class resistance to NRTIs, NNRTIs, and PR inhibitors was observed in 24 (53%) patients. Based on the mutational profiles observed, all 45 sequences were susceptible to darunavir and tipranavir, whereas 47% showed resistance to lopinavir, 58% showed resistance to atazanavir, and >60% showed resistance to saquinavir, indinavir, nelfinavir, and fosamprenavir.


CONCLUSIONS
The results of the study showed that the majority of patients receiving second-line antiretroviral therapy started to accumulate PR resistance mutations, and the mutation profiles suggest that darunavir might be the drug of choice for third-line regimens in India.
YRG Centre for AIDS Research and Education, Chennai, India. saravanan@yrgcare.org
Shanmugam
S
Saravanan
Madhavan
M
Vidya
Pachamuthu
P
Balakrishnan
Rami
R
Kantor
Sunil S
SS
Solomon
David
D
Katzenstein
Nagalingeswaran
N
Kumarasamy
Tokugha
T
Yeptomi
Sathasivam
S
Sivamalar
Samara
S
Rifkin
Kenneth H
KH
Mayer
Suniti
S
Solomon
D019380:Anti-HIV Agents / Q000008:administration & dosage* / Q000494:pharmacology; D023241:Antiretroviral Therapy, Highly Active / Q000379:methods*; D003430:Cross-Sectional Studies; D000069454:Darunavir; D024882:Drug Resistance, Viral; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007194:India; D008297:Male; D020125:Mutation, Missense; D013449:Sulfonamides / Q000008:administration & dosage / Q000494:pharmacology; D019562:Viral Load; D014764:Viral Proteins / Q000235:genetics
D019380:Anti-HIV Agents; D013449:Sulfonamides; D014764:Viral Proteins; D000069454:Darunavir