Survey of reverse transcriptase from the heterosexual epidemic of human immunodeficiency virus type 1 CRF01_AE in Thailand from 1990 to 2000

Etravirine and rilpivirine resistance in HIV-1 subtype CRF01_AE-infected adults failing non-nucleoside reverse transcriptase inhibitor-based regimens

BACKGROUND

We studied prevalence of etravirine (ETR) and rilpivirine (RPV) resistance in HIV-1 subtype CRF01_AE infection with first-line non-nucleoside reverse transcriptase inhibitor (NNRTI) failure.

METHODS

A total of 225 adults failing two nucleoside reverse transcriptase inhibitors (NRTIs) plus 1 NNRTI in Thailand with HIV RNA>1,000 copies/ml were included. Genotypic resistance results and HIV-1 subtype were interpreted by Stanford DR database. ETR resistance was calculated by the new Monogram weighted score (Monogram WS; ≥ 4 indicating high-level ETR resistance) and by DUET weighted score (DUET WS; 2.5-3.5 and ≥ 4 resulted in intermediate and reduce ETR response, respectively). RPV resistance interpretation was based on previous reports.

RESULTS

Median (IQR) age was 38 (34-42) years, 41% were female and CDC A:B:C were 22%:21%:57%. HIV subtypes were 96% CRF01_AE and 4% B. Antiretrovirals at failure were lamivudine (100%), stavudine (93%), nevirapine (90%) and efavirenz (10%) with a median (IQR) duration of 3.4 (1.8-4.5) years. Median (IQR) CD4(+) T-cell count and HIV RNA were 194 (121-280) cells/mm³ and 4.1 (3.6-4.6) log₁₀ copies/ml, respectively. The common NNRTI mutations were Y181C (41%), G190A (22%) and K103N (19%). The proportion of patients with Monogram WS score ≥ 4 was 61.3%. By DUET WS, 49.8% and 7.5% of patients were scored 2.5-3.5 and ≥4, respectively. Only HIV RNA ≥ 4 log₁₀ copies/ml at failure was associated with both Monogram WS ≥ 4 (OR 2.3, 95% CI 1.3-3.9; P=0.003) and DUET WS ≥ 2.5 (OR 1.9, 95% CI 1.1-3.3; P=0.02). The RVP resistance-associated mutations (RAMs) detected were K101P (1.8%), Y181I (2.7%) and Y181V (3.6%). All patients with RPV mutation had ETR resistance. No E138R/E138K mutations were detected.

CONCLUSIONS

Approximately 60% of patients had high-level ETR resistance. The role of ETR in second-line therapy is limited in late NNRTI failure settings. RVP RAMs were uncommon, but cross-resistance between ETR and RVP was high.

Immunologic and virologic failure after first-line NNRTI-based antiretroviral therapy in Thai HIV-infected children

Background

There are limited data of immunologic and virologic failure in Asian HIV-infected children using non-nucleoside reverse transcriptase inhibitor (NNRTI)-based highly active antiretroviral therapy (HAART). We examined the incidence rate of immunologic failure (IF) and virologic failure (VF) and the accuracy of using IF to predict VF in Thai HIV-infected children using first-line NNRTI-based HAART.

Methods

Antiretroviral (ART)-naïve HIV-infected children from 2 prospective cohorts treated with NNRTI-based HAART during 2001-2008 were included. CD4 counts were performed every 12 weeks and plasma HIV-RNA measured every 24 weeks. Immune recovery was defined as CD4%≥25%. IF was defined as persistent decline of ≥5% in CD4% in children with CD4%<15% at baseline or decrease in CD4 count ≥30% from baseline. VF was defined as HIV-RNA>1,000 copies/ml after at least 24 weeks of HAART. Clinical and laboratory parameter changes were assessed using a paired t-test, and a time to event approach was used to assess predictors of VF. Sensitivity and specificity of IF were calculated against VF.

Results

107 ART-naive HIV-infected children were included, 52% female, % CDC clinical classification N:A:B:C 4:44:30:22%. Baseline data were median (IQR) age 6.2 (4.2-8.9) years, CD4% 7 (3-15), HIV-RNA 5.0 (4.9-5.5) log₁₀copies/ml. Nevirapine (NVP) and efavirenz (EFV)-based HAART were started in 70% and 30%, respectively.

At 96 weeks, none had progressed to a CDC clinical classification of AIDS and one had died from pneumonia. Overall, significant improvement of weight for age z-score (p = 0.014), height for age z-score, hemoglobin, and CD4 were seen (all p < 0.001). The median (IQR) CD4% at 96 weeks was 25 (18-30)%. Eighty-nine percent of children had immune recovery (CD4%≥25%) and 75% of children had HIV-RNA <1.7log₁₀copies/ml.

Thirty five (32.7%) children experienced VF within 96 weeks. Of these, 24 (68.6%) and 31 (88.6%) children had VF in the first 24 and 48 weeks respectively.

Only 1 (0.9%) child experienced IF within 96 weeks and the sensitivity (95%CI) of IF to VF was 4 (0.1-20.4)% and specificity was 100 (93.9-100)%.

Conclusion

Immunologic failure, as defined here, had low sensitivity compared to VF and should not be recommended to detect treatment failure. Plasma HIV-RNA should be performed twice, at weeks 24 and 48, to detect early treatment failure.

Trial Registration

Clinicaltrials.gov identification number NCT00476606

Characterization of mutations in HIV type 1 isolates from 144 Cambodian recently infected patients and pregnant women naive to antiretroviral drugs

A baseline study has been conducted to determine the polymorphism of reverse transcriptase, protease, and envelope genes of HIV-1 isolates from 146 antiretroviral drug-naive Cambodian patients including 22 seroconverters and 124 pregnant women having been diagnosed HIV positive for less than 1 year. Amplification of at least one gene was successful for 144 isolates. All three genes were obtained for 136 isolates. Subtyping showed that CRF01_AE was predominant (130 cases). According to the ANRS September 2004 list, polymorphism substitutions (>50% versus the subtype B consensus) of CRF01_AE at drug resistance positions were observed only in protease: I13V (81%), E35D (87%), M36I (100%), R41K (96%), and H69K (100%). Two strains bore one major resistance mutation to PIs: M46I and N88D. Five other strains carried drug resistance mutations to RTIs: K70R (one strain), V75M (three strains), and K101E (one strain). Of the isolates 4.9% had drug resistance mutations to antiretroviral drugs.