Prevalence of drug resistance mutations in HAART patients infected with HIV-1 CRF06_cpx in Estonia

HIV-1 drug resistance mutations (DRMs) and substitutions were assessed after the failure of the first line non-nucleoside reverse transcriptase inhibitors (NNRTIs) + 2 nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) treatment regimens (efavirenz [EFV] + lamivudine[3TC] + zidovudine [ZDV] vs. EFV + 3TC + ddI) among the HIV-1 CRF06_cpx infected subjects in Estonia. HIV-1 genomic RNA was sequenced; DRMs and amino acid substitutions were compared in 44 treatment naïve and 45 first-line NNRTI + 2 NRTI treatment failed patients consisting of EFV + 3TC + ZDV (n = 17) and EFV + 3TC + didanosine[ddI] (n = 21) therapy failed sub-populations. At least one DRM was found in 78% of treatment experienced patients. The most common NRTI mutations were M184V (80%), L74V (31%), L74I (17%), K219E (9%), and M184I (9%), NNRTI mutations were K103N (83%), P225H (14%), L100I (11%), and Y188L (11%), reflecting generally the similar pattern of DRMs to that seen in treatment failed subtype B viruses. Sub-population analysis revealed that EFV + 3TC + ddI failed patients had more DRMs compared to EFV + 3TC + ZDV failed patients, especially the ddI DRM L74IV and several additional NNRTI DRMs. Additionally, CRF06_cpx specific mutation E179V and substitutions R32K, K122E, and V200AE were also detected in treatment experienced population. After the failure of the first-line EFV + 3TC + ddI therapy HIV-1 CRF06_cpx viruses develop additional NRTI and NNRTI mutations compared to EFV + 3TC + ZDV regimen. Therefore the usage of EFV + 3TC + ddI in this subtype decreases the options for next regimens containing abacavir, and NNRTI class agents.

Zidovudine impairs immunological recovery on first-line antiretroviral therapy: collaborative analysis of cohort studies in southern Africa

OBJECTIVES

Zidovudine (ZDV) is recommended for first-line antiretroviral therapy (ART) in resource-limited settings. ZDV may, however, lead to anemia and impaired immunological response. We compared CD4+ cell counts over 5 years between patients starting ART with and without ZDV in southern Africa.

DESIGN

Cohort study.

METHODS

Patients aged at least 16 years who started first-line ART in South Africa, Botswana, Zambia, or Lesotho were included. We used linear mixed-effect models to compare CD4+ cell count trajectories between patients on ZDV-containing regimens and patients on other regimens, censoring follow-up at first treatment change. Impaired immunological recovery, defined as a CD4+ cell count below 100 cells/μl at 1 year, was assessed in logistic regression. Analyses were adjusted for baseline CD4+ cell count and hemoglobin level, age, sex, type of regimen, viral load monitoring, and calendar year.

RESULTS

A total of 72,597 patients starting ART, including 19,758 (27.2%) on ZDV, were analyzed. Patients on ZDV had higher CD4+ cell counts (150 vs.128 cells/μl) and hemoglobin level (12.0 vs. 11.0 g/dl) at baseline, and were less likely to be women than those on other regimens. Adjusted differences in CD4+ cell counts between regimens containing and not containing ZDV were -16 cells/μl [95% confidence interval (CI) -18 to -14] at 1 year and -56 cells/μl (95% CI -59 to -52) at 5 years. Impaired immunological recovery was more likely with ZDV compared to other regimens (odds ratio 1.40, 95% CI 1.22-1.61).

CONCLUSION

In southern Africa, ZDV is associated with inferior immunological recovery compared to other backbones. Replacing ZDV with another nucleoside reverse transcriptase inhibitor could avoid unnecessary switches to second-line ART.

A comparison of the long-term durability of nevirapine, efavirenz and lopinavir in routine clinical practice in Europe: a EuroSIDA study

OBJECTIVES

The durability of combination antiretroviral therapy (cART) regimens can be measured as time to discontinuation because of toxicity or treatment failure, development of clinical disease or serious long-term adverse events. The aim of this analysis was to compare the durability of nevirapine, efavirenz and lopinavir regimens based on these measures.

METHODS

Patients starting a nevirapine, efavirenz or lopinavir-based cART regimen for the first time after 1 January 2000 were included in the analysis. Follow-up started ≥ 3 months after initiation of treatment if viral load was <500 HIV-1 RNA copies/mL. Durability was measured as discontinuation rate or development/worsening of clinical markers.

RESULTS

A total of 603 patients (21%) started nevirapine-based cART, 1465 (51%) efavirenz, and 818 (28%) lopinavir. After adjustment there was no significant difference in the risk of discontinuation for any reason between the groups on nevirapine and efavirenz (P=0.43) or lopinavir (P=0.13). Compared with the nevirapine group, those on efavirenz had a 48% (P=0.0002) and those on lopinavir a 63% (P<0.0001) lower risk of discontinuation because of treatment failure and a 31% (P=0.01) and 66% (P<.0001) higher risk, respectively, of discontinuation because of toxicities or patient/physician choice. There were no significant differences in the incidence of non-AIDS-related events, worsening anaemia, severe weight loss, increased aspartate aminotransferase (AST)/alanine aminotransferase (ALT) levels or increased total cholesterol. Compared with patients on nevirapine, those on lopinavir had an 80% higher incidence of high-density lipoprotein (HDL) cholesterol decreasing below 0.9 mmol/L (P=0.003), but there was no significant difference in this variable between those on nevirapine and those on efavirenz (P=0.39).

CONCLUSIONS

The long-term durability of nevirapine-based cART, based on risk of all-cause discontinuation and development of long-term adverse events, was comparable to that of efavirenz or lopinavir, in patients in routine clinical practice across Europe who initially tolerated and virologically responded to their regimen.