Virological failure and development of new resistance mutations according to CD4 count at combination antiretroviral therapy initiation

Epidemiologic and viral predictors of antiretroviral drug resistance among persons living with HIV in a large treatment program in Nigeria

BACKGROUND

Expanded access to combination antiretroviral therapy (cART) throughout sub-Saharan Africa over the last decade has remarkably improved the prognosis of persons living with HIV (PLWH). However, some PLWH experience virologic rebound after a period of viral suppression, usually followed by selection of drug resistant virus. Determining factors associated with drug resistance can inform patient management and healthcare policies, particularly in resource-limited settings where drug resistance testing is not routine.

METHODS

A case-control study was conducted using data captured from an electronic medical record in a large treatment program in Nigeria. Cases PLWH receiving cART who developed acquired drug resistance (ADR) and controls were those without ADR between 2004 and 2011. Each case was matched to up to 2 controls by sex, age, and education. Logistic regression was used estimate odds ratios (ORs) and 95% confidence intervals (CIs) for factors associated with ADR.

RESULTS

We evaluated 159 cases with ADR and 299 controls without ADR. In a multivariate model, factors associated with ADR included older age (OR = 2.35 [age 30-40 years 95% CI 1.29, 4.27], age 41 + years OR = 2.31 [95% CI 1.11, 4.84], compared to age 17-30), higher education level (secondary OR 2.14 [95% CI 1.1.11-4.13]), compared to primary and tertiary), non-adherence to care (OR = 2.48 [95% CI 1.50-4.00]), longer treatment duration (OR = 1.80 [95% CI 1.37-2.35]), lower CD4 count((OR = 0.95 [95% CI 0.95-0.97]) and higher viral load (OR = 1.97 [95% CI 1.44-2.54]).

CONCLUSIONS

Understanding these predictors may guide programs in developing interventions to identify patients at risk of developing ADR and implementing prevention strategies.

Associations between baseline characteristics, CD4 cell count response and virological failure on first-line efavirenz + tenofovir + emtricitabine for HIV

OBJECTIVES

The aim of this study was to investigate associations between baseline characteristics and CD4 cell count response on first-line antiretroviral therapy and risk of virological failure (VF) with or without drug resistance.

METHODS

We conducted an analysis of UK Collaborative HIV Cohort data linked to the UK HIV Drug Resistance Database. Inclusion criteria were viral sequence showing no resistance prior to initiation of first-line efavirenz + tenofovir disoproxil fumarate + emtricitabine and virological suppression within 6 months. Outcomes of VF (≥200 copies/mL) with or without drug resistance were assessed using a competing risks approach fitted jointly with a model for CD4 cell count recovery. Hazard ratios for each VF outcome were estimated for baseline CD4 cell count and viral load and characteristics of CD4 cell count response using latent variables on a standard normal scale.

RESULTS

A total of 3640 people were included with 338 VF events; corresponding viral sequences were available in 134 with ≥1 resistance mutation in 36. VF with resistance was associated with lower baseline CD4 (0.30, 0.09-0.62), lower CD4 recovery (0.04, 0.00-0.17) and higher CD4 variability (4.40, 1.22-12.68). A different pattern of associations was observed for VF without resistance, but the strength of these results was less consistent across sensitivity analyses. Cumulative incidence of VF with resistance was estimated to be <2% at 3 years for baseline CD4 ≥350 cells/μL.

CONCLUSION

Lower baseline CD4 cell count and suboptimal CD4 recovery are associated with VF with drug resistance. People with low CD4 cell count before ART or with suboptimal CD4 recovery on treatment should be a priority for regimens with high genetic barrier to resistance.

Long-term virological suppression on first-line efavirenz + tenofovir + emtricitabine/lamivudine for HIV-1

Objectives:

Evaluate long-term rates of virological failure and treatment interruption for people living with HIV (PLWHIV) with viral suppression on first-line efavirenz + tenofovir disoproxil fumarate + emtricitabine/lamivudine (EFV + TDF + FTC/3TC), and compare these according to patient characteristics.

Methods:

PLWHIV enrolled in the Collaboration of Observational HIV Epidemiological Research Europe cohort collaboration, who started first-line EFV + TDF + FTC/3TC at age at least 16 years and had viral suppression (<200 copies/ml) within 9 months were included. Rates of virological failure (≥200 copies/ml) and (complete) treatment interruption were estimated according to years since initial suppression. We used Poisson regression to examine associations of baseline characteristics with rates of virological failure or treatment interruption.

Results:

Among 19 527 eligible PLWHIV with median (interquartile range) follow-up 3.7 (2.0–5.6) years after initial viral suppression, the estimated rate of the combined incidence of virological failure or treatment interruption fell from 9.0/100 person-years in the first year to less than 4/100 person-years beyond 3 years from suppression; considering only those remaining on EFV + TDF + FTC/3TC, the combined rate dropped from 8.2/100 person-years in the first year to less than 3.5/100 person-years beyond 3 years. PLWHIV with injecting drug-related or heterosexual transmission were at higher risk of virological failure or treatment interruption, as were those of Black ethnicity. PLWHIV aged less than 35 years were at higher risk of virological failure and treatment interruption.

Conclusion:

PLWHIV starting first-line EFV + TDF + FTC/3TC had low rates of virological failure and treatment interruption up to 10 years from initial suppression. Demographic characteristics can be used to identify subpopulations with higher risks of these outcomes.

Growing up with perinatal HIV: changes in clinical outcomes before and after transfer to adult care in the UK

INTRODUCTION

With improved survival, adolescents with perinatal HIV (PHIV) are transitioning from paediatric to adult care, but there are few published data on clinical outcomes post-transfer. Using linked data from patients in the national UK/Ireland paediatric cohort (CHIPS) and an adult UK cohort of outpatient clinics (UK CHIC), we describe mortality and changes in immunological status post-transfer.

METHODS

Participants in CHIPS aged ≥13 years by the end of 2013 were linked to the UK CHIC database. Mixed effects models explored changes in CD4 count before and after transfer, including interactions between time and variables where interaction p < 0.05.

RESULTS

Of 1,215 paediatric participants aged ≥13 years, 271 (22%) had linked data in UK CHIC. One hundred and forty-six (53%) were female, median age at last visit in paediatric care was 17 [interquartile range, IQR 16,18] years, median duration in paediatric care was 11.8 [6.6,15.5] years, and in adult care was 2.9 [1.5,5.9] years. At last visit in paediatric care, 74% (n = 200) were on ART, increasing to 84% (n = 228, p = 0.001) at last visit in adult care. In the 12 months before leaving paediatric care, 92 (47%) had two consecutive viral loads >400 copies/mL or one viral load >10,000 copies/mL, and likewise 102 (52%) in the 12 months post-transfer (p = 0.79). Seven (3%) people died in adult care. In multivariable analysis, CD4 declined as patients approached transition with a greater decline in those with higher nadir CD4 count (mean rates of decline of 3, 13, 15, 30 cells/mm3 per year for those with nadir CD4 < 100, 100-199, 200-299 and ≥300 cells/mm3, respectively). Post-transition, CD4 continued to decline in some groups (e.g. black males, -20 (-34, -5) cells/mm3 per year post transition, p = 0.007)) while it improved in others. Overall CD4 was higher with later year of birth (14 (7, 21) cells/mm3 per later year). There was no effect of age at transfer or changing hospital at transfer on CD4.

CONCLUSIONS

Our findings suggest that CD4 in adolescents with perinatal HIV in the UK was declining in the period before transition to adult care, and there was some reversal in this trend post-transfer in some groups. Across the transition period, CD4 was higher in those with later birth years, suggesting improvements in clinical care and/or transition planning over time.