Safety and factors predicting the duration of first and second treatment interruptions guided by CD4+ cell counts in patients with chronic HIV infection

Outcomes after reinitiating antiretroviral therapy in children randomized to planned treatment interruptions

BACKGROUND

Excess risks for death/opportunistic disease in adults randomized to CD4-driven planned treatment interruption (PTI) in the Strategies for Management of Antiretroviral Therapy (SMART) trial remained after antiretroviral therapy (ART) re-initiation. Risks for children following PTI were evaluated in long-term follow-up of children in the PENTA 11 trial.

METHODS

Children with HIV RNA below 50 copies/ml and CD4 at least 30% (2-6 years) or at least 500 cells/μl (7-15 years) were randomized to continuous ART (cART) or PTI in PENTA 11 (ISRCTN 36694210). After the end of the trial, all were recommended to resume ART. Data were collected annually and analysed up to the second year of visit.

RESULTS

One hundred and one (51 cART, 50 PTI; median baseline age 9.2 years) children had median overall follow-up 4.6 (range 3.7-5.0) years. During 2-year post-trial period, there were no deaths or new Centers for Disease Control and Prevention (CDC) stage B/C events. Rate of clinical grade of at least two events was similar between PTI and cART [relative risk (RR) 1.03; 95% confidence interval (CI) 0.43, 2.50; P = 0.94]. At 2 years, difference in absolute CD4% between PTI and cART was -1.6% (-4.5%; 1.3%; P = 0.27), and proportions with HIV RNA below 50 copies/ml were 82 versus 86% (P = 0.57), respectively; no differences in growth or fasting lipids were observed. Key predictors of greater CD4% recovery after re-initiating ART were higher CD4% at baseline (P < 0.001) and longer time since ART re-initiation (P < 0.001). During overall follow-up, 4 (8%) PTI versus 5 (10%) CT children switched ART for failure (P = 0.75) and 9 (18%) versus 1 (2%) (P = 0.008) substituted ART for simplification.

CONCLUSIONS

No adverse clinical, immunological or virological consequences of PTI were observed 2 years after the end of PENTA 11 trial. Although ART interruption is not generally recommended, it may be an acceptable option for children, particularly when there is high risk of unplanned treatment interruptions.

Virological rebound and its consequences during treatment interruption

PURPOSE OF REVIEW

This paper provides an overview of the current knowledge on virological rebound during treatment interruption and its consequences in patients with chronic HIV-1 infection.

RECENT FINDINGS

After interruption of antiretroviral therapy, plasma viremia inevitably returns to individual pretherapy set point levels in almost all patients with chronic HIV infection. This virological rebound leads to a state of massive immune activation and consequently an increased turnover of CD4+ and CD8+ T cells resulting in a biphasic decay of T-helper cell numbers. Rebound has been shown to be associated with an increased risk of clinical events by some (albeit not all) randomized trials published during the last few months. Secondary consequences of immunologic deterioration include worsening of comorbidity (e.g. hepatitis and renal impairment) and an increased risk of cardiovascular disease as well as an elevated HIV transmission risk during treatment interruption. The individual course after treatment interruption cannot be predicted by any of the known surrogate markers.

SUMMARY

Treatment interruptions cannot be recommended in HIV-infected patients outside clinical trials, especially when profound immune deficiency is found to be preexisting.

Rates and determinants of virologic and immunological response to HAART resumption after treatment interruption in HIV-1 clinical practice

OBJECTIVE

To describe CD4 and HIV RNA changes during treatment resumption (TR) after treatment interruption (TI) compared with response to first highly active antiretroviral therapy (HAART) and to investigate predictors.

METHODS

Using Concerted Action on SeroConversion to AIDS and Death in Europe (CASCADE) data, we identified subjects who interrupted first HAART, not initiated during primary infection. We estimated rate of CD4 change during TR and time from TR to HIV RNA<500 copies per milliliter and subsequent rebound and factors associated with these outcomes.

RESULTS

Of 281 persons treated for median 18.4 months before interrupting, 259 resumed HAART. CD4 increases in the first 3 months on HAART were similar pre-TI and post-TI but after 3 months were significantly higher during pre-TI HAART, with median +106 and +172 cells per microliter at 3 and 18 months, respectively, during initial HAART compared with +99 and +142 cells per microliter during post-TI HAART, respectively. Subjects with lower CD4 counts at TI, aged older than 40 years, and those resuming the same HAART as their pre-TI regimen had lower CD4 increases during the first 3 months of TR. The majority (86%) of individuals reinitiating therapy achieved HIV RNA<500 copies per milliliter.

CONCLUSIONS

Immune reconstitution after TI is generally poorer than after first HAART, particularly for patients aged older than 40 years at TI and those with poorer immunological responses to pre-TI HAART. Reinitiation of the same HAART regimen as pre-TI also seems to have unfavorable outcomes.

Are previous treatment interruptions associated with higher viral rebound rates in patients with viral suppression?

OBJECTIVE

We investigated whether previous treatment interruptions are associated with a raised risk of viral rebound in individuals who have attained virological suppression.

METHODS

All patients achieving an undetectable viral load while on therapy were followed until viral rebound or the time of the last viral load. Poisson regression was used to describe the independent impact of treatment interruptions on rebound rates.

RESULTS

A total of 12,977 patients from the United Kingdom Collaborative HIV Cohort (UK CHIC) Study achieved a viral load of less than 50 copies/ml. These patients contributed a total of 37,314 person-years of follow-up. The overall rebound rate was 8.07 (7.78, 8.36) per 100 person-years. In adjusted analyses, rates of viral rebound were up to 64% higher (rate ratio 1.64; 1.43, 1.88) in those who had previously interrupted therapy compared with those who had not. Patients who had interrupted at detectable viral loads had up to a 74% (1.74; 1.42, 2.14) higher chance of rebounding compared with those who had not interrupted with a detectable viral load. We found no evidence to suggest interrupting treatment at an undetectable viral load was associated with viral rebound.

CONCLUSION

Among patients with an undetectable viral load, having previously interrupted therapy while the viral load was detectable is associated with a raised risk of rebound.