Quantification of CD4 responses to combined antiretroviral therapy over 5 years among HIV-infected children in Kinshasa, Democratic Republic of Congo

Regulatory T Cells Kinetics in Immune Reconstitution Inflammatory Syndrome in HIV-Tuberculosis Co-Infected Individuals

Background

Combination antiretroviral therapy (cART) can suppress human immunodeficiency virus (HIV-1) replication, but some patients develop worsening of co-infections, termed immune reconstitution inflammatory syndrome. Regulatory T cells (Tregs) are a population of CD4+ T cells that modulate immune responses. We hypothesized that immune reconstitution inflammatory syndrome (IRIS) is associated with Tregs dysfunction.

Methods

We prospectively enrolled antiretroviral naive HIV patients with co-infection with Mycobacterium tuberculosis (MTB; N = 26) or controls with no prior opportunistic infection (N = 10). We prospectively measured HIV viral load, CD4+ T cell count, regulatory T cell (CD4high, CD127low-neg, Foxp3+) proportion, and Interferon-γ (IFN-γ) response to MTB peptides before and after initiation of combination antiretroviral therapy.

Results

Eleven of the MTB patients developed IRIS; 15 did not. IRIS patients had a lower proportion of Tregs at baseline compared to no-IRIS patients (HIV/no-OI and HIV/MTB no-IRIS), but the difference did not reach statistical significance (IRIS: 9.6 [5.3-11.2]; no-IRIS: 13.9 [7.6-22.5] p = 0.066). After 2 weeks of cART the proportion of Tregs was significantly lower in HIV/MTB IRIS patients (HIV/MTB IRIS: 9.8 [6.6-13.6], HIV/MTB no-IRIS: 15.8 [11.1-18.8]. The antigen-specific IFN-γ production was greater in the patients who developed IRIS compared with those who did not develop IRIS.

Conclusion

IRIS patients had a lower proportion of Tregs and more marked IFN-γ production, suggesting that Tregs may be responsible for suppressing the antigen-specific inflammatory response.

Antiretroviral therapy timing impacts latent tuberculosis infection reactivation in a tuberculosis/simian immunodeficiency virus coinfection model

Studies using the nonhuman primate model of Mycobacteriumtuberculosis/simian immunodeficiency virus coinfection have revealed protective CD4⁺ T cell–independent immune responses that suppress latent tuberculosis infection (LTBI) reactivation. In particular, chronic immune activation rather than the mere depletion of CD4⁺ T cells correlates with reactivation due to SIV coinfection. Here, we administered combinatorial antiretroviral therapy (cART) 2 weeks after SIV coinfection to study whether restoration of CD4⁺ T cell immunity occurred more broadly, and whether this prevented reactivation of LTBI compared to cART initiated 4 weeks after SIV. Earlier initiation of cART enhanced survival, led to better control of viral replication, and reduced immune activation in the periphery and lung vasculature, thereby reducing the rate of SIV-induced reactivation. We observed robust CD8⁺ T effector memory responses and significantly reduced macrophage turnover in the lung tissue. However, skewed CD4⁺ T effector memory responses persisted and new TB lesions formed after SIV coinfection. Thus, reactivation of LTBI is governed by very early events of SIV infection. Timing of cART is critical in mitigating chronic immune activation. The potential novelty of these findings mainly relates to the development of a robust animal model of human M. tuberculosis/HIV coinfection that allows the testing of underlying mechanisms.

Global temporal changes in the proportion of children with advanced disease at the start of combination antiretroviral therapy in an era of changing criteria for treatment initiation

INTRODUCTION

The CD4 cell count and percent at initiation of combination antiretroviral therapy (cART) are measures of advanced HIV disease and thus are important indicators of programme performance for children living with HIV. In particular, World Health Organization (WHO) 2017 guidelines on advanced HIV disease noted that >80% of children aged <5 years started cART with WHO Stage 3 or 4 disease or severe immune suppression. We compared temporal trends in CD4 measures at cART start in children from low-, middle- and high-income countries, and examined the effect of WHO treatment initiation guidelines on reducing the proportion of children initiating cART with advanced disease.

METHODS

We included children aged <16 years from the International Epidemiology Databases to Evaluate acquired immunodeficiency syndrome (AIDS) (IeDEA) Collaboration (Caribbean, Central and South America, Asia-Pacific, and West, Central, East and Southern Africa), the Collaboration of Observational HIV Epidemiological Research in Europe (COHERE), the North American Pediatric HIV/AIDS Cohort Study (PHACS) and International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) 219C study. Severe immunodeficiency was defined using WHO guidelines. We used generalized weighted additive mixed effect models to analyse temporal trends in CD4 measurements and piecewise regression to examine the impact of 2006 and 2010 WHO cART initiation guidelines.

RESULTS

We included 52,153 children from fourteen low-, eight lower middle-, five upper middle- and five high-income countries. From 2004 to 2013, the estimated percentage of children starting cART with severe immunodeficiency declined from 70% to 42% (low-income), 67% to 64% (lower middle-income) and 61% to 43% (upper middle-income countries). In high-income countries, severe immunodeficiency at cART initiation declined from 45% (1996) to 14% (2012). There were annual decreases in the percentage of children with severe immunodeficiency at cART initiation after the WHO guidelines revisions in 2006 (low-, lower middle- and upper middle-income countries) and 2010 (all countries).

CONCLUSIONS

By 2013, less than half of children initiating cART had severe immunodeficiency worldwide. WHO treatment initiation guidelines have contributed to reducing the proportion of children and adolescents starting cART with advanced disease. However, considerable global inequity remains, in 2013, >40% of children in low- and middle-income countries started cART with severe immunodeficiency compared to <20% in high-income countries.

Early Antiretroviral Therapy Initiation and Mortality Among Infants Diagnosed With HIV in the First 12 Weeks of Life: Experiences From Kinshasa, DR Congo and Blantyre, Malawi

BACKGROUND

Based on clinical trial results, the World Health Organization recommends infant HIV testing at age 4-6 weeks and immediate antiretroviral therapy (ART) initiation in all HIV-infected infants. Little is known about the outcomes of HIV-infected infants diagnosed with HIV in the first weeks of life in resource-limited settings. We assessed ART initiation and mortality in the first year of life among infants diagnosed with HIV by 12 weeks of age.

METHODS

Cohort of HIV-infected infants in Kinshasa and Blantyre diagnosed before 12 weeks to estimate 12-month cumulative incidences of ART initiation and mortality, accounting for competing risks. Multivariate models were used to estimate associations between infant characteristics and timing of ART initiation.

RESULTS

One hundred and twenty-one infants were diagnosed at a median age of 7 weeks (interquartile range, 6-8). The cumulative incidence of ART initiation was 46% [95% confidence interval (CI), 36%, 55%] at 6 months and 70% (95% CI 60%, 78%) at 12 months. Only age at HIV diagnosis was associated with ART initiation by age 6 months, with a subdistribution hazard ratio of 0.70 (95% CI 0.52, 0.91) for each week increase in age at DNA polymerase chain reaction test. The 12-month cumulative incidence of mortality was 20% (95% CI 13%, 28%).

CONCLUSIONS

Despite early diagnosis of HIV, ART initiation was slow and mortality remained high, underscoring the complexity in translating clinical trial findings and World Health Organization's guidance into real-life practice. Novel and creative health system interventions will be required to ensure that all HIV-infected infants achieve optimal treatment outcomes under routine care settings.

Continuous quality improvement interventions to improve long-term outcomes of antiretroviral therapy in women who initiated therapy during pregnancy or breastfeeding in the Democratic Republic of Congo: design of an open-label, parallel, group randomized trial

Background

Despite the rapid adoption of the World Health Organization’s 2013 guidelines, children continue to be infected with HIV perinatally because of sub-optimal adherence to the continuum of HIV care in maternal and child health (MCH) clinics. To achieve the UNAIDS goal of eliminating mother-to-child HIV transmission, multiple, adaptive interventions need to be implemented to improve adherence to the HIV continuum.

Methods

The aim of this open label, parallel, group randomized trial is to evaluate the effectiveness of Continuous Quality Improvement (CQI) interventions implemented at facility and health district levels to improve retention in care and virological suppression through 24 months postpartum among pregnant and breastfeeding women receiving ART in MCH clinics in Kinshasa, Democratic Republic of Congo. Prior to randomization, the current monitoring and evaluation system will be strengthened to enable collection of high quality individual patient-level data necessary for timely indicators production and program outcomes monitoring to inform CQI interventions. Following randomization, in health districts randomized to CQI, quality improvement (QI) teams will be established at the district level and at MCH clinics level. For 18 months, QI teams will be brought together quarterly to identify key bottlenecks in the care delivery system using data from the monitoring system, develop an action plan to address those bottlenecks, and implement the action plan at the level of their district or clinics.

Discussion

If proven to be effective, CQI as designed here, could be scaled up rapidly in resource-scarce settings to accelerate progress towards the goal of an AIDS free generation.

Trial registration

The protocol was retrospectively registered on February 7, 2017. ClinicalTrials.gov Identifier: NCT03048669.

Characteristics of HIV-Infected Children at Enrollment into Care and at Antiretroviral Therapy Initiation in Central Africa

Background

Despite the World Health Organization (WHO) regularly updating guidelines to recommend earlier initiation of antiretroviral therapy (ART) in children, timely enrollment into care and initiation of ART in sub-Saharan Africa in children lags behind that of adults. The impact of implementing increasingly less restrictive ART guidelines on ART initiation in Central Africa has not been described.

Materials and Methods

Data are from the Central Africa International Epidemiologic Databases to Evaluate AIDS (IeDEA) pediatric cohort of 3,426 children (0–15 years) entering HIV care at 15 sites in Burundi, DRC, and Rwanda. Measures include CD4 count, WHO clinical stage, age, and weight-for-age Z score (WAZ), each at enrollment into HIV care and at ART initiation. Changes in the medians or proportions of each measure by year of enrollment and year of ART initiation were assessed to capture potential impacts of changing ART guidelines.

Results

Median age at care enrollment decreased from 77.2 months in 2004–05 to 30.3 months in 2012–13. The median age at ART initiation (n = 2058) decreased from 83.0 months in 2004–05 to 66.9 months in 2012–13. The proportion of children ≤24 months of age at enrollment increased from 12.7% in 2004–05 to 46.7% in 2012–13, and from 9.6% in 2004–05 to 24.2% in 2012–13 for ART initiation. The median CD4 count at enrollment into care increased from 563 (IQR: 275, 901) in 2004–05 to 660 (IQR: 339, 1071) cells/μl in 2012–13, and the median CD4 count at ART initiation increased from 310 (IQR:167, 600) in 2004–05 to 589 (IQR: 315, 1113) cells/μl in 2012–13. From 2004–05 to 2012–13, median WAZ improved from -2 (IQR: -3.4, -1.1) to -1 (IQR: -2.5, -0.2) at enrollment in care and from -2 (IQR: -3.8, -1.6) to -1 (IQR: -2.6, -0.4) at ART initiation.

Discussion and Conclusion

Although HIV-infected children ≤24 months of age accounted for half of all children enrolling in care in our cohort during 2012–13, they represented less than a quarter of all those who were initiated on ART during the same period. Further research is needed to identify barriers to timely diagnosis, linkage to care, and initiation of ART among children with HIV infection.

Implementation and Operational Research: Maternal Combination Antiretroviral Therapy Is Associated With Improved Retention of HIV-Exposed Infants in Kinshasa, Democratic Republic of Congo

BACKGROUND

Programs to prevent mother-to-child HIV transmission are plagued by loss to follow-up (LTFU) of HIV-exposed infants. We assessed if providing combination antiretroviral therapy (cART) to HIV-infected mothers was associated with reduced LTFU of their HIV-exposed infants in Kinshasa, DR Congo.

METHODS

We constructed a cohort of mother-infant pairs using routinely collected clinical data. Maternal cART eligibility was based on national guidelines in effect at the time. Infants were considered LTFU after 3 failed tracking attempts after a missed visit or if more than 6 months passed since they were last seen in clinic. Statistical methods accounted for competing risks (eg, death).

RESULTS

A total of 1318 infants enrolled at a median age of 2.6 weeks (interquartile range: 2.1-6.9), at which point 24% of mothers were receiving cART. Overall, 5% of infants never returned to care after enrollment and 18% were LTFU by 18 months. The 18-month cumulative incidence of LTFU was 8% among infants whose mothers initiated cART by infant enrollment and 20% among infants whose mothers were not yet on cART. Adjusted for baseline factors, infants whose mothers were not on cART were over twice as likely to be LTFU, with a subdistribution hazard ratio of 2.75 (95% confidence limit: 1.81 to 4.16). The association remained strong regardless of maternal CD4 count at infant enrollment.

CONCLUSIONS

Increasing access to cART for pregnant women could improve retention of HIV-exposed infants, thereby increasing the clinical and population-level impacts of prevention of mother-to-child HIV transmission interventions and access to early cART for HIV-infected infants.

Using CD4 percentage and age to optimize pediatric antiretroviral therapy initiation

BACKGROUND

Quantifying pediatric immunologic recovery by highly active antiretroviral therapy (HAART) initiation at different CD4 percentage (CD4%) and age thresholds may inform decisions about timing of treatment initiation.

METHODS

HIV-1-infected, HAART-naive children in Europe and the Americas were followed from 2002 through 2009 in PENPACT-1. Data from 162 vertically infected children, with at least World Health Organization "mild" immunosuppression and CD4% <10th percentile, were analyzed for improvement to a normal CD4% (≥10th percentile) within 4 years after HAART initiation. Data from 209 vertically infected children, regardless of immune status, were analyzed for CD4% outcomes at 4 years and viral failure within 4 years.

RESULTS

Seventy-two percent of baseline immunosuppressed children recovered to normal within 4 years. Compared with "severe" immunosuppression, more children with "mild" immunosuppression (difference 36%, 95% confidence interval [CI]: 22% to 49%) or "advanced" immunosuppression (difference 20.8%, 95% CI: 5.8% to 35.9%) recovered a normal CD4%. For each 5-year increase in baseline age, the proportion of children achieving a normal CD4% declined by 19% (95% CI: 11% to 27%). Combining baseline CD4% and age effects resulted in >90% recovery when initiating HAART with "mild" immunosuppression at any age or "advanced" immunosuppression at age <3 years. Baseline CD4% effects became greater with increasing age (P = .02). At 4 years, most immunologic benefits were still significant but diminished. Viral failure was highest in infancy (56%) and adolescence (63%).

CONCLUSIONS

Initiating HAART at higher CD4% and younger ages maximizes potential for immunologic recovery. Guidelines should weigh immunologic benefits against long-term risks.

When to start antiretroviral therapy in children aged 2-5 years: a collaborative causal modelling analysis of cohort studies from southern Africa

BACKGROUND

There is limited evidence on the optimal timing of antiretroviral therapy (ART) initiation in children 2-5 y of age. We conducted a causal modelling analysis using the International Epidemiologic Databases to Evaluate AIDS-Southern Africa (IeDEA-SA) collaborative dataset to determine the difference in mortality when starting ART in children aged 2-5 y immediately (irrespective of CD4 criteria), as recommended in the World Health Organization (WHO) 2013 guidelines, compared to deferring to lower CD4 thresholds, for example, the WHO 2010 recommended threshold of CD4 count <750 cells/mm(3) or CD4 percentage (CD4%) <25%.

METHODS AND FINDINGS

ART-naïve children enrolling in HIV care at IeDEA-SA sites who were between 24 and 59 mo of age at first visit and with ≥1 visit prior to ART initiation and ≥1 follow-up visit were included. We estimated mortality for ART initiation at different CD4 thresholds for up to 3 y using g-computation, adjusting for measured time-dependent confounding of CD4 percent, CD4 count, and weight-for-age z-score. Confidence intervals were constructed using bootstrapping. The median (first; third quartile) age at first visit of 2,934 children (51% male) included in the analysis was 3.3 y (2.6; 4.1), with a median (first; third quartile) CD4 count of 592 cells/mm(3) (356; 895) and median (first; third quartile) CD4% of 16% (10%; 23%). The estimated cumulative mortality after 3 y for ART initiation at different CD4 thresholds ranged from 3.4% (95% CI: 2.1-6.5) (no ART) to 2.1% (95% CI: 1.3%-3.5%) (ART irrespective of CD4 value). Estimated mortality was overall higher when initiating ART at lower CD4 values or not at all. There was no mortality difference between starting ART immediately, irrespective of CD4 value, and ART initiation at the WHO 2010 recommended threshold of CD4 count <750 cells/mm(3) or CD4% <25%, with mortality estimates of 2.1% (95% CI: 1.3%-3.5%) and 2.2% (95% CI: 1.4%-3.5%) after 3 y, respectively. The analysis was limited by loss to follow-up and the unavailability of WHO staging data.

CONCLUSIONS

The results indicate no mortality difference for up to 3 y between ART initiation irrespective of CD4 value and ART initiation at a threshold of CD4 count <750 cells/mm(3) or CD4% <25%, but there are overall higher point estimates for mortality when ART is initiated at lower CD4 values. Please see later in the article for the Editors' Summary.