Impact of Early Versus Late Antiretroviral Treatment Initiation on Naive T Lymphocytes in HIV-1-Infected Children and Adolescents - The-ANRS-EP59-CLEAC Study

Distinct immune profiles in children living with HIV based on timing and duration of suppressive antiretroviral treatment

Timely initiation of antiretroviral therapy (ART) remains a major challenge in the effort to treat children living with HIV ("CLH") and little is known regarding the dynamics of immune normalization following ART in CLH with varying times to and durations of ART. Here, we leveraged two cohorts of virally-suppressed CLH from Nairobi, Kenya to examine differences in the peripheral immune systems between two cohorts of age-matched children (to control for immune changes with age): one group which initiated ART during early HIV infection and had been on ART for 5-6 years at evaluation (early, long-term treated; "ELT" cohort), and one group which initiated ART later and had been on ART for approximately 9 months at evaluation (delayed, short-term treated; "DST" cohort). We profiled PBMC and purified NK cells from these two cohorts by mass cytometry time-of-flight (CyTOF). Although both groups of CLH had undetectable viral RNA load at evaluation, there were marked differences in both immune composition and immune phenotype between the ELT cohort and the DST cohort. DST donors had reduced CD4 T cell percentages, decreased naive to effector memory T cell ratios, and markedly higher expression of stress-induced markers. Conversely, ELT donors had higher naive to effector memory T cell ratios, low expression of stress-induced markers, and increased expression of markers associated with an effective antiviral response and resolution of inflammation. Collectively, our results demonstrate key differences in the immune systems of virally-suppressed CLH with different ages at ART initiation and durations of treatment and provide further rationale for emphasizing early onset of ART.

Effect of the timing of antiretroviral treatment initiation on CD4 count in children and youths living with HIV in North India

BACKGROUND

Immediate start of antiretroviral treatment (ART) among non-hospitalized outpatient children living with HIV may improve or worsen clinical outcomes due to immune reconstitution.

OBJECTIVE

Role of immediate versus post-stabilization start of antiretroviral treatment in children and youths living with HIV on CD4 count and viral load suppression.

METHODS

This was a single blinded, randomized controlled trial conducted on outpatients attending a tertiary care hospital associated HIV clinic in North India. We enrolled ART-naive children and youths living with HIV aged 18 months to 21 years in a 1:1 ratio. Block randomization was done using computerized software. Children and youths living with HIV were either started with ART on diagnosis immediately within 24 h (Group A) or post stabilization at 2 weeks (Group B) as per National AIDS Control Organization (NACO) India guidelines. Both groups were comparable for baseline characteristics.

RESULTS

There was no significant difference seen in CD4 counts between two groups at 6 months follow up. CD4 count increased significantly in immediate group but not in post-stabilization group at 6 months. No significant changes/differences was seen in WHO clinical staging or anthropometry; one patient developed tuberculosis in both groups. Viral load at 6 months in both the groups did not differ significantly.

CONCLUSION

Immediate ART in children and youths living with HIV results in significant increase in CD4 count at 6 months follow up exemplifying immunological response to ART.

Demographics of Youth With Newly Diagnosed Acute/Recent HIV Infection in Adolescent Trials Network 147: Early Treatment of Acute HIV Infection

PURPOSE

Gay, bisexual, and other cisgender men who have sex with men, and racial minority youth are at elevated risk of acquiring HIV infection. The Adolescent Trials Network 147 recruited youth with acute/recent HIV-infection for early antiretroviral treatment. The cohort make-up is described here.

METHODS

Treatment-naïve, recently identified HIV + youth, aged 12-24 years, from Los Angeles and New Orleans were recruited from community centers, clinics, social media, and a high-risk seronegative cohort (n = 1,727, the Adolescent Trials Network 149) using point-of-care assays. Acute HIV infection was determined by Fiebig staging. HIV RNA viral load (VL) and CD4 cell counts, along with demographic and behavioral data were assessed at enrollment.

RESULTS

Between July 2017 and July 2021, 103 newly diagnosed youth were enrolled, initiating antiretroviral treatment within a week. Mean age was 20.8 years (standard deviation: 2.4); 90.3% identified as cis male, 83.5% were single or in casual relationships, 71.8% were gay, bisexual, and other cisgender men who have sex with men; 60.2% were Black. One-fourth (24.3%) reported homelessness ever; 10.7% within last 4 months. At enrollment, median plasma VL was 37,313 HIV RNA copies/ml (interquartile range: 5,849-126,162) and median CD4 count 445.5 cells/mm3 (interquartile range: 357-613). 40% of youth reported acute retroviral symptoms before or at enrollment. Acutely infected, seroconverting youth had the highest VL. Sexually transmitted coinfections were present at enrollment in 56% of the cohort, with syphilis being most frequent (39%).

DISCUSSION

Early identification and treatment of HIV can increase positive HIV outcomes. A high sexually transmitted infection burden was present in recently HIV-infected youth. Acute retroviral symptoms were not reported by most participants, demonstrating that broad universal HIV screening is needed for identification of recent infection in youth.

Thirteen-year viral suppression and immunologic recovery of LPV/r-based regimens in pediatric HIV treatment: a multicenter cohort study in resource-constrained settings of China

Background

Antiretroviral Therapy (ART) in children remains challenging due to resource-constrained settings. We conducted a 13-year, prospective, multicenter cohort study on the effectiveness and safety of LPV/r-based regimens in ART-naive and ART-experienced children.

Methods

From January 2008 to May 2021, children living with HIV-1 were recruited with LPV/r-based regimens from 8 clinical research sites in 6 provinces in China. Effectiveness outcomes were virologic failure (defined as at least two consecutive measurements of VL > 200 copies/mL after 6 months of ART) and immune response (defined as CD4% recovered to more than 25% after 12 months of treatment). The safety outcomes were treatment-related grade 2-4 adverse events and abnormal laboratory test results.

Results

A total of 345 ART-naïve children and 113 ART-experienced children were included in this cohort study. The median follow-up time was 7.3 (IQR 5.5-10.5) years. The incidence density of virologic failure was 4.1 (95% CI 3.3-4.9) per 100 person-years in ART-naïve children and 5.0 (95% CI 3.5-6.5) per 100 person-years in ART-experienced children. Kaplan Meyer (KM) curve analysis showed children with ART experience were at a higher risk of virologic failure (p < 0.05). The risk factors of virologic failure in ART-naïve children were clinic setting in rural hospitals (aHR = 2.251, 1.108-4.575), annual missed dose times >5 days of LPV intake (aHR = 1.889, 1.004-3.554); The risk factor of virologic failure in ART-experienced children was missed dose times >5 days (aHR = 2.689, 1.299-5.604) and mother as caregivers for ART administration (aHR = 0.475, 0.238-0.948). However, during long-term treatment, viral suppression rates between ART-naïve and ART-experienced children remained similar. No significant differences were observed in the immune response, treatment-related grade 2-4 events, and abnormal laboratory test results between ART-naïve children and ART-experienced children.

Conclusion

Our research underscores that with consistent, long-term treatment of LPV/r-based regimens, ART-experienced children can achieve therapeutic outcomes comparable to ART-naïve children. It provides crucial insights on LPV/r-based regimens in pediatric HIV treatment, especially in resource-limited settings where high-cost Integrase Strand Transfer Inhibitors (INSTs) are inaccessible. This evidence-based understanding provides an essential addition to the global therapeutic strategies for pediatric HIV treatment.

Host Immunity to Mycobacterium tuberculosis Infection Is Similar in Simian Immunodeficiency Virus (SIV)-Infected, Antiretroviral Therapy-Treated and SIV-Naïve Juvenile Macaques

Pre-existing HIV infection increases tuberculosis (TB) risk in children. Antiretroviral therapy (ART) reduces, but does not abolish, this risk in children with HIV. The immunologic mechanisms involved in TB progression in both HIV-naive and HIV-infected children have not been explored. Much of our current understanding is based on human studies in adults and adult animal models. In this study, we sought to model childhood HIV/Mycobacterium tuberculosis (Mtb) coinfection in the setting of ART and characterize T cells during TB progression. Macaques equivalent to 4 to 8 year-old children were intravenously infected with SIVmac239M, treated with ART 3 months later, and coinfected with Mtb 3 months after initiating ART. SIV-naive macaques were similarly infected with Mtb alone. TB pathology and total Mtb burden did not differ between SIV-infected, ART-treated and SIV-naive macaques, although lung Mtb burden was lower in SIV-infected, ART-treated macaques. No major differences in frequencies of CD4+ and CD8+ T cells and unconventional T cell subsets (Vγ9+ γδ T cells, MAIT cells, and NKT cells) in airways were observed between SIV-infected, ART-treated and SIV-naive macaques over the course of Mtb infection, with the exception of CCR5+ CD4+ and CD8+ T cells which were slightly lower. CD4+ and CD8+ T cell frequencies did not differ in the lung granulomas. Immune checkpoint marker levels were similar, although ki-67 levels in CD8+ T cells were elevated. Thus, ART treatment of juvenile macaques, 3 months after SIV infection, resulted in similar progression of Mtb and T cell responses compared to Mtb in SIV-naive macaques.

Brief Report: Long-Term Clinical, Immunologic, and Virologic Outcomes Among Early-Treated Children With HIV in Botswana: A Nonrandomized Controlled Clinical Trial

BACKGROUND

Early antiretroviral treatment (ART) improves outcomes in children, but few studies have comprehensively evaluated the impact of ART started from the first week of life.

METHODS

Children diagnosed with HIV within 96 hours of life were enrolled into the Early Infant Treatment Study in Botswana and followed on ART for 96 weeks. Nevirapine, zidovudine, and lamivudine were initiated; nevirapine was switched to lopinavir/ritonavir between weeks 2-5 in accordance with gestational age. Clinical and laboratory evaluations occurred at weeks 1, 2, 4, 8, 12, 24, 36, 48, 60, 72, 84, and 96.

FINDINGS

Forty children initiated ART at a median of 2 (IQR 2, 3) days of life; 38 (95%) completed follow-up through 96 weeks, and 2 (5%) died between 12 and 24 weeks. ART was well tolerated; 9 children (24%) experienced a grade 3 or 4 hematologic event, and 2 (5%) required treatment modification for anemia. The median 96-week CD4 count was 1625 (IQR 1179, 2493) cells/mm 3 with only 5/38 (13%) having absolute counts <1000 cells/mm 3 . Although 23 (61%) had at least one visit with HIV-1 RNA ≥40 copies/mL at or after 24 weeks, 28 (74%) had HIV-1 RNA <40 copies/mL at the 96-week visit. Median cell-associated HIV-1 DNA at 84/96-week PBMCs was 1.9 (IQR 1.0, 2.6) log 10 copies/10 6 cells. Pre-ART reservoir size at birth was predictive of the viral reservoir at 84/96 weeks.

INTERPRETATION

Initiation of ART in the first week of life led to favorable clinical outcomes, preserved CD4 cell counts, and low viral reservoir through 96 weeks of life.

Advances in Pediatric HIV-1 Cure Therapies and Reservoir Assays

Significant advances in the field of HIV-1 therapeutics to achieve antiretroviral treatment (ART)-free remission and cure for persons living with HIV-1 are being made with the advent of broadly neutralizing antibodies and very early ART in perinatal infection. The need for HIV-1 remission and cure arises due to the inability of ART to eradicate the major reservoir for HIV-1 in resting memory CD4+ T cells (the latent reservoir), and the strict adherence to lifelong treatment. To measure the efficacy of these cure interventions on reservoir size and to dissect reservoir dynamics, assays that are sensitive and specific to intact proviruses are critical. In this review, we provided a broad overview of some of the key interventions underway to purge the reservoir in adults living with HIV-1 and ones under study in pediatric populations to reduce and control the latent reservoir, primarily focusing on very early treatment in combination with broadly neutralizing antibodies. We also summarized assays currently in use to measure HIV-1 reservoirs and their feasibility and considerations for studies in children.

Significance of initiating antiretroviral therapy in the early stage of HIV infection

A growing number of guidelines now recommend that human immunodeficiency virus (HIV) infected patients should be given early antiretroviral therapy (ART), especially in acute HIV infection. ART during early infection can limit viral reservoirs and improve immune cell function. From a societal prospect, early-infected individuals who achieve a state of viral suppression through ART can reduce the chance of HIV transmission and reduce the acquired immunodeficiency syndrome (AIDS)-related disease burden. However, there are many problems in the early diagnosis and treatment of HIV infection, including personal and social factors, which hinder the implementation and development of early treatment. It is recommended that initiating ART in the early stage of HIV infection, combined with other treatment strategies, so as to achieve functional cure.

Initiating Antiretroviral Treatment Early in Infancy Has Long-term Benefits on the Human Immunodeficiency Virus Reservoir in Late Childhood and Adolescence

BACKGROUND

Early combined antiretroviral therapy (cART) limits the total HIV-DNA load in children. However, data on its impact in older children and adolescents remain scarce. This study compares HIV reservoirs in children (5-12 years) and adolescents (13-17 years) who started cART <6 months (early [E-] group) or >2 years (late [L-] group).

METHODS

The ANRS-EP59-CLEAC study prospectively enrolled 76 patients perinatally infected with HIV-1 who reached HIV-RNA <400 copies/mL <24 months after cART initiation, regardless of subsequent viral suppression (E-group: 27 children, 9 adolescents; L-group: 19 children, 21 adolescents). Total and integrated HIV-DNA were quantified in blood and in CD4+ T-cell subsets. A substudy assessed HIV reservoir inducibility after ex vivo peripheral blood mononuclear cell (PBMC) stimulation.

RESULTS

Total HIV-DNA levels were lower in early- versus late-treated patients (children: 2.14 vs 2.87 log copies/million PBMCs; adolescents: 2.25 vs 2.74 log; P < .0001 for both). Low reservoir was independently associated with treatment precocity, protective HLA, and low cumulative viremia since cART initiation. The 60 participants with undetectable integrated HIV-DNA started cART earlier than other patients (4 vs 54 months; P = .03). In those with sustained virological control, transitional and effector memory CD4+ T cells were less infected in the E-group than in the L-group (P = .03 and .02, respectively). Viral inducibility of reservoir cells after normalization to HIV-DNA levels was similar between groups.

CONCLUSIONS

Early cART results in a smaller blood HIV reservoir until adolescence, but all tested participants had an inducible reservoir. This deserves cautious consideration for HIV remission strategies.