Clinical, Virological and Immunological Subphenotypes in a Cohort of Early Treated HIV-Infected Children

Insights to the HIV-associated visceral leishmaniasis clinical outcome: lessons learned about immune mediated disorders

Most cases of visceral leishmaniasis (VL) and human immunodeficiency virus (HIV) co-infection (VL/HIV) in the Americas occur in Brazil, and the prevalence of VL/HIV has been increasing since 2019, reaching 19% in 2023. This association presents a challenge for the management of VL, since both VL and HIV infection share immunopathogenic characteristics that can reciprocally affect co-infected patients. Thus, VL may contribute to the immunosuppression and other immunological disturbances associated with the rapid progression to acquired immunodeficiency syndrome (AIDS), whereas HIV infection accelerates the development of active VL and reduces the probability of a successful response to anti-Leishmania therapy, resulting in an increase in the relapse and lethality rates of VL. In this synergistic impairment, one of the most critical hallmarks of VL/HIV co-infection is the enhancement of immunosuppression and intense chronic immune activation, caused not only by each infection per se, but also by the cytokine storm and translocation of microbial products. Thus, co-infected patients present with an impaired effector immune response that may result in inefficient parasitic control. In addition, the chronic activation environment in VL/HIV patients may favor progression to early immunosenescence and exhaustion, worsening the patients' clinical condition and increasing the frequency of disease relapse. Herein, we review the immunological parameters associated with the immunopathogenesis of VL/HIV co-infection that could serve as good biomarkers of clinical prognosis in terms of relapse and severity of VL.

HIV reservoir and premature aging: risk factors for aging-associated illnesses in adolescents and young adults with perinatally acquired HIV

Despite receiving antiretroviral therapy (ART), an increasing number of adolescents and young adults with perinatally acquired HIV (PHIVAYA) are at risk of developing premature senescence and aging-associated illnesses, including cancer. Given this concern, it is crucial to assess aging biomarkers and their correlation with the HIV reservoir in order to comprehensively characterize and monitor these individuals. Fifty-five PHIVAYA (median age: 23, interquartile range [IQR]: 20-27 years, and 21 [18-23] years on ART at the time of study sampling) were studied along with 23 age-matched healthy controls. The PHIVAYA exhibited significantly higher percentages of activated, senescent, exhausted CD4 and CD8 T cells, shorter telomeres, reduced thymic output, and higher levels of circulating inflammatory markers (PAMPs, DAMPs, and pro-inflammatory cytokines IL-6, IL-8, and TNFα) as well as denervation biomarkers (neural cell adhesion molecule 1 [NCAM1] and C-terminal Agrin fragment [CAF]), compared to controls. HIV-DNA levels positively correlated with activated, senescent, exhausted CD4 and CD8 T cells, circulating biomarkers levels, and inversely with regulatory T and B cells and telomere length. According to their viremia over time, PHIVAYA were subgrouped into 14 Not Suppressed (NS)-PHIVAYA and 41 Suppressed (S)-PHIVAYA, of whom 6 who initiated ART within one year of age and maintained sustained viral suppression overtime were defined as Early Suppressed (ES)-PHIVAYA and the other 35 as Late Suppressed (LS)-PHIVAYA. ES-PHIVAYA exhibited significantly lower HIV-DNA reservoir, decreased percentages of senescent and exhausted CD4 and CD8 T cells, reduced levels of circulating inflammatory and denervation biomarkers, but longer telomere compared to LS- and NS-PHIVAYA. They differed significantly from healthy controls only in a few markers, including higher percentages of regulatory T and B cells, and higher levels of DAMPs. Overall, these results underscore the importance of initiating ART early and maintaining viral suppression to limit the establishment of the viral reservoir and to counteract immune and cellular premature aging. These findings also suggest new approaches for minimally invasive monitoring of individuals at high risk of developing premature aging and age-related illnesses.

HIV RNA/DNA Levels at Diagnosis Can Predict Immune Reconstitution: A Longitudinal Analysis

BACKGROUND

HIV DNA mirrors the number of infected cells and the size of the HIV viral reservoir. The aim of this study was to evaluate the effect of pre-cART HIV DNA levels as a predictive marker of immune reconstitution and on the post-cART CD4 counts trends.

METHODS

HIV DNA was isolated from PBMCs and quantified by real-time PCR. Immune reconstitution was assessed up to four years. Piecewise-linear mixed models were used to describe CD4 count changes.

RESULTS

148 people living with HIV (PLWH) were included. The highest rate of immune reconstitution was observed during the first trimester. There was a trend showing that high HIV RNA level resulted in greater increase in CD4 count, especially during the first trimester of cART (difference above vs. below median 15.1 cells/μL/month; 95% CI -1.4-31.5; p = 0.073). Likewise, higher HIV DNA level would predict greater CD4 increases, especially after the first trimester (difference above vs. below median 1.2 cells/μL/month; 95% CI -0.1-2.6; p = 0.071). Higher DNA and RNA levels combined were significantly associated with greater CD4 increase past the first trimester (difference high/high vs. low/low 2.1 cells/μL/month; 95% CI 0.3-4.0; p = 0.024). In multivariable analysis, lower baseline CD4 counts predicted a greater CD4 rise.

CONCLUSIONS

In successfully treated PLWH, pre-cART HIV DNA and HIV RNA levels are predictors of immune reconstitution.

Identification of CD8+ T cell subsets that normalize in early-treated people living with HIV receiving antiretroviral therapy

Background

Although combined antiretroviral therapy (cART) has decreased the mortality associated with HIV infection, complete immune reconstitution is not achieved despite viral suppression. Alterations of CD8⁺ T cells and some of their subpopulations, such as interleukin (IL)-17-producing cells, are evidenced in treated individuals and are associated with systemic inflammation and adverse disease outcomes. We sought to evaluate if different CD8⁺ T cell subsets are differentially normalized during a clinical follow-up of people living with HIV (PLWH) receiving suppressive cART.

Methods

We explored the changes in the frequencies, activation/exhaustion phenotypes (HLA-DR, CD38, PD-1, and TIM-3), and function (total and HIV-specific cells expressing CD107a, perforin, granzyme B, interferon [IFN]-γ and IL-17) of CD8⁺ T cells from early-treated PLWH receiving cART in a 1-year follow-up, using a multidimensional flow cytometry approach.

Results

Despite continuous cART-induced viral suppression and recovery of CD4⁺ T cells, after a 1-year follow-up, the CD8⁺ T cell counts, CD4:CD8 ratio, PD-1 expression, and IL-17 production by CD8⁺ T cells exhibited incomplete normalization compared with seronegative controls. However, the proportion of CD8⁺ T cells with an exhausted phenotype (co-expressing PD-1 andTIM-3), and cells co-expressing cytotoxic molecules (Perforin and Granzyme B), reached normalization.

Conclusions

Although suppressive cART achieves normalization of CD4⁺ T cell counts, only particular subsets of CD8⁺ T cells are more rapidly normalized in PLWH receiving cART, which could be routinely used as biomarkers for therapy efficiency in these patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12981-022-00465-0.