Does rapid HIV disease progression prior to combination antiretroviral therapy hinder optimal CD4+ T-cell recovery once HIV-1 suppression is achieved?

Advances in Mechanism of HIV-1 Immune Reconstitution Failure: Understanding Lymphocyte Subpopulations and Interventions for Immunological Nonresponders

In individuals diagnosed with AIDS, the primary method of sustained suppression of HIV-1 replication is antiretroviral therapy, which systematically increases CD4+ T cell levels and restores immune function. However, there is still a subset of 10-40% of people living with HIV who not only fail to reach normal CD4+ T cell counts but also experience severe immune dysfunction. These individuals are referred to as immunological nonresponders (INRs). INRs have a higher susceptibility to opportunistic infections and non-AIDS-related illnesses, resulting in increased morbidity and mortality rates. Therefore, it is crucial to gain new insights into the primary mechanisms of immune reconstitution failure to enable early and effective treatment for individuals at risk. This review provides an overview of the dynamics of key lymphocyte subpopulations, the main molecular mechanisms of INRs, clinical diagnosis, and intervention strategies during immune reconstitution failure, primarily from a multiomics perspective.

Trends and the associated factors of optimal immunological response and virological response in late anti-retroviral therapy initiation HIV cases in Taiwan from 2009 to 2020

BACKGROUND

Late cART initiation (CD4 count ≤200 cells/μL or AIDS-defining opportunistic illnesses [AOIs] at cART initiation) impedes CD4 count recovery and virologic suppression after cART initiation. However, studies to evaluate trends of and modifiable factors for optimal immunological response (IR) and virological response (VR) in people living with HIV (PLWH) with late cART initiation with the current HIV treatment strategies are limited.

METHODS

We retrospectively identified 475 PLWH with late cART initiation in 2009-2020. Patients were grouped based on the presence of IR (CD4 count ≥200 cells/μL) or VR (plasma viral load [PVL] ≤ 50 copies/mL) within 18 months after cART initiation (403 [84.8%] IR(+) and 72 [15.2%] IR(-); 422 [88.8%] VR(+) and 53 [11.2%] VR(-)). We used Joinpoint regression to identify IR (+) and VR(+) proportion changes.

RESULTS

From 2009 to 2020, the proportion of IR(+) patients remained unchanged (75% to 90%, P = 0.102), whereas that of VR(+) patients increased significantly (75% to 95%, P = 0.007). No join point was identified for either IR(+) or VR(+), and the annual percentage change was 0.56% (nonsignificant) and 1.35% (significant) for IR(+) and VR(+), respectively. Compared to IR(-) patients, IR(+) patients were more likely to have a higher pre-cART PVL, to start with a first-line INSTI-based regimen, or to start cART within 14 days of HIV diagnosis but were less likely to have chronic kidney disease, composite AOIs, or a lower pre-cART CD4 count. Compared to VR(-) patients, VR(+) patients were more likely to start a single-tablet regimen but were less likely to have a higher pre-cART PVL.

CONCLUSIONS

Our study identified several modifiable factors for optimal IR (rapid cART initiation and INSTI-based regimen initiation) and for optimal VR (STR initiation) among late initiators, which may guide early treatment modifications to reduce their AIDS-defining event incidence and mortality.

CD4+ T lymphocyte recovery in the modern antiretroviral therapy era: Toward a new threshold for defining immunological non-responders

Introduction

Despite the high level of efficacy of modern antiretroviral therapy (ART) in reducing HIV viremia and the control of viral replication, some people living with HIV (PLWH) do not recover their CD4+ T cell count.

Methods

To evaluate the frequency and predictive factors of discordant immune responses, we performed a retrospective cohort study of 324 antiretroviral-naïve PLWH who initiated first-line ART between 2008 and 2018 and maintained HIV RNA < 50 copies/ml during 36 months of follow-up. PLWH were defined as immunological non-responders (INRs) when CD4+ T cell count was < 20% compared with baseline (INR20%), or < 500 cells/mm3 (INR500) or < 200 cells/mm3 (INR200) at 36 months.

Results

The prevalence of INR20%, INR500, and INR200 was 12.5%, 34.6%, and 1.5%, respectively. After adjustment for possible confounders, CD4 nadir showed a significant association with all INR definitions, with lower values predicting INR500 (aOR 0.98, 95% CI 0.98–0.99, p < 0.001) and INR200 (aOR 0.98, 95% CI 0.95–1.01, p = 0.096). Moreover, a higher baseline CD4/CD8 ratio was inversely related to the probability of being INR500 (OR 0.03, 95% CI 0.01–0.12, p < 0.001) and INR200 (OR 0.002, 95% CI 18–7–67.72, p = 0.255). By contrast, INR20% had a higher CD4 nadir and CD4/CD8 ratio than other INRs, suggesting the identification of an heterogenous population with such definition.

Discussion

The present study highlights how INR200 has become rare in the contemporary ART era, and about one-third of PLWH meet the criteria for INR500. Overcoming the threshold of 500 CD4/mm3 could be an appropriate definition of immune response, in contrast with the older definitions of INR200 and INR20%. Early diagnosis and rapid treatment initiation, before CD4 counts and the CD4/CD8 ratio begin to decline, are critical for achieving an optimal immune response.

The Characteristics of the HIV-1 Env Glycoprotein Are Linked With Viral Pathogenesis

The understanding of HIV-1 pathogenesis and clinical progression is incomplete due to the variable contribution of host, immune, and viral factors. The involvement of viral factors has been investigated in extreme clinical phenotypes from rapid progressors to long-term non-progressors (LTNPs). Among HIV-1 proteins, the envelope glycoprotein complex (Env) has been concentrated on in many studies for its important role in the immune response and in the first steps of viral replication. In this study, we analyzed the contribution of 41 Envs from 24 patients with different clinical progression rates and viral loads (VLs), LTNP-Elite Controllers (LTNP-ECs); Viremic LTNPs (vLTNPs), and non-controller individuals contemporary to LTNPs or recent, named Old and Modern progressors. We studied the Env expression, the fusion and cell-to-cell transfer capacities, as well as viral infectivity. The sequence and phylogenetic analysis of Envs were also performed. In every functional characteristic, the Envs from subjects with viral control (LTNP-ECs and vLTNPs) showed significant lower performance compared to those from the progressor individuals (Old and Modern). Regarding sequence analysis, the variable loops of the gp120 subunit of the Env (i.e., V2, V4, and mainly V5) of the progressor individuals showed longer and more glycosylated sequences than controller subjects. Therefore, HIV-1 Envs from virus of patients presenting viremic control and the non-progressor clinical phenotype showed poor viral functions and shorter sequences, whereas functional Envs were associated with virus of patients lacking virological control and with progressor clinical phenotypes. These correlations support the role of Env genotypic and phenotypic characteristics in the in vivo HIV-1 infection and pathogenesis.

Dental implants in individuals living with HIV-1: Results from a prospective study in patients undergoing highly active antiretroviral therapy

OBJECTIVE

To assess survival and success rates of dental implants and the occurrence of peri-implant diseases (mucositis/peri-implantitis) in HIV-1-infected individuals.

MATERIAL AND METHODS

In this prospective study, 13 HIV-1-infected individuals undergoing highly active antiretroviral therapy (with undetectable plasma HIV RNA levels, and CD4+ T cells > 350/mm³ ) were followed after implant placement, as well as 13 non-HIV-1-infected matched controls. Patients enrolled in this study were followed up to 120 months (mean = 40.6 months; standard deviation = 22.2; range 18 -120 months). Twenty-five implants were placed in pristine healed sites for each group and bone augmentation procedures, when needed, were done only for contour augmentation. Patients were enrolled in a strict periodontal/peri-implant supportive therapy protocol with three recalls per year. The two groups were compared regarding subject-level characteristics (age, gender, smoking, diabetes) and implant-level characteristics (marginal bone level, peri-implant health status).

RESULTS

All the implants healed uneventfully and reached 100% survival rates (after at least 18 months) in both groups. There were no significant differences between groups for peri-implant diseases (mucositis/peri-implantitis) and for all subject-level co-variables (p > .05). Only the variables dental implant prosthesis type (DIPT) (p = .021, d = .86) and follow up (p = .011, d = .77) showed statistically significant differences between groups.

CONCLUSION

The findings suggest that well-controlled HIV-1-infected individuals are eligible to undergo implant therapy, achieving survival and success rates comparable to non-HIV-1-infected controls.

Characteristics of suboptimal immune response after initiating antiretroviral therapy among people living with HIV with a pre-treatment CD4 T cell count <200 ​cells/mm3 in Thailand

Background

Complete recovery of the CD4 T cell count is uncommon among chronically HIV-infected individuals with very low pre-treatment CD4 count. We studied the prevalence of chronically immune recovery and its associated factors including immune characteristics chronic HIV-infected Thais.

Methods

Treatment-naïve participants (n ​= ​375) from the HIV-NAT 006 cohort with a pre-treatment CD4 T cell count after initiating antiretroviral therapy (ART) and having achieved a suppressed viremia (HIV-RNA level ​< ​400 copies/mL) were retrospectively followed at the Thai Red Cross AIDS Research Centre, Bangkok, Thailand. Suboptimal immune recovery (SIR) was defined as having a CD4⁺ T cell count <200 ​cells/mm³ for 3 years after ART initiation. A case-control sub-study matched for age, sex and pre-ART CD4 T cell count was conducted to compare immunological characteristics between SIR (n ​= ​17) and non-SIR (n ​= ​24) participants. Immunological biomarkers such as interleukin-7 (IL-7) and soluble CD14 (sCD14) and other covariates including cytomegalovirus (CMV) DNA level, baseline hemoglobin level, hepatitis B and C co-infections, and T cell subsets associated with immune activation and exhaustion were evaluated.

Results

Among 375 participants with pre-ART CD4 T cell counts < 200 ​cells/mm³, the prevalence of SIR was 39.7%, 19.7% and 7.7% at years 1, 2 and 3 after starting ART, respectively. In a multivariate analysis, a pre-ART CD4 T cell count ≤100 ​cells/mm³ (adjusted odds ratio [aOR] 9.45, 95% CI 2.92–30.61, p ​< ​0.001), older age (aOR 1.07, 95% CI 1.01–1.13, p ​= ​0.029) and baseline HIV-RNA level (aOR 0.36, 95% CI 0.21–0.59, p ​< ​0.001) were independently associated with SIR at year 3 after ART initiation. In the matched case-control sub-study (cases ​= ​17, controls ​= ​24), there was a higher prevalence of hepatitis C co-infection (18.8% vs. 0%, p ​= ​0.05), lower sCD14 levels (mean, 6.23 vs. 6.27 log₁₀ ​pg/mL, p ​= ​0.04), lower CD8 T cell counts (mean, 514 vs. 876, p ​= ​0.0003), lower CD4/CD8 T cell ratio (mean, 0.27 vs. 0.41, p ​= ​0.01) and higher expression of PD1 on CD8⁺ T cells (74.2% vs. 65.1%, p ​= ​0.02) observed in SIR participants compared to their non-SIR counterparts at year 3 after ART initiation.

Conclusions

Nearly 10% of the study participants who had achieved virological suppression failed to recover a CD4 T cell count > 200 cells/mm³ after 3 years of ART which was with a very low pre-ART CD4 T cell count and older age. The long-term clinical outcomes of SIR participants need to be further explored.

The factors associated with natural disease progression from HIV to AIDS in the absence of ART, a propensity score matching analysis

This study aimed at comparing the factors associated with the natural progression between typical progressors (TPs) and rapid progressors (RPs) in HIV-infected individuals. A retrospective study was conducted on 2095 eligible HIV-infected individuals from 1995 to 2016 in a high-risk area of Henan Province, China. Propensity score matching was used to balance covariates, and the conditional logistic regression analyses were performed to explore the factors of natural disease progression among HIV infectors. A total of 379 pairs of RPs and TPs were matched. The standardised difference values of all covariates were less than 10%. HIV-infected individuals transmitted through sexual transmission (odds ratio (OR) 0.56, 95% confidence interval (CI) 0.36-0.85) were more likely to progress to AIDS compared with those infected through contaminated blood. Older age at diagnosis of HIV-infected individuals (OR 0.72, 95% CI 0.58-0.89) exhibited a faster progression to AIDS. HIV-infected individuals identified through a unique survey (OR 7.01, 95% CI 2.99-16.44) were less likely to progress to AIDS compared with those identified through medical institutions. HIV-infected individuals who had higher baseline CD4+T cell counts (OR 3.37, 95% CI 2.59-4.38) had a slower progression to AIDS. These findings provide evidence for natural disease progression from HIV to AIDS between TPs and RPs.

Incomplete immune reconstitution in HIV/AIDS patients on antiretroviral therapy: Challenges of immunological non-responders

The morbidity and mortality of HIV type-1 (HIV-1)-related diseases were dramatically diminished by the grounds of the introduction of potent antiretroviral therapy, which induces persistent suppression of HIV-1 replication and gradual recovery of CD4⁺ T-cell counts. However, ∼10-40% of HIV-1-infected individuals fail to achieve normalization of CD4⁺ T-cell counts despite persistent virological suppression. These patients are referred to as "inadequate immunological responders," "immunodiscordant responders," or "immunological non-responders (INRs)" who show severe immunological dysfunction. Indeed, INRs are at an increased risk of clinical progression to AIDS and non-AIDS events and present higher rates of mortality than HIV-1-infected individuals with adequate immune reconstitution. To date, the underlying mechanism of incomplete immune reconstitution in HIV-1-infected patients has not been fully elucidated. In light of this limitation, it is of substantial practical significance to deeply understand the mechanism of immune reconstitution and design effective individualized treatment strategies. Therefore, in this review, we aim to highlight the mechanism and risk factors of incomplete immune reconstitution and strategies to intervene.

Polymorphism rs1385129 Within Glut1 Gene SLC2A1 Is Linked to Poor CD4+ T Cell Recovery in Antiretroviral-Treated HIV+ Individuals

Untreated HIV infection is associated with progressive CD4+ T cell depletion, which is generally recovered with combination antiretroviral therapy (cART). However, a significant proportion of cART-treated individuals have poor CD4+ T cell reconstitution. We investigated associations between HIV disease progression and CD4+ T cell glucose transporter-1 (Glut1) expression. We also investigated the association between these variables and specific single nucleotide polymorphisms (SNPs) within the Glut1 regulatory gene AKT (rs1130214, rs2494732, rs1130233, and rs3730358) and in the Glut1-expressing gene SLC2A1 (rs1385129 and rs841853) and antisense RNA 1 region SLC2A1-AS1 (rs710218). High CD4+Glut1+ T cell percentage is associated with rapid CD4+ T cell decline in HIV-positive treatment-naïve individuals and poor T cell recovery in HIV-positive individuals on cART. Evidence suggests that poor CD4+ T cell recovery in treated HIV-positive individuals is linked to the homozygous genotype (GG) associated with SLC2A1 SNP rs1385129 when compared to those with a recessive allele (GA/AA) (odds ratio = 4.67; P = 0.04). Furthermore, poor response to therapy is less likely among Australian participants when compared against American participants (odds ratio: 0.12; P = 0.01) despite there being no difference in prevalence of a specific genotype for any of the SNPs analyzed between nationalities. Finally, CD4+Glut1+ T cell percentage is elevated among those with a homozygous dominant genotype for SNPs rs1385129 (GG) and rs710218 (AA) when compared to those with a recessive allele (GA/AA and AT/TT respectively) (P < 0.04). The heterozygous genotype associated with AKT SNP 1130214 (GT) had a higher CD4+Glut1+ T cell percentage when compared to the dominant homozygous genotype (GG) (P = 0.0068). The frequency of circulating CD4+Glut1+ T cells and the rs1385129 SLC2A1 SNP may predict the rate of HIV disease progression and CD4+ T cell recovery in untreated and treated infection, respectively.

Survival of dental implants placed in HIV-positive patients: a systematic review

No consensus has been reached on the use of dental implants in human immunodeficiency virus (HIV)-positive patients. This systematic review evaluated dental implants in HIV-positive patients in terms of implant survival and success rates, marginal bone loss, and complications. The review was conducted according to the PRISMA checklist. Two independent reviewers performed a comprehensive search of the PubMed/MEDLINE, Scopus, and Cochrane Library databases for studies published until October 2017. Six studies were selected for review. In total, 821 implants were placed: 493 in 169 HIV-positive patients, and 328 in 135 HIV-negative patients. The mean duration of follow-up was 47.9 months. Weighted mean survival rate, success rate, and marginal bone loss values were calculated for the HIV-positive patients. Mean survival and success rates at the patient level (according to the number of patients) were 94.76% and 93.81%, respectively; when calculated at the implant level (according to the number of implants), these rates were 94.53% and 90.37%, respectively. Mean marginal bone loss was 0.83mm at the patient level and 0.99mm at the implant level. Thus, dental implants are suitable for the rehabilitation of HIV-positive patients with controlled risk factors and normal CD4+ cell counts.

Predictors of CD4 cell recovery following initiation of antiretroviral therapy among HIV-1 positive patients with well-estimated dates of seroconversion

OBJECTIVES

To investigate factors that predict speed of recovery and long-term CD4 cell count in HIV-1 seroconverters initiating combination antiretroviral therapy (cART), and to quantify the influence of very early treatment initiation. We make use of all pre-treatment CD4 counts, because analyses using only a single observation at initiation may be subject to biases.

METHODS

We used data from the CASCADE (Concerted Action on SeroConversion to AIDS and Death in Europe) multinational cohort collaboration of HIV-1 seroconverters. We analysed pre- and post-treatment data of patients with seroconversion dates estimated January 2003-March 2014 (n = 7600 for primary analysis) using a statistical model in which the characteristics of recovery in CD4 counts are determined by multiple predictive factors. Secondary analyses were performed incorporating uncertainty in the exact timing of seroconversion to allow more precise estimation of the benefit of very early treatment initiation.

RESULTS

'True' CD4 count at cART initiation was the strongest predictor of CD4 count beyond 3 years on cART. Allowing for lack of complete certainty in the date of seroconversion, CD4 recovery was more rapid for patients in whom treatment was initiated within 4 months. For a given CD4 count, higher viral load (VL) at initiation was strongly associated with higher post-treatment CD4 recovery. For other patient and drug characteristics, associations with recovery were statistically significant but small in magnitude.

CONCLUSIONS

CD4 count at cART initiation is the most important factor in predicting post-treatment recovery, but VL provides substantial additional information. If cART is initiated in the first 4 months following seroconversion, recovery of CD4 counts appears to be more rapid.

High CXCL10/IP-10 levels are a hallmark in the clinical evolution of the HIV infection

The aim of this study was to investigate the modulation of plasma CXCL10, CCL20, CCL22, CCL2, CCL17 and CCL24 levels in HIV-positive patients grouped according to extreme phenotypes of progression to AIDS, and at different stages of HIV infection. HIV-positive individuals with extreme phenotypes of AIDS progression (n=58) at different clinical stages (chronic individuals, both pre-HAART and under-HAART) and HIV-negative controls (n=20) were evaluated. Additionally, HIV-positive individuals that initiated HAART with >350CD4⁺T-cells/mm³ were compared with those who initiated treatment with <350CD4⁺T-cells/mm³. Plasma levels of six chemokines were quantified by a Luminex assay. Higher CXCL10 levels were observed in individuals immediately before their CD4⁺T-cell levels were indicative for HAART (pre-HAART), independently of their progressor status, i.e. slow (SPs) or rapid progressors (RPs). SPs pre-HAART showed higher CXCL10 levels compared to elite controllers and RPs under HAART (p_c=0.009 and p_c=0.007, respectively). CXCL10 levels were higher in SPs HAART CD4<350 (initiated HAART with <350 CD4⁺T-cells) when compared with SPs HAART CD4>350 (initiated HAART with >350 CD4⁺T-cells) (1096 vs. 360.33pg/mL, p=0.0101). Normalisation of CXCL10 levels seems to depend on the CD4⁺T-cell nadir at HAART initiation. CCL20 levels were higher in chronic SPs, SPs pre-HAART, SPs HAART and RPs HAART compared with the HIV-negative controls, indicating persistent CCL20 expression. In conclusion, our results indicate that CXCL10 levels are a hallmark in the clinical evolution of HIV infection. However, our results must be verified in a study evaluating a larger number of AIDS progressors.

HIV Progression Depends on Codon and Amino Acid Usage Profile of Envelope Protein and Associated Host-Genetic Influence

Acquired immune deficiency syndrome (AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV). Two types of HIV have been characterized: HIV-1 and HIV-2. The present study investigated whether evolutionary selection pressure differs between rapid progressor (RP), slow progressor (SP), and long-term non-progressor (LTNP) of HIV-I infected individuals. An unexpected association between the evolutionary rate of substitution in envelope (env) gene and disease progression is observed. Our present study suggests that env genes of LTNP are subject to unusually strong functional constraint with respect to RP. We also observed that the three categories of env genes i.e., RP, SP, and LTNP, had their own characteristic pattern of amino acid usage and SP and LTNP sequences shared similar patterns of amino acid usage different from RP sequences and evolutionary rate significantly influenced the amino acid usage pattern of the three different types of env gene sequences. It was also noted that the evolutionary rate for the glycosylation sites of LTNP and SP sequences were even significantly less than the RP sequences. Comparative analysis on the influence of human host on the three categories of env genes are well correlated with the rates of disease progression suggesting the adaptive strategies of the viruses for successful residence and infection. Host associated selective constraints appeared most relaxed on the RP sequences and strongest in LTNP sequences. The present study clearly portrays how evolutionary selection pressure differs between three categories of env genes i.e., RP, SP, and LTNP. The env genes, coding for the env glycoproteins, experience severe selection constraints from the host due to their constant exposure to the host immune system. In this perspective it might be suggested that env gene evolution occurs mainly by negative selection with the occurrence of mutation that might not reach fixation in the viral population. This work also confers a deeper insight into the crucial effects of host factors that govern the overall progression of HIV infection.

Higher levels of IL-6, CD4 turnover and Treg frequency are already present before cART in HIV-infected subjects with later low CD4 recovery

Immunological characterization of HIV-infected subjects with low CD4-recovery (LR-subjects) has been extensively performed after a variable period of combined antiretroviral therapy (cART). We now explore immunological alterations present before the cART onset. In a case-control study, we selected pre-cART samples of HIV-subjects with and without low CD4-recovery after cART (n = 21 per group). CD4 T-cell activation, senescence and exhaustion related markers were not found specifically altered before cART initiation. On the other hand, we found that LR-subjects before cART already showed increased levels of IL6 (p = 0.009) and increased frequencies of Ki67+CD4⁺ T-cells (p = 0.026), CD45RA-CD27+CD4⁺ T-cells (p = 0.008) and Treg (p = 0.001), as well as increased expression of CD95 and CD127 on CD4 T-cells (p = 0.016; p = 0.032, respectively). These parameters characterize the immunological damage in LR-subjects before the cART onset and could be associated to the mechanisms hindering the subsequent CD4 recovery.

Antiretroviral therapy suppressed participants with low CD4+ T-cell counts segregate according to opposite immunological phenotypes

Supplemental Digital Content is available in the text

Background:

The failure to increase CD4⁺ T-cell counts in some antiretroviral therapy suppressed participants (immunodiscordance) has been related to perturbed CD4⁺ T-cell homeostasis and impacts clinical evolution.

Methods:

We evaluated different definitions of immunodiscordance based on CD4⁺ T-cell counts (cutoff) or CD4⁺ T-cell increases from nadir value (ΔCD4) using supervised random forest classification of 74 immunological and clinical variables from 196 antiretroviral therapy suppressed individuals. Unsupervised clustering was performed using relevant variables identified in the supervised approach from 191 individuals.

Results:

Cutoff definition of CD4⁺ cell count 400 cells/μl performed better than any other definition in segregating immunoconcordant and immunodiscordant individuals (85% accuracy), using markers of activation, nadir and death of CD4⁺ T cells. Unsupervised clustering of relevant variables using this definition revealed large heterogeneity between immunodiscordant individuals and segregated participants into three distinct subgroups with distinct production, programmed cell-death protein-1 (PD-1) expression, activation and death of T cells. Surprisingly, a nonnegligible number of immunodiscordant participants (22%) showed high frequency of recent thymic emigrants and low CD4⁺ T-cell activation and death, very similar to immunoconcordant participants. Notably, human leukocyte antigen - antigen D related (HLA-DR) PD-1 and CD45RA expression in CD4⁺ T cells allowed reproducing subgroup segregation (81.4% accuracy). Despite sharp immunological differences, similar and persistently low CD4⁺ values were maintained in these participants over time.

Conclusion:

A cutoff value of CD4⁺ T-cell count 400 cells/μl classified better immunodiscordant and immunoconcordant individuals than any ΔCD4 classification. Immunodiscordance may present several, even opposite, immunological patterns that are identified by a simple immunological follow-up. Subgroup classification may help clinicians to delineate diverse approaches that may be needed to boost CD4⁺ T-cell recovery.