Expanding HIV clinical monitoring: the role of CD4, CD8, and CD4/CD8 ratio in predicting non-AIDS events

Immune-microbiota dysregulation in maintenance hemodialysis: a 16S rRNA sequencing-based analysis of gut flora and T cell profiles

BACKGROUND

Maintenance hemodialysis (MHD) patients frequently exhibit immune dysregulation and gut dysbiosis, both of which contribute to increased infection risk and adverse outcomes. However, the relationship between gut microbial composition and immune competence in this population remains underexplored.

METHODS

This study assessed 45 MHD patients and 30 healthy controls, stratifying MHD patients into immunocompetent (HD-NLI, CD4+/CD8+ ≥ 1) and immunodeficient (HD-LI, CD4+/CD8+ < 1) groups. Circulating cytokines (IL-6, IL-10, IL-12, TNF-α, IFN-γ) were quantified using ELISA. Gut microbiota profiles were derived via 16S rRNA gene sequencing (V3-V4 regions), followed by QIIME2 and LEfSe-based bioinformatics analyses.

RESULTS

HD-LI patients displayed severe T cell dysregulation and elevated pro-inflammatory cytokines. Compared to controls, HD patients had reduced abundance of beneficial taxa (e.g., Prevotella copri, Bacteroides vulgatus, Agathobacter), and enrichment of pro-inflammatory taxa (e.g., Escherichia-Shigella, Blautia, Citrobacter). LEfSe identified 39 discriminatory taxa with distinct immune group signatures. Redundancy analysis revealed that CD4+ levels, CD4+/CD8+ ratios, and TNF-α significantly shaped microbiota composition. Correlation analysis confirmed strong associations between immune parameters and microbial taxa involved in short-chain fatty acid (SCFA) metabolism.

CONCLUSION

This study provides novel evidence linking gut microbial dysbiosis to immune impairment in MHD patients. The findings suggest that SCFA-producing bacteria are depleted in immunodeficient states, offering a potential target for microbiota-directed immunomodulatory therapies in ESRD.

Immunosenescence markers in T- and NK-cells according to the CD4/CD8 ratio in successfully treated people living with HIV

Introduction

The CD4/CD8 ratio has emerged as a useful indicator of immune dysfunction and comorbid conditions in people living with HIV (PLWH). However, its optimal cut-off value is unclear. We explored the correlation between the CD4/CD8 ratio, immunosenescence markers and comorbid conditions.

Methods

We prospectively included PLWH on successful and stable ART (antiretroviral therapy) > 60 years old and receiving either BIC/FTC/TAF or DTG/3TC, in Nice, France. HIV-negative healthy subjects were included as controls. We measured T-cell subsets (naïve, central memory, effector memory and terminally differentiated cells) and the distribution of KLRG1 + CD57+ senescent cells. We correlated CD4/CD8 ratio, background measurements and comorbid conditions.

Results

We included 68 PLWH (median age 69 years, 31 years on ART, median CD4/CD8 ratio 0.76). PLWH had higher levels of senescence markers than controls (n = 8). Among PLWH, adjusting for age, gender, HIV follow-up and duration on ART, those with a CD4/CD8 ratio < 0.76 had more senescent CD8+ cells (AdjOR = 0.93, 95%CI = [0.88; 0.97], p-value = 0.003). Higher levels of CD8+ senescence persisted for lower CD4/CD8 ratios, with, in addition, a significant decrease in NK cells in case of a ratio < 0.4. After adjustment, CD8+ effector memory senescent cells were significantly more abundant in PLWH with hypertension.

Conclusion

PLWH on successful ART display elevated immunosenescence markers, mainly on CD8+ T-cells. A CD4/CD8 cut-off value below 0.4 showed the strongest association with immune dysfunction, including NK+ cells. Such results could be useful for identifying patients requiring closer follow-up and screening for complications.

Immunological Features and Potential Biomarkers of Systemic Sclerosis-Associated Interstitial Lung Disease and Idiopathic Pulmonary Fibrosis

BACKGROUND

This study aims to summarize the similarities and differences in immune cell characteristics, and potential therapeutic targets between systemic sclerosis-associated interstitial lung disease (SSc-ILD) and idiopathic pulmonary fibrosis (IPF).

METHODS

This study included SSc-ILD and SSc-nonILD patients who were admitted to Beijing Chaoyang Hospital between April 4th, 2013, to June 30th, 2023. Publicly available datasets, including peripheral blood monocular cell (pbmc) single-cell data, SSc, SSc-ILD pbmc transcriptome data, and SSc-ILD, IPF lung tissue transcriptome data were analyzed. Statistical analyses were conducted using the SPSS and R software, employing standard statistical methods and bioinformatics packages such as Seurat, DESeq2, enrichR, and CellChat.

RESULTS

The results revealed that the CD4+/CD8+ T cell ratio of pbmc in SSc-ILD patients was significantly higher than in SSc-nonILD patients. In IPF patients, an elevated CD4+/CD8+ T cell ratio was also observed in progressive group, and Treg and mature CD4+ T cells might cause this change. JAK-STAT pathway and the cytokine-cytokine receptor interaction pathway were activated in peripheral blood T cells of IPF patients. The CD30, CD40, and FLT3 signaling pathways were found to play crucial roles in T cell interactions with other immune cells among IPF patients. SPA17 as a commonly upregulated gene among SSc, SSc-ILD, and IPF pbmc and lung, with its expression correlating positively with disease severity and lung function progression.

CONCLUSION

CD4+/CD8+ T cell ratio might associate with ILD initiation and progression; Treg cells and mature CD4+ T cells play key roles of it. SPA17 might serve as a pan-ILD marker and associated with lung function progression.

Mortality and immunological indicators of men who have sex with men living with HIV on antiretroviral therapy: a 10-year retrospective cohort study in Southern China

BACKGROUND

The proportion of people living with HIV (PLHIV) in Guangxi who are men who have sex with men (MSM) increased rapidly to nearly 10% in 2023; notably, over 95% of this particular population is currently receiving antiretroviral therapy (ART). This study aimed to describe the survival of MSM PLHIV, depict the characteristics and trends of changes in CD4+ T cell counts, CD4+/CD8+ T cell ratio, and viral load, and explore immunological indicators that may be related to mortality during different stages of treatment.

METHODS

Immunological indicators of MSM PLHIV receiving ART were extracted and categorized into baseline, mid-treatment, and last values. These were then incorporated into the Cox models in the form of repeated measurements to evaluate the associations (Adjusted-hazard ratios, aHRs) and 95% confidence intervals (95% CIs) of these immunological indicators with mortality at different stages.

RESULTS

A total of 5,642 patients who met the criteria were enrolled in the study, and 160 died, representing a mortality of 2.8%. The first, median, and last values of the CD4+ count and the CD4+/CD8+ ratio in surviving patients were significantly greater than the corresponding values in nonsurviving patients (P < 0.001). Except for the first viral load (P = 0.379), the median and last viral loads of the former were significantly lower than those of the latter (P < 0.001). In Cox model, with 2,144 cases, immunological indicators of increased mortality risk included a baseline CD4+ count below 200 cells/µL (aHR: 4.58, 95% CI: 2.28-9.19), a median (aHR: 8.46, 95% CI: 3.05-23.46), and a final (aHR: 4.43, 95% CI: 1.06-18.45) ratio below 0.7 and a median (aHR: 9.47, 95% CI: 4.02-22.35) and final (aHR: 14.46, 95% CI: 4.50-46.50) viral load 100,000 copies/mL and above.

CONCLUSIONS

Mortality among MSM PLHIV on ART in Guangxi is relatively low, and both high viral loads and low CD4+/CD8+ T cell ratios during treatment and at recent follow-up are strongly predictive of a serious prognosis and should be closely monitored.

Therapeutic microbiome modulation: new frontiers in HIV treatment

PURPOSE OF REVIEW

Dysbiosis may be a key driver of systemic inflammation, which increases the risk of non-AIDS events in people living with HIV (PLWH). Modulation of the microbiome to reverse this dysbiosis may be a novel approach to decrease inflammation and therefore morbidity and mortality in PLWH.

RECENT FINDINGS

Fecal microbiota transplantation (FMT), probiotics, prebiotics, synbiotics, postbiotics, and dietary modifications have the potential to modulate the microbiome. These interventions have been well tolerated in clinical trials to date. However, these interventions have not resulted in consistent or lasting changes to the microbiome or consistent changes in biomarkers of intestinal permeability, microbial translocation, inflammation, immune activation, or CD4 + T cell counts. Sustained engraftment may require prebiotics and/or dietary modifications added to either probiotics or FMT.

SUMMARY

Adequately powered randomized controlled trials are needed to elucidate whether microbiome modulation can be achieved and impact systemic inflammation in PLWH.

Demographic and clinical factors correlated with clinical outcomes among people with HIV treated by antiretroviral therapy: a retrospective cohort study

BACKGROUND

As is known, CD4 cell count is a significant parameter predicting HIV progression, opportunistic infections and death in HIV-infected individuals, as well was an important indicator for initiating antiretroviral therapy (ART). In China's National Free Antiretroviral Treatment Program, people with HIV (PWH) on ART can receive a CD4 count test at least once every six months. Importantly, the baseline CD4 count (before ART initiation) is significantly correlated with ART and even prognosis, but the influence of the peak CD4 cell count on ART and/or clinical outcomes is still unknown.

METHODS

A retrospective study was conducted among 7965 PWH who received ART from October 2003 to September 2022 at Yunnan Infectious Disease Hospital. Clinical features and laboratory data were collected and analyzed by Chi-square test, univariate and multivariate Cox regression analysis. After elimination of confounding variables, multivariate Cox regression analysis was performed to identify survival-related factors.

RESULTS

Of a total of 7965 PWH in the ART treatment cohort who met the inclusion and exclusion criteria, 7939 were finally included in the subsequent analyses. First, it was found that the proportion of clinical variables, including sex, age distribution, interval from diagnosis to ART initiation, marital status, and others, was significantly different between the living and dead groups (P < 0.05). Impressively, significantly more PWH had the higher level of baseline, peak and recent CD4 cell counts in the living group compared to those in the dead group. Due to multicollinearity effect, after excluding confounders, the following factors were found to be significantly associated with mortality by multivariate Cox regression analysis: (1) male sex (hazard ratio (HR) = 1.268 [1.032, 1.559]; P = 0.024); (2) time from HIV confirmation to ART initiation ≥ 6 months (HR = 1.962 [1.631, 2.360]; P < 0.001); (3) peak CD4 cell count: Peak CD4 < 100cells/µL group (HR = 16.093 [12.041, 21.508]; P < 0.001), 100cells/µL ≤ x < 200cells/µL group (HR = 7.904 [6.148, 10.160]; P < 0.001), 200cells/µL ≤ x < 350cells/µL group (HR = 3.166 [2.519, 3.980]; P < 0.001), 350cells/µL ≤ x < 500cells/µL group (HR = 1.668 [1.291, 2.155]; P < 0.001).

CONCLUSION

Interestingly, patients in male, time from HIV confirmation to ART initiation ≥ 6 months, or peak CD4 count < 500 cells/µl had inferior clinical outcomes, in other word, a lower peak CD4 cell count significantly increased the risk of death, and peak CD4 cell was independent in predicting the overall survival of PWH. It is important to promote "early diagnosis and treatment of HIV" and regularly monitor CD4 levels in HIV/AIDS to evaluate the efficacy of ART and immune reconstitution, and optimize the ART regimen in time to further reduce the mortality of PWH.

A Novel Humanized Mouse Model for HIV and Tuberculosis Co-infection Studies

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), continues to be a major public health problem worldwide. The human immunodeficiency virus (HIV) is another equally important life-threatening pathogen. Further, co-infections with HIV and Mtb have severe effects in the host, with people infected with HIV being fifteen to twenty-one times more likely to develop active TB. The use of an appropriate animal model for HIV/Mtb co-infection that can recapitulate the diversity of the immune response in humans would be a useful tool for conducting basic and translational research in HIV/Mtb infections. The present study was focused on developing a humanized mouse model for investigations on HIV-Mtb co-infection. Using NSG-SGM3 mice that can engraft human stem cells, our studies showed that they were able to engraft human CD34+ stem cells which then differentiate into a full-lineage of human immune cell subsets. After co-infection with HIV and Mtb, these mice showed decrease in CD4+ T cell counts overtime and elevated HIV load in the sera, similar to the infection pattern of humans. Additionally, Mtb caused infections in both lungs and spleen, and induced the development of granulomatous lesions in the lungs, detected by CT scan and histopathology. Distinct metabolomic profiles were also observed in the tissues from different mouse groups after co-infections. Our results suggest that the humanized NSG-SGM3 mice are able to recapitulate the effects of HIV and Mtb infections and co-infection in the human host at pathological, immunological and metabolism levels, providing a dependable small animal model for studying HIV/Mtb co-infection.