The CD4:CD8 ratio is associated with markers of age-associated disease in virally suppressed HIV-infected patients with immunological recovery

Exercise to Prevent Accelerated Vascular Aging in People Living With HIV

Given advances in antiretroviral therapy, the mortality rate for HIV infection has dropped considerably over recent decades. However, people living with HIV (PLWH) experience longer life spans coupled with persistent immune activation despite viral suppression and potential toxicity from long-term antiretroviral therapy use. Consequently, PLWH face a cardiovascular disease (CVD) risk more than twice that of the general population, making it the leading cause of death among this group. Here, we briefly review the epidemiology of CVD in PLWH highlighting disparities at the intersections of sex and gender, age, race/ethnicity, and the contributions of social determinants of health and psychosocial stress to increased CVD risk among individuals with marginalized identities. We then overview the pathophysiology of HIV and discuss the primary factors implicated as contributors to CVD risk among PLWH on antiretroviral therapy. Subsequently, we highlight the functional evidence of premature vascular dysfunction as an early pathophysiological determinant of CVD risk among PLWH, discuss several mechanisms underlying premature vascular dysfunction in PLWH, and synthesize current research on the pathophysiological mechanisms underlying accelerated vascular aging in PLWH, focusing on immune activation, chronic inflammation, and oxidative stress. We consider understudied aspects such as HIV-related changes to the gut microbiome and psychosocial stress, which may serve as mechanisms through which exercise can abrogate accelerated vascular aging. Emphasizing the significance of exercise, we review various modalities and their impacts on vascular health, proposing a holistic approach to managing CVD risks in PLWH. The discussion extends to critical future study areas related to vascular aging, CVD, and the efficacy of exercise interventions, with a call for more inclusive research that considers the diversity of the PLWH population.

Impact of Chronic HIV Infection on Acute Immune Responses to SARS-CoV-2

ABSTRACT

There is mounting evidence that HIV infection is a risk factor for severe presentations of COVID-19. We hypothesized that the persistent immune activation associated with chronic HIV infection contributes to worsened outcomes during acute COVID-19. The goals of this study were to provide an in-depth analysis of immune response to acute COVID-19 and investigate relationships between immune responses and clinical outcomes in an unvaccinated, sex- and race-matched cohort of people with HIV (PWH, n = 20) and people without HIV (PWOH, n = 41). We performed flow cytometric analyses on peripheral blood mononuclear cells from PWH and PWOH experiencing acute COVID-19 (≤21-day postsymptom onset). PWH were younger (median 52 vs 65 years) and had milder COVID-19 (40% vs 88% hospitalized) compared with PWOH. Flow cytometry panels included surface markers for immune cell populations, activation and exhaustion surface markers (with and without SARS-CoV-2-specific antigen stimulation), and intracellular cytokine staining. We observed that PWH had increased expression of activation (eg, CD137 and OX40) and exhaustion (eg, PD1 and TIGIT) markers as compared to PWOH during acute COVID-19. When analyzing the impact of COVID-19 severity, we found that hospitalized PWH had lower nonclassical (CD16 + ) monocyte frequencies, decreased expression of TIM3 on CD4 + T cells, and increased expression of PDL1 and CD69 on CD8 + T cells. Our findings demonstrate that PWH have increased immune activation and exhaustion as compared to a cohort of predominately older, hospitalized PWOH and raises questions on how chronic immune activation affects acute disease and the development of postacute sequelae.

Association of age at antiretroviral therapy initiation with CD4 + : CD8 + ratio recovery among virally suppressed people with HIV

OBJECTIVE

To investigate the association of age at antiretroviral therapy (ART) initiation with CD4 +  : CD8 + T-cell ratio in virally suppressed people with HIV on long-term ART, and to characterize potential CD4 +  : CD8 + ratio recovery in this population by age.

DESIGN

A longitudinal study of people attending an HIV clinic at the Royal Free Hospital NHS Trust, London, who initiated ART between 2001 and 2015, and achieved and maintained HIV-1 viral suppression (viral load <1,000 copies/ml). The association of age group at ART initiation with CD4 +  : CD8 + ratio at 5 and 10 years was assessed.

METHODS

Multivariable linear regression was used to investigate the relationship between age at ART initiation and log CD4 +  : CD8 + ratio, adjusting for demographic factors (gender/HIV transmission route, ethnicity), baseline CD4 + count and calendar year.

RESULTS

The sample included 1859 people aged 20-78 (75% men, 56% white ethnicity). Overall, median CD4 +  : CD8 + T-cell ratio increased from 0.24 at baseline to 0.77 at year 5 and 0.88 at year 10. Ratios increased among all age groups in unadjusted and adjusted models but increased less among older ages (baseline ages 60-69 and 70-79). Median ratios at year 5 were 0.85, 0.80, 0.72, 0.76, 0.6, and 0.44, respectively, among people aged 20-29, 30-39, 40-49, 50-59, 60-69 and 70-79 years at baseline.

CONCLUSION

In a virally suppressed London population, age had a substantial impact on CD4 +  : CD8 + ratio recovery, especially for those starting ART after age 60 years. Results may indicate the level of CD4 +  : CD8 + ratio recovery possible in an HIV-positive, virally suppressed, aging population.

Sarcopenia risk, sarcopenia-related quality of life, and associated factors in people living with human immunodeficiency virus (HIV): A web-based survey

OBJECTIVES

We aimed to screen for the risk of sarcopenia and sarcopenia-related quality of life and associated factors of people living with HIV (PLWH).

RESEARCH METHODS AND PROCEDURES

This nonprobabilistic web-based survey evaluated PLWH. The participants were invited directly from a university-based inpatient clinic and responded to a web questionnaire that included the SARC-F and SarQoL to screen people at risk of sarcopenia and their quality of life. People at risk of sarcopenia were defined by the proposed cutoff points for SARC-F (≥ 4 points), and SarQoL overall score was categorized according to the median. Moreover, we performed a logistic regression to investigate associations between HIV-, lifestyle-, and health-associated factors (i.e., physical activity, dietary pattern, sleep quality, gastrointestinal symptoms, HIV diagnosis, type, combinations, and duration of ART, smoking, drinking, BMI, and weight loss), and outcomes (SARC-F and SarQoL).

RESULTS

The sample comprised 202 PLWH, mainly middle-aged (50.6-60.5 y; n = 101). Only 5.9% (n = 12) are at risk of sarcopenia according to SARC-F, and only 17.3% (n = 35) exhibited lower sarcopenia-related quality of life according to SarQoL. In the multiple models, only the gastrointestinal symptoms increased the odds of sarcopenia risk (OR: 1.058; P = 0.01) and poor sarcopenia-associated quality of life (OR: 1.041; P = 0.013).

CONCLUSIONS

We verified that only 5.9% and 17.3% of PLWH are at risk of sarcopenia and presented lower sarcopenia-related quality of life, respectively. Only the gastrointestinal symptoms were associated with a risk of sarcopenia and lower sarcopenia-related quality of life, without significant differences between age groups.

Evolving mechanisms and presentations of cardiovascular disease in people with HIV: implications for management

People with HIV (PWH) are at elevated risk for cardiovascular diseases (CVDs), including myocardial infarction, heart failure, and sudden cardiac death, among other CVD manifestations. Chronic immune dysregulation resulting in persistent inflammation is common among PWH, particularly those with sustained viremia and impaired CD4+ T cell recovery. This inflammatory milieu is a major contributor to CVDs among PWH, in concert with common comorbidities (such as dyslipidemia and smoking) and, to a lesser extent, off-target effects of antiretroviral therapy. In this review, we discuss the clinical and mechanistic evidence surrounding heightened CVD risks among PWH, implications for specific CVD manifestations, and practical guidance for management in the setting of evolving data.

Efficacy and safety of raltegravir plus lamivudine maintenance therapy

BACKGROUND

Decreasing medication burden with raltegravir plus lamivudine in virologically suppressed persons with HIV (PWH) maintained efficacy and was well tolerated at 24 weeks, but more comprehensive data over longer follow-up are required.

METHODS

Prospective 48 week extension phase of the raltegravir plus lamivudine arm from a previous 24 week pilot randomized clinical trial in which virologically suppressed PWH were randomized 2:1 to switch to fixed-dose combination 150 mg lamivudine/300 mg raltegravir twice daily or to continue therapy. In this 48 week extension phase, raltegravir was dosed at 1200 mg/day and lamivudine 300 mg/day. Primary outcome was the proportion of PWH with treatment failure at Week 48. Secondary outcomes were changes in ultrasensitive plasma HIV RNA, HIV DNA in CD4 cells, serum IL-6, ultrasensitive C-reactive protein and sCD14, body composition, sleep quality, quality of life and adverse effects.

RESULTS

Between May 2018 and June 2019, 33 PWH were enrolled. One participant experienced virological failure without resistance mutations and re-achieved sustained virological suppression without therapy discontinuation, and two others discontinued therapy due to adverse effects. Treatment failure was 9% (95% CI 2%-24%) and 3% (95% CI 0%-17%) in the ITT and on-treatment populations. There were significant changes between baseline and Week 48 in serum cytokines but not in other secondary outcomes.

CONCLUSIONS

Switching to raltegravir and lamivudine in PWH with virological suppression maintains efficacy and is well tolerated. This maintenance regimen might be a cost-effective option for PWH at risk of drug-drug interactions or needing to avoid specific toxicities of certain antiretroviral drugs or their negative impact on comorbidities.

Shorter total sleep time is associated with lower CD4+/CD8+ T cell ratios in virally suppressed men with HIV

Study Objectives

Although poor sleep quality is associated with lower CD4+ T cell counts among people living with HIV (PLWH), the association between objective sleep metrics and T lymphocyte subset counts is unknown. We evaluated the association between polysomnography (PSG) derived sleep metrics and T lymphocyte subpopulations in a cohort of men living with HIV.

Methods

Virally suppressed men living with HIV participating in the Multicenter AIDS Cohort Study underwent home overnight PSG. We assessed the association of PSG parameters with CD4+ and CD8+ T cell counts and the CD4+/CD8+ T cell ratio.

Results

Overall, 289 men with mean (±SD) age 55.3 ± 11.3 years and mean CD4+ T cell count 730 ± 308 cells/mm3 were evaluated. Total sleep time (TST) was significantly associated with CD8+ but not CD4+ T cell counts. After adjusting for age, race, depressive symptoms, antidepressant use, and non-nucleoside reverse transcriptase inhibitors use, every hour of shorter TST was associated with an additional 33 circulating CD8+ T cells/mm3 (p = 0.05) and a 5.6% (p = 0.0007) decline in CD4+/CD8+ T cell ratio. In adjusted models, every hour of shorter rapid eye movement (REM) sleep was associated with an additional 113 CD8+ T cells/mm3 (p = 0.02) and a 15.1% lower CD4+/CD8+ T cell ratio (p = 0.006). In contrast, measures of sleep efficiency and sleep-disordered breathing were not associated with differences in T lymphocyte subpopulations.

Conclusions

Our findings suggest that shorter TST and REM sleep durations are associated with differences in T lymphocyte subpopulations among men living with HIV. Addressing sleep may reflect a novel opportunity to improve immune function in PLWH.

The use of non-invasive imaging modalities for the assessment of skeletal muscle quantity and quality in people with HIV: A narrative review

BACKGROUND

People with HIV (PWH) are prone to mobility impairments and physical dysfunction, with the loss of skeletal muscle quantity and quality being a major contributor to the dysfunction. Assessment of skeletal muscle is an important component of care for this patient population for early intervention and treatment. The use of non-invasive imaging techniques to evaluate skeletal muscle, such as dual X-ray absorptiometry, computer tomography and magnetic resonance imaging, has increased in popularity in recent years.

PURPOSE

This narrative review synthesizes the use of these techniques and summarizes the associations between outcomes from these imaging modalities and physical function in PWH.

Health and sociodemographic factors associated with low muscle strength, muscle mass, and physical performance among people living with HIV

ABSTRACTThis study examined the factors associated with low muscle strength, muscle mass, and physical performance in 331 people living with HIV. Participants completed handgrip as a strength measure, appendicular skeletal muscle mass using bioimpedance analysis, and chair rise was a physical performance measure. Multivariate logistic regression was used to analyze the association between low values on these measures with sociodemographic, HIV-related factors, and comorbidities. Higher body mass index (BMI) (OR = 0.91; CI = 0.86-0.97) and higher CD4/CD8 ratio (OR = 0.38; 95% CI = 0.18-0.82) were associated with decreased likelihood of low handgrip strength. Being non-employed (OR = 2.08; 95% CI = 1.07-4.06), having hypertension (OR = 2.27; 95% CI = 1.13-4.54) and rheumatism (OR = 5.46; 95% CI = 1.68-17.74) increased the chance of low handgrip strength. Higher BMI (OR = 0.43; 95% CI = 0.34-0.56), CD4/CD8 ratio (OR = 0.29; 95% CI = 0.09-0.93), and bioimpedance phase angle (OR = 0.22; 95% CI = 0.12-0.40) were associated with decreased likelihood of low muscle mass. Lastly, having less than eight years of education (OR = 1.87; 95% CI = 1.02-3.41) and being non-employed (OR = 8.18; 95% CI = 3.09-21.61) increased the chance of low chair stand performance. In addition, higher CD4 + lymphocytes count (OR = 0.99; 95% CI = 0.99-0.99) was associated with a decreased likelihood of low chair stand performance. In conclusion, specific and non-specific HIV-related factors are associated with low handgrip strength, low muscle mass, and/or low chair stand performance.

SARS-CoV-2 mRNA Vaccine Response in People Living with HIV According to CD4 Count and CD4/CD8 Ratio

BACKGROUND

Our aim was to estimate the rates of not achieving a robust/above-average humoral response to the COVID-19 mRNA vaccine in people living with HIV (PLWH) who received ≥2 doses and to investigate the role of the CD4 and CD4/CD8 ratio in predicting the humoral response.

METHODS

We evaluated the humoral anti-SARS-CoV-2 response 1-month after the second and third doses of COVID-19 mRNA vaccine as a proportion of not achieving a robust/above-average response using two criteria: (i) a humoral threshold identified as a correlate of protection against SARS-CoV-2 (<90% vaccine efficacy): anti-RBD < 775 BAU/mL or anti-S < 298 BAU/mL, (ii) threshold of binding antibodies equivalent to average neutralization activity from the levels of binding (nAb titer < 1:40): anti-RBD < 870 BAU/mL or anti-S < 1591 BAU/mL. PLWH were stratified according to the CD4 count and CD4/CD8 ratio at first dose. Logistic regression was used to compare the probability of not achieving robust/above-average responses. A mixed linear model was used to estimate the mean anti-RBD titer at various time points across the exposure groups.

RESULTS

a total of 1176 PLWH were included. The proportions of participants failing to achieve a robust/above-average response were significantly higher in participants with a lower CD4 and CD4/CD8 ratio, specifically, a clearer gradient was observed for the CD4 count. The CD4 count was a better predictor of the humoral response of the primary cycle than ratio. The third dose was pivotal in achieving a robust/above-average humoral response, at least for PLWH with CD4 > 200 cells/mm3 and a ratio > 0.6.

CONCLUSIONS

A robust humoral response after a booster dose has not been reached by 50% of PLWH with CD4 < 200 cells mm3. In the absence of a validated correlate of protections in the Omicron era, the CD4 count remains the most solid marker to guide vaccination campaigns in PLWH.

Towards a better preclinical cancer model - human immune aging in humanized mice

BACKGROUND

Preclinical models are often used for cancer studies and evaluation of novel therapeutics. The relevance of these models has vastly improved with mice bearing a human immune system, especially in the context of immunotherapy. Nonetheless, cancer is an age-related disease, and studies often overlook the effects of aging. Here we have established a humanized mouse model of human immune aging to investigate the role of this phenomenon on liver tumor dynamics.

METHODS

Multiple organs and tissues (blood, thymus, lung, liver, spleen and bone marrow) were harvested from NOD-scid IL2rγ-/- (NIKO) mice reconstituted with human immune cells, over a period of 60 weeks post-birth, for immune profiling. Young and aging immune cells were compared for transcriptomic changes and functional differences. Effect of immune aging was investigated in a liver cancer humanized mouse model.

RESULTS

Focusing on the T cell population, which is central to cancer immunosurveillance and immunotherapy, we showed that the proportion of naïve T cells declined while memory subsets and senescent-like cells increased with age. RNA-sequencing revealed that downregulated genes were related to immune responses and processes, and this was corroborated by reduced cytokine production in aging T cells. Finally, we showed faster liver tumor growth in aging than younger humanized mice, which could be attributed to specific pathways of aging T cell exhaustion.

CONCLUSION

Our work improves on existing humanized (immune) mouse model and highlights the importance of considering immune aging in liver cancer modeling.

CD4/CD8 Ratio Outcome According to the Class of the Third Active Drug in Antiretroviral Therapy Regimens: Results From the Quebec Human Immunodeficiency Virus Cohort Study

BACKGROUND

The impact of different therapeutic classes of drugs in antiretroviral therapy (ART) regimens on the CD4/CD8 ratio is not well documented in people treated for HIV. The objective of this study was to analyze the long-term effect of exposure to integrase strand transfer inhibitor (INSTI) on CD4/CD8 ratio compared with nonnucleoside reverse transcriptase inhibitor (NNRTI) or protease inhibitor (PI) among ART-treated persons with HIV (PWH).

METHODS

Data from the Quebec HIV Cohort collected from 31 August 2017 were used. Our analysis included all patients in the cohort who received a first or subsequent ART regimen composed of 2 nucleoside reverse transcriptase inhibitors (NRTIs) and a third active drug of a different class (NNRTI, PI, or INSTI) for at least 16 weeks. Marginal structural Cox models were constructed to estimate the effect of different therapeutic classes on the CD4/CD8 ratio outcome.

RESULTS

Among the 3907 eligible patients, 972 (24.9%), 1996 (51.1%), and 939 (24.0%) were exposed to an ART regimen whose third active agent was an NNRTI, PI, or INSTI, respectively. The total follow-up time was 13 640.24 person-years. The weighted hazard ratio for the association between the third active class and CD4/CD8 ratio ≥1 was .56 (95% confidence interval [CI]: .48-.65) for patients exposed to NNRTI + 2 NRTIs and .41 (95% CI: .35-.47) for those exposed to PI + 2 NRTIs, compared with those exposed INSTI + 2 NRTIs.

CONCLUSIONS

For people treated for HIV, INSTI-based ART appears to be associated with a higher CD4/CD8 ratio than NNRTI and PI-based ART.

The severity of COVID-19 across the spectrum of HIV

PURPOSE OF REVIEW

We review the intersection between the HIV and COVID-19 pandemics, particularly the impact of HIV infection on the development of severe COVID-19.

RECENT FINDINGS

Studies early in the COVID-19 pandemic did not find a clear link between HIV infection and increased COVID-19 severity or mortality. People with HIV (PWH) were more likely to have severe COVID-19, but much of the risk for worse outcomes was related to high rates of comorbidities and social determinants of health. Although comorbidities and social determinants of health are certainly critically important reasons for severe COVID-19 among PWH, recent large studies have found HIV infection - particularly when the CD4 cell count is low or HIV RNA is not suppressed - is an independent risk factor for COVID-19 severity. The link between HIV and severe COVID-19 highlights the need to diagnose and treat HIV as well as the importance of COVID-19 vaccination and treatment among PWH.

SUMMARY

People with HIV have faced increased challenges during the COVID-19 pandemic because of high rates of comorbidities and social determinants of health as well as the impact of HIV on COVID-19 severity. Information on the intersection of the two pandemics has been crucial to improving care for people with HIV.

Evaluation of host cellular responses to Epstein-Barr virus (EBV) in adult lung transplant patients with EBV-associated diseases

Epstein-Barr virus (EBV) reactivation is commonly observed in lung transplant recipients (LTRs). However, cellular immune responses to EBV in adult LTRs have not been well described. We aimed to study CD4/CD8 ratio, EBV-specific T cells polyfunctional responses and phenotypic changes in natural killer (NK) cells in adult LTRs presenting with EBV-associated diseases. The CD4/CD8 ratio was significantly decreased in LTRs with EBV DNAemia compared with LTRs without EBV DNAemia and healthy controls (HCs). Stimulation with EBV lytic antigen BZLF1 peptide pools induced significant individual and polyfunctional responses from CD8+ CD69+ T cells. Frequencies of CD8+ CD69+ T cells expressing CD107a were significantly higher in LTRs without EBV DNAemia than in LTRs with DNAemia. Frequencies of CD8+ CD69+ T cells concurrently expressing CD107a, IFN-γ, and TNF-α were significantly greater in LTRs with and without EBV DNAemia than in HCs. Finally, BZLF1 induced significantly higher frequencies of CD8+ CD69+ T cells expressing CD107a and IFN-γ in LTRs without EBV DNAemia when compared with EBNA3B. Frequency of more differentiated CD56dim CD16pos NK cells was significantly decreased in LTRs with EBV DNAemia and PTLD compared with HCs. In conclusion, we noted the presence of significant changes in circulating cellular immune responses to EBV in adult LTRs.

Predictors of subclinical atherosclerosis in HIV

BACKGROUND

Cardiovascular disease is a major cause of morbidity and mortality in people with HIV. The detection of subclinical atherosclerosis through vascular ultrasound allows us to identify patients at an increased risk of cardiovascular disease as a primary prevention strategy; this test is not routine. Our objective is to identify predictors of subclinical atherosclerosis in a population with HIV.

METHODS

People with HIV infection were selected for primary prevention and underwent carotid and femoral ultrasound to detect atheromatous plaques. Logistic regression analysis including vascular risk factors was performed to predict the presence of atherosclerosis.

RESULTS

One hundred eighty-three patients were included, 54% of whom were smokers; the mean duration of HIV infection was 9.52 years, and all patients were undergoing antiretroviral treatment. Subclinical atherosclerosis was present in 62.29% of the patients; 83.32% had plaque in the carotid territory, 57.93% in the femoral territory and 25.6% in both vascular territories. Compared to those without atherosclerosis, patients with atherosclerosis were on average 5.35 years older (53.86 vs. 48.51, p < 0.001) and had a higher prevalence of smoking (63.23% vs. 39.12%, p = 0.020) and a CD4/CD8 ratio below 0.7 (44.23% vs. 29.02%, p = 0.043). A CD4/CD8 ratio lower than 0.3 was always associated with subclinical atherosclerosis (95% confidence interval (CI): 83.9-100%). The inclusion of smoking, the CD4/CD8 ratio and age in the logistic regression analysis led to a diagnostic yield of 72% measured by the area under the receiving operator characteristic (ROC) curve (95% CI: 64-80%).

CONCLUSIONS

Tobacco use, age and a CD4/CD8 ratio below 0.7 allow prediction of the presence of subclinical atherosclerosis in primary prevention. A CD4/CD8 ratio below 0.3 was a diagnostic indicator of atherosclerosis in HIV patients undergoing primary prevention in our sample.

Chitinase-3-like Protein 1 Is Associated with Poor Virologic Control and Immune Activation in Children Living with HIV

Perinatally infected children living with HIV (CLWH) face lifelong infection and associated inflammatory injury. Chitinase-like 3 protein-1 (CHI3L1) is expressed by activated neutrophils and may be a clinically informative marker of systemic inflammation in CLWH. We conducted a multi-centre, cross-sectional study of CLWH, enrolled in the Early Pediatric Initiation Canadian Child Cure Cohort Study (EPIC⁴). Plasma levels of CHI3L1, pro-inflammatory cytokines, and markers of microbial translocation were measured by enzyme-linked immunosorbent assays. Longitudinal clinical characteristics (viral load, neutrophil count, CD4+ and CD8+ T-lymphocyte counts, and antiretroviral (ARV) regimen) were abstracted from patient medical records. One-hundred-and-five (105) CLWH (median age 13 years, 62% female) were included in the study. Seventy-seven (81%) had viral suppression on combination antiviral therapy (cART). The median CHI3L1 level was 25 μg/L (IQR 19-39). CHI3L1 was directly correlated with neutrophil count (ρ = 0.22, p = 0.023) and inversely correlated with CD4/CD8 lymphocyte ratio (ρ = -0.35, p = 0.00040). Children with detectable viral load had higher levels of CHI3L1 (40 μg/L (interquartile range, IQR 33-44) versus 24 μg/L (IQR 19-35), p = 0.0047). CHI3L1 levels were also correlated with markers of microbial translocation soluble CD14 (ρ = 0.26, p = 0.010) and lipopolysaccharide-binding protein (ρ = 0.23, p = 0.023). We did not detect differences in CHI3L1 between different cART regimens. High levels of neutrophil activation marker CHI3L1 are associated with poor virologic control, immune dysregulation, and microbial translocation in CLWH on cART.

Healthy Ageing Reflected in Innate and Adaptive Immune Parameters

Purpose

The aim of the paper is to establish and quantify the relation between healthy ageing and the innate and adaptive immune parameters as indicators of age-related diseases.

Patients

In order to observe the immunological changes that occur according to age, several humoral and cellular immune parameters were investigated for 288 healthy donors (30-80 years). Subjects' selection was done using clinical, biochemical and immunological parameters of inclusion/exclusion criteria from SENIEUR protocol.

Results

Age-related changes were observed for both humoral and cellular immune parameters. Lymphocyte immunophenotyping revealed several significant differences in the distribution of cells, both intra- and inter-age groups, namely decreased values of T-CD3⁺, T-CD8⁺ and NK cells, and elevated values for T-CD4⁺, T-CD4⁺/T-CD8⁺ ratio and B cells. The percentages of unstimulated neutrophils that show basal oxidative activity and the intensity of this activity had an increasing tendency age-related. The percentage of N-Formyl-Methionyl-Leucyl-Phenylalanine stimulated neutrophils clearly decreases with age, and is associated with an increasing intensity of oxidative activity. Our data also have shown an increased percentage of oxidative neutrophils after phorbol 12-myristate 13-acetate stimulation and an elevated oxidative activity with age.

Conclusion

Overall healthy ageing is governed by some immune-related deregulations that account for immune exhaustion due to numerous developed immune processes during a life-time and the age-related diseases.

Individual Differences in CD4/CD8 T-Cell Ratio Trajectories and Associated Risk Profiles Modeled From Acute HIV Infection

OBJECTIVE

We examined individual differences in CD4/CD8 T-cell ratio trajectories and associated risk profiles from acute HIV infection (AHI) through 144 weeks of antiretroviral therapy (ART) using a data-driven approach.

METHODS

A total of 483 AHI participants began ART during Fiebig I-V and completed follow-up evaluations for 144 weeks. CD4+, CD8+, and CD4/CD8 T-cell ratio trajectories were defined followed by analyses to identify associated risk variables.

RESULTS

Participants had a median viral load (VL) of 5.88 copies/ml and CD4/CD8 T-cell ratio of 0.71 at enrollment. After 144 weeks of ART, the median CD4/CD8 T-cell ratio was 1.3. Longitudinal models revealed five CD4/CD8 T-cell ratio subgroups: group 1 (3%) exhibited a ratio >1.0 at all visits; groups 2 (18%) and 3 (29%) exhibited inversion at enrollment, with normalization 4 and 12 weeks after ART, respectively; and groups 4 (31%) and 5 (18%) experienced CD4/CD8 T-cell ratio inversion due to slow CD4+ T-cell recovery (group 4) or high CD8+ T-cell count (group 5). Persistent inversion corresponded to ART onset after Fiebig II, higher VL, soluble CD27 and TIM-3, and lower eosinophil count. Individuals with slow CD4+ T-cell recovery exhibited higher VL, lower white blood cell count, lower basophil percent, and treatment with standard ART, as well as worse mental health and cognition, compared with individuals with high CD8+ T-cell count.

CONCLUSIONS

Early HIV disease dynamics predict unfavorable CD4/CD8 T-cell ratio outcomes after ART. CD4+ and CD8+ T-cell trajectories contribute to inversion risk and correspond to specific viral, immune, and psychological profiles during AHI. Adjunctive strategies to achieve immune normalization merit consideration.

Correlation between CD4/CD8 ratio and neurocognitive performance during early HIV infection

INTRODUCTION

CD4/CD8 ratio is a marker of immune activation in HIV infection and has been associated with neurocognitive performance during chronic infection, but little is known about the early phases. The aim of this study was to examine the relationship between blood CD4/CD8 ratio and central nervous system endpoints in primary HIV infection (PHI) before and after antiretroviral treatment (ART).

METHODS

This was a retrospective analysis of the Primary Infection Stage CNS Events Study (PISCES) cohort. We longitudinally assessed blood and cerebrospinal fluid (CSF) markers of inflammation, immune activation and neuronal injury, and neuropsychological testing performance (NPZ4, an average of three motor and one processing speed tests, and a summarized total score, NPZ11, including also executive function, learning and memory) in ART-naïve participants enrolled during PHI. Spearman correlation and linear mixed models assessed the relationships between the trajectory of CD4/CD8 ratio over time and neurocognitive performance, blood and CSF markers of immune activation and neuronal injury.

RESULTS

In all, 109 PHI participants were enrolled. The mean CD4/CD8 ratio decreased with longer time from infection to starting treatment (p < 0.001). Every unit increase in NPZ4 score was independently associated with a 0.15 increase in CD4/CD8 ratio (95% CI: 0.002-0.29; p = 0.047), whereas no correlation was found between CD4/CD8 ratio and NPZ11. Among the cognitive domains, only a change in processing speed was correlated with CD4/CD8 ratio over time (p = 0.03). The trajectory of the CD4/CD8 ratio was negatively correlated with change in CSF neurofilament light chain (p = 0.04).

CONCLUSIONS

The trajectory of CD4/CD8 ratio was independently associated with motor/psychomotor speed performance, suggesting that immune activation is involved in brain injury during the early stages of the infection.

The FlagT4G Vaccine Confers a Strong and Regulated Immunity and Early Virological Protection against Classical Swine Fever

Control of classical swine fever virus (CSFV) in endemic countries relies on vaccination, mostly using vaccines that do not allow for differentiation of vaccinated from infected animals (DIVA). FlagT4G vaccine is a novel candidate that confers robust immunity and shows DIVA capabilities. The present study assessed the immune response elicited by FlagT4G and its capacity to protect pigs for a short time after vaccination. Five days after a single dose of FlagT4G vaccine, animals were challenged with a highly virulent CSFV strain. A strong, but regulated, interferon-α response was found after vaccination. Vaccinated animals showed clinical and virological protection against the challenge, in the absence of antibody response at 5 days post-vaccination. Upon challenge, a rapid rise in the titers of CSFV neutralizing antibodies and an increase in the IFN-γ producing cells were noticed in all vaccinated-challenged pigs. Meanwhile, unvaccinated pigs showed severe clinical signs and high viral replication, being euthanized before the end of the trial. These animals were unable to generate neutralizing antibodies and IFN-γ responses after the CSFV challenge. The results from the present study assert the fast and efficient protection by FlagT4G, a highly promising tool for CSFV control worldwide.

CD4/CD8 Ratio and Cancer Risk Among Adults With HIV

BACKGROUND

Independent of CD4 cell count, a low CD4/CD8 ratio in people with HIV (PWH) is associated with deleterious immune senescence, activation, and inflammation, which may contribute to carcinogenesis and excess cancer risk. We examined whether low CD4/CD8 ratios predicted cancer among PWH in the United States and Canada.

METHODS

We examined all cancer-free PWH with 1 or more CD4/CD8 values from North American AIDS Cohort Collaboration on Research and Design observational cohorts with validated cancer diagnoses between 1998 and 2016. We evaluated the association between time-lagged CD4/CD8 ratio and risk of specific cancers in multivariable, time-updated Cox proportional hazard models using restricted cubic spines. Models were adjusted for age, sex, race and ethnicity, hepatitis C virus, and time-updated CD4 cell count, HIV RNA, and history of AIDS-defining illness.

RESULTS

Among 83 893 PWH, there were 5628 incident cancers, including lung cancer (n = 755), Kaposi sarcoma (n = 501), non-Hodgkin lymphoma (n = 497), and anal cancer (n = 439). The median age at cohort entry was 43 years. The overall median 6-month lagged CD4/CD8 ratio was 0.52 (interquartile range = 0.30-0.82). Compared with a 6-month lagged CD4/CD8 of 0.80, a CD4/CD8 of 0.30 was associated with increased risk of any incident cancer (adjusted hazard ratio = 1.24 [95% confidence interval = 1.14 to 1.35]). The CD4/CD8 ratio was also inversely associated with non-Hodgkin lymphoma, Kaposi sarcoma, lung cancer, anal cancer, and colorectal cancer in adjusted analyses (all 2-sided P < .05). Results were similar using 12-, 18-, and 24-month lagged CD4/CD8 values.

CONCLUSIONS

A low CD4/CD8 ratio up to 24 months before cancer diagnosis was independently associated with increased cancer risk in PWH and may serve as a clinical biomarker.

Aging, trends in CD4+/CD8+ cell ratio, and clinical outcomes with persistent HIV suppression in a dynamic cohort of ambulatory HIV patients

BACKGROUND

Age blunts CD4+ lymphocyte cell count/μl (CD4+) improvements observed with antiretroviral therapy (ART)-induced viral suppression among people with HIV (PWH). Prolonged viral suppression reduces immune dysregulation, reflected by rising CD4+/CD8+ ratios (CD4+/CD8+). We studied CD4+/CD8+ over time to determine whether it predicts risk for select comorbidities and mortality among aging PWH with viral suppression.

METHODS

We studied HIV Outpatient Study (HOPS) participants prescribed ART during 2000-2018 who achieved a viral load less than 200 copies/ml on or after 1 January 2000, and remained virally suppressed at least 1 year thereafter. We modeled associations of CD4+/CD8+ with select incident comorbidities and all-cause mortality using Cox regression and controlling for demographic and clinical factors.

RESULTS

Of 2480 eligible participants,1145 (46%) were aged less than 40 years, 835 (34%) 40-49 years, and 500 (20%) ≥ 50 years. At baseline, median CD4+/CD8+ was 0.53 (interquartile range: 0.30-0.84) and similar among all age groups (P = 0.18). CD4+/CD8+ values and percentage of participants with CD4+/CD8+ at least 0.70 increased within each age group (P < 0.001 for all). CD4+/CD8+ increase was greatest for PWH aged less than 40 years at baseline. In adjusted models, most recent CD4+/CD8+less than 1.00 and less than 0.70 were independently associated with higher risk of non-AIDS cancer and mortality, respectively.

CONCLUSION

Pretreatment immune dysregulation may persist as indicated by CD4+/CD8+ less than 0.70. Persistent viral suppression can improve immune dysregulation over time, reducing comorbidity, and mortality risk. Monitoring CD4+/CD8+ among ART-treated PWH with lower values provide a means to assess for mortality and comorbidity risk.

Low CD4/CD8 ratio is associated with increased morbidity and mortality in late and non-late presenters: results from a multicentre cohort study, 2004–2018

Background

To study whether the association between the CD4/CD8 ratio variation over time and the development of clinical outcomes vary in late presenters (CD4 count < 350/µL or AIDS event at enrolment) or advanced presenters (CD4 count < 200/µL or AIDS event at enrolment).

Methods

We included ART-naïve adults from the Cohort of the Spanish HIV/AIDS Research Network (CoRIS) enrolled between January 2004 up to November 2018 and with at least 6 months of follow-up. We used extended Cox proportional hazard models to estimate the hazard ratios (HRs) for the association between CD4/CD8 ratio over time and a composite endpoint of the occurrence of the first AIDS event, first serious non-AIDS event or overall mortality occurring from 6 months after enrolment. HRs in non-late, late and advanced presenters were obtained by including an interaction term between late presentation status and CD4/CD8 ratio over time.

Results

Of 10,018 participants, 55.6% were late presenters and 26.5% were advanced presenters. Compared with CD4/CD8 ratio > 0.4, CD4/CD8 ratio ≤ 0.4 over time was associated with an increased risk of experiencing the composite endpoint in non-late (HR 1.90; 95%CI 1.48, 2.43), late (HR 1.94; 1.46, 2.57) and advanced presenters (HR 1.72; 1.26, 2.34). Similarly, CD4/CD8 ratio ≤ 0.4 over time was associated with a higher risk of developing an AIDS event (HR 3.31; 2.23, 4.93 in non-late; HR 2.75; 1.78, 4.27 in late and HR 2.25; 1.34, 3.76 in advanced presenters) or serious non-AIDS event (HR 1.39; 0.96, 2.02 in non-late, HR 1.62; 1.10, 2.40 in late and HR 1.49; 0.97, 2.29 in advanced presenters) as well as with a higher risk of overall mortality (HR 1.49; 0.92, 2.41 in non-late, HR 1.80; 1.04, 3.11 in late and HR 1.61; 0.92, 2.83 in advanced presenters) compared to CD4/CD8 > 0.4, regardless of the late presentation status.

Conclusions

A low CD4/CD8 measured over time is associated with increased risk of morbidity and mortality in people living with HIV independently of their late presentation status. These data support the prognostic role of CD4/CD8 over time and can help defining a subgroup of patients who need closer monitoring to avoid comorbidities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07352-z.

Persistence of High Peripheral Activated CD8+ T-cells and Not a Low CD4:CD8 Ratio Predict cytologic HPV-Related Dysplasia in cART-Treated, HIV-Positive Subjects

Background

People with HIV are at increased risk of HPV-disease progression, given the persistence of immune activation and residual inflammation despite effective cART. Whether a low CD4:CD8 T-cell ratio, known to mirror peripheral immune dysfunction, associates with Squamous Intraepithelial Lesions (SIL) is unknown.

Methods

Retrospective cohort study on cART-treated HIV-positive subjects undergoing screening for HPV-related dysplasia (anal/cervical cytology and HPV genotyping). SIL was defined as the presence of either atypical squamous cells of undetermined significance (ASCUS), Low-grade SIL or High-grade SIL. Demographic and viro-immunological parameters (T-cell count, CD4:CD8 T-cell ratio, CD8+CD38+ T-cells percentage) at the time of screening were analyzed by Chi square, Mann Whitney test and multivariate logistic regression analysis.

Results

419 cART-treated subjects were included. Half of the patients had cervical/anal SIL. Individuals with SIL were more commonly males, MSM, co-infected with Treponema pallidum, treated with Integrase Inhibitors (INSTI)-based cART regimens and with a shorter time since HIV diagnosis and cART initiation than subjects with normal cytology. CD38+CD8+ T-cells percentage, but not the CD4:CD8 T-cell ratio, correlated with SIL. HPV infection, especially with multiple and high-risk genotypes, was confirmed associated with SIL. In multivariate analysis, the only factors independently associated with cervical/anal dysplasia were HPV infection and harbouring higher percentages of peripheral activated CD38+CD8+ T-cells.

Conclusions

HPV infection is the major driver of dysplasia in the setting of HIV infection. CD8+CD38+ T-cells also resulted an independent predictor of dysplasia in cART-treated subjects, while the CD4:CD8 T-cell ratio did not. In the setting of HIV-HPV co-infection, the CD4:CD8 T-cell ratio may not fully capture the alterations of HPV-specific immunity.

CD4+/CD8+ Ratio and Growth Differentiation Factor 8 Levels in Peripheral Blood of Large Canine Males Are Useful Parameters to Build an Age Prediction Model

Purpose

To build an age prediction model, we measured CD4+ and CD8+ cells, and humoral components in canine peripheral blood.

Materials and Methods

Large Belgian Malinois (BGM) and German Shepherd Dog (GSD) breeds (n=27), aged from 1 to 12 years, were used for this study. Peripheral bloods were obtained by venepuncture, then plasma and peripheral blood mononuclear cells (PBMCs) were separated immediately. Six myokines, including interleukin (IL)-6, IL-8, IL-15, leukemia inhibitory factor (LIF), growth differentiation factor 8 (GDF8), and GDF11 were measured from plasma and CD4+/CD8+ T-lymphocytes ratio were measured from PBMC. These parameters were then tested with age prediction models to find the best fit model.

Results

We found that the T-lymphocyte ratio (CD4+/CD8+) was significantly correlated with age (r=0.46, p=0.016). Among the six myokines, only GDF8 showed a significant correlation with age (r=0.52, p=0.005). Interestingly, these two markers showed better correlations in male dogs than females, and BGM breed than GSD. Using these two age biomarkers, we could obtain the best fit in a quadratic linear mixed model (r=0.77, p=3×10^-6).

Conclusions

Age prediction is a challenging task because of complication with biological age. Our quadratic linear mixed model using CD4+/CD8+ ratio and GDF8 level showed a meaningful age prediction.

Characterization of humoral and SARS-CoV-2 specific T cell responses in people living with HIV

There is an urgent need to understand the nature of immune responses against SARS-CoV-2, to inform risk-mitigation strategies for people living with HIV (PLWH). Here we show that the majority of PLWH with ART suppressed HIV viral load, mount a detectable adaptive immune response to SARS-CoV-2. Humoral and SARS-CoV-2-specific T cell responses are comparable between HIV-positive and negative subjects and persist 5-7 months following predominately mild COVID-19 disease. T cell responses against Spike, Membrane and Nucleoprotein are the most prominent, with SARS-CoV-2-specific CD4 T cells outnumbering CD8 T cells. We further show that the overall magnitude of SARS-CoV-2-specific T cell responses relates to the size of the naive CD4 T cell pool and the CD4:CD8 ratio in PLWH. These findings suggest that inadequate immune reconstitution on ART, could hinder immune responses to SARS-CoV-2 with implications for the individual management and vaccine effectiveness in PLWH.

Immunologic Abnormalities Associated With Health Status of Heart Recipients Long Term After Transplantation

BACKGROUND

With improvements in survival rates, health-related quality of life is an important outcome parameter to evaluate the effectiveness of transplantation. We aimed to identify potential immunologic abnormalities as factors associated with poorer health-related quality of life at distinct scales of the 36-Item Short Form Health Survey in heart transplant recipients long term after transplantation.

METHODS

One hundred heart transplant recipients were evaluated in a single center. Short-form 36 questionnaires were sent by mail to participants. All patients were clinically and immunologically evaluated after the first year of heart transplantation.

RESULTS

A high prevalence of several immunologic abnormalities persisted even after the first year of transplantation, including IgG hypogammaglobulinemia, low IgG-specific antipneumococcal antibodies, C4 hypocomplementemia, CD8 T-cell lymphocytopenia, and CD19 B-cell lymphocytopenia. Older recipients (>55 years), posttransplant diabetes, digestive complications, and posttransplant infections were associated with lower physical functioning scores (scale < 60). Older recipients (>55 years), pretransplant diabetes, pretransplant arterial hypertension, posttransplant digestive complications, and lower CD8 counts were associated with lower physical role scores (scale <25).

CONCLUSION

In a single center study, lower CD8 cell counts were found to be associated with poorer health status in heart recipients after the first year of transplantation.

Consequences of HIV/Syphilis Co-Infection on HIV Viral Load and Immune Response to Antiretroviral Therapy

Introduction

Although syphilis is a frequent co-infection in patients with human immunodeficiency virus (HIV) infection, the influence of syphilis on immune response and virologic failure in HIV-infected patients following initiation of antiretroviral therapy (ART) is not well-defined.

Methods

A retrospective study was conducted at Tianjin Second People's Hospital to evaluate the prevalence of syphilis and immune status in 4171 ART-naïve patients. The study included patients who initiated ART between August 2009 and June 2019.

Results

The prevalence of syphilis was 40.1% in all ART-naïve patients and 42.5% in ART-naïve men who have sex with men. HIV/syphilis co-infection was associated with higher virologic failure (odds ratio (95% confidence interval): 1.30 (1.04, 1.63)). Patients with HIV/syphilis co-infection had lower median CD4⁺ T cell counts and CD4/CD8 ratios at baseline. After initiation of ART, patients co-infected with HIV/syphilis had smaller increases in CD4⁺ T cell counts and CD4/CD8 ratios than patients infected only with HIV. The rate of recurrence of syphilis or reinfection was 9% (n = 128) during seven years of ART.

Conclusion

HIV/syphilis co-infection had a negative impact on immune recovery and antiretroviral effectiveness. RPR titer and HIV viral load should be monitored in patients co-infected with HIV/syphilis, especially in patients with high RPR titers.

Cordyceps sinensis aqueous extract regulates the adaptive immunity of mice subjected to 60 Co γ irradiation

Cordyceps sinensis (CS) is a traditional Chinese medicine that is known for treating various diseases, and particularly for exerting therapeutic effects in immune disorders. The adaptive immunoregulatory effects of CS aqueous extract (CSAE) on γ-irradiated mice have not been reported previously. The study aimed to evaluate the therapeutic effects of CSAE in mice immunosuppressed by irradiation. We observed that CSAE administration significantly increased body weight and spleen index, as well as the number of white blood cells, lymphocytes, and platelets in peripheral blood, T and B lymphocytes in spleen tissue, and total serum immunoglobulins in irradiated mice, whereas total serum pro-inflammatory cytokine levels were decreased. Collectively, CSAE maintained the structural integrity of spleen tissue and repaired its damage in irradiated mice as shown by hematoxylin and eosin staining, and decreased the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive splenocytes. Mechanistically, CSAE upregulated Bcl-2, and downregulated Bax and cleaved caspase-3 in spleen of irradiated mice. However, there were no significant differences in red blood cells and neutrophils in different groups. The results revealed that CSAE had protective effects against irradiation-induced immunosuppression, which was likely associated with an antiapoptotic effect and the regulation of adaptive immunity.

Association of HIV Infection and Antiretroviral Therapy With Arterial Stiffness: A Systematic Review and Meta-Analysis

[Figure: see text].

Multimorbidity in Elderly Persons According to the Year of Diagnosis of Human Immunodeficiency Virus Infection: A Cross-sectional Dat'AIDS Cohort Study

BACKGROUND

We assessed prevalence of multimorbidity (MM) according to year of human immunodeficiency virus (HIV) diagnosis in elderly people living with HIV (PLWH).

METHODS

This was a cross-sectional study of MM in PLWH aged ≥70 years from the Dat'AIDS French multicenter cohort. MM was defined as at least 3 coexistent morbidities of high blood pressure, diabetes mellitus, osteoporosis, non-AIDS cancer, chronic renal failure, cardiovascular and cerebrovascular disease, obesity, undernutrition, or hypercholesterolemia. Logistic regression models evaluated the association between MM and calendar periods of HIV diagnosis (1983-1996, 1997-2006, and 2007-2018). The secondary analysis evaluated MM as a continuous outcome, and a sensitivity analysis excluded PLWH with nadir CD4 count <200 cells/μL.

RESULTS

Between January 2017 and September 2018, 2476 PLWH were included. Median age was 73 years, 75% were men, median CD4 count was 578 cells/μL, and 94% had controlled viremia. MM prevalence was 71%. HBP and hypercholesterolemia were the most prevalent comorbidities. After adjustment for age, gender, smoking status, hepatitis C and hepatitis B virus coinfection, group of exposure, nadir CD4 count, CD4:CD8 ratio, and last CD4 level, calendar period of diagnosis was not associated with MM (P = .169). MM was associated with older age, CD4/CD8 ratio <0.8, and nadir CD4 count <200 cells/μL. Similar results were found with secondary and sensitivity analyses.

CONCLUSIONS

MM prevalence was high and increased with age, low CD4/CD8 ratio, and nadir CD4 count <200 cells/μL but was not associated with calendar periods of HIV diagnosis. Known duration of HIV diagnosis does not seem to be a criterion for selecting elderly PLWH at risk of MM.

Characterization of innate and adaptive immune cells involved in the foreign body reaction to polypropylene meshes in the human abdomen

Background

Polypropylene (PP) mesh is widely used to reinforce tissues. The foreign body reaction (FBR) to the implant is dominated by innate immune cells, especially macrophages. However, considerable numbers of adaptive immune cells, namely T cells, have also been regularly observed, which appear to play a crucial role in the long-term host response.

Methods

This study investigated the FBR to seven human PP meshes, which were removed from the abdomen for recurrence after a median of one year. Using immunofluorescence microscopy, the FBR was examined for various innate (CD11b⁺ myeloid, CD68⁺ macrophages, CD56⁺ NK) and adaptive immune cells (CD3⁺ T, CD4⁺ T-helper, CD8⁺ cytotoxic, FoxP3⁺ T-regulatory, CD20⁺ B) as well as “conventional” immune cells (defined as cells expressing their specific immune cell marker without co-expressing CD68).

Results

T-helper cells (19%) and regulatory T-cells (25%) were present at comparable rates to macrophages, and clustered significantly toward the mesh fibers. For all cell types the lowest proportions of “conventional” cells (< 60%) were observed at the mesh–tissue interface, but increased considerably at about 50–100 µm, indicating reduced stimulation with rising distance to the mesh fibers.

Conclusion

Both innate and adaptive immune cells participate in the chronic FBR to PP meshes with T cells and macrophages being the predominant cell types, respectively. In concordance with the previous data, many cells presented a “hybrid” pattern near the mesh fibers. The complexity of the immune reaction seen within the foreign body granuloma may explain why approaches focusing on specific cell types have not been very successful in reducing the chronic FBR.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10029-021-02396-7.

Characterization of humoral and SARS-CoV-2 specific T cell responses in people living with HIV

There is an urgent need to understand the nature of immune responses against SARS-CoV-2, to inform risk-mitigation strategies for people living with HIV (PLWH). We show that the majority of PLWH, controlled on ART, mount a functional adaptive immune response to SARS-CoV-2. Humoral and SARS-CoV-2-specific T cell responses are comparable between HIV-positive and negative subjects and persist 5-7 months following predominately mild COVID-19 disease. T cell responses against Spike, Membrane and Nucleocapsid are the most prominent, with SARS-CoV-2-specific CD4 T cells outnumbering CD8 T cells. We further show that the overall magnitude of SARS-CoV-2-specific T cell responses relates to the size of the naive CD4 T cell pool and the CD4:CD8 ratio in PLWH, in whom disparate antibody and T cell responses are observed. These findings suggest that inadequate immune reconstitution on ART, could hinder immune responses to SARS-CoV-2 with implications for the individual management and vaccine effectiveness in PLWH.

The association between cigarette smoking and efavirenz plasma concentration using the population pharmacokinetic approach

AIMS

Efavirenz is still widely used as the preferred first-line antiretroviral agent in middle- and low-income countries, including Malaysia. The efavirenz population pharmacokinetic profile among HIV-positive smokers is still unknown. We aimed to assess the association of smoking with efavirenz and the differences in HIV clinical outcomes.

METHODS

A total of 154 stable HIV-positive patients on efavirenz in northern Malaysia were recruited with a sparse sampling for this multicentre prospective cohort study. The association between smoking and efavirenz pharmacokinetic parameters was determined using the nonlinear mixed-effect model. A mixture model of clearance was adopted to describe the metaboliser status because genetic data are unavailable. The effect of smoking on HIV clinical markers (CD4, CD4/CD8 ratio and viral blips) for at least 2 years after the antiretroviral initiation was also investigated.

RESULTS

Our data were best fitted with a 1-compartment mixture model with first-order absorption without lag time. Smoking significantly associated with higher clearance (β = 1.39; 95% confidence interval: 1.07 to 1.91), while weight affected both clearance and volume. From the mixture model, 20% of patients were in the slow clearance group, which mimic the genotype distribution of slow metaboliser. An efavirenz dose reduction is not recommended for smokers ≥60 kg with normal metabolism rate. Smoking significantly associated with slower normalisation of CD4 and CD4/CD8 ratio.

CONCLUSIONS

HIV-positive smokers presented with significantly higher efavirenz clearance and unfavourable clinical outcomes. Close monitoring of adherence and clinical response among smokers is warranted.

Characterization of humoral and SARS-CoV-2 specific T cell responses in people living with HIV

There is an urgent need to understand the nature of immune responses generated against SARS-CoV-2, to better inform risk-mitigation strategies for people living with HIV (PLWH). Although not all PLWH are considered immunosuppressed, residual cellular immune deficiency and ongoing inflammation could influence COVID-19 disease severity, the evolution and durability of protective memory responses. Here, we performed an integrated analysis, characterizing the nature, breadth and magnitude of SARS-CoV-2-specific immune responses in PLWH, controlled on ART, and HIV negative subjects. Both groups were in the convalescent phase of predominately mild COVID-19 disease. The majority of PLWH mounted SARS-CoV-2 Spike- and Nucleoprotein-specific antibodies with neutralizing activity and SARS-CoV-2-specific T cell responses, as measured by ELISpot, at levels comparable to HIV negative subjects. T cell responses against Spike, Membrane and Nucleocapsid were the most prominent, with SARS-CoV-2-specific CD4 T cells outnumbering CD8 T cells. Notably, the overall magnitude of SARS-CoV-2-specific T cell responses related to the size of the naive CD4 T cell pool and the CD4:CD8 ratio in PLWH, in whom disparate antibody and T cell responses were observed. Both humoral and cellular responses to SARS-CoV-2 were detected at 5-7 months post-infection, providing evidence of medium-term durability of responses irrespective of HIV serostatus. Incomplete immune reconstitution on ART and a low CD4:CD8 ratio could, however, hamper the development of immunity to SARS-CoV-2 and serve as a useful tool for risk stratification of PLWH. These findings have implications for the individual management and potential effectiveness of vaccination against SARS-CoV-2 in PLWH.

Increased CD4 : CD8 ratio normalization with implementation of current ART management guidelines

OBJECTIVES

To determine the time to CD4 : CD8 ratio normalization among Canadian adults living with HIV in the modern ART era. To identify characteristics associated with ratio normalization.

PATIENTS AND METHODS

Retrospective analysis of the Canadian Observational Cohort (CANOC), an interprovincial cohort of ART-naive adults living with HIV, recruited from 11 treatment centres across Canada. We studied participants initiating ART between 1 January 2011 and 31 December 2016 with baseline CD4 : CD8 ratio <1.0 and ≥2 follow-up measurements. Normalization was defined as two consecutive CD4 : CD8 ratios ≥1.0. Kaplan-Meier estimates and log-rank tests described time to normalization. Univariable and multivariable proportional hazards (PH) models identified factors associated with ratio normalization.

RESULTS

Among 3218 participants, 909 (28%) normalized during a median 2.6 years of follow-up. Participants with higher baseline CD4+ T-cell count were more likely to achieve normalization; the probability of normalization by 5 years was 0.68 (95% CI 0.62-0.74) for those with baseline CD4+ T-cell count >500 cells/mm3 compared with 0.16 (95% CI 0.11-0.21) for those with ≤200 cells/mm3 (P < 0.0001). In a multivariable PH model, baseline CD4+ T-cell count was associated with a higher likelihood of achieving ratio normalization (adjusted HR = 1.5, 95% CI 1.5-1.6 per 100 cells/mm3, P < 0.0001). After adjusting for baseline characteristics, time-dependent ART class was not associated with ratio normalization.

CONCLUSIONS

Early ART initiation, at higher baseline CD4+ T-cell counts, has the greatest impact on CD4 : CD8 ratio normalization. Our study supports current treatment guidelines recommending immediate ART start, with no difference in ratio normalization observed based on ART class used.

Imaging modalities for cardiovascular phenotyping in asymptomatic people living with HIV

Cardiovascular disease (CVD) has emerged as a leading cause of non-HIV-related mortality among people living with HIV (PLWH). Despite the growing CVD burden in PLWH, there is concern that general population risk score models may underestimate CVD risk in these patients. Imaging modalities have received mounting attention lately to better understand the pathophysiology of subclinical CVD and provide improved risk assessment in this population. To date, traditional and well-established techniques such as echocardiography, pulse wave velocity, and carotid intima thickness continue to be the basis for the diagnosis and subsequent monitoring of vascular atherosclerosis and heart failure. Furthermore, novel imaging tools such as cardiac computed tomography (CT) and cardiac CT angiography (CCTA), positron emission tomography/CT (PET/CT), and cardiac magnetic resonance (CMR) have provided new insights into accelerated cardiovascular abnormalities in PLWH and are currently evaluated with regards to their potential to improve risk stratification.

The effect of T helper (Th)/T cytotoxic (Tc) ratio on disease severity in type A hemophilia patients

BACKGROUND AND OBJECTIVES

The aim of this study was to investigate the T helper (Th) to T cytotoxic (Tc) ratio in children suffering from type A hemophilia disease and to evaluate the correlation of this ratio with disease severity.

MATERIAL AND METHOD

Two mls of EDTA anti coagulated whole blood was collected. Immunophenotyping of lymphocytes count was carried out by FACS analysis using a double CD4 and CD8 kit. The mean ± SD of absolute numbers of CD4 and CD8 lymphocytes/ml was calculated and the ratio of CD4/CD8 was evaluated by statistical method.

RESULTS

Among 80 type A hemophilia patients, 66 (82.5%) were male. The mean age was 15 ± 3.51 years. 12 (15%) of them were suffering from mild disease and 68 (85%) had sever disease. The CD4 /CD8 ratio was obtained between 0.45 and 1.44 with mean1.79 ± 0.78. The correlation between this ration and disease severity was 0.019.

CONCLUSION

The results showed that CD4/CD8 ratio has correlation with disease severity in type A hemophilia patients, however there was no association between this ratio and gender.

Integrase Inhibitors Use and Cytomegalovirus Infection Predict Immune Recovery in People Living With HIV Starting First-Line Therapy

BACKGROUND

We explored predictors of CD4/CD8 ratio improvement and optimal immunological recovery (OIR) after initiation of antiretroviral therapy (ART) in naive people living with HIV (PLWH).

METHODS

Retrospective multicenter study including naive PLWH starting ART with 2 nucleos(t)ide reverse transcriptase inhibitors + 1 integrase strand transfer inhibitor (InSTI) or non-NRTI or protease inhibitor (PI). PLWH were followed from the time of ART initiation (baseline) to the discontinuation of first-line regimen, virological failure, death, or loss to follow-up. Estimated incidence and predictors of time to CD4/CD8 ratio normalization (defined as ≥1) and OIR (defined as CD4/CD8 ratio ≥ 1 plus CD4 ≥ 500 cells/µL plus CD4% ≥ 30%) were explored by Kaplan-Meier curves and Cox regression analysis.

RESULTS

Overall, 1428 PLWH (77.8% males, median age 39 years, 55.1% with positive cytomegalovirus (CMV) antibodies, median HIV-RNA 4.80 log copies/mL, median CD4 323 cells/µL, median CD4/CD8 ratio 0.32) were included, of which 21.5% (n = 307), 44.5% (n = 636), and 34% (n = 485) treated with InSTI-, PI-, and NNRTI-based regimens, respectively. The estimated proportion of CD4/CD8 normalization and OIR at 36 months was 38.6% and 32.9%, respectively. Multivariate analysis showed that InSTI-based regimens had a higher probability of CD4/CD8 ratio normalization and OIR both in the total population (P < 0.001 versus PI) and in advanced naive PLWH (P ≤ 0.001 versus PI and NNRTI). Moreover, subjects with positive CMV serology showed a lower probability of CD4/CD8 ratio normalization and OIR (P < 0.001).

CONCLUSIONS

InSTI-based regimens showed a better immune recovery, suggesting that the type of first-line ART can influence immune reconstitution. PLWH with positive CMV serology showed an increased risk of suboptimal immune recovery.

Residual immune dysfunction under antiretroviral therapy

The usage of combination antiretroviral therapy in people with HIV (PWH) has incited profound improvement in morbidity and mortality. Yet, PWH may not experience full restoration of immune function which can manifest with non-AIDS comorbidities that frequently associate with residual inflammation and can imperil quality of life or longevity. In this review, we discuss the pathogenesis underlying chronic inflammation and residual immune dysfunction in PWH, as well as potential therapeutic interventions to ameliorate them and prevent incidence or progression of non-AIDS comorbidities. Current evidence advocates that early diagnosis and prompt initiation of therapy at high CD4 counts may represent the best available approach for an improved immune recovery in PWH.

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.

Managing HIV-associated inflammation and ageing in the era of modern ART

OBJECTIVES

This paper aims to address the concerns around ongoing immune activation, inflammation, and resistance in those ageing with HIV that represent current challenges for clinicians.

METHODS

Presentations at a symposium addressing issues of ageing with HIV infection were reviewed and synthesised.

RESULTS

The changing natural history and demographics of human immunodeficiency virus (HIV)-infected individuals means new challenges in contemporary management. In the early years of the epidemic,management was focussed on acute, potentially life-threatening AIDS-related complications. From initial monotherapy with first-generation antiretroviral therapy (ART), the development of combination highly active ART (HAART) allowed HIV control but ART toxicities, treatment adherence and drug resistance emerged as major issues. Today, the availability of potent and tolerable ART has made viral suppression achievable in most people living with HIV (PLHIV), and clinicians are confronted with managing a chronic condition among an ageing population. The combination of diseases of ageing and the co-morbidities associated with HIV-infection, even when well controlled, results in a complex set of challenges for many older PLHIV. There is a growing appreciation that many non-AIDS-related co-morbidities are caused, at least in part, by persistent, low-grade immune activation, inflammation, and hypercoagulability, despite suppressive ART.

CONCLUSIONS

In order to further improve HIV management, it is important to understand the enduring effects of chronically suppressed HIV infection, the potential contribution of these factors to the ageing process, the possibility of drug resistance, and the impact of different treatment strategies, including early ART initiation.

Sex Differences in People Aging With HIV

BACKGROUND

To evaluate differences between older women and men with HIV regarding HIV variables, comorbidity, physical function, and quality of life (QOL).

SETTING

The Modena HIV clinic.

METHODS

Prospective cohort study. Cross-sectional analysis. Patients >50 years were included, stratified by sex. We recorded sociodemographic data, comorbidities, variables related to HIV infection, frailty, data on body composition, physical function, physical activity, and QOL.

RESULTS

We evaluated 1126 older adults with HIV, of which 284 (25.2%) were women. Median age was 55 (IQR 6) years. There were significant differences between women and men in the median current CD4 T-cell and the mean CD4/CD8 ratio. There were differences regarding alcohol consumption, cardiovascular (CV) disease, hypertension, diabetes mellitus, and renal failure. Sarcopenia and slower gait speed were found more prevalent among men, but without significant differences. Significant differences were found regarding lower extremity strength measured by the chair stand test and in the short physical performance battery score. Short physical performance battery <9 was detected for 11.1% women vs. 5.6% men (P = 0.002). EQ5D5L score was 0.87 in women vs. 0.89 in men (P = 0.002).

CONCLUSIONS

In our cohort, older women represented one in 4 of the total patients. Despite the fact that women have better immunological recovery measured by CD4 T-cell count and CD4/CD8 ratio, and fewer CV disease and CV risk factors than men, their physical function and their QOL are worse. Therefore, older HIV-infected women have special characteristics, and the assessment of physical function in this group seems to be crucial.

Harnessing regulatory T cell neuroprotective activities for treatment of neurodegenerative disorders

Emerging evidence demonstrates that adaptive immunity influences the pathobiology of neurodegenerative disorders. Misfolded aggregated self-proteins can break immune tolerance leading to the induction of autoreactive effector T cells (Teffs) with associated decreases in anti-inflammatory neuroprotective regulatory T cells (Tregs). An imbalance between Teffs and Tregs leads to microglial activation, inflammation and neuronal injury. The cascade of such a disordered immunity includes the drainage of the aggregated protein antigens into cervical lymph nodes serving to amplify effector immune responses. Both preclinical and clinical studies demonstrate transformation of this altered immunity for therapeutic gain. We posit that the signs and symptoms of common neurodegenerative disorders such as Alzheimer's and Parkinson's diseases, amyotrophic lateral sclerosis, and stroke can be attenuated by boosting Treg activities.

Incidence of hypertension among persons living with HIV in China: a multicenter cohort study

BACKGROUND

Life expectancy among persons living with HIV (PLWH) has improved with increasing access to antiretroviral therapy (ART), however incidence of chronic comorbidities has simultaneously increased. No data are available regarding the incidence of hypertension among Chinese PLWH.

METHODS

We analyzed data collected from patients enrolled in two prospective longitudinal multicenter studies of PLWH initiating ART in China. Incidence rate of hypertension per 100 person-years (PYs) among PLWH was calculated, and Cox proportional hazards models was used to evaluate the association between incident hypertension and traditional and HIV-associated risk factors.

RESULTS

Of 1078 patients included in this analysis, 984 ART-naïve patients were hypertension-free at baseline, and contributed 2337.7 PYs of follow up, with a median follow-up period of 1.8 years (range: 1.2-3.2) after initiation of ART. Incidence of hypertension was 7.6 [95% confidence interval (CI): 6.5-8.7] per 100 PYs. In the Cox regression analysis, incidence of hypertension was positively associated with body mass index [adjusted hazard ratio (aHR) 1.07 (1.01,1.13), p = 0.02] and recent viral load (aHR 1.28, 95% CI:1.08-1.51, p < 0.01), and negatively associated with recent CD4+/CD8+ ratio (aHR 0.14, 95% CI:0.06-0.31, p < 0.001), zidovudine exposure (aHR 0.15, 95% CI: 0.10-0.24, p < 0.001) and tenofovir disoproxil fumarate exposure (aHR 0.13, 95% CI: 0.08-0.21, p < 0.001).

CONCLUSIONS

The incidence of hypertension was relatively high among Chinese PLWH initiating ART. Recent low CD4+/CD8+ ratio and detectable HIV viremia were associated with incident hypertension, whereas receipt of ART was associated with reduced risk. Hypertension may be mitigated, in part, by excellent HIV care, including viral suppression with ART.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00872417 registered on 31 March, 2009, and NCT01844297 registered on 1 May, 2013.

Cardiovascular disease in HIV patients: recent advances in predicting and managing risk

INTRODUCTION

Cardiovascular disease (CVD) is one of the leading causes of mortality in virally suppressed people living with HIV (PLWH) and with an aging population, is likely to become one of the leading challenges in maintaining good health outcomes in HIV infection. However, factors driving the risk of CVD in PLWH are multiple and may be different from those of the general population, raising challenges to predicting and managing CVD risk in this population.

AREAS COVERED

In this review, we examine the relevant data regarding CVD in HIV infection including CVD prevalence, pathogenesis, and other contributing factors. We review the data regarding CVD risk prediction in PLWH and summarize factors, both general and HIV specific, that may influence CVD risk in this population. And finally, we discuss appropriate management of CVD risk in PLWH and explore potential therapeutic pathways which may mitigate CVD risk in the future in this population.

EXPERT OPINION

Following a comprehensive review of CVD risk in PLWH, we give our opinion on the primary issues in risk prediction and management of CVD in HIV infected individuals and discuss the future direction of CVD management in this population.

Intraocular leucocyte subpopulations analysis by multiparametric flow cytometry in human uveitis

PURPOSE

The aim of this study was to describe the cellular infiltrate in aqueous and vitreous samples of patients with uveitis analysed by multiparametric flow cytometry.

METHODS

This is a retrospective analysis of aqueous and vitreous samples analysed by flow cytometry for diagnostic purposes, in cases of masquerade syndromes and infectious and non-infectious uveitis. Data collected included demographics, anatomical classification of uveitis, phenotypic diagnosis, anterior chamber cells grading, vitreous haze and time of follow-up since presentation to sample obtained.

RESULTS

Thirty-one samples (17 aqueous and 14 vitreous fluids) from 31 patients, 18 men, were analysed. The mean age at the time of sample collection was 60.23±17.03 years. The most frequent anatomical classification was panuveitis (14 of 31). T cells accounted for the main cellular component in the majority of the samples (10 of 13 aqueous samples; 7 of 14 in vitreous samples). CD4:CD8 ratios ranged from 0.21 to 16.3 in the case of aqueous samples and from 0.5 to 9.7 in the case of vitreous samples.

DISCUSSION

Flow cytometry analysis of aqueous and vitreous samples from patients with uveitis could provide insight into the pathogenesis of human uveitis and help develop accurate animal models which better mimic human disease.

Dynamic study of oral Candida infection and immune status in HIV infected patients during HAART

OBJECTIVE

To dynamically monitor oral Candida infection, CD4⁺ T lymphocyte counts, CD8⁺ T lymphocyte counts and CD4/CD8 ratios in HIV/AIDS patients during their first year of HAART and to preliminarily explore the relationships between them.

DESIGN

Forty-six patients with HIV/AIDS receiving HAART at the Infection Department of Chongqing Red Cross Hospital were followed for one year. At baseline and 3, 6, and 12 months after HAART initiation, oral rinses were collected and cultured to identify Candida species. Further, blood samples were collected to detect CD4⁺ T lymphocyte counts, CD8⁺ T lymphocyte counts and CD4/CD8 ratios.

RESULTS

The prevalence of OC decreased after HAART initiation (P ＜ 0.05), and Candida albicans was the dominant species isolated from the oral cavity (66/93). At 3, 6 and 12 months after HAART initiation, CD4⁺ T lymphocyte counts were 327.91 ± 138.82, 329.65 ± 142.66 and 319.98 ± 97.90 cells/mm³, respectively, which were significantly higher than the level at baseline (263.39 ± 126.01 cells/mm³) (P = 0.016, P = 0.014, and P = 0.035, respectively). During the first year of HAART, CD4/CD8 ratios increased gradually, and CD8⁺ T lymphocyte counts decreased continually. OC was associated with low CD4⁺ T lymphocyte counts and a low CD4/CD8 ratio. CD4⁺ T lymphocyte counts <200 cells/mm³ and Candida load ≥300 CFU/mL were risk factors for OC (P ＜ 0.05), and oral Candida load was negatively correlated with CD4⁺ T lymphocyte counts and the CD4/CD8 ratio.

CONCLUSION

OC might be a useful marker for the evaluation of immune status in patients with HIV/AIDS.

Sarcopenia in people living with the Human Immunodeficiency Virus: a systematic review and meta-analysis

People living with HIV (PLHIV) experience greater loss of muscle mass and function than people without HIV. However, HIV is not routinely recognized as a sarcopenia risk factor outside of HIV literature. The purposes of this study were to establish the prevalence and predictors of sarcopenia among PLHIV, and to compare the prevalence of sarcopenia among PLHIV and people without HIV. A systematic literature search of the PubMed, Embase, Cinahl, and Scielo databases was performed following PRISMA and MOOSE guidelines. Identified articles were included if they evaluated sarcopenia among PLHIV using either the presence of low muscle mass only or low muscle mass in association with low muscle function. The pooled prevalence of sarcopenia among PLHIV and the odds ratio for sarcopenia in PLHIV compared with controls were calculated. From 13 studies and 2267 participants, the prevalence of sarcopenia among PLHIV was 24.1% (95% CI = 17.8-31.0%). PLHIV presented 6.1 greater odds (95% CI = 1.1-33.5) of sarcopenia compared with people without HIV, matched by age, sex, BMI, and ethnicity. Longer exposure to specific HIV drugs, tobacco and alcohol, lower education and employment rates, and greater HIV duration were associated with sarcopenia. In conclusion, PLHIV had a high prevalence of sarcopenia, related to both HIV and non-HIV risk factors. HIV should be considered a risk factor for sarcopenia in the general population. CRD42019131449.

Foetal Immune Response Activation and High Replication Rate during Generation of Classical Swine Fever Congenital Infection

Classical swine fever virus (CSFV) induces trans-placental transmission and congenital viral persistence; however, the available information is not updated. Three groups of sows were infected at mid-gestation with either a high, moderate or low virulence CSFV strains. Foetuses from sows infected with high or low virulence strain were obtained before delivery and piglets from sows infected with the moderate virulence strain were studied for 32 days after birth. The low virulence strain generated lower CSFV RNA load and the lowest proportion of trans-placental transmission. Severe lesions and mummifications were observed in foetuses infected with the high virulence strain. Sows infected with the moderately virulence strain showed stillbirths and mummifications, one of them delivered live piglets, all CSFV persistently infected. Efficient trans-placental transmission was detected in sows infected with the high and moderate virulence strain. The trans-placental transmission occurred before the onset of antibody response, which started at 14 days after infection in these sows and was influenced by replication efficacy of the infecting strain. Fast and solid immunity after sow vaccination is required for prevention of congenital viral persistence. An increase in the CD8+ T-cell subset and IFN-alpha response was found in viremic foetuses, or in those that showed higher viral replication in tissue, showing the CSFV recognition capacity by the foetal immune system after trans-placental infection.