HIV-associated Immune Dysfunction Research Articles

HIV-Associated Immune Dysfunction and Hematological Abnormalities: A Detailed Examination of Pathophysiology and Clinical Implications

Human Immunodeficiency Virus (HIV) exerts profound effects on both the immune and hematological systems, leading to a range of complications that significantly influence patient outcomes and quality of life. This review examines the intricate interplay between HIV infection, immune system dysfunction, and hematological abnormalities. We detail the mechanisms underlying these complications, including the direct impact of HIV on CD4+ T lymphocytes, the persistent immune activation observed despite antiretroviral therapy (ART), and the diverse etiologies of HIV- associated anemia, thrombocytopenia, and leukopenia. Additionally, we address the clinical implications of these issues, emphasizing their role in disease progression and the current therapeutic approaches. This review highlights the imperative for continued research and the advancement of integrated care strategies to enhance long-term outcomes for individuals living with HIV.

Photogallery. Combination of syphilis and HIV infection

In recent decades, the world has seen an increase in the number of patients suffering from syphilis and HIV infection at the same time. There is a traditional opinion that concomitant HIV infection can aggravate the clinical manifestations and course of syphilis. However, in the era of widespread use of antiretroviral therapy, most people living with HIV have a typical course of syphilis. However, with quantitative and/or qualitative HIV-associated immune dysfunction, deviations in the clinical picture of syphilitic infection from its classical patterns are possible. This is evidenced by annual publications in Russian and foreign specialized publications. We present to your attention a photo gallery of cases of syphilis in HIV-positive patients with characteristic and atypical manifestations.

B Cell Dynamics in HIV Pathogenesis: Insights and Implications

Human Immunodeficiency Virus (HIV) infection remains a global health challenge, with intricate interactions between the virus and the immune system, particularly B cells, significantly influencing disease progression. This review aims to provide a comprehensive examination of B cell dynamics during HIV pathogenesis, offering insights into the implications for therapeutic interventions, vaccine design, and the broader understanding of HIV-associated immune dysfunction. The review begins by outlining the epidemiology of HIV and emphasizing the critical impact of the virus on the immune system, with a specific focus on B cells. It explores the alterations in B cell subpopulations, including memory B cell depletion and dysregulation, highlighting their implications for immune function during HIV infection. This review consolidates current knowledge on B cell dynamics in HIV pathogenesis, providing a foundation for advancing our understanding of the intricate host-virus interactions. The insights gained from this exploration hold significant implications for the development of targeted therapeutic strategies and informed approaches to HIV prevention and treatment.

Monocyte and T Cell Immune Phenotypic Profiles Associated With Age Advancement Differ Between People With HIV, Lifestyle-Comparable Controls and Blood Donors.

MotivationPeople with HIV on successful antiretroviral therapy show signs of premature aging and are reported to have higher rates of age-associated comorbidities. HIV-associated immune dysfunction and inflammation have been suggested to contribute to this age advancement and increased risk of comorbidities.MethodPartial least squares regression (PLSR) was used to explore associations between biological age advancement and immunological changes in the T cell and monocyte compartment in people with HIV (n=40), comparable HIV-negative individuals (n=40) participating in the Comorbidity in Relation to AIDS (COBRA) cohort, and blood donors (n=35).ResultsWe observed that age advancement in all three groups combined was associated with a monocyte immune phenotypic profile related to inflammation and a T cell immune phenotypic associated with immune senescence and chronic antigen exposure. Interestingly, a unique monocyte and T cell immune phenotypic profile predictive for age advancement was found within each group. An inflammatory monocyte immune phenotypic profile associated with age advancement in HIV-negative individuals, while the monocyte profile in blood donors and people with HIV was more reflective of loss of function. The T cell immune phenotypic profile in blood donors was related to loss of T cell function, whereas the same set of markers were related to chronic antigen stimulation and immune senescence in HIV-negative individuals. In people with HIV, age advancement was related to changes in the CD4+ T cell compartment and more reflective of immune recovery after cART treatment.ImpactThe identified monocyte and T cell immune phenotypic profiles that were associated with age advancement, were strongly related to inflammation, chronic antigen exposure and immune senescence. While the monocyte and T cell immune phenotypic profile within the HIV-negative individuals reflected those observed in the combined three groups, a distinct profile related to immune dysfunction, was observed within blood donors and people with HIV. These data suggest that varying exposures to lifestyle and infection-related factors may be associated with specific changes in the innate and adaptive immune system, that all contribute to age advancement.

Editorial introductions

Editorial introductions

Global Longitudinal Strain and Immune Status in Patients Living With Human Immunodeficiency Virus

Improvement in survival in patients living with human immunodeficiency virus (PLHIV) has led to increased prevalence of cardiovascular disease. Whether HIV-associated immune dysfunction is associated with preclinical left ventricular (LV) dysfunction despite normal LV ejection fraction (LVEF) is unclear. Accordingly, we investigated the relation of immune status and LV function in PLHIV. Global longitudinal strain (GLS) analyses were performed retrospectively on all echocardiograms for PLHIV who had available HIV-1 RNA viral load, nadir, and proximal CD4 cell count data at Duke University Medical Center between 2001 and 2012. The relation between HIV-1 RNA viral load, nadir, and proximal CD4 count and GLS as a continuous dependent variable was assessed with unadjusted and adjusted linear regression. GLS was calculated for 253 PLHIV. Median GLS in our cohort was - 15.1% with interquartile range from (-16.7 to -13.6). All participants had an LVEF ≥50%. In adjusted analyses, proximal CD4 <500 cells/mm3 and nadir CD4 <250 cells/mm3 were significantly inversely correlated with GLS (p = 0.01 and p = 0.004, respectively). In PLHIV, patient with plasma HIV RNA <400 copies/ml at baseline had a trend toward significantly more negative values of GLS compared with those patients without viral suppression at baseline (p = 0.08). In conclusion, this study is the first to demonstrate such a high prevalence of abnormal GLS in PLHIV, and the first to identify that proximal and nadir CD4 cell count are independently associated with GLS despite normal LVEF.

Circulating LPS and (1→3)-β-D-Glucan: A Folie à Deux Contributing to HIV-Associated Immune Activation.

Immune activation is the driving force behind the occurrence of AIDS and non-AIDS events, and is only partially reduced by antiretroviral therapy (ART). Soon after HIV infection, intestinal CD4+ T cells are depleted leading to epithelial gut damage and subsequent translocation of microbes and/or their products into systemic circulation. Bacteria and fungi are the two most abundant populations of the gut microbiome. Circulating lipopolysaccharide (LPS) and (1→3)-β-D-Glucan (βDG), major components of bacterial and fungal cell walls respectively, are measured as markers of microbial translocation in the context of compromised gut barriers. While LPS is a well-known inducer of innate immune activation, βDG is emerging as a significant source of monocyte and NK cell activation that contributes to immune dysfunction. Herein, we critically evaluated recent literature to untangle the respective roles of LPS and βDG in HIV-associated immune dysfunction. Furthermore, we appraised the relevance of LPS and βDG as biomarkers of disease progression and immune activation on ART. Understanding the consequences of elevated LPS and βDG on immune activation will provide insight into novel therapeutic strategies against the occurrence of AIDS and non-AIDS events.

Terminal differentiation of T cells is strongly associated with CMV infection and increased in HIV-positive individuals on ART and lifestyle matched controls.

HIV-1-positive individuals on successful antiretroviral therapy (ART) are reported to have higher rates of age-associated non-communicable comorbidities (AANCCs). HIV-associated immune dysfunction has been suggested to contribute to increased AANCC risk. Here we performed a cross-sectional immune phenotype analysis of T cells in ART-treated HIV-1-positive individuals with undetectable vireamia (HIV-positives) and HIV-1-negative individuals (HIV-negatives) over 45 years of age. In addition, two control groups were studied: HIV negative adults selected based on lifestyle and demographic factors (Co-morBidity in Relation to AIDS, or COBRA) and unselected age-matched donors from a blood bank. Despite long-term ART (median of 12.2 years), HIV-infected adults had lower CD4+ T-cell counts and higher CD8+ T-cell counts compared to well-matched HIV-negative COBRA participants. The proportion of CD38+HLA-DR+ and PD-1+ CD4+ T-cells was higher in HIV-positive cohort compared to the two HIV-negative cohorts. The proportion CD57+ and CD27−CD28− cells of both CD4+ and CD8+ T-cells in HIV-positives was higher compared to unselected adults (blood bank) as reported before but this difference was not apparent in comparison with well-matched HIV-negative COBRA participants. Multiple regression analysis showed that the presence of an increased proportion of terminally differentiated T cells was strongly associated with CMV infection. Compared to appropriately selected HIV-negative controls, HIV-positive individuals on ART with long-term suppressed viraemia exhibited incomplete immune recovery and increased immune activation/exhaustion. CMV infection rather than treated HIV infection appears to have more consistent effects on measures of terminal differentiation of T cells.

Cardiovascular Complications of HIV-Associated Immune Dysfunction.

Prolonged survival in HIV infection is accompanied by an increased frequency of non-HIV-related comorbidities. It is suggested that cardiovascular diseases (CVD) occur earlier among HIV-positive patients compared with HIV-negative patients, and at a higher rate. Several factors have been proposed which can be categorized into traditional and nontraditional risk factors. Immune dysfunction is a nontraditional risk factor that contributes significantly to cardiovascular pathology. Markers of inflammation are elevated in HIV-infected patients, and elevations in markers such as high-sensitivity C-reactive protein, D-dimer, and interleukin-6 (IL-6) have been associated with increased risk for cardiovascular disease. However, the data currently suggest the most practical advice is to start antiretroviral therapy early and to manage traditional risk factors for CVD aggressively. A better understanding of the mechanisms of CVD in this population and further efforts to modify chronic inflammation remain an important research area.

Fatal Pancreatitis in Simian Immunodeficiency Virus SIV mac251 -Infected Macaques Treated with 2′,3′-Dideoxyinosine and Stavudine following Cytotoxic-T-Lymphocyte-Associated Antigen 4 and Indoleamine 2,3-Dioxygenase Blockade

Human immunodeficiency virus (HIV) infection is associated with immune activation, CD4⁺-T-cell loss, and a progressive decline of immune functions. Antiretroviral therapy (ART) only partially reverses HIV-associated immune dysfunction, suggesting that approaches that target immune activation and improve virus-specific immune responses may be needed. We performed a preclinical study in rhesus macaques infected with the pathogenic simian immunodeficiency virus SIV(mac251) and treated with ART. We tested whether vaccination administered together with cytotoxic-T-lymphocyte-associated antigen 4 (CTLA-4) blockade and treatment with the indoleamine 2,3-dioxygenase (IDO) inhibitor 1-methyl-D-tryptophan (D-1mT), decreased immune activation and improved vaccine efficacy. The treatment did not augment vaccine immunogenicity; rather, it dramatically increased ART-related toxicity, causing all treated animals to succumb to acute pancreatitis and hyperglycemic coma. The onset of fulminant diabetes was associated with severe lymphocyte infiltration of the pancreas and complete loss of the islets of Langerhans. Thus, caution should be used when considering approaches aimed at targeting immune activation during ART.

HIV-associated immune dysfunction and viral infection: role in the pathogenesis of AIDS-related lymphoma

HIV infection is associated with a much higher risk for the development of non-Hodgkin lymphoma (AIDS-NHL). The principal causes of lymphomagenesis in HIV-infected individuals are thought to be the loss of immune function seen in HIV infection, which results in the loss of immunoregulation of Epstein-Barr virus-infected B cells, as well as HIV infection-associated immune dysregulation, including chronic B-cell activation. In this review, we discuss recent reports that further support the importance of these factors, and we highlight emerging evidence of different mechanisms that potentially drive lymphomagenesis in HIV-infected individuals.

Generalized immune activation as a direct result of activated CD4+T cell killing

BackgroundIn addition to progressive CD4+ T cell immune deficiency, HIV infection is characterized by generalized immune activation, thought to arise from increased microbial exposure resulting from diminishing immunity.ResultsHere we report that, in a virus-free mouse model, conditional ablation of activated CD4+ T cells, the targets of immunodeficiency viruses, accelerates their turnover and produces CD4+ T cell immune deficiency. More importantly, activated CD4+ T cell killing also results in generalized immune activation, which is attributable to regulatory CD4+ T cell insufficiency and preventable by regulatory CD4+ T cell reconstitution. Immune activation in this model develops independently of microbial exposure. Furthermore, microbial translocation in mice with conditional disruption of intestinal epithelial integrity affects myeloid but not T cell homeostasis.ConclusionsAlthough neither ablation of activated CD4+ T cells nor disruption of intestinal epithelial integrity in mice fully reproduces every aspect of HIV-associated immune dysfunction in humans, ablation of activated CD4+ T cells, but not disruption of intestinal epithelial integrity, approximates the two key immune alterations in HIV infection: CD4+ T cell immune deficiency and generalized immune activation. We therefore propose activated CD4+ T cell killing as a common etiology for both immune deficiency and activation in HIV infection.See minireview http://www.jbiol.com/content/8/10/91

Peripheral CD4 loss of regulatory T cells is associated with persistent viraemia in chronic HIV infection

Chronic HIV infection is associated with T cell abnormalities and altered effector function. Regulatory T cells (Treg) are CD4+ T cells that play a critical role in regulating the immune system. The impact of regulatory T cells on HIV infection and disease progression may be highly significant. We hypothesize that chronic antigenic stimulation from a persistent, high viraemic state may promote a population of Treg that contributes to HIV-associated immune dysfunction. We evaluated the pattern of Treg in chronically infected, HIV-positive individuals over a course of 6 months. Treg are depleted at a distinct rate from that of absolute CD4 cells and loss of Treg is slower in the presence of viral suppression. In vitro depletion of CD25+ CD4+ cells resulted in increased Gag-specific CD4 and CD8 responses. A significant correlation between ex vivo measurement of Treg and Gag-specific CD4 T cell responses was observed (r=-0 x 41, P=0 x 018) with a trend observed with Gag-specific CD8 T cell responses (P=0 x 07). The impact of HIV infection on the Treg population directly complicates the measured effect of Treg on the immune dysfunction although our data support the important role of Treg on modulating the effector T cell response in chronic infection.

HIV-Specific IL-10-Positive CD8+ T Cells Are Increased in Advanced Disease and Are Associated with Decreased HIV-Specific Cytolysis

IL-10-producing T cells have been shown to inhibit Ag-specific CD8+ T cell responses, and may play a role in the immune dysregulation observed in HIV-1 infection. We characterized the Gag-specific IL-10 responses by CD8+ T cells in HIV-1-positive volunteers from Uganda. HIV-specific IL-10 responses were detected in 32 of 61 (52.4%) antiretroviral naive and 2 of 15 (13.3%) volunteers with a complete virologic response on antiretroviral therapy (< 400 copies/ml). The frequency of HIV-specific IL-10-positive cells was significantly higher in volunteers with advanced disease (CD4+ T cell count <200 cells/mm3; p = 0.0004), and correlated positively with plasma HIV RNA (r = 0.43, p = 0.0004). Interestingly, the frequency of Gag-specific CD107a/b-, but not IFN-gamma-, positive cells was significantly lower in individuals with detectable IL-10-positive CD8+ T cells (p = 0.004). Gag-specific IL-10-positive CD8+ T cells demonstrated a pattern of surface memory marker expression that is distinct compared with CD107a/b- and IFN-gamma-positive CD8+ T cell populations (p < 0.0001). Our study describes a distinct population of IL-10-positive CD8+ T cells that may play a role in HIV-associated immune dysfunction.

HIV-associated immune dysfunction and delayed pubertal development in a cohort of young hemophiliacs. Hemophilia Growth and Development Study.

As part of the Hemophilia Growth and Development Study (HGDS), we investigated the relationship between HIV-associated immune dysfunction and delayed pubertal development in a cohort of 333 boys and adolescents with moderate or severe hemophilia who were between the ages of 6 and 19 years at study entry in 1989. Sixty-two percent of the cohort was infected with HIV in the late 1970s and early 1980s through exposure to contaminated clotting factor concentrates. The cohort was observed during follow-up at 6-month intervals; measurements taken at each follow-up visit included Tanner stage and CD4+ cell count. This analysis of data from the first 4 years of follow-up revealed statistically significant delays in pubertal development associated with increasing levels of immune dysfunction. Our results emphasize the importance of following pubertal development in HIV-infected adolescent boys since delays in maturation may reflect underlying disease progression.

Sequential autonomic function tests in HIV infection

Cardiovascular autonomic function tests were carried out on 22 men at varying stages of HIV infection. Thirteen were asymptomatic, seven had persistent generalized lymphadenopathy, and two had Kaposi's sarcoma. Pupil cycle times were also measured. Except for one subject with definite autonomic abnormalities, all the rest had almost normal test results. There were no correlations between individual tests of immune function and the autonomic test results. The tests were repeated 9-18 months later in 12 men, four of whom were taking zidovudine at that time. Although there was evidence of progression of HIV-associated immune dysfunction, there was no significant deterioration in autonomic function. In the single patient with abnormal autonomic function, these changes appeared to reverse on treatment with zidovudine.