Interactions of HIV and Antiretroviral Therapy With Neutrophils and Platelets

Lower Neutrophil Count Without Clinical Consequence Among Children of African Ancestry Living With HIV in Canada

OBJECTIVE

To investigate the association between African ancestry and neutrophil counts among children living with HIV (CLWH). We also examined whether medications, clinical conditions, hospitalization, or HIV virologic control were associated with low neutrophil counts or African ancestry.

DESIGN

We conducted a secondary analysis of the Early Pediatric Initiation Canada Child Cure Cohort (EPIC4) Study, a multicenter prospective cohort study of CLWH across 8 Canadian pediatric HIV care centers.

METHODS

We classified CLWH according to African ancestry, defined as "African," "Caribbean," or "Black" maternal race. Longitudinal laboratory data (white blood cells, neutrophils, lymphocytes, viral load, and CD4 count) and clinical data (hospitalizations, AIDS-defining conditions, and treatments) were abstracted from medical records.

RESULTS

Among 217 CLWH (median age 14, 55% female), 145 were of African ancestry and 72 were of non-African ancestry. African ancestry was associated with lower neutrophil counts, white blood cell counts, and neutrophil-lymphocyte ratios. Neutrophil count <1.5 × 109/L was detected in 60% of CLWH of African ancestry, compared with 31% of CLWH of non-African ancestry (P < 0.0001), representing a 2.0-fold higher relative frequency (95% CI: 1.4-2.9). Neutrophil count was on average 0.74 × 109/L (95% CI: 0.45 to 1.0) lower in CLWH of African ancestry (P < 0.0001). Neither neutrophil count<1.5 × 109/L nor African ancestry was associated with medications, hospitalizations, AIDS-defining conditions, or markers of virologic control (viral load, sustained viral suppression, and lifetime nadir CD4).

CONCLUSIONS

In CLWH, African ancestry is associated with lower neutrophil counts, without clinical consequences. A flexible evaluation of neutrophil counts in CLWH of African ancestry may avoid unnecessary interventions.

Production and characterization of novel Anti-HIV Fc-fusion proteins in plant-based systems: Nicotiana benthamiana & tobacco BY-2 cell suspension

Multifunctional anti-HIV Fc-fusion proteins aim to tackle HIV efficiently through multiple modes of action. Although results have been promising, these recombinant proteins are hard to produce. This study explored the production and characterization of anti-HIV Fc-fusion proteins in plant-based systems, specifically Nicotiana benthamiana plants and tobacco BY-2 cell suspension. Fc-fusion protein expression in plants was optimized by incorporating codon optimization, ER retention signals, and hydrophobin fusion elements. Successful transient protein expression was achieved in N. benthamiana, with notable improvements in expression levels achieved through N-terminal hydrophobin fusion and ER retention signals. Stable expression in tobacco BY-2 resulted in varying accumulation levels being at highest 2.2.mg/g DW. The inclusion of hydrophobin significantly enhanced accumulation, providing potential benefits for downstream processing. Mass spectrometry analysis confirmed the presence of the ER retention signal and of N-glycans. Functional characterization revealed strong binding to CD64 and CD16a receptors, the latter being important for antibody-dependent cellular cytotoxicity (ADCC). Interaction with HIV antigens indicated potential neutralization capabilities. In conclusion, this research highlights the potential of plant-based systems for producing functional anti-HIV Fc-fusion proteins, offering a promising avenue for the development of these novel HIV therapies.

Altered neutrophil responses to dengue virus serotype three: delayed apoptosis is regulated by stabilisation of Mcl-1

Dengue is a global health concern, and the host-viral interactions that regulate disease severity are largely unknown. Detrimental effects of neutrophils in this disease have been reported, but the precise mechanisms and functional properties of dengue-activated neutrophils are not fully characterised. Here, we measured the effects of dengue virus serotype 3 (DV3) on neutrophil lifespan and functions. We show that DV3 extends neutrophil survival with a significant proportion of cells surviving for 72 h post-incubation. These effects on neutrophil survival were greater than those observed by adding GM-CSF and TNF-α alone, but these cytokines enhanced survival induced by the virus. Enhanced reactive oxygen species (ROS) generation was observed following incubation with DV3 activation and this ROS production was enhanced by co-incubation with priming agents. In addition, DV triggered the enhanced IL-8 expression by the majority of neutrophils and a low percentage of cells were activated to express MCP-1 (CCL2). A low number of neutrophils showed increased co-expression of the migratory markers, CCR7 and CXCR4 which could promote their migration towards lymph nodes. DV3 significantly upregulated the BCL-XL gene at 3, 12, and 24 h, and the Mcl-1 gene at 12 h, following treatment. We also show that DV3 induces the Mcl-1 protein stabilization similar to GM-CSF. This report sheds new light on the mechanisms by which neutrophils may contribute to the pathology of dengue disease via delayed apoptosis and generation of pro-inflammatory molecules, and raises the possibility that dengue-activated neutrophils may play a role in activating cells of adaptive immunity.

The role of autophagy in the progression of HIV infected cardiomyopathy

Although highly active antiretroviral therapy (HAART) has changed infection with human immunodeficiency virus (HIV) from a diagnosis with imminent mortality to a chronic illness, HIV positive patients who do not develop acquired immunodeficiency syndrome (AIDs) still suffer from a high rate of cardiac dysfunction and fibrosis. Regardless of viral load and CD count, HIV-associated cardiomyopathy (HIVAC) still causes a high rate of mortality and morbidity amongst HIV patients. While this is a well characterized clinical phenomena, the molecular mechanism of HIVAC is not well understood. In this review, we consolidate, analyze, and discuss current research on the intersection between autophagy and HIVAC. Multiple studies have linked dysregulation in various regulators and functional components of autophagy to HIV infection regardless of mode of viral entry, i.e., coronary, cardiac chamber, or pericardial space. HIV proteins, including negative regulatory factor (Nef), glycoprotein 120 (gp120), and transactivator (Tat), have been shown to interact with type II microtubule-associated protein-1 β light chain (LC3-II), Rubiquitin, SQSTM1/p62, Rab7, autophagy-specific gene 7 (ATG7), and lysosomal-associated membrane protein 1 (LAMP1), all molecules critical to normal autophagy. HIV infection can also induce dysregulation of mitochondrial bioenergetics by altering production and equilibrium of adenosine triphosphate (ATP), mitochondrial reactive oxygen species (ROS), and calcium. These changes alter mitochondrial mass and morphology, which normally trigger autophagy to clear away dysfunctional organelles. However, with HIV infection also triggering autophagy dysfunction, these abnormal mitochondria accumulate and contribute to myocardial dysfunction. Likewise, use of HAART, azidothymidine and Abacavir, have been shown to induce cardiac dysfunction and fibrosis by inducing abnormal autophagy during antiretroviral therapy. Conversely, studies have shown that increasing autophagy can reduce the accumulation of dysfunctional mitochondria and restore cardiomyocyte function. Interestingly, Rapamycin, a mammalian target of rapamycin (mTOR) inhibitor, has also been shown to reduce HIV-induced cytotoxicity by regulating autophagy-related proteins, making it a non-antiviral agent with the potential to treat HIVAC. In this review, we synthesize these findings to provide a better understanding of the role autophagy plays in HIVAC and discuss the potential pharmacologic targets unveiled by this research.

Increased platelet-CD8+ T-cell aggregates displaying high activation, exhaustion, and tendency to death correlate with disease progression in people with HIV-1

Platelets engage in HIV-1 infection by interacting with immune cells, which has been realized broadly. However, the potential interaction between platelets and CD8+ T cells remains unidentified. Here, treatment-naive individuals with HIV-1, complete immunological responders to antiretroviral therapy, and healthy controls were enrolled. First, we found that treatment-naive individuals with HIV-1 had low platelet numbers and high CD8+ T-cell counts when compared with complete immunological responders to antiretroviral therapy and healthy controls, leading to a low platelet/CD8+ T-cell ratio in peripheral blood, which could effectively differentiate the status of HIV-1 infection. Moreover, cytokines that may have been derived from platelets were higher in the plasma of people with HIV-1 despite viral suppression. Furthermore, we demonstrated that platelet-CD8+ T-cell aggregates were elevated in treatment-naive individuals with HIV-1, which positively correlated with HIV-1 viral load but negatively correlated with CD4+ T-cell count and CD4/CD8 ratio. Finally, we revealed that platelet-CD8+ T-cell aggregates correlate with enhanced activation/exhaustion and pyroptosis/apoptosis compared with free CD8+ T cells. Moreover, platelet-induced caspase 1 activation of CD8+ T cells correlated with IL-1β and IL-18 plasma levels. In brief, we reveal the importance of platelets in HIV-1 infection, which might secrete more cytokines and mediate CD8+ T-cell phenotypic characteristics by forming platelet-CD8+ T-cell aggregates, which are related to poor prognosis.

Platelet index ratios in HIV: Emerging biomarkers for immune health and disease management

Human Immunodeficiency Virus (HIV) infection is a global health challenge that requires continuous advancements in diagnostic and prognostic tools. Traditional markers, such as CD4 cell counts and viral load, have played a crucial role in monitoring disease progression and guiding therapeutic interventions. However, emerging research suggests that platelet index ratios may serve as valuable biomarkers in assessing immune health and managing HIV-associated complications. This paper explores the significance of platelet index ratios, including platelet-to-lymphocyte ratio and mean platelet volume-to-lymphocyte ratio, as potential indicators of immune system status in individuals living with HIV. The interplay between platelets, lymphocytes, and their ratios reflects the dynamic nature of the immune response and inflammatory processes during HIV infection. Understanding the role of platelet index ratios in HIV could lead to the development of accessible and cost-effective biomarkers for monitoring immune health. Implementation of these ratios in routine clinical practice may enhance the precision of disease prognosis and guide personalized treatment strategies. Additionally, the exploration of platelet index ratios may pave the way for innovative therapeutic interventions aimed at modulating immune responses in HIV-infected individuals. In conclusion, platelet index ratios represent promising emerging biomarkers for evaluating immune health and managing HIV-related complications. Further research and clinical validation are warranted to establish the utility of these ratios in routine HIV care, potentially revolutionizing the approach to monitoring and improving the health outcomes of individuals living with HIV.

Utilization of immunological ratios in HIV: Implications for monitoring and therapeutic strategies

Human immunodeficiency virus (HIV) infection remains a significant global health concern, necessitating ongoing research and innovation in the quest for improved disease management. Traditional markers for monitoring HIV progression and the effectiveness of antiretroviral therapy have limitations in capturing the intricate immune responses and inflammatory dynamics in people with HIV. In recent years, the concept of inflammation ratios has gained prominence as a valuable tool for assessing and understanding the complex interplay between inflammation, immune function, and HIV. In this abstract, we provide an overview of the emerging field of utilizing inflammation ratios in the context of HIV and its implications for disease monitoring and therapeutic strategies. These ratios, such as the CD4/CD8 ratio, neutrophil-to-lymphocyte ratio, and monocyte-to-lymphocyte ratio, offer a more comprehensive assessment of an individual's immune status and inflammatory state. By exploring the clinical implications of inflammation ratios, including their potential to predict disease complications and guide personalized treatment approaches, this publication sheds light on the potential benefits of incorporating inflammation ratios into routine HIV care. Furthermore, we emphasize the importance of ongoing research in this field to further refine our understanding of the utility and significance of inflammation ratios in improving the lives of people with HIV.

Integrase inhibitors: current protagonists in antiretroviral therapy

Since HIV was identified as the etiological agent of AIDS, there have been significant advances in antiretroviral therapy (ART) that has reduced morbidity/mortality. Still, the viral genome's high mutation rate, suboptimal ART regimens, incomplete adherence to therapy and poor control of the viral load generate variants resistant to multiple drugs. Licensing over 30 anti-HIV drugs worldwide, including integrase inhibitors, has marked a milestone since they are potent and well-tolerated drugs. In addition, they favor a faster recovery of CD4+ T cells. They also increase the diversity profile of the gut microbiota and reduce inflammatory markers. All of these highlight the importance of including them in different ART regimens.

Prevalence of Cytopenia and its Correlation with Immunosuppression in Naïve HIV-1 Infected Patients Initiating First-Line Antiretroviral Therapy: A Pilot Study

BACKGROUND

Cytopenias serve as common indicators and crucial predictive tools for evaluating disease progression and therapeutic outcomes in individuals with human immunodeficiency virus (HIV) infection. This study aimed to assess the prevalence of cytopenias and their correlation with the level of immunosuppression in treatment-naive HIV-infected participants after initiating highly active combined antiretroviral drug therapy (cART24).

MATERIALS AND METHODS

This prospective study focused on evaluating cytopenia in 44 treatment-naive HIV-infected patients who consented to initiate cART and were consecutively enrolled. The research was conducted at the Nasara HIV Treatment & Care Centre of Ahmadu Bello University Teaching Hospital (ABUTH), Zaria, Nigeria, spanning from December 2016 to January 2018. Cytopenias, including anemia, leucopenia, lymphocytopenia, and thrombocytopenia, were defined and assessed according to World Health Organization guidelines. A combination of cross-sectional and longitudinal mixed-design two-step analysis was employed to validate our findings.

RESULTS

The median time from enrollment to cART initiation was 7 days, following the universal test and treat protocol. The prevalence of cytopenia was 75% at the baseline before treatment and increased to 84% after cART24 administration. There were no statistically significant differences in the median values of immuno-hematological parameters between baseline and after cART24 initiation (P >0.05). In terms of longitudinal assessment, the prevalence of anemia, leucopenia, lymphopenia, and thrombocytopenia at baseline were 66%, 23%, 0%, and 11%, respectively, and after cART24, the rates were 66%, 29%, 5%, and 20%. Notably, the prevalence of cytopenia correlated with declining CD4+ T cell counts. Among instances of unicytopenia, 58% exhibited isolated anemia, 6% had lone leucopenia, and 6% had solitary thrombocytopenia. Additionally, 27% demonstrated bi-cytopenia, and 3% exhibited pancytopenia. Interestingly, none of the study participants presented with lymphopenia. The most common combination was anemia and thrombocytopenia. Both longitudinal and cross-sectional analytical findings were consistent.

CONCLUSION

In treatment-naive HIV-infected individuals, the prevalence of cytopenias, particularly anemia and thrombocytopenia, was substantial and correlated with the degree of immunosuppression as indicated by CD4+ T cell counts. These cytopenias persisted despite initiation of cART24, highlighting the complexity of hematological manifestations in HIV infection. Our study underscores the significant hematopathological impact of HIV and antiretroviral therapy, highlighting the necessity for preventive strategies to mitigate these adverse effects.

Platelet and HIV Interactions and Their Contribution to Non-AIDS Comorbidities

Platelets are anucleate cytoplasmic cell fragments that circulate in the blood, where they are involved in regulating hemostasis. Beyond their normal physiologic role, platelets have emerged as versatile effectors of immune response. During an infection, cell surface receptors enable platelets to recognize viruses, resulting in their activation. Activated platelets release biologically active molecules that further trigger host immune responses to protect the body against infection. Their impact on the immune response is also associated with the recruitment of circulating leukocytes to the site of infection. They can also aggregate with leukocytes, including lymphocytes, monocytes, and neutrophils, to immobilize pathogens and prevent viral dissemination. Despite their host protective role, platelets have also been shown to be associated with various pathophysiological processes. In this review, we will summarize platelet and HIV interactions during infection. We will also highlight and discuss platelet and platelet-derived mediators, how they interact with immune cells, and the multifaceted responsibilities of platelets in HIV infection. Furthermore, we will give an overview of non-AIDS comorbidities linked to platelet dysfunction and the impact of antiretroviral therapy on platelet function.

Current drugs for HIV-1: from challenges to potential in HIV/AIDS

The human immunodeficiency virus (HIV) persists in latently infected CD4+T cells and integrates with the host genome until cell death. Acquired immunodeficiency syndrome (AIDS) is associated with HIV-1. Possibly, treating HIV/AIDS is an essential but challenging clinical goal. This review provides a detailed account of the types and mechanisms of monotherapy and combination therapy against HIV-1 and describes nanoparticle and hydrogel delivery systems. In particular, the recently developed capsid inhibitor (Lenacapavir) and the Ainuovirine/tenofovir disoproxil fumarate/lamivudine combination (ACC008) are described. It is interestingly to note that the lack of the multipass transmembrane proteins serine incorporator 3 (SERINC3) and the multipass transmembrane proteins serine incorporator 5 (SERINC5) may be one of the reasons for the enhanced infectivity of HIV-1. This discovery of SERINC3 and SERINC5 provides new ideas for HIV-1 medication development. Therefore, we believe that in treating AIDS, antiviral medications should be rationally selected for pre-exposure and post-exposure prophylaxis to avoid the emergence of drug resistance. Attention should be paid to the research and development of new drugs to predict HIV mutations as accurately as possible and to develop immune antibodies to provide multiple guarantees for the cure of AIDS.

Severe anemia, severe leukopenia, and severe thrombocytopenia of amphotericin B deoxycholate-based induction therapy in patients with HIV-associated talaromycosis: a subgroup analysis of a prospective multicenter cohort study

BACKGROUND

This study's objective was to investigate the predictors for severe anemia, severe leukopenia, and severe thrombocytopenia when amphotericin B deoxycholate-based induction therapy is used in HIV-infected patients with talaromycosis.

METHODS

A total of 170 HIV-infected patients with talaromycosis were enrolled from January 1st, 2019, to September 30th, 2020.

RESULTS

Approximately 42.9%, 20.6%, and 10.6% of the enrolled patients developed severe anemia, severe leukopenia, and severe thrombocytopenia, respectively. Baseline hemoglobin level < 100 g/L (OR = 5.846, 95% CI: 2.765 ~ 12.363), serum creatinine level > 73.4 µmol/L (OR = 2.573, 95% CI: 1.157 ~ 5.723), AST/ALT ratio > 1.6 (OR = 2.479, 95% CI: 1.167 ~ 5.266), sodium level ≤ 136 mmol/liter (OR = 4.342, 95% CI: 1.747 ~ 10.789), and a dose of amphotericin B deoxycholate > 0.58 mg/kg/d (OR = 2.504, 95% CI:1.066 ~ 5.882) were observed to be independent risk factors associated with the development of severe anemia. Co-infection with tuberculosis (OR = 3.307, 95% CI: 1.050 ~ 10.420), and platelet level (per 10 × 109 /L) (OR = 0.952, 95% CI: 0.911 ~ 0.996) were shown to be independent risk factors associated with the development of severe leukopenia. Platelet level < 100 × 109 /L (OR = 2.935, 95% CI: 1.075 ~ 8.016) was identified as the independent risk factor associated with the development of severe thrombocytopenia. There was no difference in progression to severe anemia, severe leukopenia, and severe thrombocytopenia between the patients with or without fungal clearance at 2 weeks. 10 mg on the first day of amphotericin B deoxycholate was calculated to be independent risk factors associated with the development of severe anemia (OR = 2.621, 95% CI: 1.107 ~ 6.206). The group receiving a starting amphotericin B dose (10 mg, 20 mg, daily) exhibited the highest fungal clearance rate at 96.3%, which was significantly better than the group receiving a starting amphotericin B dose (5 mg, 10 mg, 20 mg, daily) (60.9%) and the group receiving a starting amphotericin B dose (5 mg, 15 mg, and 25 mg, daily) (62.9%).

CONCLUSION

The preceding findings reveal risk factors for severe anemia, severe leukopenia, and severe thrombocytopenia. After treatment with Amphotericin B, these severe adverse events are likely unrelated to fungal clearance at 2 weeks. Starting amphotericin B deoxycholate at a dose of 10 mg on the first day may increase the risk of severe anemia but can lead to earlier fungal clearance.

TRIAL REGISTRATION

ChiCTR1900021195. Registered 1 February 2019.

HIV-Related Atherosclerosis: State-of-the-Art-Review

The infection caused by the Human Immunodeficiency Virus (HIV) has spread rapidly across the globe, assuming the characteristics of an epidemic in some regions. Thanks to the introduction of antiretroviral therapy into routine clinical practice, there was a considerable breakthrough in the treatment of HIV, that is now HIV is potentially well-controlled even in low-income countries. To date, HIV infection has moved from the group of life-threatening conditions to the group of chronic and well controlled ones and the quality of life and life expectancy of HIV+ people, with an undetectable viral load is closer to that of an HIV- people. However, unsolved issues still persist. For example: people living with HIV are more prone to the age-related diseases, especially atherosclerosis. For this reason, a better understanding of the mechanisms of HIV-associated destabilization of vascular homeostasis seems to be an urgent duty, that may lead to the development of new protocols, bringing the possibilities of pathogenetic therapies to a new level. The purpose of the article was to evaluate the pathological aspects of HIV-induced atherosclerosis.

Effect of TB Treatment on Neutrophil-Derived Soluble Inflammatory Mediators in TB Patients with and without HIV Coinfection

The mycobacteriological analysis of sputum samples is the gold standard for tuberculosis diagnosis and treatment monitoring. However, sputum production can be challenging after the initiation of TB treatment. As a possible alternative, we therefore investigated the dynamics of neutrophil-derived soluble inflammatory mediators during TB treatment in relation to HIV ART status and the severity of lung impairment. Plasma samples of TB patients with (N = 47) and without HIV (N = 21) were analyzed at baseline, month 2, month 6 (end of TB treatment) and month 12. Plasma levels of MMP-1, MMP-8, MPO and S100A8 markedly decreased over the course of TB treatment and remained at similar levels thereafter. Post-TB treatment initiation, significantly elevated plasma levels of MMP-8 were detected in TB patients living with HIV, especially if they were not receiving ART treatment at baseline. Our data confirm that the plasma levels of neutrophil-based biomarkers can be used as candidate surrogate markers for TB treatment outcome and HIV-infection influenced MMP-8 and S100A8 levels. Future studies to validate our results and to understand the dynamics of neutrophils-based biomarkers post-TB treatment are needed.

COVID-19 outcomes in people living with HIV: Peering through the waves

OBJECTIVE

To evaluate clinical characteristics and outcomes of COVID-19 patients infected with HIV, and to compare with a paired sample without HIV infection.

METHODS

This is a substudy of a Brazilian multicentric cohort that comprised two periods (2020 and 2021). Data was obtained through the retrospective review of medical records. Primary outcomes were admission to the intensive care unit, invasive mechanical ventilation, and death. Patients with HIV and controls were matched for age, sex, number of comorbidities, and hospital of origin using the technique of propensity score matching (up to 4:1). They were compared using the Chi-Square or Fisher's Exact tests for categorical variables and the Wilcoxon for numerical variables.

RESULTS

Throughout the study, 17,101 COVID-19 patients were hospitalized, and 130 (0.76%) of those were infected with HIV. The median age was 54 (IQR: 43.0;64.0) years in 2020 and 53 (IQR: 46.0;63.5) years in 2021, with a predominance of females in both periods. People Living with HIV (PLHIV) and their controls showed similar prevalence for admission to the ICU and invasive mechanical ventilation requirement in the two periods, with no significant differences. In 2020, in-hospital mortality was higher in the PLHIV compared to the controls (27.9% vs. 17.7%; p = 0.049), but there was no difference in mortality between groups in 2021 (25.0% vs. 25.1%; p > 0.999).

CONCLUSIONS

Our results reiterate that PLHIV were at higher risk of COVID-19 mortality in the early stages of the pandemic, however, this finding did not sustain in 2021, when the mortality rate is similar to the control group.

Association of Antiretroviral Therapy with Platelet Function and Systemic Inflammatory Response in People Living with HIV: A Cross-Sectional Study

People living with HIV (PLWHIV) present an increased risk of adverse cardiovascular events. We aimed to assess whether antiretroviral therapy (ART) pharmacologically enhances platelet reactivity and platelet activation intensity, and explore the potential association with underlying inflammatory status. This was a cross-sectional cohort study carried out among PLWHIV on diverse ART regimens. Platelet reactivity and activation intensity were assessed using the bedside point-of-care VerifyNow assay, in P2Y12 reaction units (PRU), measurements of monocyte-platelet complexes, and P-selectin and GPIIb/IIIa expression increase, following activation with ADP, respectively. Levels of major inflammatory markers and whole blood parameters were also evaluated. In total, 71 PLWHIV, 59 on ART and 22 healthy controls, were included in this study. PRU values were significantly elevated in PLWHIV compared to controls [Mean; 257.85 vs. 196.67, p < 0.0001], but no significant differences were noted between ART-naïve or ART-experienced PLWHIV, or between TAF/TDF and ABC based regimens, similar to systemic inflammatory response. However, within-group analysis showed that PRUs were significantly higher in ABC/PI vs ABC/INSTI or TAF/TDF + PI patients, in line with levels of IL-2. PRU values did not correlate strongly with CD4 counts, viral load, or cytokine values. P-selectin and GPIIb/IIIa expression increased following ADP activation and were significantly more prominent in PLWHIV (p < 0.005). Platelet reactivity and platelet activation intensity were shown to be increased in PLWHIV, but they did not appear to be related to ART initiation, similar to the underlying systemic inflammatory response.

Neutrophils in Mycobacterium tuberculosis

Mycobacterium tuberculosis (M. tb) continues to be a leading cause of mortality within developing countries. The BCG vaccine to promote immunity against M. tb is widely used in developing countries and only in specific circumstances within the United States. However, current the literature reports equivocal data on the efficacy of the BCG vaccine. Critical within their role in the innate immune response, neutrophils serve as one of the first responders to infectious pathogens such as M. tb. Neutrophils promote effective clearance of M. tb through processes such as phagocytosis and the secretion of destructive granules. During the adaptative immune response, neutrophils modulate communication with lymphocytes to promote a strong pro-inflammatory response and to mediate the containment M. tb through the production of granulomas. In this review, we aim to highlight and summarize the role of neutrophils during an M. tb infection. Furthermore, the authors emphasize the need for more studies to be conducted on effective vaccination against M. tb.

Immune and Metabolic Alterations in Children with Perinatal HIV Exposure

With the global rollout of mother-to-child prevention programs for women living with HIV, vertical transmission has been all but eliminated in many countries. However, the number of children who are exposed in utero to HIV and antiretroviral therapy (ART) is ever-increasing. These children who are HIV-exposed-but-uninfected (CHEU) are now well recognized as having persistent health disparities compared to children who are HIV-unexposed-and-uninfected (CHUU). Differences reported between these two groups include immune dysfunction and higher levels of inflammation, cognitive and metabolic abnormalities, as well as increased morbidity and mortality in CHEU. The reasons for these disparities remain largely unknown. The present review focuses on a proposed link between immunometabolic aberrations and clinical pathologies observed in the rapidly expanding CHEU population. By drawing attention, firstly, to the significance of the immune and metabolic alterations observed in these children, and secondly, the impact of their healthcare requirements, particularly in low- and middle-income countries, this review aims to sensitize healthcare workers and policymakers about the long-term risks of in utero exposure to HIV and ART.

Pro-Inflammatory Interactions of Dolutegravir with Human Neutrophils in an In Vitro Study

There is increasing awareness of an association between the uptake of the HIV integrase inhibitor, dolutegravir, in first-line antiretroviral regimens with unusual weight gain and development of the metabolic syndrome, particularly in African women. Although seemingly unexplored, the development of systemic inflammation linked to the putative pro-inflammatory activity of dolutegravir represents a plausible pathophysiological mechanism of this unusual weight gain. This possibility was explored in the current study undertaken to investigate the effects of dolutegravir (2.5−20 μg/mL) on several pro-inflammatory activities of neutrophils isolated from the blood of healthy, adult humans. These activities included the generation of reactive oxygen species (ROS), degranulation (elastase release) and alterations in the concentrations of cytosolic Ca2+ using chemiluminescence, spectrophotometric and fluorimetric procedures, respectively. Exposure of neutrophils to dolutegravir alone resulted in the abrupt, dose-related, and significant (p < 0.0039−p < 0.0022) generation of ROS that was attenuated by the inclusion of the Ca2+-chelating agent, EGTA, or inhibitors of NADPH oxidase (diphenyleneiodonium chloride, DPI), phospholipase C (U733122), myeloperoxidase (sodium azide) and phosphoinositol-3-kinase (wortmannin). In addition, exposure to dolutegravir augmented the release of elastase by stimulus-activated neutrophils. These pro-inflammatory effects of dolutegravir on neutrophils were associated with significant, rapid, and sustained increases in the concentrations of cytosolic Ca2+ that appeared to originate from the extracellular compartment, seemingly consistent with an ionophore-like property of dolutegravir. These findings are preliminary and necessitate verification in the clinical setting of HIV infection. Nevertheless, given the complex link between inflammation and obesity, these pro-inflammatory interactions of dolutegravir with neutrophils may contribute to unexplained weight gain, possibly via the development of insulin resistance.

Dolutegravir potentiates platelet activation by a calcium-dependent, ionophore-like mechanism

Dolutegravir is a highly potent HIV integrase strand transfer inhibitor that is recommended for first-line anti-retroviral treatment in all major treatment guidelines. A recent study has shown that people taking this class of anti-retroviral treatment have a substantially higher risk of early-onset cardiovascular disease, a condition shown previously to be associated with increased platelet reactivity. To date, few studies have explored the effects of dolutegravir on platelet activation. Accordingly, the current study was undertaken with the primary objective of investigating the effects of dolutegravir on the reactivity of human platelets in vitro. Platelet-rich plasma, isolated platelets, or buffy coat cell suspensions prepared from the blood of healthy adults were treated with dolutegravir (2.5-10 µg/ml), followed by activation with adenosine 5'-diphosphate (ADP), thrombin, or a thromboxane A₂ receptor agonist U46619. Expression of platelet CD62P (P-selectin), formation of heterotypic neutrophil:platelet aggregates, and calcium (Ca²⁺) fluxes were measured using flow cytometry and fluorescence spectrometry, respectively. Dolutegravir caused dose-related potentiation of ADP-, thrombin- and U46619-activated expression of CD62P by platelets, as well as a significant increases in formation of neutrophil:platelet aggregates. These effects were paralleled by a spontaneous, receptor-independent elevation in cytosolic Ca²⁺ that appears to underpin the mechanism by which the antiretroviral agent augments the responsiveness of these cells to ADP, thrombin and U46619. The most likely mechanism of dolutegravir-mediated increases in platelet cytosolic Ca²⁺ relates to a combination of lipophilicity and divalent/trivalent metal-binding and/or chelating properties of the anti-retroviral agent. These properties are likely to confer ionophore-type activities on dolutegravir that would promote movement of Ca²⁺ across the plasma membrane, delivering the cation to the cytosol where it would augment Ca²⁺-dependent intracellular signaling mechanisms. These effects of dolutegravir may lead to hyper-activation of platelets which, if operative in vivo, may contribute to an increased risk for cardiometabolic co-morbidities.

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.

Effect of Single Housing on Innate Immune Activation in Immunodeficiency Virus-Infected Pigtail Macaques ( Macaca nemestrina ) as a Model of Psychosocial Stress in Acute HIV Infection

OBJECTIVE

Simian immunodeficiency virus (SIV) infection of macaques recapitulates many aspects of HIV pathogenesis and is similarly affected by both genetic and environmental factors. Psychosocial stress is associated with immune system dysregulation and worse clinical outcomes in people with HIV. This study assessed the impact of single housing, as a model of psychosocial stress, on innate immune responses of pigtailed macaques ( Macaca nemestrina ) during acute SIV infection.

METHODS

A retrospective analysis of acute SIV infection of 2- to si6-year-old male pigtailed macaques was performed to compare the innate immune responses of socially ( n = 41) and singly ( n = 35) housed animals. Measures included absolute monocyte count and subsets, and in a subset ( n ≤ 18) platelet counts and activation data.

RESULTS

SIV infection resulted in the expected innate immune parameter changes with a modulating effect from housing condition. Monocyte number increased after infection for both groups, driven by classical monocytes (CD14 + CD16 - ), with a greater increase in socially housed animals (227%, p < .001, by day 14 compared with preinoculation time points). Platelet numbers recovered more quickly in the socially housed animals. Platelet activation (P-selectin) increased by 65% ( p = .004) and major histocompatibility complex class I surface expression by 40% ( p = .009) from preinoculation only in socially housed animals, whereas no change in these measures occurred in singly housed animals.

CONCLUSIONS

Chronic psychosocial stress produced by single housing may play an immunomodulatory role in the innate immune response to acute retroviral infection. Dysregulated innate immunity could be one of the pathways by which psychosocial stress contributes to immune suppression and increased disease severity in people with HIV.

Changes in Coagulation and Platelet Reactivity in People with HIV-1 Switching Between Abacavir and Tenofovir

Background:

Several studies have shown an association between abacavir (ABC) and increased risk of myocardial infarction (MI), but the causative mechanism has not been established. Both vascular endothelial inflammation and platelet activation have been proposed as contributing factors.

Objective:

The study aims to investigate the effects of ABC relative to tenofovir disoproxil (TDF) on functional assays of primary and secondary hemostasis and a comprehensible range of relevant biomarkers.

Methods:

In an investigator-initiated, open-labeled, crossover trial, we included HIV-infected males receiving either ABC or TDF and switched treatment to the alternate drug. At inclusion and after three months on the new regimen, we performed Multiplate® and thromboelastography (TEG®) and measured biomarkers of coagulation, inflammation, platelet reactivity, endothelial disruption and activation, and fibrinolysis, lipids, HIV RNA, CD4, CD8, and creatinine. Treatment effects were assessed by comparing intraindividual differences between the two treatment orders by the Wilcoxon Rank Sum test.

Results:

In total, 43 individuals completed the study. No intraindividual differences were observed for Multiplate® or TEG® when switching between regimens. We observed a significant treatment effect on coagulation factors II-VII-X (p<0.0001), sCD40L (a biomarker of platelet reactivity, p=0.04), thrombomodulin (biomarker of endothelial damage, p=0.04), lipids, and CD8 cell counts (p=0.04), with higher values during ABC treatment compared to TDF.

Conclusion:

Compared to TDF, ABC treatment affected several outcome measures in a pro-coagulant direction. Suggesting that the risk of MI associated with ABC may be caused by the sum of multiple, discrete disturbances in the hemostatic system and endothelium.

Study Registration:

The trial was registered at clinicaltrials.gov (NCT02093585).

Increased platelet activation and platelet-inflammasome engagement during chikungunya infection

Chikungunya fever is a viral disease transmitted by mosquitoes of the genus Aedes. The infection is usually symptomatic and most common symptoms are fever accompanied by joint pain and swelling. In most cases symptoms subside within a week. However, severe prolonged and disabling joint pain, that may persist for several months, even years, are reported. Although the pathogenesis of Chikungunya infection is not fully understood, the evolution to severe disease seems to be associated with the activation of immune mechanisms and the action of inflammatory mediators. Platelets are recognized as inflammatory cells with fundamental activities in the immune response, maintenance of vascular stability and pathogenicity of several inflammatory and infectious diseases. Although the involvement of platelets in the pathogenesis of viral diseases has gained attention in recent years, their activation in Chikungunya has not been explored. The aim of this study was to analyze platelet activation and the possible role of platelets in the amplification of the inflammatory response during Chikungunya infection. We prospectively included 132 patients attended at the Quinta D’Or hospital and 25 healthy volunteers during the 2016 epidemic in Rio de Janeiro, Brazil. We observed increased expression of CD62P on the surface of platelets, as well as increased plasma levels of CD62P and platelet-derived inflammatory mediators indicating that the Chikungunya infection leads to platelet activation. In addition, platelets from chikungunya patients exhibit increased expression of NLRP3, caspase 4, and cleaved IL-1β, suggestive of platelet-inflammasome engagement during chikungunya infection. In vitro experiments confirmed that the Chikungunya virus directly activates platelets. Moreover, we observed that platelet activation and soluble p-selectin at the onset of symptoms were associated with development of chronic forms of the disease. Collectively, our data suggest platelet involvement in the immune processes and inflammatory amplification triggered by the infection.

Following successful anti-leishmanial treatment, neutrophil counts, CD10 expression and phagocytic capacity remain reduced in visceral leishmaniasis patients co-infected with HIV

Visceral leishmaniasis (VL) patients co-infected with HIV (VL/HIV patients) experience frequent treatment failures, VL relapses, opportunistic infections, and higher mortality. Their immune system remains profoundly suppressed after clinical cure and they maintain higher parasite load. This is in contrast with patients with VL alone (VL patients). Since neutrophils play a critical role in the control of Leishmania replication and the regulation of immune responses, we tested the hypothesis that neutrophil activation status and effector functions are fully restored in VL, but not in VL/HIV patients. Our results show the neutrophil counts and all activation markers and effector functions tested in our study were reduced at the time of diagnosis in VL and VL/HIV patients as compared to controls. CD62L, CD63, arginase 1 expression levels and reactive oxygen species production were restored at the end of treatment in both groups. However, neutrophil counts, CD10 expression and phagocytosis remained significantly lower throughout follow-up in VL/HIV patients; suggesting that dysregulated neutrophils contribute to the impaired host defence against pathogens in VL/HIV patients.

Integrase inhibitor-based regimens are related to favorable systemic inflammatory index and platecrit scores in people living with HIV (PLWH) up to 2 years

OBJECTIVES

Despite the advances in antiretroviral treatment (ART), persistent inflammation remained a challenge. We analyzed the inflammatory-score changes through 2-years in people living with HIV (PLWH) treated with different antiretroviral regimes.

METHODS

This study was conducted in Hacettepe University HIV/AIDS Treatment and Research Center. PLWH diagnosed between 2014 and 2020 were included. Inflammatory and metabolic markers (CD4/CD8 ratio, C-reactive protein (CRP), Systemic Inflammatory Index (SII), Neutrophil-Lymphocyte Ratio (NLR), Mean Platelet Volume (MPV), Platecrite (PCT), and Low-Density Lipoprotein/High-Density Lipoprotein (LDL/HDL), Platelet-to-Lymphocyte Ratio (PLR) and ARTs were captured from database through 2-years from the diagnosis. The 2-year change (Δ) in markers was calculated and compared by ART type (backbone and 3rd agent). Mann-Whitney-U test and T-test were used for statistical analysis.

RESULTS

This study included 205 PLWH; 175 (85.4%) were male, and the mean age was 38.98 (±10.88) years. The number of PLWH with suppressed viremia (<40 HIV-RNA copies/ml) was 164 (80%) at the end of the second year. MPV increased significantly higher among PLWH receiving ABC/3TC compared to PLWH receiving TDF/FTC (p < 0.05). The CD4:CD8 ratio increased, and SII, NLR, LDL/HDL ratios decreased significantly among PLWH treated with integrase strand transfer inhibitors (INSTI) compared with protease inhibitors (PI) and Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) (p < 0.05).

CONCLUSIONS

Integrase inhibitor treatment is related to favorable inflammatory marker profile among PLWH in the 2-year follow-up. A favorable inflammatory profile may, in turn, contribute to the prevention of non-communicable diseases (NCD) among PLWH. This study showed that simple, easy-to-calculate markers could be implemented to define ongoing inflammation among PLWH under suppressive ART.

Inflammation-mediated vitamin K and vitamin D effects on vascular calcifications in people with HIV on active antiretroviral therapy

BACKGROUND

People with HIV (PWH) experience increased systemic inflammation and monocyte activation, leading to increased risk of cardiovascular events (death, stroke, and myocardial infarction) and higher coronary artery calcium scores (CACs). Vitamins D and K2 have significant anti-inflammatory effects; in addition, vitamin K2 is involved in preventing vascular calcifications in the general population. The roles of vitamins D and K in increased coronary calcifications in successfully treated PWH is less understood.

METHODS

We prospectively recruited 237 PWH on antiretroviral treatment (ART) and 67 healthy controls. CACs were derived from noncontrast chest computed tomography (CT) and levels of 25-hydroxyvitamin D (vitamin D) and inactive vitamin K-dependent dephosphorylated-uncarboxylated matrix Gla protein (dp-uc MGP, marker of vitamin K deficiency) were measured in plasma during a fasting state. The relationship between inflammation markers, dp-uc MGP, and vitamin D on CACs were estimated using zero-inflated negative binomial regression. Adjusted models included 25(OH)D, MGP, sex, race, age, and markers of inflammation or monocyte activation.

RESULTS

Overall, controls had lower median age (45.8 vs. 48.8; P = 0.03), a larger proportion of female individuals (55.2 vs. 23.6%; P < 0.0001), and nonwhite (33.8 vs. 70%; P < 0.0001). Among PWH, less than 1% had detectable viral load and the median CD4+ cell count was 682 (IQR: 473.00-899.00). 62.17% of the participants had zero CACs and 51.32% were vitamin D-deficient (<20 ng/ml). There was no difference in detectable CACs (P = 0.19) or dp-uc MGP (P = 0.42) between PWH and controls. In adjusted models, PWH with nonzero CACs have three times greater expected CAC burden compared with controls. Every 1% increase in MGP (worse K status) decreases the probability of having CACs equal to zero by 21.33% (P = 0.01). Evidence suggests that the effects of 25(OH)D and MGP are inflammation-mediated, specifically through sVCAM, TNF-αRI, and TNF-αRII.

CONCLUSION

Vitamin K deficiency is a modifiable preventive factor against coronary calcification in PWH. Further research should determine whether vitamin K supplementation would reduce systemic inflammation, vascular calcification, and risk of cardiovascular events in PWH.

Platelets as Key Factors in Inflammation: Focus on CD40L/CD40

Platelets are anucleate cytoplasmic fragments derived from the fragmentation of medullary megakaryocytes. Activated platelets adhere to the damaged endothelium by means of glycoproteins on their surface, forming the platelet plug. Activated platelets can also secrete the contents of their granules, notably the growth factors contained in the α-granules, which are involved in platelet aggregation and maintain endothelial activation, but also contribute to vascular repair and angiogenesis. Platelets also have a major inflammatory and immune function in antibacterial defence, essentially through their Toll-like Receptors (TLRs) and Sialic acid-binding immunoglobulin-type lectin (SIGLEC). Platelet activation also contributes to the extensive release of anti- or pro-inflammatory mediators such as IL-1β, RANTES (Regulated on Activation, Normal T Expressed and Secreted) or CD154, also known as the CD40-ligand. Platelets are involved in the direct activation of immune cells, polynuclear neutrophils (PNNs) and dendritic cells via the CD40L/CD40 complex. As a general rule, all of the studies presented in this review show that platelets are capable of covering most of the stages of inflammation, primarily through the CD40L/CD40 interaction, thus confirming their own role in this pathophysiological condition.

Two-Drug Regimens for HIV-Current Evidence, Research Gaps and Future Challenges

During the last 30 years, antiretroviral treatment (ART) for human immunodeficiency virus (HIV) infection has been continuously evolving. Since 1996, three-drug regimens (3DR) have been standard-of-care for HIV treatment and are based on a protease inhibitor (PI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI) plus two nucleoside reverse transcriptase inhibitors (NRTIs). The effectiveness of first-generation 3DRs allowed a dramatic increase in the life expectancy of HIV-infected patients, although it was associated with several side effects and ART-related toxicities. The development of novel two-drug regimens (2DRs) started in the mid-2000s in order to minimize side effects, reduce drug-drug interactions and improve treatment compliance. Several clinical trials compared 2DRs and 3DRs in treatment-naïve and treatment-experienced patients and showed the non-inferiority of 2DRs in terms of efficacy, which led to 2DRs being used as first-line treatment in several clinical scenarios, according to HIV clinical guidelines. In this review, we summarize the current evidence, research gaps and future prospects of 2DRs.

Airway hyperresponsiveness and inflammation in Japanese patients with human immunodeficiency virus 1 infection

INTRODUCTION

Despite the growing population of long-term survivors with human immunodeficiency virus 1 (HIV) exhibiting asthma-like features worldwide, the pathogenesis underlying airway hyperresponsiveness (AHR) and airway inflammation remains unclear. We aimed to investigate AHR and airway inflammation in an HIV-infected Japanese population.

METHODS

Of 94 Japanese participants, 10 HIV-infected participants with asthma were excluded from the study. We compared the characteristics of HIV-infected (n = 34) and non-HIV-infected participants (n = 50). Eosinophilic, neutrophilic, mixed (eosinophilic and neutrophilic), and paucigranulocytic airway inflammatory phenotypes were classified based on induced sputum characteristics.

RESULTS

The prevalence of AHR in HIV-infected participants (32.4%) was significantly higher than that in their non-HIV-infected counterparts (10.0%) (P = 0.0213). The multivariate nominal logistic regression analysis revealed HIV as an independent risk factor for AHR. HIV-infected participants were significantly more likely to have a neutrophilic airway inflammatory phenotype than non-HIV-infected participants (P = 0.0358). Furthermore, HIV-infected participants with AHR demonstrated a significant correlation between AHR levels and the percentage of sputum neutrophils (r = -0.65, P = 0.0316). The percentage of sputum neutrophils was negatively associated with the blood CD4 cell count (r = -0.66, P = 0.0266).

CONCLUSIONS

We observed the high prevalence of AHR and neutrophilic airway inflammatory phenotype in Japanese participants with stable HIV infection. Our findings provide insight into the mechanisms of AHR and may facilitate the development of novel treatment for individuals with AHR and HIV infection.