Interleukin-6 is associated with mortality and neuropsychiatric outcomes in antiretroviral-naïve adults in Rakai, Uganda

Markers of Inflammation, Tissue Damage, and Fibrosis in Individuals Diagnosed with Human Immunodeficiency Virus and Pneumonia: A Cohort Study

Previous studies have noted that persons living with human immunodeficiency virus (HIV) experience persistent lung dysfunction after an episode of community-acquired pneumonia (CAP), although the underlying mechanisms remain unclear. We hypothesized that inflammation during pneumonia triggers increased tissue damage and accelerated pulmonary fibrosis, resulting in a gradual loss of lung function. We carried out a prospective cohort study of people diagnosed with CAP and/or HIV between 2016 and 2018 in three clinical institutions in Medellín, Colombia. Clinical data, blood samples, and pulmonary function tests (PFTs) were collected at baseline. Forty-one patients were included, divided into two groups: HIV and CAP (n = 17) and HIV alone (n = 24). We compared the concentrations of 17 molecules and PFT values between the groups. Patients with HIV and pneumonia presented elevated levels of cytokines and chemokines (IL-6, IL-8, IL-18, IL-1RA, IL-10, IP-10, MCP-1, and MIP-1β) compared to those with only HIV. A marked pulmonary dysfunction was evidenced by significant reductions in FEF25, FEF25-75, and FEV1. The correlation between these immune mediators and lung function parameters supports the connection between pneumonia-associated inflammation and end organ lung dysfunction. A low CD4 cell count (<200 cells/μL) predicted inflammation and lung dysfunction. These results underscore the need for targeted clinical approaches to mitigate the adverse impacts of CAP on lung function in this population.

Bidirectional Relationship between HIV/HBV Infection and Comorbid Depression and/or Anxiety: A Systematic Review on Shared Biological Mechanisms

BACKGROUND

Mental disorders that are comorbid with chronic infectious diseases may worsen clinical outcomes and patients' quality of life. We hypothesized that depression and/or anxiety syndromes or symptoms comorbid with human immunodeficiency virus (HIV) or hepatitis B virus (HBV) infection might stem from shared biological mechanisms.

METHODS

We conducted a systematic review applying the PRISMA statement by searching into the PubMed, APA PsycInfo, and Scopus databases. We examined the literature on HIV/HBV infection comorbid with depression and/or anxiety in adults ≥18 years.

RESULTS

Thirty-one studies on HIV and three on HBV were analyzed. The Tat protein contributed to HIV-associated mood disorders due to the protein's ability to cause neurodegeneration and induce hypothalamic-pituitary-adrenal (HPA) axis dysregulation in response to natural stressors. The decreased brain-derived neurotrophic factor (BDNF) levels also emerged as a mechanism involved in HIV neuropathogenesis and the associated mood symptoms. Neuroinflammation was implicated in depression and/or anxiety onset in patients with HIV/HBV infections. Microglial activation and release of cytokines, in particular, appeared as potential pathogenetic mechanisms. Furthermore, an altered balance between quinolinic acid and kynurenic acid production emerged in HIV patients with comorbid depression, indicating a glutamatergic dysfunction. Inflammatory cytokine production and the downregulation of cellular immune responses contributed to persisting inflammation, delayed healing, and functional decline in patients with chronic hepatitis B (CHB) infection. A shift in type 1-type 2 cytokine balance might be implicated in HBV-related immune pathogenesis, and depression and anxiety might be considered immunomodulatory factors. Cytokines also caused HPA axis hyperactivity, frequently observed in HIV/HBV patients with comorbid depression/anxiety.

CONCLUSIONS

The present systematic review showed, for the first time, that HIV/HBV and depression and/or anxiety might have several biological mechanisms as common denominators. The longitudinal course of the highlighted biological mechanisms should be explored to establish the causative interrelationship among the involved mechanisms. In addition, future research should investigate the possibility that a patient's clinical outcome might improve using pharmacological treatments acting on the biological mechanisms we described as common denominators of chronic inflammatory infective diseases and depression/anxiety.

Depression and HIV: a scoping review in search of neuroimmune biomarkers

People with HIV are at increased risk for depression, though the neurobiological mechanisms underlying this are unclear. In the last decade, there has been a substantial rise in interest in the contribution of (neuro)inflammation to depression, coupled with rapid advancements in the resolution and sensitivity of biomarker assays such as Luminex, single molecular array and newly developed positron emission tomography radioligands. Numerous pre-clinical and clinical studies have recently leveraged these next-generation immunoassays to identify biomarkers that may be associated with HIV and depression (separately), though few studies have explored these biomarkers in co-occurring HIV and depression. Using a systematic search, we detected 33 publications involving a cumulative N = 10 590 participants which tested for associations between depressive symptoms and 55 biomarkers of inflammation and related processes in participants living with HIV. Formal meta-analyses were not possible as statistical reporting in the field was highly variable; future studies must fully report test statistics and effect size estimates. The majority of included studies were carried out in the United States, with samples that were primarily older and primarily men. Substantial further work is necessary to diversify the geographical, age, and sex distribution of samples in the field. This review finds that alterations in concentrations of certain biomarkers of neuroinflammation (interleukin-6, tumour necrosis factor-α, neopterin) may influence the association between HIV and depression. Equally, the chemokines monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) or the metabolic index kynurenine:tryptophan (Kyn:Trp), which have been the focus of several studies, do not appear to be associated with depressive symptoms amongst people living with HIV, as all (MCP-1) or most (IL-8 and Kyn:Trp) available studies of these biomarkers reported non-significant associations. We propose a biomarker-driven hypothesis of the neuroimmunometabolic mechanisms that may precipitate the increased risk of depression among people with HIV. Chronically activated microglia, which trigger key neuroinflammatory cascades shown to be upregulated in people with HIV, may be the central link connecting HIV infection in the central nervous system with depressive symptoms. Findings from this review may inform research design in future studies of HIV-associated depression and enable concerted efforts towards biomarker discovery.

Sex-specific associations between plasma interleukin-6 and depression in persons with and without HIV

Background

Persons with HIV (PWH) have both more frequent depression and higher levels of plasma inflammatory biomarkers compared to persons without HIV (PWoH). Inflammation and depressive symptoms are linked, including in PWH; however, it is unclear whether these associations differ by HIV serostatus and biological sex.

Methods

Six plasma inflammatory biomarkers were assessed using samples from PWH and PWoH who participated in six NIH-funded studies through the UCSD HIV Neurobehavioral Research Program (HNRP) from 2011 to 2019. Factor analysis was performed to identify intercorrelated groups of biomarkers. Factors and their components were then examined for relationships with Beck Depression Inventory-II (BDI-II) and modifying effects of sex or HIV serostatus using multivariable linear regression, adjusting for demographics, substance use diagnoses, and relevant co-morbidities.

Results

Participants included 150 PWH (age = 48.3 ± 13.1 yr; 88% biologically male) and 138 PWoH (age = 46.3 ± 15.9; 56% male). Two inflammatory factors were identified: Factor 1 loaded on interleukin-6 (IL-6), C-reactive protein (CRP), and D-dimer; Factor 2 loaded on interleukin-8, chemokine C-C ligand 2 (CCL2), and chemokine C-X-C ligand 10 (CXCL10). Sex modified the effect of Factor 1 on BDI-II, with a more positive association for men than women (p = 0.04). No significant association between Factor 2 and BDI-II was found. Of the biomarkers in Factor 1, only IL-6 was significantly associated with BDI-II and was modified by sex (p = 0.003). In sex-stratified analysis, a positive association was found for men (β = 5.42; 95% confidence interval = [1.32, 9.52]) but not women (β = -3.88; 95% C.I. = [-11.02, 3.26]). No HIV-related interactions were detected.

Interpretation

We identified a depression-associated inflammatory factor present in both PWH and PWoH, consistent with prior studies of PWH only. The association was driven by a correlation between IL-6 and depression exclusively in men, suggesting that the depression-inflammation link differs by sex. Future studies of depression etiology or treatment, including those on persons with HIV, should consider the impact of biological sex in both design and analysis.

Examining Depression as a Risk Factor for Cardiovascular Disease in People with HIV: A Systematic Review

BACKGROUND

People with human immunodeficiency virus (HIV) have an increased risk of cardiovascular disease (CVD) not fully accounted for by traditional or HIV-specific risk factors. Successful management of HIV does not eliminate this excess risk. Thus, there is a need to identify novel risk factors for CVD among people with HIV (PWH).

PURPOSE

Our objective was to systematically review the literature on one such candidate CVD risk factor in PWH-depression.

METHODS

A systematic literature search of PubMed, PsycINFO, EMBASE, Web of Science, and CINAHL was performed to identify published English-language studies examining associations of depression with clinical CVD, subclinical CVD, and biological mechanisms (immune activation, systemic inflammation, altered coagulation) among PWH between the earliest date and June 22, 2021.

RESULTS

Thirty-five articles were included. For clinical CVD (k = 8), findings suggests that depression is consistently associated with an increased risk of incident CVD. For subclinical CVD (k = 5), one longitudinal analysis reported a positive association, and four cross-sectional analyses reported null associations. For immune activation (k = 13), systemic inflammation (k = 17), and altered coagulation (k = 5), findings were mixed, and there was considerable heterogeneity in sample characteristics and methodological quality across studies.

CONCLUSIONS

Depression may be an independent risk factor for CVD among PWH. Additional research is needed to confirm depression's association with clinical CVD and to determine whether depression is consistently and meaningfully associated with subclinical CVD and biological mechanisms of CVD in HIV. We propose a research agenda for this emerging area.

Neurocognitive outcomes of tuberculous meningitis in a primarily HIV-positive Ugandan cohort

Background: The toll of tuberculous meningitis (TBM) in both mortality and disability is considerable, but advancements in rehabilitation have the potential to improve the functional abilities and the quality of survivors' lives. However, the typical phenotype of neurocognitive impairment in TBM survivors remains unstudied in HIV-predominant populations in sub-Saharan Africa. Methods: We tested 36 survivors of TBM in Uganda with a comprehensive battery of neurocognitive assessments at 8 and 24 weeks after diagnosis, and compared results to a representative cohort of HIV-uninfected Ugandans. Results: While participants had a broad range of impairments at eight weeks, there was marked improvement by 24 weeks, when a phenotype of impairment including deficits in motor functioning, verbal learning and memory, processing speed, and executive function emerged. These deficits were present despite good clinician-rated functional status. The majority (23/27, 85%) had evidence of moderate to severe depression at week 8, and at week 24 (18/24, 75%). Conclusion: These findings highlight the need for more comprehensive neurocognitive assessment in the survivors of TBM, and further investment in and study of rehabilitation, including management of depression, to improve long-term outcomes in this population.

Evaluating the Relationship Between Depression and Cognitive Function Among Children and Adolescents with HIV in Zambia

Depression is common among people living with HIV. Multiple studies demonstrate a link between depression and cognitive dysfunction in adults with HIV, but the association has been minimally investigated in children and adolescents with HIV in Africa. We conducted a cross-sectional analysis as part of the HIV-associated Neurocognitive Disorders in Zambia study, a prospective cohort study in Lusaka, Zambia. We included 208 perinatally-infected children with HIV ages 8-17 taking antiretroviral therapy and 208 HIV-exposed uninfected (HEU) controls. Cognition was assessed with a comprehensive neuropsychological battery. Depressive symptoms were evaluated using self-report and parent-report versions of the NIH Toolbox Sadness module and the Patient Health Questionnaire-9 (PHQ-9). Risk factors for depression and associations between depressive symptoms and cognition were evaluated in bivariable and multivariable regression models. Participants with HIV demonstrated higher levels of depressive symptoms than controls (mean NIH Toolbox Sadness T-Score 50 vs. 44, p < 0.01; mean PHQ-9 score 2.0 vs. 1.5, p = 0.03), and were more likely to have cognitive impairment (30% vs. 13%, p < 0.001). Risk factors for depressed mood included self-reported poor health (OR 7.8, p < 0.001) and negative life events (OR 1.3, p = 0.004) Depressed mood was associated with cognitive impairment in participants with HIV (OR = 2.9, 95% CI 1.2-7.2, p = 0.02) but not in HEU participants (OR 1.7, 95% CI 0.18-15.7, p = 0.6). In conclusion, depressed mood is common among youth with HIV in Zambia, and is associated with cognitive impairment. Depression may be a result of HIV-related stress and stigma, or may be part of the spectrum of HIV-associated neurocognitive disorders. The causal relationship between depressed mood and cognitive impairment is unclear and should be evaluated in future longitudinal studies.

Neurocognitive outcomes of HIV-associated tuberculous meningitis

Background: The toll of tuberculous meningitis (TBM) in both mortality and disability is considerable, but advancements in rehabilitation have the potential to improve the functional abilities and the quality of survivors' lives. However, the typical phenotype of neurocognitive impairment in TBM survivors remains unstudied in HIV-predominant populations in sub-Saharan Africa. Methods: We tested 36 survivors of TBM in Uganda with a comprehensive battery of neurocognitive assessments at 8 and 24 weeks after diagnosis, and compared results to a representative cohort of HIV-uninfected Ugandans. Results: While participants had a broad range of impairments at eight weeks, there was marked improvement by 24 weeks, when a phenotype of impairment including deficits in motor functioning, verbal learning and memory, processing speed, and executive function emerged. These deficits were present despite good clinician-rated functional status. The majority (23/27, 85%) had evidence of moderate to severe depression at week 8, and at week 24 (18/24, 75%). Conclusion: These findings highlight the need for more comprehensive neurocognitive assessment in the survivors of TBM, and further investment in and study of rehabilitation, including management of depression, to improve long-term outcomes in this population.

Assessment, prevalence, and correlates of frailty among middle-aged adults with HIV in rural Uganda

We investigated the prevalence and risk factors for frailty among people with HIV (PWH) in rural Uganda (n = 55, 47% male, mean age 44 years). Frailty was defined according to the Fried criteria with self-reported physical activity level replacing the Minnesota Leisure Time Activity Questionnaire. Alternate classifications for physical activity utilized were the sub-Saharan Africa Activity Questionnaire and the International Physical Activity Questionnaire. Eleven participants (19%) were frail. Frail participants were older (p < 0.001), less likely to be on antiretroviral therapy (p = 0.03), and had higher rates of depression (p < .001) and HIV-associated neurocognitive disorder (p = 0.003). Agreement between physical activity measures was sub-optimal. Prevalence of frailty was high among PWH in rural Uganda, but larger sample sizes and local normative data are needed.

Sex-specific associations between cerebrospinal fluid inflammatory marker levels and cognitive function in antiretroviral treated people living with HIV in rural Uganda

People with HIV (PWH) taking antiretroviral therapy (ART) have persistent cognitive impairment. The prevalence of cognitive impairment is higher in women with HIV (WWH) compared to men with HIV (MWH), possibly due to sex differences in immune function. Here we report sex differences in cerebrospinal fluid (CSF) immune markers in relation to cognitive performance. A subset of 83 PWH on ART (52% WWH; mean age = 37.6 years, SD = 7.9) from the Rakai community cohort study Cohort and Rakai Health Sciences Program supported clinics in rural Uganda completed a neuropsychological (NP) assessment and a lumbar puncture. CSF was used to measure 16 cytokines/chemokines. Individual NP test z-scores were generated based on local normative data. A series of least absolute shrinkage and selection operator (lasso) regressions examined associations between CSF inflammatory markers and NP outcomes. Overall, there were no sex differences in CSF inflammatory marker levels. However, MWH displayed more associations between inflammatory markers and cognitive performance than WWH. Among MWH, inflammatory markers were associated with a number of cognitive domains, including attention, processing speed, fluency, executive function, learning and memory. MIP-1β, INF-γ, GM-CSF, IL-7 and IL-12p70 were associated with multiple domains. Among WWH, few inflammatory markers were associated cognition. Degree of associations between CSF inflammatory biomarkers and cognitive performance varied by sex in this young, ART-treated, Ugandan cohort. Further investigation into sex-specific inflammatory mechanisms of cognitive impairment among PWH is warranted to inform sex-specific management strategies.