Chronic Pain in HIV

Incarceration history and opioid use among adults living with HIV and chronic pain: a secondary analysis of a prospective cohort study

BACKGROUND

Adults living with HIV have disproportionately high chronic pain, prescription opioid use, history of substance use, and incarceration. While incarceration can have long-lasting health impacts, prior studies have not examined whether distant (>1 year prior) incarceration is associated with opioid use for chronic pain, or with opioid misuse or opioid use disorder among people living with HIV and chronic pain.

METHODS

We conducted a secondary analysis of a prospective cohort study of adults living with HIV and chronic pain. The independent variables were any distant incarceration and drug-related distant incarceration (both dichotomous). Dependent variables were current long-term opioid therapy, current opioid misuse, and current opioid use disorder. A series of multivariate logistic regression models were conducted, adjusting for covariates.

RESULTS

In a cohort of 148 participants, neither distant incarceration nor drug-related incarceration history were associated with current long-term opioid therapy. Distant incarceration was associated with current opioid misuse (AOR 3.28; 95% CI: 1.41-7.61) and current opioid use disorder (AOR 4.40; 95% CI: 1.54-12.56). Drug-related incarceration history was also associated with current opioid misuse (AOR 4.31; 95% CI: 1.53-12.17) and current opioid use disorder (AOR 7.28; 95% CI: 2.06-25.71).

CONCLUSIONS

The positive associations of distant incarceration with current opioid misuse and current opioid use disorder could indicate a persistent relationship between incarceration and substance use in people living with HIV and chronic pain. Additional research on opioid use among formerly incarcerated individuals in chronic pain treatment is needed.

A Review of FDA-Approved Anti-HIV-1 Drugs, Anti-Gag Compounds, and Potential Strategies for HIV-1 Eradication

Acquired immunodeficiency syndrome (AIDS) is an enormous global health threat stemming from human immunodeficiency virus (HIV-1) infection. Up to now, the tremendous advances in combination antiretroviral therapy (cART) have shifted HIV-1 infection from a fatal illness into a manageable chronic disorder. However, the presence of latent reservoirs, the multifaceted nature of HIV-1, drug resistance, severe off-target effects, poor adherence, and high cost restrict the efficacy of current cART targeting the distinct stages of the virus life cycle. Therefore, there is an unmet need for the discovery of new therapeutics that not only bypass the limitations of the current therapy but also protect the body's health at the same time. The main goal for complete HIV-1 eradication is purging latently infected cells from patients' bodies. A potential strategy called "lock-in and apoptosis" targets the budding phase of the life cycle of the virus and leads to susceptibility to apoptosis of HIV-1 infected cells for the elimination of HIV-1 reservoirs and, ultimately, for complete eradication. The current work intends to present the main advantages and disadvantages of United States Food and Drug Administration (FDA)-approved anti-HIV-1 drugs as well as plausible strategies for the design and development of more anti-HIV-1 compounds with better potency, favorable pharmacokinetic profiles, and improved safety issues.

Physiologically based pharmacokinetic modeling of ritonavir-oxycodone drug interactions and its implication for dosing strategy

The concomitant administration of ritonavir and oxycodone may significantly increase the plasma concentrations of oxycodone. This study was aimed to simulate DDI between ritonavir and oxycodone, a widely used opioid, and to formulate dosing protocols for oxycodone by using physiologically based pharmacokinetic (PBPK) modeling. We developed a ritonavir PBPK model incorporating induction and competitive and time-dependent inhibition of CYP3A4 and competitive inhibition of CYP2D6. The ritonavir model was evaluated with observed clinical pharmacokinetic data and validated for its CYP3A4 inhibition potency. We then used the model to simulate drug interactions between oxycodone and ritonavir under various dosing scenarios. The developed model captured the pharmacokinetic characteristics of ritonavir from clinical studies. The model also accurately predicts exposure changes of midazolam, triazolam, and oxycodone in the presence of ritonavir. According to model simulations, the steady-state maximum, minimum and average concentrations of oxycodone increased by up to 166% after co-administration with ritonavir, and the total exposure increased by approximately 120%. To achieve similar steady-state concentrations, halving the dose with an unchanged dosing interval or doubling the dosing interval with an unaltered single dose should be practical for oxycodone, whether formulated in uncoated or controlled-release tablets during long-term co-medication with ritonavir. The results revealed exposure-related risks of oxycodone-ritonavir interactions that have not been studied clinically and emphasized PBPK as a workable method to direct judicious dosage.

Environmental factors and their impact on chronic pain development and maintenance

It is more than recognized and accepted that the environment affects the physiological responses of all living things, from bacteria to superior vertebrates, constituting an important factor in the evolution of all species. Environmental influences range from natural processes such as sunlight, seasons of the year, and rest to complex processes like stress and other mood disorders, infections, and air pollution, being all of them influenced by how each creature deals with them. In this chapter, it will be discussed how some of the environmental elements affect directly or indirectly neuropathic pain, a type of chronic pain caused by a lesion or disease of the somatosensory nervous system. For that, it was considered the edge of knowledge in translational research, thus including data from human and experimental animals as well as the applicability of such findings.

An Analysis of Biopsychosocial Factors Associated With Chronic Pain Severity Among Hospitalized People Living With HIV in Shenzhen, China: A Cross-Sectional Study

ABSTRACT

Chronic pain is a primary health problem in people living with HIV (PWH). However, there is limited research regarding chronic pain among PWH in Chinese health care settings. To investigate biopsychosocial factors of chronic pain severity, we conducted a cross-sectional study in Shenzhen, China. Chronic pain was defined as pain lasting for more than three months. Pain intensity was measured using the numeric rating scale (NRS). Among 123 hospitalized PWH, 78.86% of participants had mild pain and 21.14% had moderate-severe pain. Multiple logistic regression results indicated that PWH in moderate-severe pain group were more likely to have higher levels of interleukin [IL]-6 (OR = 1.034, 95% CI: 1.003-1.066, p = .029) and anxiety (OR = 1.334, 95% CI: 1.071-1.662, p = .010) than those in the mild chronic pain group. Targeted pain management interventions should be explored in clinical practices and future studies regarding PWH with high levels of IL-6 and anxiety.

Pathogenic mechanisms of human immunodeficiency virus (HIV)-associated pain

Chronic pain is a prevalent neurological complication among individuals living with human immunodeficiency virus (PLHIV) in the post-combination antiretroviral therapy (cART) era. These individuals experience malfunction in various cellular and molecular pathways involved in pain transmission and modulation, including the neuropathology of the peripheral sensory neurons and neurodegeneration and neuroinflammation in the spinal dorsal horn. However, the underlying etiologies and mechanisms leading to pain pathogenesis are complex and not fully understood. In this review, we aim to summarize recent progress in this field. Specifically, we will begin by examining neuropathology in the pain pathways identified in PLHIV and discussing potential causes, including those directly related to HIV-1 infection and comorbidities, such as antiretroviral drug use. We will also explore findings from animal models that may provide insights into the molecular and cellular processes contributing to neuropathology and chronic pain associated with HIV infection. Emerging evidence suggests that viral proteins and/or antiretroviral drugs trigger a complex pathological cascade involving neurons, glia, and potentially non-neural cells, and that interactions between these cells play a critical role in the pathogenesis of HIV-associated pain.

Astrocytes: Role in pathogenesis and effect of commonly misused drugs in the HIV infected brain

The roles of astrocytes as reservoirs and producers of a subset of viral proteins in the HIV infected brain have been studied extensively as a key to understanding HIV-associated neurocognitive disorders (HAND). However, their comprehensive role in the context of intersecting substance use and neurocircuitry of the reward pathway and HAND has yet to be fully explained. Use of methamphetamines, cocaine, or opioids in the context of HIV infection have been shown to lead to a faster progression of HAND. Glutamatergic, dopaminergic, and GABAergic systems are implicated in the development of HAND-induced cognitive impairments. A thorough review of scientific literature exploring the variety of mechanisms in which these drugs exert their effects on the HIV brain and astrocytes has revealed marked areas of convergence in overexcitation leading to increased drug-seeking behavior, inflammation, apoptosis, and irreversible neurotoxicity. The present review investigates astrocytes, the neural pathways, and mechanisms of drug disruption that ultimately play a larger holistic role in terms of HIV progression and drug use. There are opportunities for future research, therapeutic intervention, and preventive strategies to diminish HAND in the subset population of patients with HIV and substance use disorder.

Global Prevalence of Chronic Pain in Women with HIV: A Systematic Review and Meta-analysis

Chronic pain is common among people with human immunodeficiency virus (HIV) and detrimental to quality of life and overall health. It is often underdiagnosed, undertreated, and frankly dismissed in women with HIV, despite growing evidence that it is highly prevalent in this population. Thus, we conducted a systematic review and meta-analysis to estimate the global prevalence of chronic pain in women with HIV. The full protocol can be found on PROSPERO (identifier CRD42022301145). Of the 2984 references identified in our search, 36 were included in the systematic review and 35 in the meta-analysis. The prevalence of chronic pain was 31.2% (95% confidence interval [CI], 24.6%-38.7%; I2 = 98% [95% CI, 97%-99%]; P < .0001). In this global assessment, we found a high prevalence of chronic pain among women with HIV, underscoring the importance of understanding the etiology of chronic pain, identifying effective treatments, and conducting regular assessments in clinical practice.

Cannabis use frequency and pain interference among people with HIV

Cannabis is often used by people with HIV (PWH) for pain, yet study results are inconsistent regarding whether and how it affects pain. This study examines whether greater cannabis use frequency is associated with lower pain interference and whether cannabis use modifies the association of pain severity and pain interference among 134 PWH with substance dependence or a lifetime history of injection drug use. Multi-variable linear regression models examined the association between past 30-day cannabis use frequency and pain interference. Additional models evaluated whether cannabis use modified the association between pain severity and pain interference. Cannabis use frequency was not significantly associated with pain interference. However, in a model with interaction between cannabis use frequency and pain severity, greater cannabis use frequency attenuated the strength of the association between pain severity and pain interference (p = 0.049). The adjusted mean difference (AMD) in pain interference was +1.13, + 0.81, and +0.05 points for each 1-point increase in pain severity for those with no cannabis use, 15 days of use, and daily use, respectively. These findings suggest that attenuating the impact of pain severity on pain-related functional impairment is a potential mechanism for a beneficial role of cannabis for PWH.

High Heme and Low Heme Oxygenase-1 Are Associated with Mast Cell Activation/Degranulation in HIV-Induced Chronic Widespread Pain

An overwhelming number of people with HIV (PWH) experience chronic widespread pain (CWP) throughout their lifetimes. Previously, we demonstrated that PWH with CWP have increased hemolysis and attenuated heme oxygenase 1 (HO-1) levels. HO-1 degrades reactive, cell-free heme into antioxidants like biliverdin and carbon monoxide (CO). We found that high heme or low HO-1 caused hyperalgesia in animals, likely through multiple mechanisms. In this study, we hypothesized that high heme or low HO-1 caused mast cell activation/degranulation, resulting in the release of pain mediators like histamine and bradykinin. PWH who self-report CWP were recruited from the University of Alabama at Birmingham HIV clinic. Animal models included HO-1-/- mice and hemolytic mice, where C57BL/6 mice were injected intraperitoneally with phenylhydrazine hydrochloride (PHZ). Results demonstrated that plasma histamine and bradykinin were elevated in PWH with CWP. These pain mediators were also high in HO-1-/- mice and in hemolytic mice. Both in vivo and in vitro (RBL-2H3 mast cells), heme-induced mast cell degranulation was inhibited by treatment with CORM-A1, a CO donor. CORM-A1 also attenuated mechanical and thermal (cold) allodynia in hemolytic mice. Together, the data suggest that mast cell activation secondary to high heme or low HO-1 seen in cells and animals correlates with elevated plasma levels of heme, histamine, and bradykinin in PWH with CWP.

Feasibility of remote self-collection of dried blood spots, hair, and nails among people with HIV with hazardous alcohol use

BACKGROUND

The use of biomarkers in behavioral HIV research can help to address limitations of self-reported data. The COVID-19 pandemic forced many researchers to transition from standard in-person data collection to remote data collection. We present data on the feasibility of remote self-collection of dried blood spots (DBS), hair, and nails for the objective assessment of alcohol use, antiretroviral therapy adherence, and stress in a sample of people with HIV (PWH) who are hazardous drinkers.

METHODS

Standardized operating procedures for remote self-collection of DBS, hair, and nails were developed for an ongoing pilot study of a transdiagnostic alcohol intervention for PWH. Prior to each study appointment, participants were mailed a kit containing materials for self-collection, instructions, a video link demonstrating the collection process, and a prepaid envelope for returning samples.

RESULTS

A total of 133 remote study visits were completed. For DBS and nail collection at baseline, 87.5% and 83.3% of samples, respectively, were received by the research laboratory, of which 100% of samples were processed. Although hair samples were intended to be analyzed, most of the samples (77.7%) were insufficient or the scalp end of the hair was not marked. We, therefore, decided that hair collection was not feasible in the framework of this study.

CONCLUSION

An increase in remote self-collection of biospecimens may significantly advance the field of HIV-related research, permitting the collection of specimens without resource-intensive laboratory personnel and facilities. Further research is needed on the factors that impeded participants' ability to complete remote biospecimen collection.

Development of Frail RISC-HIV: a Risk Score for Predicting Frailty Risk in the Short-term for Care of People with HIV

OBJECTIVE

Frailty is common among people with HIV (PWH), so we developed frail risk in the short-term for care (RISC)-HIV, a frailty prediction risk score for HIV clinical decision-making.

DESIGN

We followed PWH for up to 2 years to identify short-term predictors of becoming frail.

METHODS

We predicted frailty risk among PWH at seven HIV clinics across the United States. A modified self-reported Fried Phenotype captured frailty, including fatigue, weight loss, inactivity, and poor mobility. PWH without frailty were separated into training and validation sets and followed until becoming frail or 2 years. Bayesian Model Averaging (BMA) and five-fold-cross-validation Lasso regression selected predictors of frailty. Predictors were selected by BMA if they had a greater than 45% probability of being in the best model and by Lasso if they minimized mean squared error. We included age, sex, and variables selected by both BMA and Lasso in Frail RISC-HIV by associating incident frailty with each selected variable in Cox models. Frail RISC-HIV performance was assessed in the validation set by Harrell's C and lift plots.

RESULTS

Among 3170 PWH (training set), 7% developed frailty, whereas among 1510 PWH (validation set), 12% developed frailty. BMA and Lasso selected baseline frailty score, prescribed antidepressants, prescribed antiretroviral therapy, depressive symptomology, and current marijuana and illicit opioid use. Discrimination was acceptable in the validation set, with Harrell's C of 0.76 (95% confidence interval: 0.73-0.79) and sensitivity of 80% and specificity of 61% at a 5% frailty risk cutoff.

CONCLUSIONS

Frail RISC-HIV is a simple, easily implemented tool to assist in classifying PWH at risk for frailty in clinics.

Painful to Discuss: The Intersection of Chronic Pain, Mental Health, and Analgesic Use among People with HIV

Objective

This retrospective chart review study aims to identify patients in an HIV clinical setting in an area of high HIV prevalence in Atlanta, Georgia, USA who have chronic pain, analgesic prescriptions, and/or mental health diagnoses.

Design

People living with HIV (PLWH) are at higher risk for experiencing trauma, mental health conditions, and chronic pain than their HIV-negative counterparts. This study was designed to evaluate the intersection of these factors within an urban HIV clinic.

Methods

Retrospective chart review study.

Results

Of the adult patients enrolled at an HIV clinic in Atlanta, Georgia USA between 2011-2022 (n=15,970), 93.7% were prescribed analgesics, 40.5% had documented pain diagnoses, and 23.5% had documented mental health diagnoses. Additionally, 14.3% of all enrolled patients had all three factors concurrently.

Conclusions

The complexity of HIV, chronic pain, mental health challenges, and analgesic use demand a patient-centered, collaborative approach including a multidisciplinary care team. Seeing persistent pain among PLWH with a trauma-informed approach to care within the lens of co-occurring mental health diagnoses will allow us to better understand, treat, and sustain patients in life-saving HIV care.

Mitochondrial reactivity following acute exposure to experimental pain testing in people with HIV and chronic pain

Background: Physical stressors can cause a physiological response that can contribute to an increase in mitochondrial dysfunction and Mitochondrial DNA damage (mtDNA damage). People living with HIV (PWH) are more likely to suffer from chronic pain and may be more susceptible to mitochondrial dysfunction following exposure to a stressor. We used Quantitative Sensory Testing (QST) as an acute painful stressor in order to investigate whether PWH with/without chronic pain show differential mitochondrial physiological responses. Methods: The current study included PWH with (n = 26), and without (n = 29), chronic pain. Participants completed a single session that lasted approximately 180 min, including QST. Blood was taken prior to and following the QST battery for assays measuring mtDNA damage, mtDNA copy number, and mtDNA damage-associated molecular pattern (DAMP) levels (i.e., ND1 and ND6). Results: We examined differences between those with and without pain on various indicators of mitochondrial reactivity following exposure to QST. However, only ND6 and mtDNA damage were shown to be statistically significant between pain groups. Conclusion: PWH with chronic pain showed greater mitochondrial reactivity to laboratory stressors. Consequently, PWH and chronic pain may be more susceptible to conditions in which mitochondrial damage/dysfunction play a central role, such as cognitive decline.

Persistent sensory changes and sex differences in transgenic mice conditionally expressing HIV-1 Tat regulatory protein

HIV-associated sensory neuropathies (HIV-SN) are prevalent in >50% of patients aged over 45 years many of which report moderate to severe chronic pain. Previous preclinical studies have investigated the mechanisms by which HIV-1 causes sensory neuropathies and pain-like behaviors. The aim of the present study is to delineate the role of chronic HIV-1 trans-activator of transcription protein (Tat) exposure in the development of neuropathy in mice. The temporal effects of conditional Tat expression on the development of hypersensitivity to mechanical (von Frey filaments) and thermal (heat or cold) stimuli were tested in male and female mice that transgenically expressed HIV-1 Tat in a doxycycline-inducible manner. Inducing Tat expression produced an allodynic response to mechanical or cold (but not heat) stimuli that respectively persisted for at least 23-weeks (mechanical hypersensitivity) or at least 8-weeks (cold hypersensitivity). Both allodynic states were greater in magnitude among females, compared to males, and mechanical increased hypersensitivity progressively in females over time. Acute morphine or gabapentin treatment partly attenuated allodynia in males, but not females. Irrespective of sex, Tat reduced intraepidermal nerve fiber density, the mean amplitude of sensory nerve action potentials (but not conductance), engagement in some pain-related ethological behaviors (cage-hanging and rearing), and down-regulated PPAR-α gene expression in lumbar spinal cord while upregulating TNF-α expression in dorsal root ganglion. Taken together, these data reveal fundamental sex differences in mechanical and cold hypersensitivity in response to Tat and demonstrate the intractable nature in female mice to current therapeutics. Understanding the role of Tat in these pathologies may aid the design of future therapies aimed at mitigating the peripheral sensory neuropathies that accompany neuroHIV.

Sleep Disturbances and Chronic Pain in People with HIV: Implications for HIV-Associated Neurocognitive Disorders

Purpose of Review

Antiretroviral therapy has significantly reduced morbidity and mortality in people with HIV. Despite being virally suppressed, sleep disturbances, chronic pain, and neurocognitive impairments persist which can negatively impact quality of life for people with HIV. This article presents relevant literature related to sleep disturbances and chronic pain in people with HIV. The potential impact of these comorbidities on cognition is discussed with implications for managing HIV-associated neurocognitive disorder (HAND).

Recent Findings

People with HIV and chronic pain report greater insomnia and depressive symptoms compared to those without chronic pain. The neurotoxic effects of HIV itself and sleep and chronic pain induced inflammation can contribute to poorer cognitive outcomes.

Summary

Sleep disturbances and chronic pain are prevalent conditions in people with HIV that may perpetuate the development and exacerbation of HAND. Sleep and pain interventions may preserve cognitive function and improve quality of life for people aging with HIV.

Chronic Pain and Opioid Use in Older People With HIV

Chronic pain is common among older people with HIV. Etiologies of chronic pain are multifactorial in this population. A careful and thorough initial assessment of pain is important. Associated conditions that can contribute to pain should be explored and managed as indicated. Special consideration is warranted for some of the unique aspects of pain in people with HIV. Chronic pain management is multimodal; a variety of pharmacologic and nonpharmacologic strategies are effective. Among medications, opioids can be used but carry a risk of significant harms. The use and monitoring of opioids is discussed here, and recommendations are made for the safe prescribing of opioids for chronic pain.

A neuron-to-astrocyte Wnt5a signal governs astrogliosis during HIV-associated pain pathogenesis

Chronic pain is the most common neurological disorder of HIV patients. Multiple neuropathologies were identified in the pain pathway. Among them is the prominent astrocytic reaction (also know an astrogliosis). However, the pathogenic role and mechanism of the astrogliosis are unclear. Here, we show that the astrogliosis is crucial for the pain development induced by a key neurotoxic HIV protein gp120 and that a neuron-to-astrocyte Wnt5a signal controls the astrogliosis. Ablation of astrogliosis blocked the development of gp120-induced mechanical hyperalgesia, and concomitantly the expression of neural circuit polarization in the spinal dorsal horn. We demonstrated that conditional knockout of either Wnt5a in neurons or its receptor ROR2 in astrocytes abolished not only gp120-induced astrogliosis but also hyperalgesia and neural circuit polarization. Furthermore, we found that the astrogliosis promoted expression of hyperalgesia and NCP via IL-1β regulated by a Wnt5a-ROR2-MMP2 axis. Our results shed light on the role and mechanism of astrogliosis in the pathogenesis of HIV-associated pain.

T cell responses to SARS-CoV-2 in people with and without neurologic symptoms of long COVID

Many people experiencing long COVID syndrome, or post-acute sequelae of SARS-CoV-2 infection (PASC), suffer from debilitating neurologic symptoms (Neuro-PASC). However, whether virus-specific adaptive immunity is affected in Neuro-PASC patients remains poorly understood. We report that Neuro-PASC patients exhibit distinct immunological signatures composed of elevated humoral and cellular responses toward SARS-CoV-2 Nucleocapsid protein at an average of 6 months post-infection compared to healthy COVID convalescents. Neuro-PASC patients also had enhanced virus-specific production of IL-6 from and diminished activation of CD8+ T cells. Furthermore, the severity of cognitive deficits or quality of life disturbances in Neuro-PASC patients were associated with a reduced diversity of effector molecule expression in T cells but elevated IFN-γ production to the C-terminal domain of Nucleocapsid protein. Proteomics analysis showed enhanced plasma immunoregulatory proteins and reduced pro-inflammatory and antiviral response proteins in Neuro-PASC patients compared with healthy COVID convalescents, which were also correlated with worse neurocognitive dysfunction. These data provide new insight into the pathogenesis of long COVID syndrome and a framework for the rational design of predictive biomarkers and therapeutic interventions.

Engagement in HIV care and viral suppression following changes in long-term opioid therapy for treatment for chronic pain

Chronic pain is common among persons living with HIV and changes in opioid prescribing practices may complicate HIV care management. Using medical record data from a retrospective cohort study conducted January 1, 2012 to June 30, 2019 for 300 publicly insured HIV-positive primary care patients prescribed opioids for chronic non-cancer pain in San Francisco, we examined associations between opioid dose changes and both time to disengagement from HIV care and experiencing virologic failure using logistic regression. Discontinuation of prescribed opioids was associated with increased odds of disengagement in care at 3, 6, and 9 months after discontinuation. There were no associations with virologic failure. Providers and policy makers must weigh impacts on HIV care when implementing necessary changes in opioid prescribing.

Health-Related Quality of Life of HIV Positive Patients with Hypertension: Is There an Association with Blood Pressure Control?

INTRODUCTION

The presence of comorbidities could affect the health-related quality of life (HRQoL) of people living with HIV (PLHIV).

AIM

To assess the HRQoL of PLHIV and Hypertension, as well as its association with blood pressure (BP) control.

METHODS

This cross-sectional study was conducted in the HIV clinic of the University of Uyo Teaching Hospial in Akwa Ibom State, Nigeria, between August and October 2018. The EQ-5D-5L was administered to 201 eligible outpatients in the waiting area of the clinic before consulting the physician. Patients' socio-demographic and clinical data were obtained from the medical records. Blood pressure was measured using an automatic BP monitor. Data were analyzed with SPSS version 20.0.

RESULTS

Majority (58.6%) of the respondents were females; mean age was 49.59 ± 8.97 years; mean systolic and diastolic BP were 152.77 ± 19.38 mmHg and 90.28 ± 11.33 mmHg, respectively. EQ-VAS and EQ-5D index scores were 80.99 ± 15.97 and 0.86 ± 0.05, respectively. There were no significant differences in EQ-VAS score (z = - 0.113,  p = 0.910) or EQ-5D utility (z = - 0.523,  p = 0.601) between participants with controlled and uncontrolled BP. Duration on antihypertensive drugs was associated with EQ-VAS score (χ²(2) = 6.558,  p = 0.038), while employment status was associated with EQ-5D utility (z = - 2.661,   p = 0.008).

CONCLUSIONS

PLHIV and hypertension accessing care at a Nigerian hospital reported a high HRQoL, irrespective of BP control status. Nevertheless, there is a need to provide psychological support and employment for this population to maximise their HRQoL.

Green Light Antinociceptive and Reversal of Thermal and Mechanical Hypersensitivity Effects Rely on Endogenous Opioid System Stimulation

Benefits of phototherapy were characterized in multiple diseases including depression, circadian rhythm disruptions, and neurodegeneration. Studies on migraine and fibromyalgia patients revealed that green light-emitting diodes (GLED) exposure provides a pragmatic and safe therapy to manage chronic pain. In rodents, GLED reversed hypersensitivity related to neuropathic pain. However, little is known about the underlying mechanisms of GLED efficacy. Here, we sought to understand how green light modulates the endogenous opioid system. We first characterized how exposure to GLED stimulates release of β-endorphin and proenkephalin in the central nervous system of male rats. Moreover, by individually editing each of the receptors, we found that µ- and δ-opioid receptors are required for green light's antinociceptive effect in naïve rats and a model of HIV-induced peripheral neuropathy. We investigated how GLED could increase pain thresholds, and explored its potential in reversing hypersensitivity in a model of HIV-related neuropathy. Through behavioral and gene editing approaches, we identified that green light provides antinociception via modulation of the endogenous opioid system in the spinal cord. This work identifies a previously unknown mechanism by which GLED can improve pain management. Clinical translation of these results will advance the development of an innovative therapy devoid of adverse effects. PERSPECTIVE: Development of new pain management therapies, especially for HIV patients, is crucial as long-term opioid prescription is not recommended due to adverse side effects. Green light addresses this necessity. Characterizing the underlying mechanisms of this potentially groundbreaking and safe antinociceptive therapy will advance its clinical translation.

Neuroinflammation in HIV-Related Neuropathic Pain

In the management of human immunodeficiency virus (HIV) infection around the world, chronic complications are becoming a new problem along with the prolonged life expectancy. Chronic pain is widespread in HIV infected patients and even affects those with a low viral load undergoing long-term treatment with antiviral drugs, negatively influencing the adherence to disease management and quality of life. A large proportion of chronic pain is neuropathic pain, which defined as chronic pain caused by nervous system lesions or diseases, presenting a series of nervous system symptoms including both positive and negative signs. Injury caused by HIV protein, central and peripheral sensitization, and side effects of antiretroviral therapy lead to neuroinflammation, which is regarded as a maladaptive mechanism originally serving to promote regeneration and healing, constituting the main mechanism of HIV-related neuropathic pain. Gp120, as HIV envelope protein, has been found to be the major toxin that induces neuropathic pain. Particularly, the microglia, releasing numerous pro-inflammatory substances (such as TNFα, IL-1β, and IL-6), not only sensitize the neurons but also are the center part of the crosstalk bridging the astrocytes and oligodendrocytes together forming the central sensitization during HIV infection, which is not discussed detailly in recent reviews. In the meantime, some NRTIs and PIs exacerbate the neuroinflammation response. In this review, we highlight the importance of clarifying the mechanism of HIV-related neuropathic pain, and discuss about the limitation of the related studies as future research directions.

Computational Functional Genomics-Based AmpliSeq™ Panel for Next-Generation Sequencing of Key Genes of Pain

The genetic background of pain is becoming increasingly well understood, which opens up possibilities for predicting the individual risk of persistent pain and the use of tailored therapies adapted to the variant pattern of the patient's pain-relevant genes. The individual variant pattern of pain-relevant genes is accessible via next-generation sequencing, although the analysis of all "pain genes" would be expensive. Here, we report on the development of a cost-effective next generation sequencing-based pain-genotyping assay comprising the development of a customized AmpliSeq™ panel and bioinformatics approaches that condensate the genetic information of pain by identifying the most representative genes. The panel includes 29 key genes that have been shown to cover 70% of the biological functions exerted by a list of 540 so-called "pain genes" derived from transgenic mice experiments. These were supplemented by 43 additional genes that had been independently proposed as relevant for persistent pain. The functional genomics covered by the resulting 72 genes is particularly represented by mitogen-activated protein kinase of extracellular signal-regulated kinase and cytokine production and secretion. The present genotyping assay was established in 61 subjects of Caucasian ethnicity and investigates the functional role of the selected genes in the context of the known genetic architecture of pain without seeking functional associations for pain. The assay identified a total of 691 genetic variants, of which many have reports for a clinical relevance for pain or in another context. The assay is applicable for small to large-scale experimental setups at contemporary genotyping costs.

Immune cell-mediated opioid analgesia

Pathological pain is regulated by a balance between pro-algesic and analgesic mechanisms. Interactions between opioid peptide-producing immune cells and peripheral sensory neurons expressing opioid receptors represent a powerful intrinsic pain control in animal models and in humans. Therefore, treatments based on general suppression of immune responses have been mostly unsuccessful. It is highly desirable to develop strategies that specifically promote neuro-immune communication mediated by opioids. Promising examples include vaccination-based recruitment of opioid-containing leukocytes to painful tissue and the local reprogramming of pro-algesic immune cells into analgesic cells producing and secreting high amounts of opioid peptides. Such approaches have the potential to inhibit pain at its origin and be devoid of central and systemic side effects of classical analgesics. In support of these concepts, in this article, we describe the functioning of peripheral opioid receptors, migration of opioid-producing immune cells to inflamed tissue, opioid peptide release, and the consequent pain relief. Conclusively, we provide clinical evidence and discuss therapeutic opportunities and challenges associated with immune cell-mediated peripheral opioid analgesia.