HIV peripheral neuropathy progression: protection with glucose-lowering drugs?

Higher Levels of Cerebrospinal Fluid and Plasma Neurofilament Light in Human Immunodeficiency Virus-Associated Distal Sensory Polyneuropathy

BACKGROUND

Neurofilament light (NFL) chain concentrations, reflecting axonal damage, are seen in several polyneuropathies but have not been studied in human immunodeficiency virus (HIV) distal sensory polyneuropathy (DSP). We evaluated NFL in cerebrospinal fluid (CSF) and plasma in relation to DSP in people with HIV (PWH) from 2 independent cohorts and in people without HIV (PWoH).

METHODS

Cohort 1 consisted of PWH from the CHARTER Study. Cohort 2 consisted of PWH and PWoH from the HIV Neurobehavioral Research Center (HNRC). We evaluated DSP signs and symptoms in both cohorts. Immunoassays measured NFL in CSF for all and for plasma as well in Cohort 2.

RESULTS

Cohort 1 consisted of 111 PWH, mean ± SD age 56.8 ± 8.32 years, 15.3% female, 38.7% Black, 49.6% White, current CD4+ T-cells (median, interquartile range [IQR]) 532/µL (295, 785), 83.5% with plasma HIV RNA ≤50 copies/mL. Cohort 2 consisted of 233 PWH of similar demographics to PWH in Cohort 1 but also 51 PWoH, together age 58.4 ± 6.68 years, 41.2% female, 18.0% Black, Hispanic, non-Hispanic White 52.0%, 6.00% White. In both cohorts of PWH, CSF and plasma NFL were significantly higher in both PWH with DSP signs. Findings were similar, albeit not significant, for PWoH. The observed relationships were not explained by confounds.

CONCLUSIONS

Both plasma and CSF NFL were elevated in PWH and PWoH with DSP. The convergence of our findings with others demonstrates that NFL is a reliable biomarker reflecting peripheral nerve injury. Biomarkers such as NFL might provide, validate, and optimize clinical trials of neuroregenerative strategies in HIV DSP.

Beneficial and Adverse Effects of cART Affect Neurocognitive Function in HIV-1 Infection: Balancing Viral Suppression against Neuronal Stress and Injury

HIV-associated neurocognitive disorders (HAND) persist despite the successful introduction of combination antiretroviral therapy (cART). While insufficient concentration of certain antiretrovirals (ARV) may lead to incomplete viral suppression in the brain, many ARVs are found to cause neuropsychiatric adverse effects, indicating their penetration into the central nervous system (CNS). Several lines of evidence suggest shared critical roles of oxidative and endoplasmic reticulum stress, compromised neuronal energy homeostasis, and autophagy in the promotion of neuronal dysfunction associated with both HIV-1 infection and long-term cART or ARV use. As the lifespans of HIV patients are increased, unique challenges have surfaced. Longer lives convey prolonged exposure of the CNS to viral toxins, neurotoxic ARVs, polypharmacy with prescribed or illicit drug use, and age-related diseases. All of these factors can contribute to increased risks for the development of neuropsychiatric conditions and cognitive impairment, which can significantly impact patient well-being, cART adherence, and overall health outcome. Strategies to increase the penetration of cART into the brain to lower viral toxicity may detrimentally increase ARV neurotoxicity and neuropsychiatric adverse effects. As clinicians attempt to control peripheral viremia in an aging population of HIV-infected patients, they must navigate an increasingly complex myriad of comorbidities, pharmacogenetics, drug-drug interactions, and psychiatric and cognitive dysfunction. Here we review in comparison to the neuropathological effects of HIV-1 the available information on neuropsychiatric adverse effects and neurotoxicity of clinically used ARV and cART. It appears altogether that future cART aiming at controlling HIV-1 in the CNS and preventing HAND will require an intricate balancing act of suppressing viral replication while minimizing neurotoxicity, impairment of neurocognition, and neuropsychiatric adverse effects. Graphical abstract Schematic summary of the effects exerted on the brain and neurocognitive function by HIV-1 infection, comorbidities, psychostimulatory, illicit drugs, therapeutic drugs, such as antiretrovirals, the resulting polypharmacy and aging, as well as the potential interactions of all these factors.

Neuropathy complication of antiretroviral therapy in HIV/AIDS patients

OBJECTIVES

Significant pain from HIV-associated sensory neuropathy (HIV-SN) affects 40% of HIV-infected individuals treated with antiretroviral therapy (ART). The most salient symptom of the neuropathy is pain, which frequently is moderate-to-severe intensity, associated with reduced activities and physical function, sleep disruption, increased severity of depression, and anxiety. Yet, evidence for managing painful HIV-SN is poor. The purpose of this study was to verify by scientific evidence the neuropathy complication in HIV/AIDS patients to develop effective pain management strategies.

METHODS

Design: Systematic review.

DATA SOURCES

PubMed (MEDLINE), Cochrane, www.controlled-trials.com.

SELECTION CRITERIA

the filter "English" was used, timeframed searched was 2009-2019, randomized controlled trials (RCT). Keywords were verified in MeSH "Peripheral Nervous System Disease" and "Antiretroviral Agents" or "Antiretroviral therapy."

REVIEW METHOD

the PRISMA flowchart was used.

RESULT

A systematic search following PRISMA guidelines was carried out, and 12 specific articles/studies on the subject were selected. The results revealed that HIV therapy, aging, body mass index, height, and systemic conditions influence neuropathy conditions in HIV/AIDS patients. The multistudies focused on pain management approaches such as administration of pain medication, drug combination to prevent side effects, or ART with minimal side effects.

CONCLUSION

Sensory neuropathy is a frequent complication of HIV infection and ART. An understanding of the mechanism and pathophysiology of neuropathy in HIV is urgently required to develop alternative treatment modalities and to evaluate preventive strategies.

Epidemiology and factors associated with peripheral neuropathy among HIV infected patients in Gondar, Ethiopia: A cross-sectional study

Background

Antiretroviral therapy has surely increased the life expectancy of people living with HIV. However, long term complications like HIV associated sensory neuropathy has a negative impact on quality of life among people living with HIV (PLHIV). In Ethiopia, lack of data on magnitude of the burden and predictors of HIV associated sensory neuropathy in many resource limited setting has led to under diagnosis and eventually under management of HIV-SN. Hence, this study was set out to establish the burden of HIV-associated sensory neuropathy and, its association with demographic, health and clinical characteristics among people living with HIV in Ethiopia.

Methods

Cross-sectional study was conducted to assess the prevalence of HIV-associated sensory neuropathy and the associated factors among adult HIV patients at University of Gondar Teaching Hospital, Gondar, Ethiopia. Brief Peripheral Neuropathy Screening tool validated by AIDs Clinical trial group was used for screening HIV-associated sensory neuropathy. Data were analyzed descriptively and through uni- and multivariate logistic regression.

Results

In total 359 adult PLHIV with a mean age of 36.5± 9.07 years participated, their median duration of HIV infection was 60 months (IQR 36–84) and their median CD4 count 143cells/μL (IQR 69.5–201.5). Age above 40 years, anti-tuberculosis regimen, tallness, and exposure to didanosine contained antiretroviral therapy were found to be associated with HIV-associated sensory neuropathy (AOR 1.82, 1.84, 1.98 and 4.33 respectively).

Conclusions

More than half of the HIV patients who attended HIV care clinic at University of Gondar hospital during the study period were found to present with peripheral sensory neuropathy. Higher age, tallness, TB medication, and didanosine in ART were significantly associated with HIV-SN as screened by effective diagnostic (BPNS) tool.

Evolution of sensory neuropathy after initiation of antiretroviral therapy

INTRODUCTION

We studied the evolution of sensory neuropathy after antiretroviral therapy (ART) in human immunodeficiency virus-infected South Africans.

METHODS

Enrolment commenced before ART with 6-monthly follow-ups for 24 months. Symptomatic distal sensory polyneuropathy (SDSP) was defined as one symptom and sign. Symptom/sign scores were compared between visits.

RESULTS

We enrolled 184 participants. Pre-ART, 16% had SDSP. After 18 months of ART, pain prevalence decreased in those with pre-ART SDSP (odds ratio [OR], 0.09; 95% confidence interval [95%CI], 0.03-0.29). Symptoms improved in 50% ever experiencing pain (mean improvement = 4.5 on 11-point scale). Participants SDSP-free pre-ART developed SDSP at a rate of 18 per 100 person-years. After 24 months (n = 102), 18% had SDSP. Stavudine (60% of cohort) did not predict incident SDSP, but associated with increased prevalence of reduced/absent reflexes at 18 months (OR, 2.24; 95% CI, 1.08-4.65).

DISCUSSION

Painful symptoms improved during ART. Evolving sensory neuropathy was due to increasing small and large fiber dysfunction. Muscle Nerve 57: 371-379, 2018.

Neuronal Stress and Injury Caused by HIV-1, cART and Drug Abuse: Converging Contributions to HAND

Multiple mechanisms appear to contribute to neuronal stress and injury underlying HIV-associated neurocognitive disorders (HAND), which occur despite the successful introduction of combination antiretroviral therapy (cART). Evidence is accumulating that components of cART can itself be neurotoxic upon long-term exposure. In addition, abuse of psychostimulants, such as methamphetamine (METH), seems to compromise antiretroviral therapy and aggravate HAND. However, the combined effect of virus and recreational and therapeutic drugs on the brain is still incompletely understood. However, several lines of evidence suggest a shared critical role of oxidative stress, compromised neuronal energy homeostasis and autophagy in promotion and prevention of neuronal dysfunction associated with HIV-1 infection, cART and psychostimulant use. In this review, we present a synopsis of recent work related to neuronal stress and injury induced by HIV infection, antiretrovirals (ARVs) and the highly addictive psychostimulant METH.

Diagnosing and treating HIV-associated sensory neuropathy: a global perspective

HIV-associated sensory neuropathy (HIV-SN) is a common complication of HIV and remains highly prevalent even with modern HIV management strategies, causing debilitating pain in millions globally. We review HIV-SN diagnosis and management. We suggest most HIV-SN cases are easily recognized using clinical screening tools, with physician assessment and/or specialized testing prioritized for atypical cases. Management aims to prevent further nerve damage and optimize symptom control. Symptom relief is difficult and rarely complete, with a lack of proven pharmacological strategies. Work is needed to clarify optimal use of available medications. This includes understanding the marked placebo effect in HIV-SN analgesic trials and exploring 'responder phenotypes'. Limited data support nondrug strategies including hypnosis, meditation, psychology, physical activity and a positive therapeutic relationship.

Antiretrovirals, Methamphetamine, and HIV-1 Envelope Protein gp120 Compromise Neuronal Energy Homeostasis in Association with Various Degrees of Synaptic and Neuritic Damage

HIV-1 infection frequently causes HIV-associated neurocognitive disorders (HAND) despite combination antiretroviral therapy (cART). Evidence is accumulating that components of cART can themselves be neurotoxic upon long-term exposure. In addition, abuse of psychostimulants, such as methamphetamine, seems to aggravate HAND and compromise antiretroviral therapy. However, the combined effect of virus and recreational and therapeutic drugs on the brain is poorly understood. Therefore, we exposed mixed neuronal-glial cerebrocortical cells to antiretrovirals (ARVs) (zidovudine [AZT], nevirapine [NVP], saquinavir [SQV], and 118-D-24) of four different pharmacological categories and to methamphetamine and, in some experiments, the HIV-1 gp120 protein for 24 h and 7 days. Subsequently, we assessed neuronal injury by fluorescence microscopy, using specific markers for neuronal dendrites and presynaptic terminals. We also analyzed the disturbance of neuronal ATP levels and assessed the involvement of autophagy by using immunofluorescence and Western blotting. ARVs caused alterations of neurites and presynaptic terminals primarily during the 7-day incubation and depending on the specific compounds and their combinations with and without methamphetamine. Similarly, the loss of neuronal ATP was context specific for each of the drugs or combinations thereof, with and without methamphetamine or viral gp120. Loss of ATP was associated with activation of AMP-activated protein kinase (AMPK) and autophagy, which, however, failed to restore normal levels of neuronal ATP. In contrast, boosting autophagy with rapamycin prevented the long-term drop of ATP during exposure to cART in combination with methamphetamine or gp120. Our findings indicate that the overall positive effect of cART on HIV infection is accompanied by detectable neurotoxicity, which in turn may be aggravated by methamphetamine.

Distal leg epidermal nerve fiber density as a surrogate marker of HIV-associated sensory neuropathy risk: risk factors and change following initial antiretroviral therapy

Distal leg epidermal nerve fiber density (ENFD) is a validated predictor of HIV sensory neuropathy (SN) risk. We assessed how ENFD is impacted by initiation of first-time antiretroviral therapy (ART) in subjects free of neuropathy and how it is altered when mitochondrial toxic nucleoside medications are used as part of ART. Serial changes in proximal thigh and distal leg ENFD were examined over 72 weeks in 150 Thai subjects randomized to a regimen of stavudine (d4T) switching to zidovudine (ZDV) at 24 weeks vs ZDV vs tenofovir (TDF) for the entire duration of study, all given in combination with nevirapine. We found individual variations in ENFD change, with almost equal number of subjects who decreased or increased their distal leg ENFD over 72 weeks and no relationship to nucleoside backbone or to development of neuropathic signs or symptoms. Lower baseline distal leg ENFD and greater increases in mitochondrial oxidative phosphorylation complex I (CI) activity were associated with larger increases in distal leg ENFD over 72 weeks. Distal leg ENFD correlated with body composition parameters (body surface area, body mass index, height) as well as with blood pressure measurements. Assessed together with a companion cross-sectional study, we found that mean distal leg ENFD in all HIV+ subjects was lower than in HIV- subjects but similar among HIV+ groups whether ART-naïve or on d4T with/without neuropathy/neuropathic symptoms. The utility of ENFD as a useful predictor of small unmyelinated nerve fiber damage and neuropathy risk in HIV may be limited in certain populations.

Patterns of peripheral neuropathy in ART-naïve patients initiating modern ART regimen

The purpose of this study was to evaluate associations of pre-ART CD4 with peripheral neuropathy (PN) and estimate the prevalence of PN in HIV-positive patients starting modern combination antiretroviral therapy (cART) regimens. ART-naïve subjects initiating cART were followed longitudinally and screened for signs/symptoms of PN. Lower pre-ART CD4 count was associated with post-ART PN. After 7 years (n = 117), the prevalence (95% CI) of PN and SPN were 31% (23, 40%) and 5% (2, 11%) with pre-ART CD4 count >250 copies/μL. PN continues to be identified in HIV-infected individuals on modern cART by targeted assessment but is generally without symptoms.

Diabetes mellitus type 2 and abnormal glucose metabolism in the setting of human immunodeficiency virus

As the modern era of combination antiretroviral therapy has increased life expectancy for individuals infected with the human immunodeficiency virus (HIV), type 2 diabetes mellitus and disorders of glucose metabolism have emerged as an important issue in the care of this population. Multiple mechanisms, both specific and nonspecific to HIV, underlie a significant prevalence. Although best-practice diagnostic testing remains unclear, the risks associated with diabetes in the setting of HIV are well characterized, ranging from organ-specific damage to socioeconomic decline. As population-specific treatment data are limited, current guidelines serve as a basis for ongoing management.

Peripheral neuropathy in ART-experienced patients: prevalence and risk factors

Peripheral neuropathy (PN) is a common neurological complication of HIV infection that has debilitating effects on quality of life. While there has been a comprehensive evaluation of the prevalence of neuropathic signs/symptoms and risk factors (RFs) for PN or symptomatic PN (SPN) with initiation of combination antiretroviral therapy (cART) in ART-naïve patients, similar evaluation in ART-experienced patients is limited. This study investigated the prevalence and RFs for PN/SPN in ART-experienced patients enrolled in clinical salvage therapy studies. Between February 2000 and June 2007, 522 ART-experienced participants who experienced virologic failure with a prior regimen and started new regimens were followed longitudinally and annually screened for signs and symptoms of PN. Rates of PN/SPN at 3 years since parent study entry were 52.8 and 24.0 %, respectively. Aging, taller height, protease inhibitor use, and female sex were significant RFs for PN/SPN. The use of statin drugs was significantly associated with lower odds of SPN, and it may prevent progression from no SPN to SPN.

Manifestations of HIV infection in the peripheral nervous system

Peripheral nerve disorders are associated with all stages of HIV infection. Distal sensory polyneuropathy is characterised by often-disabling pain that is difficult to treat. It is prevalent in both high-income and low-income settings. In low-income settings, use of potentially neurotoxic antiretrovirals, which are inexpensive and widely available, contributes substantially to incidence. Research has focused on identification of factors that predict risk of distal sensory polyneuropathy and elucidation of the multifactorial mechanisms behind pathogenesis. Sensorimotor polyneuropathies and polyradiculopathies are less frequent than distal sensory polyneuropathy, but still occur in low-income settings and have potentially devastating consequences. However, many of these diseases can be treated successfully with a combination of antiretroviral and immune-modulating therapies. To distinguish between peripheral nerve disorders that have diverse, overlapping, and frequently atypical presentations can be challenging; a framework based on a clinicoanatomical approach might assist in the diagnosis and management of such disorders.

HIV peripheral neuropathy

Peripheral neuropathies are the most common neurological manifestations occurring in HIV-infected individuals. Distal symmetrical sensory neuropathy is the most common form encountered today and is one of the few that are specific to HIV infection or its treatment. The wide variety of other neuropathies is akin to the neuropathies seen in the general population and should be managed accordingly. In the pre-ART era, neuropathies were categorized according to the CD4 count and HIV viral load. In the early stages of HIV infection when CD4 count is high, the inflammatory demyelinating neuropathies predominate and in the late stages with the decline of CD4 count opportunistic infection-related neuropathies prevail. That scenario has changed with the present almost universal use of ART (antiretroviral therapy). Hence, HIV-associated peripheral neuropathies are better classified according to their clinical presentations: distal symmetrical polyneuropathy, acute inflammatory demyelinating polyradiculoneuropathy (AIDP) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), mononeuropathies, mononeuropathies multiplex and cranial neuropathies, autonomic neuropathy, lumbosacral polyradiculomyelopathy, and amyotrophic lateral sclerosis (ALS)-like motor neuropathy. Treated with ART, HIV-infected individuals are living longer and are at a higher risk of metabolic and age-related complications; moreover they are also prone to the potentially neurotoxic effects of ART. There are no epidemiological data regarding the incidence and prevalence of the peripheral neuropathies. In the pre-ART era, most data were from case reports, series of patients, and pooled autopsy data. At that time the histopathological evidence of neuropathies in autopsy series was almost 100%. In large prospective cohorts presently being evaluated, it has been found that 57% of HIV-infected individuals have distal symmetrical sensory neuropathy and 38% have neuropathic pain. It is now clear that distal symmetrical sensory neuropathy is caused predominantly by the ART's neurotoxic effect but may also be caused by the HIV itself. With a sizeable morbidity, the neuropathic pain caused by distal symmetrical sensory neuropathy is very difficult to manage; it is often necessary to change the ART regimen before deciding upon the putative role of HIV infection itself. If the change does not improve the pain, there are few options available; the most common drugs used for neuropathic pain are usually not effective. One is left with cannabis, which cannot be recommended as routine therapy, recombinant human nerve growth factor, which is unavailable, and topical capsaicin with its side-effects. Much has been done to and learned from HIV infection in humans; HIV-infected individuals, treated with ART, are now dying mostly from cardiovascular disease and non-AIDS-related cancers. It hence behooves us to find new approaches to mitigate the residual neurological morbidity that still impacts the quality of life of that population.