Manifestations of HIV infection in the peripheral nervous system

Chronic Morphine Treatment and Antiretroviral Therapy Exacerbate HIV-Distal Sensory Peripheral Neuropathy and Induce Distinct Microbial Alterations in the HIV Tg26 Mouse Model

Distal Sensory Peripheral Neuropathy (DSP) is a common complication in HIV-infected individuals, leading to chronic pain and reduced quality of life. Even with antiretroviral therapy (ART), DSP persists, often prompting the use of opioid analgesics, which can paradoxically worsen symptoms through opioid-induced microbial dysbiosis. This study employs the HIV Tg26 mouse model to investigate HIV-DSP development and assess gut microbiome changes in response to chronic morphine treatment and ART using 16S rRNA sequencing. Our results reveal that chronic morphine and ART exacerbate HIV-DSP in Tg26 mice, primarily through mechanical pain pathways. As the gut microbiome may be involved in chronic pain persistence, microbiome analysis indicated distinct bacterial community changes between WT and Tg26 mice as well as morphine- and ART-induced microbial changes in the Tg26 mice. This study reveals the Tg26 mouse model to be a relevant system that can help elucidate the pathogenic mechanisms of the opioid- and ART-induced exacerbation of HIV-associated pain. Our results shed light on the intricate interplay between HIV infection, ART, opioid use, and the gut microbiome in chronic pain development. They hold implications for understanding the mechanisms underlying HIV-associated pain and microbial dysbiosis, with potential for future research focused on prevention and treatment strategies.

Peripheral Neuropathy in Virologically Suppressed People Living with HIV: Evidence from the PIVOT Trial

The aim of this study is to identify the factors associated with peripheral neuropathy and to explore neurofilament light chain (NfL) as a biomarker for peripheral neuropathy (PN) in effectively virologically suppressed adults living with HIV. All protease inhibitor monotherapy versus ongoing triple therapy in the long-term management of HIV infection (PIVOT) trial participants with data on PN at baseline were included in the study. NfL plasma levels (pNfL) were measured in a sub-set of participants. Multivariable logistic regression was used to examine the associations of PN with potential risk factors (including age, sex, nadir CD4 cell count, history of dideoxynucleoside (d-drugs) exposure, and blood glucose levels) and NfL levels. Of the 585 participants included, 131 (22.4%) reported PN during the study period (median of 44 months). The participants were predominantly male (76.6%), White (68.2%), and virologically suppressed for a median period of 37 months (range of 20-63) before recruitment. The age at baseline was 44.3 years (standard deviation (SD) of 9.2). PN was independently associated with age (adjusted odds ratio (aOR) = 1.35, 95% CI of 1.20-1.52; additional 5 years), history of d-drugs (aOR 1.88, 95% CI of 1.12-3.16), height (aOR 1.19, 95% CI of 1.05-1.35; additional 5 cm), nadir CD4 cell count (aOR 1.10 CI of 1.00-1.20; 50 cells fewer), and metabolic syndrome (aOR 2.31, 95% CI of 1.27 4.20), but not pNfL. The excess risk for PN associated with d-drug use remains after the exposure has stopped for years, suggesting non-reversible toxicity. In people with HIV, metabolic syndrome is independently associated with PN. There was no additional value for pNfL as a screening test for peripheral neuropathy in effectively virologically suppressed adults living with HIV.

Infectious Neuropathies

OBJECTIVE

This article discusses the clinical manifestations and management of infectious peripheral neuropathies.

LATEST DEVELOPMENTS

Several infectious etiologies of peripheral neuropathy are well-recognized and their treatments are firmly established. The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with several central and peripheral nervous system manifestations, including peripheral neuropathies. Additionally, some COVID-19 vaccines have been associated with Guillain-Barré syndrome. These disorders are an active area of surveillance and research. Recent evidence-based guidelines have provided updated recommendations for the diagnosis and treatment of Lyme disease.

ESSENTIAL POINTS

Infectious agents of many types (primarily bacteria and viruses) can affect the peripheral nerves, resulting in various clinical syndromes such as mononeuropathy or mononeuropathy multiplex, distal symmetric polyneuropathy, radiculopathy, inflammatory demyelinating polyradiculoneuropathy, and motor neuronopathy. Knowledge of these infections and the spectrum of peripheral nervous system disorders associated with them is essential because many have curative treatments. Furthermore, understanding the neuropathic presentations of these disorders may assist in diagnosing the underlying infection.

Post-Infectious Autoimmunity in the Central (CNS) and Peripheral (PNS) Nervous Systems: An African Perspective

The direct impact and sequelae of infections in children and adults result in significant morbidity and mortality especially when they involve the central (CNS) or peripheral nervous system (PNS). The historical understanding of the pathophysiology has been mostly focused on the direct impact of the various pathogens through neural tissue invasion. However, with the better understanding of neuroimmunology, there is a rapidly growing realization of the contribution of the innate and adaptive host immune responses in the pathogenesis of many CNS and PNS diseases. The balance between the protective and pathologic sequelae of immunity is fragile and can easily be tipped towards harm for the host. The matter of immune privilege and surveillance of the CNS/PNS compartments and the role of the blood-brain barrier (BBB) and blood nerve barrier (BNB) makes this even more complex. Our understanding of the pathogenesis of many post-infectious manifestations of various microbial agents remains elusive, especially in the diverse African setting. Our exploration and better understanding of the neuroimmunology of some of the infectious diseases that we encounter in the continent will go a long way into helping us to improve their management and therefore lessen the burden. Africa is diverse and uniquely poised because of the mix of the classic, well described, autoimmune disease entities and the specifically "tropical" conditions. This review explores the current understanding of some of the para- and post-infectious autoimmune manifestations of CNS and PNS diseases in the African context. We highlight the clinical presentations, diagnosis and treatment of these neurological disorders and underscore the knowledge gaps and perspectives for future research using disease models of conditions that we see in the continent, some of which are not uniquely African and, where relevant, include discussion of the proposed mechanisms underlying pathogen-induced autoimmunity. This review covers the following conditions as models and highlight those in which a relationship with COVID-19 infection has been reported: a) Acute Necrotizing Encephalopathy; b) Measles-associated encephalopathies; c) Human Immunodeficiency Virus (HIV) neuroimmune disorders, and particularly the difficulties associated with classical post-infectious autoimmune disorders such as the Guillain-Barré syndrome in the context of HIV and other infections. Finally, we describe NMDA-R encephalitis, which can be post-HSV encephalitis, summarise other antibody-mediated CNS diseases and describe myasthenia gravis as the classic antibody-mediated disease but with special features in Africa.

A review of the genetic spectrum of hereditary spastic paraplegias, inherited neuropathies and spinal muscular atrophies in Africans

Background

Genetic investigations of inherited neuromuscular disorders in Africans, have been neglected. We aimed to summarise the published data and comment on the genetic evidence related to inherited neuropathies (Charcot-Marie-Tooth disease (CMT)), hereditary spastic paraplegias (HSP) and spinal muscular atrophy (SMA) in Africans.

Methods

PubMed was searched for relevant articles and manual checking of references and review publications were performed for African-ancestry participants with relevant phenotypes and identified genetic variants. For each case report we extracted phenotype information, inheritance pattern, variant segregation and variant frequency in population controls (including up to date frequencies from the gnomAD database).

Results

For HSP, 23 reports were found spanning the years 2000–2019 of which 19 related to North Africans, with high consanguinity, and six included sub-Saharan Africans. For CMT, 19 reports spanning years 2002–2021, of which 16 related to North Africans and 3 to sub-Saharan Africans. Most genetic variants had not been previously reported. There were 12 reports spanning years 1999–2020 related to SMN1-SMA caused by homozygous exon 7 ± 8 deletion. Interestingly, the population frequency of heterozygous SMN1-exon 7 deletion mutations appeared 2 × lower in Africans compared to Europeans, in addition to differences in the architecture of the SMN2 locus which may impact SMN1-SMA prognosis.

Conclusions

Overall, genetic data on inherited neuromuscular diseases in sub-Saharan Africa, are sparse. If African patients with rare neuromuscular diseases are to benefit from the expansion in genomics capabilities and therapeutic advancements, then it is critical to document the mutational spectrum of inherited neuromuscular disease in Africa.

Highlights

Review of genetic variants reported in hereditary spastic paraplegia in Africans

Review of genetic variants reported in genetic neuropathies in Africans

Review of genetic underpinnings of spinal muscular atrophies in Africans

Assessment of pathogenic evidence for candidate variants

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02280-2.

HIV Neuropathy-a Review of Mechanisms, Diagnosis, and Treatment of Pain

PURPOSE OF REVIEW

This article is a systematic review of data from 2018 to 2020 regarding information from publications on epidemiologic, diagnostic, and therapeutic advancements in human immunodeficiency virus-associated peripheral neuropathy.

RECENT FINDINGS

The epidemiology/pathology of HIV neuropathy is discussed. Diagnostics includes skin wrinkling-eutectic mixture of local anesthetic test and neurologic examinations. Therapeutic interventions include pharmacologic and nonpharmacologic management as well as self-management strategies. Peripheral neuropathy continues to affect the lives of persons living with HIV. First-line treatment with pregabalin or gabapentin for HIV neuropathic pain has limited data on adequate response. Exercise and self-management strategies may provide benefit in pain reduction. Continuing research on risk factors and biomarkers for HIV-related peripheral neuropathy will be critical for future diagnostic and therapeutic agents.

Polyneuropathy following COVID-19 infection: the rehabilitation approach

A range of neurological manifestations associated with COVID-19 have been reported in the literature, but the pathogenesis of these have yet to be fully explained. The majority of cases of peripheral nervous system disease published thus far have shown a symmetrical pattern. In contrast, we describe the case of a patient with asymmetrical predominantly upper-limb sensorimotor polyneuropathy following COVID-19 infection, likely due to a multifactorial pathological process involving critical illness neuropathy, mechanical injury and inflammatory disease. His presentation, management and recovery contribute to the understanding of this complex condition and informs rehabilitation approaches.

Brief Report: Demographic and Genetic Associations With Markers of Small and Large Fiber Sensory Neuropathy in HIV Patients Treated Without Stavudine

Neurotoxic antiretroviral therapy (ART) such as stavudine has been now replaced with safer therapies, reducing the prevalence of neuropathy from 34% to 15% in HIV+ Indonesians. However, it is unclear whether the residual cases display damage to small or large nerve fibers and whether both are influenced by known risk factors, including alleles of CAMKK2 associated with neuropathy in HIV patients. The encoded protein influences the growth and repair of nerve fibers. HIV-positive adults on ART for >12 months without exposure to stavudine were screened for neuropathy using the AIDS Clinical Trials Group Brief Peripheral Neuropathy Screen (BPNS). Large fiber neuropathy was assessed by nerve conduction (NC) and small fiber neuropathy using stimulated skin wrinkling (SSW) applied to the fingers. CAMKK2 alleles were assessed by TaqMan OpenArray technology. Neuropathy diagnoses were more common with SSW than BPNS (49/173 vs 26/185, χ; P = 0.0009), with poor alignment between these outcomes (P = 0.60). NC and BPNS diagnosed neuropathy at similar frequencies (29/151 vs 26/185; P = 0.12) and were aligned (P < 0.0001). In bivariate analyses, all diagnoses were associated with patients' age and persistent HIV replication, with minor effects from CD4 T-cell counts and time on ART. CAMKK2 alleles associated with neuropathy diagnosed with BPNS and SSW but not NC. Multivariable analyses confirmed the importance of age and HIV replication, with distinct CAMKK2 polymorphisms affecting BPNS and SSW. Paradoxically, height was protective against skin wrinkling. Overall the data link CAMKK2 genotypes with small rather than large fiber damage. SSW may reflect pathology distinct from that identified using BPNS.

Acupuncture for HIV-associated distal symmetric peripheral neuropathy: A protocol for systematic review and meta-analysis

BACKGROUND

Human immunodeficiency virus (HIV)-associated distal symmetric peripheral neuropathy (DSPN) is one of the most frequent neurological complications of HIV infection, and causes pain and dysaesthesias in millions globally. Many individuals with this infection report using acupuncture to manage their symptoms, but evidence supporting the use of acupuncture is limited. This systematic review will assess the effectiveness and safety of acupuncture for patients with HIV-associated DSPN.

METHODS

Databases including MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Scopus, Web of science, AMED (Allied and Complementary Medicine), the Chinese Biomedical Literature Database, the China National Knowledge Infrastructure, Wanfang Database, VIP Database and clinical trials registers (the WHO International Clinical Trials Registry Platform portal and www.ClinicalTrials.gov) will be electronically searched from inception to December 1, 2020. All randomized controlled trials in English or Chinese without restriction on publication status will be included. Selection of studies, extraction of data, and assessment of studies quality will be independently performed by 2 reviewers. The primary outcome measure will be the change in pain intensity assessed by validated scales. Secondary outcomes include change in neurologic summary scores, quality of life, physical function evaluated by admitted tools, and adverse events related to acupuncture reported in the included trials. If possible, a meta-analysis will be conducted to provide an estimate of the pooled treatment effect using Review Manager 5.3 statistical software. Otherwise, qualitative descriptive analysis will be given. The results will be presented as the risk ratio for binary data and the mean difference (MD) or standardized MD for continuous data.

RESULTS

The results of the systematic review will be disseminated via publication in a peer-reviewed journal and presented at a relevant conference.

CONCLUSION

This review will be the first review entirely focused on assessing the effectiveness and safety of acupuncture for HIV-associated DSPN.

PROSPERO REGISTRATION NUMBER

CRD42020210994.

Correlates of diabetic polyneuropathy of the elderly in Sub-Saharan Africa

Background

Diabetic polyneuropathy is associated with significant physical disability among older adults. However, their frequency and correlates are not well known in the older adults in Sub-Saharan-Africa. The objectives were to evaluate the hospital-based prevalence of diabetic polyneuropathy and identify its correlates in older adults.

Methods

Over a period of 5 months, a cross-sectional survey was carried out at Douala Laquintinie Hospital (DLH), a main reference hospital in Douala, the economic capital of Cameroon. Participants in our study group comprised all patients with type 2 diabetes, whatever the reason for their reporting to the hospital. Diabetic Polyneuropathy was defined according to a Diabetic Neuropathy Examination score > 3/16.

Results

A total of 159 older adults with diabetes were examined during this recruitment period, among whom 106 (66.7%) were women. The mean age was 68.3 ± 6.5 years. Diabetes median duration was 108 months. For all patients assessed using the Diabetic Neuropathy Examination score, polyneuropathy was reported in 31.4%; among them, polyneuropathy proved symptomatic in 78% of them. Correlates of polyneuropathy were glycated hemoglobin (p = 0.049), HIV infection (p = 0.031) and albuminuria (p< 0.001), even after adjustment for age, gender and duration of diabetes.

Conclusion

A third of older adults with diabetes who visited our hospital were diagnosed with prevalent diabetes-related polyneuropathy. It shows that early detection is required through routine screening and regular follow-up examinations in order to reduce the risk of disability and improve the quality of life in elderly diabetics.

Epidemics and outbreaks of peripheral nervous system disorders: I. infectious and immune-mediated causes

The history of mankind is marked by numerous epidemics, some of which involved diseases of the peripheral nervous system, either infectious or otherwise. We describe here the three main infectious causes of epidemics that affect the peripheral nervous system: leprosy, poliomyelitis and diphtheria. We then discuss the main epidemics of immune-mediated origin.

Management Issues in Myasthenia Gravis Patients Living With HIV: A Case Series and Literature Review

South Africa is home to more than seven million people living with human immunodeficiency virus (HIV) and a high prevalence of tuberculosis. Human immunodeficiency virus–infected individuals may develop myasthenia gravis (MG), which raises questions regarding their management. An MG database, with 24 years of observational data, was audited for HIV-infected persons. Case reports of MG in HIV-infected persons were reviewed. We identified 17 persons with MG and HIV infection. All had generalized MG with a mean age at onset of 37.8 years. Eleven had acetylcholine receptor antibody–positive MG; one had antibodies against muscle-specific kinase. Six developed MG prior to HIV infection (mean CD4⁺ 361 cells/mm³); four worsened <6 months of starting antiretrovirals. Eleven developed MG while HIV-infected (mean CD4⁺ 423 cells/mm³); five presented with mild MG; three in MG crisis requiring rescue therapies (intravenous immune globulin or plasma exchange and/or intravenous cyclophosphamide). Two were diagnosed with HIV infection and MG at the same time. Fifteen required maintenance steroid-sparing immune therapies, predominantly azathioprine, or methotrexate. Plasma HIV viral loads remained below detectable levels on antiretrovirals during immunosuppressant treatment. Over the average follow-up of 6 years, 10 achieved minimal manifestation status, and the remainder improved to mild symptoms. Three cases had tuberculosis before MG, but none developed tuberculosis reactivation on immunosuppressive therapy; one used isoniazid prophylaxis. Herpes zoster reactivation during treatment occurred in one. Conclusions include the following: MG in HIV-infected patients should be managed similarly to individuals without HIV infection; half develop moderate–severe MG; MG symptoms may worsen within 6 months of antiretroviral initiation; safety monitoring must include plasma HIV viral load estimation. Isoniazid prophylaxis may not be indicated in all cases.

Distal Sensory Peripheral Neuropathy in Human Immunodeficiency Virus Type 1-Positive Individuals Before and After Antiretroviral Therapy Initiation in Diverse Resource-Limited Settings

BACKGROUND

Distal sensory peripheral neuropathy (DSPN) is a complication of human immunodeficiency virus (HIV). We estimate DSPN prevalence in 7 resource-limited settings (RLSs) for combination antiretroviral therapy (cART)-naive people living with HIV (PLWH) compared with matched participants not living with HIV and in PLWH virally suppressed on 1 of 3 cART regimens.

METHODS

PLWH with a CD4+ count <300 cells/mm3 underwent standardized neurological examination and functional status assessments before and every 24 weeks after starting cART. Matched individuals not living with HIV underwent the same examinations once.Associations between covariates with DSPN at entry were assessed using the χ2 test, and virally suppressed PLWH were assessed using generalized estimating equations.

RESULTS

Before initiating cART, 21.3% of PLWH had DSPN compared with 8.5% of people not living with HIV (n = 2400; χ2(df = 1) = 96.5; P < .00001). PLWH with DSPN were more likely to report inability to work [χ2(df = 1) = 10.6; P = .001] and depression [χ2(df = 1) = 8.9; P = .003] than PLWH without DSPN. Overall prevalence of DSPN among those virally suppressed on cART decreased: 20.3%, week 48; 15.3%, week 144; and 10.3%, week 192. Incident DSPN was seen in 127 PLWH. Longitudinally, DSPN was more likely in older individuals (P < .001) and PLWH with less education (P = .03). There was no significant association between cART regimen and DSPN.

CONCLUSIONS

Although the prevalence of DSPN decreased following cART initiation in PLWH, further research could identify strategies to prevent or ameliorate residual DSPN after initiating cART in RLSs.

Motor lumbosacral radiculopathy in HIV-infected patients

Background

This study is a review of the clinical findings and treatment outcome of 11 HIV-infected patients with motor lumbosacral radiculopathy.

Objectives

To describe the clinical, laboratory, electrophysiological features and treatment outcome in HIV-infected motor lumbosacral radiculopathy which is a rare manifestation of HIV.

Method

A retrospective review of HIV-infected patients with motor lumbosacral radiculopathy was performed at Inkosi Albert Luthuli Central Hospital (IALCH), Durban, South Africa between 2010 and 2015.

Results

Eleven black African patients met the inclusion criteria. There were six women. The median age was 29 years, the interquartile range (IQR) was 23-41 years, the median duration of symptom progression was 6.5 months (IQR 3-7.5 months). The median CD4 count was 327 cells/µL (IQR 146-457). The cerebrospinal fluid (CSF) median polymorphocyte count was 0 cells/µL (IQR 0 cells/µL - 2 cells/µL), lymphocyte count was 16 cells/µL (IQR 1 cells/µL - 18 cells/µL), glucose level was 3.1 mmol/L (IQR 2.8 mmol/L - 3.4 mmol/L) and protein level was 1.02 g/dL (IQR 0.98 g/dL - 3.4 g/dL). All patients were treated with corticosteroid therapy. Ninety-one per cent recovered fully within 6 months of treatment, the median time for recovery was 3.4 months (IQR 1.8-5.6 months). There were no relapses during the 18-month follow-up.

Conclusion

HIV-infected patients with motor lumbosacral radiculopathy responded to corticosteroids, with no relapses during the 18-month follow-up period.

Muscle strength is impaired in men but not in women living with HIV taking antiretroviral therapy

BACKGROUND

There is evidence that HIV antiretroviral therapy adverse effects may be sex-dependent, but data examining these sex differences in muscle strength is scarce. Our aim was to compare dynamic and isokinetic parameters of muscle strength between HIV-infected men and women to HIV-uninfected subjects.

METHODS

In this cross-sectional study, muscle strength was evaluated in 44 HIV-infected (20 men, 24 women) and 25 age-, race- and body mass index-matched HIV-uninfected subjects (11 men, 14 women). We assessed knee flexion and extension efforts in isokinetic dynamometer at angular velocities of 60° and 180°/s, and 1 repetition maximum test (1RM) for bench press, leg press and arm curl exercises, respectively. Lean body mass (LBM) was measured using bioelectrical impedance.

RESULTS

HIV-infected men had significantly less dynamic muscle strength for 1RM total (262.5 versus 357.2 kg), bench press (48.6 versus 60.3 kg), leg press (182.7 versus 261 kg) and arm curl (31.2 versus 36.5 kg) compared to HIV-uninfected men (P≤0.05); no differences were found among women. Men had lower values for peak torque in extension and flexion movements at 60°/s and 180°/s, while HIV-infected women presented higher peak torque in extension movement at 60°/s compared to controls. No differences were found in LBM. Moreover, isokinetic evaluation demonstrated that HIV-infected subjects showed greater acceleration and deceleration time in some variables, compared to controls, related to difficulty in activating motor units.

CONCLUSIONS

HIV infection is associated with impaired dynamic and isokinetic strength in men compared to HIV-uninfected controls, but not in women.

Peripheral neuropathy in HIV patients on antiretroviral therapy: Does it impact function?

HIV-associated distal sensory polyneuropathy (DSP), with or without neuropathic symptoms, can develop after anti-retroviral therapy (ART). Symptoms frequently involve small fibres but reports on autonomic dysfunction in HIV-DSP are sparse. We studied an HIV-infected cohort after 5 years of ART, and report on the frequency and severity of autonomic symptoms and the impact of DSP on everyday function. This cross-sectional study comprised of participants from a community-based South African HIV-clinic. The Brief Peripheral Neuropathy Screen and reduced Total Neuropathy Score evaluated neuropathic symptoms/signs. DSP was defined as ≥2 symmetrical DSP-signs, and symptomatic DSP when accompanied by neuropathic symptoms. Autonomic symptoms questionnaires, heart rate variability and postural blood pressure changes were assessed. The Lower Extremity Functional Scale (LEFS) was completed. The 67 participants had a median age of 42 years and median ART exposure of 7 years with viral suppression in 84%. Most (81%) met our criteria for DSP and 36% had additional neuropathic symptoms. Autonomic symptoms and signs (above normative values) were present in 15% and more likely in those with symptomatic DSP (P < .001). Participants with DSP, even without symptoms, had lower LEFS scores (P ≤ .039) than those without. HIV-DSP is prevalent and impacts on daily living.

HIV-1 gp120 Promotes Lysosomal Exocytosis in Human Schwann Cells

Human immunodeficiency virus type 1 (HIV-1) associated neuropathy is the most common neurological complication of HIV-1, with debilitating pain affecting the quality of life. HIV-1 gp120 plays an important role in the pathogenesis of HIV neuropathy via direct neurotoxic effects or indirect pro-inflammatory responses. Studies have shown that gp120-induced release of mediators from Schwann cells induce CCR5-dependent DRG neurotoxicity, however, CCR5 antagonists failed to improve pain in HIV- infected individuals. Thus, there is an urgent need for a better understanding of neuropathic pain pathogenesis and developing effective therapeutic strategies. Because lysosomal exocytosis in Schwann cells is an indispensable process for regulating myelination and demyelination, we determined the extent to which gp120 affected lysosomal exocytosis in human Schwann cells. We demonstrated that gp120 promoted the movement of lysosomes toward plasma membranes, induced lysosomal exocytosis, and increased the release of ATP into the extracellular media. Mechanistically, we demonstrated lysosome de-acidification, and activation of P2X4 and VNUT to underlie gp120-induced lysosome exocytosis. Functionally, we demonstrated that gp120-induced lysosome exocytosis and release of ATP from Schwann cells leads to increases in intracellular calcium and generation of cytosolic reactive oxygen species in DRG neurons. Our results suggest that gp120-induced lysosome exocytosis and release of ATP from Schwann cells and DRG neurons contribute to the pathogenesis of HIV-1 associated neuropathy.

Neurological disorders in HIV in Africa: a review

BACKGROUND

Neurological disorders in HIV infection are a common cause of morbidity and mortality. The aim of this paper is to provide a narrative overview of up to date information concerning neurological disorders affecting HIV infected persons in Africa.

METHODS

Seminal research concerning neurological disorders among HIV-infected adults in sub-Saharan Africa from prior to 2000 was combined with an in-depth search of PubMed to identify literature published from 2000 to 2017. The following Mesh terms were used. "Nervous System Diseases" "HIV Infections" and "Africa South of the Sahara" and "Seizures" or "Spinal Cord Diseases" or "Peripheral Nervous System Diseases" or "AIDS Dementia Complex" or "Opportunistic Infections" or "Immune Reconstitution Inflammatory Syndrome" or "Stroke". Only those articles written in English were used. A total of 352 articles were identified, selected and reviewed and 180 were included in the study. These included case series, observational studies, interventional studies, guidelines and reviews with metanalyses. The author also included 15 publications on the subject covering the earlier phase of the HIV epidemic in Africa from 1987 to 1999 making a total of 195 references in the study. This was combined with extensive personal experience diagnosing and treating these neurological disorders.

RESULTS

Neurological disorders were common, typically occurring in WHO stages III/IV. These were in three main categories: those arising from opportunistic processes mostly infections, direct HIV infection and autoimmunity. The most common were those arising from direct HIV infection occurring in >50%. These included HIV-associated neurocognitive dysfunction (HAND), neuropathy and myelopathy. Opportunistic infections occurred in >20% and frequently had a 6-9-month mortality rate of 60-70%. The main causes were cryptococcus, tuberculosis, toxoplasmosis and acute bacterial meningitis. Concurrent systemic tuberculosis occurred in almost 50%.

CONCLUSION

Neurological disorders are common in HIV in Africa and the main CNS opportunistic infections result in high mortality rates. Strategies aimed at reducing their high burden, morbidity and mortality include early HIV diagnosis and anti-retroviral therapy (ART), screening and chemoprophylaxis of main opportunistic infections, improved clinical diagnosis and management and programme strengthening.

Vibrotactile sensitivity of patients with HIV-related sensory neuropathy: An exploratory study

BACKGROUND

HIV-associated distal polyneuropathy (HIV-PN) affects large and small sensory nerve fibers and can cause tactile insensitivity. This exploratory study forms part of an effort to apply subsensory electrical nerve stimulation (SENS) to improve tactile sensitivity of patients with HIV-PN. This work presented an opportunity to use a robust protocol to quantitatively describe the vibrotactile sensitivity of individuals with HIV-PN on effective antiretroviral therapy (ART) and correlate these findings with commonly used clinical vibration testing and scoring grades.

METHODS

The vibration perception thresholds (VPTs) of 20 patients with HIV-PN at three vibration frequencies (25, 50, and 128 Hz) were measured. We compare the vibration perception threshold (VPT) outcomes to an age- and gender-matched control cohort. We further correlated VPT findings with 128 Hz tuning fork (TF) assessments performed on the HIV-PN participants, accrued as part of a larger study. HIV-PN was defined as having at least one distal symmetrical neuropathic sign, although 18 of 20 had at least two neuropathic signs.

CONCLUSIONS

HIV-PN participants were found to have lower VPT sensitivity than controls for all three vibration frequencies, and VPT was more sensitive at higher vibration frequencies for both HIV-PN and controls. VPT sensitivity was reduced with older age. Years on ART was correlated with VPT-25 Hz but not with VPT in general. Notably, VPT sensitivity did not correlate with the clinically used 128 Hz TF severity grades. Outcomes of tests for interaction with vibration frequency suggest that HIV-PN pathology does not affect all mechanoreceptors similarly.

Factors associated with distal symmetric polyneuropathies in adult Zambians: A cross-sectional, observational study of the role of HIV, non-antiretroviral medication exposures, and nutrition

BACKGROUND

Non-antiretroviral (ART) drug exposures and poor nutrition may be important modifiable risk factors for distal symmetric polyneuropathies (DSP) in sub-Saharan Africa.

METHODS

We conducted a cross-sectional study of DSP prevalence and factors associated with DSP among clinic attendees in urban and rural Zambia. All participants underwent neurologist-performed examination. Laboratory investigations seeking comorbid risk factors for DSP were performed for DSP cases.

RESULTS

We identified 31/137 (22.6%) HIV+ and 21/177 (11.9%) HIV- DSP cases. DSP prevalence did not differ by urbanicity, although rural participants were significantly more likely to have one asymptomatic DSP sign. Low dietary diversity, history of syphilis, history of tuberculosis, and prior metronidazole and ciprofloxacin use were associated with DSP amongst HIV+ cases, while age and education were associated with DSP in HIV- participants (all p-values < 0·05). In a multivariate logistic regression model, HIV (p = 0·0001) and age (p < 0·0001), and ciprofloxacin exposure (p = 0·01) remained independently associated with DSP. While diabetes was rare, supoptimal micronutrients levels were common among DSP cases regardless of HIV status.

CONCLUSIONS

While HIV infection is strongly associated with DSP in Zambia, history of non-ART drug exposures and low dietary diversity are also important determinants of DSP in HIV+ individuals. Treatable micronutrient deficiencies were common.

Neuromuscular diseases associated with Human Immunodeficiency Virus infection

From the most common distal symmetric polyneuropathy (Bilgrami and O'Keefe, 2014) to the rare motor neuron diseases, HIV infection is associated with pathology at all levels of the peripheral nervous system. HIV infection can cause these conditions due to viral exposure itself, the resulting immune dysregulation, opportunistic infections found in untreated patients, and from the therapy used in treatment of the virus. Before the advent of antiretroviral therapy, 5 neuromuscular diseases associated with HIV often resulted from opportunistic infections. With advances in antiretroviral therapy, the etiologies of neuromuscular complications more frequently become the result of prolonged HIV exposure, comorbid diseases, and side effects of medications. In this article we review the literature on HIV associated neuromuscular diseases, emphasizing the more recent studies in the post antiretroviral era, but also reviewing conditions more prevalent in the pre antiretroviral era which continue to be seen in developing countries and resource poor areas. This discussion includes the following conditions: distal symmetric polyneuropathy, autonomic neuropathy, inflammatory demyelinating polyneuropathy, mononeuropathy, mononeuropathy multiplex, polyradiculopathies, myelopathy, myopathy, motor neuron disease, and antiretroviral treatment related conditions.

Knee extension and flexion strength asymmetry in Human Immunodeficiency Virus positive subjects: a cross-sectional study

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HIV-positive subjects present higher strength indices for the dominant versus the non-dominant leg.

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Strength asymmetry between limbs was observed in up to 58% of subjects.

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Lower-limb strength asymmetry is associated with impaired balance and gait.

Background

Human Immunodeficiency Virus positive subjects present impairment in muscle function, neural activation, balance, and gait. In other populations, all of these factors have been associated with muscle strength asymmetry.

Objective

To investigate the existence of muscle strength asymmetry between dominant and non-dominant lower limbs and to determine the hamstrings-to-quadriceps strength ratio in Human Immunodeficiency Virus positive subjects.

Methods

In this cross-sectional study, 48 subjects were included (22 men and 26 women; mean age 44.6 years), all of them under highly active antiretroviral therapy. They performed isokinetic strength efforts at speeds of 60°/s and 180°/s for knee extension and flexion in concentric-concentric mode.

Results

Peak torque was higher (p < 0.01) at 60°/s for quadriceps (193, SD = 57 vs. 173, SD = 55% body mass) and hamstrings (97, SD = 36 vs. 90, SD = 37% body mass) in dominant compared to non-dominant. Similarly, peak torque was higher at 180°/s (quadriceps 128, SD = 44 vs. 112, SD = 42; hamstrings 64, SD = 24 vs. 57, SD = 26% body mass) in dominant. Average power was also higher for all muscle groups and speeds, comparing dominant with non-dominant. The hamstrings-to-quadriceps ratio at 60°/s was 0.50 for dominant and 0.52 for non-dominant, and at 180°/s, it was 0.51 for both limbs, with no significant difference between them. The percentage of subjects with strength asymmetry ranged from 46 to 58%, depending upon muscle group and speed analyzed.

Conclusion

Human Immunodeficiency Virus positive subjects present muscle strength asymmetry between lower limbs, assessed through isokinetic dynamometry.

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.

Prevalence of Peripheral Neuropathy and associated factors in HIV-infected patients

The progress on HIV infection treatment has allowed a longer survival for HIV-infected patients. However, chronic comorbidities are emerging. Peripheral Neuropathy (PN) represents one of the most prevalent neurologic disorders among these patients, and comprehensive studies may contribute to a reduction in the morbidity of this condition. This is a cross-sectional analytic study conducted in a tertiary referral hospital in southern Brazil. This study investigates the prevalence of PN among HIV-infected patients and associated demographic, clinical and laboratory variables. A number of 150 HIV-infected patients admitted between January and May 2016 were interviewed, submitted to physical and neurological examination, and data from their medical records were obtained. The prevalence of PN was 31.3%. It was increased among older patients (p=0.02), patients with higher CD4 lymphocytes levels (p=0.02), and smokers (OR=3.4; 95% CI 1.6-6.9; p<0.01). The research identified a high prevalence of PN in HIV-infected patients. Older age and higher CD4 levels have been associated with PN. To the best of our knowledge, this was one of the first studies reporting an association between tobacco use and PN among HIV-infected patients. Further studies are necessary to elucidate the pathological mechanisms linking PN and tobacco.

A comparative study of CIDP in a cohort of HIV-infected and HIV-uninfected patients

OBJECTIVE

To investigate differences in clinical presentation, electrodiagnostic measures, CSF changes, and treatment outcome measures in HIV-infected and HIV-uninfected patients with chronic inflammatory demyelinating polyneuropathy (CIDP).

METHODS

A retrospective analysis of medical records of all patients meeting the European Federation of Neurology diagnostic criteria for idiopathic CIDP was performed in 2 neuromuscular units in Kwa-Zulu Natal between 2003 and 2015.

RESULTS

Eighty-four patients were included in the study; 39 were HIV-infected and 45 were HIV-uninfected. Among the HIV-infected patients, the majority were younger, were female, and had a monophasic progressive illness. Eighty-six percent (86%) were corticosteroid-responsive and 76% were in remission within 6-12 months requiring no further treatment. Among the HIV- uninfected patients, the majority were older, were male, and had a relapsing-remitting course. Twenty-seven percent (27%) were corticosteroid-responsive, 95% required combination therapy, and 33% were not in remission by 18 months on therapy.

CONCLUSION

This study shows that HIV-infected patients with CIDP were younger, were more often female, displayed a monophasic progressive course, were highly steroid-responsive, and went into remission within 12 months of corticosteroid initiation.

The effects of prenatal HIV exposure on language functioning in Kenyan children: establishing an evaluative framework

BACKGROUND

HIV infection has been associated with impaired language development in prenatally exposed children. Although most of the burden of HIV occurs in sub-Saharan Africa, there have not been any comprehensive studies of HIV exposure on multiple aspects of language development using instruments appropriate for the population.

METHODS

We compared language development in children exposed to HIV in utero to community controls (N = 262, 8-30 months) in rural Kenya, using locally adapted and validated communicative development inventories.

RESULTS

The mean score of the younger HIV-exposed uninfected infants (8-15 months) was not significantly below that of the controls; however older HIV-exposed uninfected children had significantly poorer language scores, with HIV positive children scoring more poorly than community controls, on several measures.

CONCLUSIONS

Our preliminary data indicates that HIV infection is associated with impaired early language development, and that the methodology developed would be responsive to a more detailed investigation of the variability in outcome amongst children exposed to HIV, irrespective of their infection status.

Treatment of human immunodeficiency virus-related peripheral neuropathy with Scrambler Therapy: a case report

Peripheral neuropathy is one of the most common neurological complications of HIV infection with a 30-60% lifetime prevalence. Newer HIV drugs cause less peripheral neuropathy, but patients are now living long enough to develop concomitant diabetes-related, vascular-related, and chemotherapy-related neuropathy so it continues as a major debilitating issue. Recent national CDC guidelines have stressed the importance of non-opioid therapies, especially in this population that may have had drug abuse problems. We treated a 52-year-old man who had severe disabling classic peripheral neuropathy since 1998 with Scrambler Therapy (Calmare), an FDA-cleared peripheral non-invasive neuromodulation device. His pain rapidly improved, as did his motor and sensory function, with just four 45-min treatments, and he was able to come off opioids for the first time in years. When his pain returned six months later, only two treatments were needed to resolve it. This represents the first published use of this novel, inexpensive, and non-invasive pain modality in HIV peripheral neuropathy, and should engender further trials.

CIDP in a HIV endemic population: A prospective case series from Johannesburg, South Africa

OBJECTIVE

To describe patients with Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) in Johannesburg, South Africa, a setting of high HIV prevalence, and to determine the influence, if any, of HIV on CIDP.

METHODS

Patients were recruited prospectively. The study design was a hospital based case series of unselected consecutive CIDP patients. CIDP was diagnosed according to the European Federation of Neurological Societies/Peripheral Nerve Society criteria for the diagnosis of CIDP (First Revision). Demographic, clinical, laboratory and electrophysiological data were documented.

RESULTS

Twenty three patients with CIDP were recruited over a two year period. Mean age was 38 years. The female to male ratio was 3.6:1. Less than half (43%) had a raised cerebrospinal fluid (CSF) protein. All patients had idiopathic CIDP, three had associated diabetes mellitus. Ten patients (43%) were HIV positive. Thirteen patients were HIV negative. Clinical and electrophysiological characteristics were identical in the two groups. In the HIV positive group all the patients were black females. The CD4 counts ranged from 87 to 747 cells/mm(3). HIV positive status was associated with a progressive disease course and significantly with a CSF lymphocytic pleocytosis (p=0.007). Albuminocytological dissociation was associated with HIV negative status.

CONCLUSIONS

Testing for HIV in patients with CIDP in a region of high HIV prevalence is recommended. CSF lymphocytic pleocytosis occurs in HIV associated CIDP.

Association of tumor necrosis factor-alpha and interferon gamma gene polymorphisms and their plasma levels in leprosy, HIV and other peripheral neuropathies

OBJECTIVE

Mycobacterium leprae and Human Immunodeficiency Virus (HIV) are causative agents known to be involved in nerve damage in leprosy and HIV-peripheral neuropathy (HIV-PN) respectively. Among other peripheral neuropathies the most common is diabetic neuropathy, which is metabolically induced. The proinflammatory cytokines TNF-α and IFN-γ have been implicated in the pathogenesis of peripheral neuropathy. The association between the plasma levels of these cytokines and their single nucleotide polymorphisms (SNPs) were investigated in leprosy neuropathy (LN), HIV-PN and other peripheral neuropathies (OPN).

METHODS

Eighty-eight individuals with LN (PB=36; MB=52), 39 with HIV-PN, 52 patients with OPN, 101 HIV positive individuals without neuropathy (HIV) and 113 healthy subjects (HS) were included in the study. Plasma cytokine levels were measured by sandwich ELISA and one way ANOVA was carried out among the groups. SNPs of TNF-α- 308 G/A, -238 G/A and IFN-γ +874 T/A were investigated by amplification refractory mutation system polymerase chain reaction (ARMS-PCR). Their frequencies were compared between groups by Pearson's chi squared test.

RESULTS

Plasma TNF-α and IFN-γ was significantly increased in LN (p<0.05), HIV-PN (p<0.05) and OPN (p<0.05) as compared to HS. A significant association was found between IFN-γ +874 A/A genotype in LN (p<0.05; OR=7.9), HIV-PN (p<0.05; OR=8.9) and OPN (p<0.05; OR=8.9) as compared to HS.

CONCLUSION

Elevated levels of plasma TNF-α and IFN-γ and the association of IFN-γ +874 A/A genotype SNP in LN, HIV-PN and OPN suggests a common involvement of these cytokines in susceptibility/pathogenesis of peripheral neuropathy.

Sensory neuropathy and metabolic risk factors in human immune deficiency virus infected South Africans receiving protease inhibitors

Background

Protease inhibitors (PI)s have been associated with distal sensory polyneuropathy (DSP) and metabolic complications in high-income countries. No data exist in Africans where second-line antiretroviral therapy (ART) often include PIs.

Method

We performed a cross-sectional study to assess the DSP frequency and metabolic risk factors in community-based South Africans taking ritonavir-boosted lopinavir as PI. Examination findings categorized subjects as having DSP (≥1 neuropathic sign) or symptomatic DSP [DSP with symptom(s)]. Fasting-state glucose and lipid profiles were assessed. We compared the ritonavir/lopinavir-group to a nested group on first-line ART [dideoxy-nucleoside reverse transcriptase inhibitors (d-drugs)] selected from a dataset collected at the same time and matched for d-drug exposure.

Results

The ritonavir/lopinavir-group (n = 86) consisted predominantly of women (84 %) with a median age of 36 years (IQR 32–41). The median current CD4+ count was 489 cells/μL (IQR 291–665). The median exposure time to ritonavir/lopinavir was 18 months (IQR 10–26) and to d-drugs, 24 months (IQR 16–38). DSP was present in 78 % and symptomatic DSP in 48 %; symptoms were most frequently of moderate intensity. Only age independently associated with DSP and symptomatic DSP (p = 0.08 and p = 0.04, respectively). None of the metabolic syndrome components showed associations with DSP or symptomatic DSP despite a trend towards hypertriglyceridemia overall. The ritonavir/lopinavir-group had less DSP compared to the d-drug only group (p = 0.002) but the frequency of symptomatic DSP was similar (p = 0.49).

Conclusion

Ritonavir-boosted lopinavir did not add additional risk to developing DSP in this community-based African cohort after a median of 18 months on second-line ART.

Electronic supplementary material

The online version of this article (doi:10.1186/s12981-015-0073-8) contains supplementary material, which is available to authorized users.

Prevalence and determinants of diabetic polyneuropathy in a sub-Saharan African referral hospital

BACKGROUND

Diabetic peripheral neuropathy is the commonest complication of diabetes mellitus, and a major cause of limb amputations. In general however, the magnitude of diabetic neuropathy in sub-Saharan Africans with diabetes has been less reliably quantified. We assessed the prevalence and determinants of diabetic polyneuropathy in hospital settings in Cameroon.

METHODS

We conducted a cross-sectional survey at the Douala Laquintinie Hospital, which is one of the main reference hospital in the economic capital of Cameroon (3 million populations). Participants included all patients with type 1 (T1DM) or type 2 (T2DM) diabetes who reported to the hospital regardless of the reason, during a 5-month recruitment period. Polyneuropathy was defined as diabetic in a patient with a Diabetic Neuropathy Examination score of >3/16 and/or a monofilament score of <5/9.

RESULTS

A total of 306 patients were recruited, including 196 women (64%) and 294 (96%) with T2DM. The mean (standard deviation) values were 59.8 (11.2) years for age and 8.4 (8.2) years for diabetes duration. Clinical signs of polyneuropathy were present in 102 (crude prevalence rate: 33.3%) patients. The polyneuropathy was symptomatic in 79/102 (77.4%) patients. Determinants of polyneuropathy were urban residence (p=0.02), infection with hepatitis C virus (p=0.002), infection with HIV (p=0.012) and presence of albuminuria (p=0.0001).

CONCLUSION

About one in three patients with diabetes reporting to the hospital in our setting has prevalent diabetes related polyneuropathy. This emphasizes the importance of routine implementation of therapeutic education and other measures to limit the complications.

Mitotoxicity in distal symmetrical sensory peripheral neuropathies

Chronic distal symmetrical sensory peripheral neuropathy is a common neurological complication of cancer chemotherapy, HIV treatment and diabetes. Although aetiology-specific differences in presentation are evident, the clinical signs and symptoms of these neuropathies are clearly similar. Data from animal models of neuropathic pain suggest that the similarities have a common cause: mitochondrial dysfunction in primary afferent sensory neurons. Mitochondrial dysfunction is caused by mitotoxic effects of cancer chemotherapeutic drugs of several chemical classes, HIV-associated viral proteins, and nucleoside reverse transcriptase inhibitor treatment, as well as the (possibly both direct and indirect) effects of excess glucose. The mitochondrial injury results in a chronic neuronal energy deficit, which gives rise to spontaneous nerve impulses and a compartmental neuronal degeneration that is first apparent in the terminal receptor arbor--that is, intraepidermal nerve fibres--of cutaneous afferent neurons. Preliminary data suggest that drugs that prevent mitochondrial injury or improve mitochondrial function could be useful in the treatment of these conditions.

Infectious neuropathies

PURPOSE OF REVIEW

Infectious neuropathies are heterogeneous neuropathies with multiple causes. They still represent an important world health burden and some of them have no current available therapy.

RECENT FINDINGS

Leprosy incidence has decreased by 50% during the last years, but leprosy-related neuropathies still cause severe disability. The pure neuritic leprosy is a diagnostic challenge that may require nerve biopsy or nerve aspiration cytology. The treatment itself may lead to a 'reversal reaction', which further causes injuries to the nerve. HCV-related neuropathies may be related or not to the presence of cryoglobulins. The absence of vasculitis, the most frequent form is a peripheral sensory neuropathy involving small nerve fibers, and more accurately diagnosed by pain-related evoked potentials. HIV-related neuropathy has become the major neurological complication of HIV infection. Both HIV-induced neuropathy and antiretroviral toxic neuropathy are clinically indistinguishable. The existence of an isolated chronic polyneuropathy due to Borrelia burgdorferi remains highly controversial. Lastly, an active infectious ganglioneuritis caused by varicella zoster virus, producing shingles, is the most frequent infectious neuropathy in the world and may cause various neurological complications. Zoster sine herpete remains frequently undiagnosed.

SUMMARY

Recent data have improved our knowledge and diagnostic tools of infectious neuropathies. Treatment of the injured nerves is not yet available, and prevention and rapid diagnosis remain the main priorities for the clinician.

Plasma cytokine profiles in HIV-1 infected patients developing neuropathic symptoms shortly after commencing antiretroviral therapy: a case-control study

BACKGROUND

In patients infected with human immunodeficiency virus 1 (HIV-1) neuropathic symptoms may develop within weeks of starting combination antiretroviral therapy (cART). This timing coincides with the occurrence of immune reconstitution inflammatory syndrome. Our objective was to investigate the longitudinal association of plasma cytokine and soluble receptor concentrations with incident neuropathic symptoms within 12 weeks of starting programme-based cART in a nested case-control study.

METHODS

One hundred and twenty adults without neuropathic symptoms and about to initiate cART were followed longitudinally for 24 weeks after cART initiation. Subjects were examined for peripheral neuropathy at baseline (pre-cART) and 2-, 4-, 12- and 24 weeks thereafter. Individuals developing neuropathic symptoms within 12 weeks of starting cART were matched in a nested case-control design with those remaining symptom-free for at least 24 weeks. Plasma was collected at each visit. Cytokines and soluble receptors were quantified using multiplex immunometric assays.

RESULTS

Incident neuropathic symptoms occurred in 32 (27%) individuals within 12 weeks of starting cART for the first time. Cytokine concentrations increased at 2 weeks, irrespective of symptom-status, returning to baseline concentrations at 12 weeks. Compared to the control group, the symptomatic group had higher baseline levels of interleukin-1 receptor (IL-1R)-antagonist. The symptomatic group also showed greater increases in soluble interleukin-2 receptor-alpha and tumour necrosis factor (TNF) receptor-II levels at week 2 and soluble interleukin-6 receptor levels at week 12. Ratios of pro-inflammatory- vs anti-inflammatory cytokines were higher for TNF-alpha/IL-4 (p = 0.022) and interferon-gamma/IL-10 (p = 0.044) in those developing symptoms. After 24 weeks of cART, the symptomatic group showed higher CD4+ counts (p = 0.002).

CONCLUSIONS

The initiation of cART in previously treatment naïve individuals was associated with a cytokine 'burst' between 2- and 4 weeks compared with pre-cART levels. Individuals developing neuropathic symptoms within 12 weeks of starting cART showed evidence of altered cytokine concentrations even prior to initiating cART, most notably higher circulating IL-1R-antagonist levels, and altered ratios of "pain-associated" cytokine and soluble receptors shortly after cART initiation.

Mimics and chameleons in motor neurone disease

The progression of motor neurone disease (MND) is currently irreversible, and the grave implications of diagnosis naturally fuels concern among neurologists over missing a potential mimic disorder. There is no diagnostic test for MND but in reality there are few plausible mimics in routine clinical practice. In the presence of a progressive pure motor disorder, signs such as florid fasciculations, bilateral tongue wasting, the ‘split hand’, head drop, emotionality, and cognitive or behavioural impairment carry high positive predictive value. MND is clinically heterogeneous, however, with some important chameleon-like presentations and considerable variation in clinical course. Lack of confidence about the scope of such variation, or an approach to diagnosis emphasising investigations over clinical common sense, has the potential to exacerbate diagnostic delay in MND and impede timely planning of the care which is essential to maximising quality of life.