Hypertriglyceridemia in combination antiretroviral-treated HIV-positive individuals: potential impact on HIV sensory polyneuropathy

Lipids and apolipoproteins C-III and E among treatment-naïve and treatment-experienced persons with HIV in Nigeria

Background

Dyslipidaemia is a known cause of cardiovascular mortality. Persons living with HIV are at high risk of developing cardiovascular disease due to lipid metabolism disorders associated with HIV or its therapy.

Objective

This study evaluated concentrations of lipoproteins and apolipoprotein C-III and E, as a way of assessing cardiometabolic risks among HIV patients.

Methods

We enrolled 50 HIV-negative persons and 100 HIV-positive patients, 50 on antiretroviral therapy (ART) and 50 treatment-naïve persons, from the Central Hospital and the Stella Obasanjo Hospital, Benin City, Edo State, Nigeria, between May 2015 and November 2015. Participants with a history of metabolic abnormalities were excluded. Apolipoproteins were assessed by enzyme-linked immunosorbent assay, while lipids were measured by spectrophotometry.

Results

There were significant abnormalities in the lipid profile of patients with HIV. Triglycerides levels of HIV patients (ART-naïve: 1.44 ± 0.65 mmol/L; p < 0.001 and ART-experienced: 1.49 ± 0.70 mmol/L; p = 0.001) were significantly higher than among controls (0.95 ± 0.54 mmol/L). HIV patients had higher concentrations of apolipoprotein C-III than controls (p < 0.001) and higher low-density lipoprotein cholesterol levels (treatment-naïve: 2.83 mmol/L and ART-experienced patients: 3.59 mmol/L) than controls (2.50 mmol/L; p = 0.003). Conversely, HIV patients had significantly lowered high-density lipoprotein cholesterol levels compared to controls (p < 0.001).

Conclusion

Dyslipidaemia was observed among HIV participants, irrespective of their ART experience. Therefore, it is crucial that the lipids of HIV patients be closely monitored to enable early intervention and decrease cardiovascular death.

What this study adds

This study affirms that dyslipidemia is a complication of HIV or the prolonged use of ART.

A Comparison of Self-reported Pain Measures Between Sensory Phenotypes in HIV-associated Sensory Neuropathy

Painful HIV-associated neuropathy (HIV-SN) is a prevalent co-morbidity of HIV infection. Sensory phenotyping, using quantitative sensory testing (QST) could allow for improved stratification to guide personalized treatment. However, previous methods of QST interpretation have demonstrated limited association with self-reported pain measures. This study sought to identify differences in self-reported pain measures between composite QST-derived sensory phenotypes, and to examine any differences in participants reporting multi-site, multi-etiology chronic pain. In this cross-sectional observational study of participants with HIV (n = 133), individuals were allocated to neuropathy and neuropathic pain groups through clinical assessment and nerve conduction testing. They completed symptom-based questionnaires and underwent standardized QST. Participants were assigned, by pre-determined algorithm, to a QST-derived sensory phenotype. Symptoms were compared between sensory phenotypes. Symptom characteristics and Neuropathic Pain Symptom Inventory scores differed between QST-derived sensory phenotypes: 'sensory loss' was associated with more paroxysmal and paraesthetic symptoms compared to 'thermal hyperalgesia' and 'healthy' phenotypes (P = .023-0.001). Those with painful HIV-SN and additional chronic pain diagnoses were more frequently allocated to the 'mechanical hyperalgesia' phenotype compared to those with painful HIV-SN alone (P = .006). This study describes heterogeneous sensory phenotypes in people living with HIV. Differences in self-reported pain outcomes between sensory phenotypes has the potential to guide future stratified trials and eventually more targeted therapy. PERSPECTIVE: This article presents quantitative sensory testing derived phenotypes, thought to reflect differing pathophysiological pain mechanisms and relates them to self-reported pain measures in people with HIV infection. This could help clinicians stratify patients to individualize analgesic interventions more effectively.

Lipids and peripheral neuropathy

PURPOSE OF REVIEW

Hyperlipidaemia is associated with the development of neuropathy. Indeed, a mechanistic link between altered lipid metabolism and peripheral nerve dysfunction has been demonstrated in a number of experimental and clinical studies. Furthermore, post hoc analyses of clinical trials of cholesterol and triglyceride-lowering pharmacotherapy have shown reduced rates of progression of diabetic neuropathy. Given, there are currently no FDA approved disease-modifying therapies for diabetic neuropathy, modulation of lipids may represent a key therapeutic target for the treatment of diabetic nerve damage. This review summarizes the current evidence base on the role of hyperlipidaemia and lipid lowering therapy on the development and progression of peripheral neuropathy.

RECENT FINDINGS

A body of literature supports a detrimental effect of dyslipidaemia on nerve fibres resulting in somatic and autonomic neuropathy. The case for an important modulating role of hypertriglyceridemia is stronger than for low-density lipoprotein cholesterol (LDL-C) in relation to peripheral neuropathy. This is reflected in the outcomes of clinical trials with the different therapeutic agents targeting hyperlipidaemia reporting beneficial or neutral effects with statins and fibrates. The potential concern with the association between proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor therapy and cognitive decline raised the possibility that extreme LDL-C lowering may result in neurodegeneration. However, studies in murine models and data from small observational studies indicate an association between increased circulating PCSK9 levels and small nerve fibre damage with a protective effect of PCSK9i therapy against small fibre neuropathy. Additionally, weight loss with bariatric surgery leads to an improvement in peripheral neuropathy and regeneration of small nerve fibres measured with corneal confocal microscopy in people with obesity with or without type 2 diabetes. These improvements correlate inversely with changes in triglyceride levels.

SUMMARY

Hyperlipidaemia, particularly hypertriglyceridemia, is associated with the development and progression of neuropathy. Lipid modifying agents may represent a potential therapeutic option for peripheral neuropathy. Post hoc analyses indicate that lipid-lowering therapies may halt the progression of neuropathy or even lead to regeneration of nerve fibres. Well designed randomized controlled trials are needed to establish if intensive targeted lipid lowering therapy as a part of holistic metabolic control leads to nerve fibre regeneration and improvement in neuropathy symptoms.

Prevalence and risk factors of type II diabetes mellitus among people living with HIV in Texas

This study aimed to determine the prevalence and risk factors associated with type II diabetes mellitus (T2DM) among people living with HIV (PLWH). Cross-sectional data of 989 PLWH in Texas obtained from the 2015-2017 Texas and Houston Medical Monitoring Project were examined. T2DM was identified by formal medical chart diagnosis, insulin/oral hypoglycemic prescriptions, or most recent fasting blood glucose ≥126 mg/dL. T2DM adjusted prevalence ratios and 95% confidence intervals (CIs) were estimated using multiple logistic regression. Participants were mostly male (72%), ≥40 years (68%), overweight (31%) or obese (28%) and virally suppressed (62%). T2DM prevalence was 15% with variations by age, body mass index, education and health insurance (p < 0.05 for all). Compared to PLWH ≥60 years, 18-39-year-olds had significantly lower likelihood of T2DM (p < 0.001). Overweight and obese PLWH were 2.11 (95% CI: 1.23-3.63) and 3.89 times (95% CI: 2.30-6.56) more likely to have T2DM compared to normal weight PLWH. Over 1 in 6 PLWH in Texas had T2DM, with age and BMI as significant predictors. Since DM is a risk factor for cardiovascular disease and PLWH are living longer, increased education and lifestyle modification interventions are warranted to prevent T2DM development among PLWH.

Williams AC. Psychosocial factors associated with persistent pain in people with HIV: a systematic review with meta-analysis

Chronic pain remains a prevalent and disabling problem for people living with HIV in the current antiretroviral treatment era. Psychosocial treatments may have promise for managing the impact of this pain. However, research is needed to identify psychosocial processes to target through such treatments. The current systematic review and meta-analysis examined the evidence for psychosocial factors associated with pain, disability, and quality of life in people living with HIV and persistent pain. Observational and experimental studies reporting on the association between one or more psychosocial factors and one or more pain-related variables in an adult sample of people living with HIV and pain were eligible. Two reviewers independently conducted eligibility screening, data extraction, and quality assessment. Forty-six studies were included in the review and 37 of these provided data for meta-analyses (12,493 participants). "Some" or "moderate" evidence supported an association between pain outcomes in people with HIV and the following psychosocial factors: depression, psychological distress, posttraumatic stress, drug abuse, sleep disturbance, reduced antiretroviral adherence, health care use, missed HIV clinic visits, unemployment, and protective psychological factors. Surprisingly, few studies examined protective psychological factors or social processes, such as stigma. There were few high-quality studies. These findings can inform future research and psychosocial treatment development in this area. Greater theoretical and empirical focus is needed to examine the role of protective factors and social processes on pain outcomes in this context. The review protocol was registered with PROSPERO (CRD42016036329).

Neuromuscular complications of HIV infection

With the introduction of combination antiretroviral therapy, human immunodeficiency virus (HIV)-infected individuals are living longer, and are commonly confronted with chronic neuromuscular complications. The spectrum of neuromuscular disorders in patients living with HIV infection is wide, and is caused by HIV per se and its products, particular antiretroviral drugs, or a combination of both. The purpose of this chapter is to review peripheral nervous system disorders in the setting of HIV infection, and to provide a general approach to diagnosis and management of these disorders. The early identification of these conditions may help with early intervention and management, allow prevention of morbidities associated with these disorders, and contribute to future research efforts in the field of HIV.

A rodent model of HIV protease inhibitor indinavir induced peripheral neuropathy

HIV-associated sensory neuropathy (HIV-SN) is the most frequent manifestation of HIV disease. It often presents with significant neuropathic pain and is associated with previous exposure to neurotoxic nucleoside reverse transcriptase inhibitors. However, HIV-SN prevalence remains high even in resource-rich settings where these drugs are no longer used. Previous evidence suggests that exposure to indinavir, a protease inhibitor commonly used in antiretroviral therapy, may link to elevated HIV-SN risk. Here, we investigated whether indinavir treatment was associated with the development of a "dying back" axonal neuropathy and changes in pain-relevant limb withdrawal and thigmotactic behaviours. After 2 intravenous injections of indinavir (50 mg/kg, 4 days apart), adult rats developed hind paw mechanical hypersensitivity, which peaked around 2 weeks post first injection (44% reduction from baseline). At this time, animals also had (1) significantly changed thigmotactic behaviour (62% reduction in central zone entries) comparing with the controls and (2) a significant reduction (45%) in hind paw intraepidermal nerve fibre density. Treatment with gabapentin, but not amitriptyline, was associated with a complete attenuation of hind paw mechanical hypersensitivity observed with indinavir treatment. Furthermore, we found a small but significant increase in microglia with the effector morphology in the lumbar spinal dorsal horn in indinavir-treated animals, coupled with significantly increased expression of phospho-p38 in microglia. In summary, we have reported neuropathic pain-related sensory and behavioural changes accompanied by a significant loss of hind paw skin sensory innervation in a rat model of indinavir-induced peripheral neuropathy that is suitable for further pathophysiological investigation and preclinical evaluation of novel analgesics.

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.

Pain in amaXhosa women living with HIV/AIDS: a cross-sectional study of ambulant outpatients

Background

Pain is one of the most commonly reported symptoms in people living with HIV/AIDS, whether or not they are receiving anti-retroviral therapy. A recent systematic review identified a paucity of studies exploring pain in women in low and middle income countries. The prevalence and characteristics of pain in women living with HIV/AIDS may differ from that of men as many chronic pain conditions are more prevalent in women. The aims of this study were to establish pain prevalence, characteristics and management in amaXhosa women living with HIV/AIDS. In addition, we aimed to identify whether there were associations between pain in this population and the psychosocial factors of employment, education, self-efficacy, depression, post-traumatic stress disorder, health related quality of life and childhood trauma.

Methods

A cross-sectional study of 229 women who had undergone HIV testing and were registered patients at a community health centre was conducted. Data were collected by interview with a demographic questionnaire, the Brief Pain Inventory-Xhosa, Childhood Trauma Questionnaire–Xhosa, Harvard Trauma Questionnaire–Xhosa for PTSD, Self-Efficacy for Managing Chronic Disease 6-Item Scale-Xhosa; the EQ-5D health related quality of life instrument, and the Beck Depression Inventory.

Results

170 of the women had pain, a prevalence rate of 74.24% (95%CI 68.2 – 79.47%). The women reported significant pain with pain severity of 5.06 ± 1.57 and pain interference of 6.39 ± 1.96 out of 10. Only two women were receiving adequate pain management according to the pain management index. Participants reported a mean of 2.42 ± 1.21 different anatomical sites of pain. There were more unemployed participants in the group with pain and they had significantly fewer years of schooling. Those with pain had lower self-efficacy; health related quality of life and increased depression and PTSD symptom severity.

Conclusion

This study highlights that pain is a common problem for amaXhosa women living with HIV/AIDS. These data emphasise the need to prioritise pain assessment and management in amaXhosa women living with HIV/AIDS. Routinely assessing for the presence of pain in women with HIV/AIDS has the potential to improve pain management and minimise the impact of pain on function.

Prevalent neuropathy in a cohort of HIV-infected Kenyan sex workers using antiretroviral drugs

INTRODUCTION

Several risk factors including stavudine and age have been strongly associated with polyneuropathy. However, conflicting data exist on height as an independent risk factor in polyneuropathy. The objective of this study is to exclude height as an independent polyneuropathy risk factor in a cohort of human immunodeficiency virus (HIV)-infected Kenyan sex workers.

METHODS

This was an analysis of prospectively collected data of treatment-naive subjects initiating either stavudine or tenofovir diphosphate fumarate or zidovudine-based antiretroviral therapy (ART) regimens from January 2008 to August 2012. Polyneuropathy was characterised as burning sensation, numbness, or dysesthesia. The study used arithmetic means of weight (kg) and height (cm) measured in duplicates using calibrated scales.

RESULTS

After exclusion of duplicate data sets and un-confirmed cases of polyneuropathy, the study identified 212 patients without polyneuropathy, 14 pre-ART and 94 post-ART related polyneuropathy cases. Polyneuropathy cases were older but did not differ in demographic, clinical and laboratory parameters at baseline. There was a significant difference in first-line ART regimens with more patients on tenofovir disoproxil fumarate in the post-ART group (p=0.017).

CONCLUSION

Polyneuropathy is a common disorder among HIV-infected Kenyan sex workers. These data cannot support the postulated increased risk by height after matching for gender and ART duration. Though stavudine is associated with polyneuropathy, in this study many patients previously not exposed to stavudine developed polyneuropathy. This suggests the involvement of unknown risk factors such as genetic and metabolite differences in the development of polyneuropathy.

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.

HIV neuropathy

PURPOSE OF REVIEW

To present an overview of HIV-associated distal symmetric polyneuropathy (HIV-DSP) and other HIV-related peripheral neuropathies in the post-highly active retroviral therapy era.

RECENT FINDINGS

HIV-DSP has become the most common neurologic complication of HIV largely due to the prolonged survival of HIV-positive patients with the advent of highly active retroviral therapy. HIV-DSP can be attributed to the disease itself or to secondary effects of certain HAART agents, and often the two disease entities cannot be distinguished. HIV-DSP can lead to significant morbidity and interfere with daily activities. Diagnosis can be obtained from a detailed history and neurologic exam revealing absent ankle jerks and abnormal, vibratory perception or decreased pinprick or temperature. Supporting studies include nerve conduction studies and skin biopsy. Although there are no United States Food and Drug Administration-approved treatments for HIV-DSP, clinicians often use off-label medications, including antidepressants, anticonvulsants, topical agents and other analgesics.

SUMMARY

The prevalence of those affected by HIV-DSP will continue to grow with the aging population of HIV-infected individuals. Compared to the diabetic neuropathy drug trials, trials in both symptomatic and disease-modifying agents for HIV-DSP have had little success. Other forms of HIV-related peripheral neuropathies are discussed briefly, and include acute and chronic inflammatory demyelinating polyneuropathy, autonomic neuropathy, polyradiculopathy, mononeuropathies, mononeuritis multiplex, cranial neuropathies, and amyotrophic lateral sclerosis-like motor neuropathy.

Predictors of new-onset distal neuropathic pain in HIV-infected individuals in the era of combination antiretroviral therapy

Despite modern combination antiretroviral therapy, distal neuropathic pain (DNP) continues to affect many individuals with HIV infection. We evaluated risk factors for new-onset DNP in the CNS Antiretroviral Therapy Effects Research (CHARTER) study, an observational cohort. Standardized, semiannual clinical evaluations were administered at 6 US sites. Distal neuropathic pain was defined by using a clinician-administered instrument standardized across sites. All participants analyzed were free of DNP at study entry. New-onset DNP was recorded at the first follow-up visit at which it was reported. Mixed-effects logistic regression was used to evaluate potential predictors including HIV disease and treatment factors, demographics, medical comorbidities, and neuropsychiatric factors. Among 493 participants, 131 (27%) reported new DNP over 2306 visits during a median follow-up of 24 months (interquartile range 12-42). In multivariable regression, after adjusting for other covariates, significant entry predictors of new DNP were older age, female sex, current and past antiretroviral treatment, lack of virologic suppression, and lifetime history of opioid use disorder. During follow-up, more severe depression symptoms conferred a significantly elevated risk. The associations with opioid use disorders and depression reinforce the view that the clinical expression of neuropathic pain with peripheral nerve disease is strongly influenced by neuropsychiatric factors. Delineating such risk factors might help target emerging preventive strategies, for example, to individuals with a history of opioid use disorder, or might lead to new treatment approaches such as the use of tools to ameliorate depressed mood.

Sensory, psychological, and metabolic dysfunction in HIV-associated peripheral neuropathy: A cross-sectional deep profiling study

HIV-associated sensory neuropathy (HIV-SN) is a frequent complication of HIV infection and a major source of morbidity. A cross-sectional deep profiling study examining HIV-SN was conducted in people living with HIV in a high resource setting using a battery of measures which included the following: parameters of pain and sensory symptoms (7day pain diary, Neuropathic Pain Symptom Inventory [NPSI] and Brief Pain Inventory [BPI]), sensory innervation (structured neurological examination, quantitative sensory testing [QST] and intraepidermal nerve fibre density [IENFD]), psychological state (Pain Anxiety Symptoms Scale-20 [PASS-20], Depression Anxiety and Positive Outlook Scale [DAPOS], and Pain Catastrophizing Scale [PCS], insomnia (Insomnia Severity Index [ISI]), and quality of life (Short Form (36) Health Survey [SF-36]). The diagnostic utility of the Brief Peripheral Neuropathy Screen (BPNS), Utah Early Neuropathy Scale (UENS), and Toronto Clinical Scoring System (TCSS) were evaluated. Thirty-six healthy volunteers and 66 HIV infected participants were recruited. A novel triumvirate case definition for HIV-SN was used that required 2 out of 3 of the following: 2 or more abnormal QST findings, reduced IENFD, and signs of a peripheral neuropathy on a structured neurological examination. Of those with HIV, 42% fulfilled the case definition for HIV-SN (n=28), of whom 75% (n=21) reported pain. The most frequent QST abnormalities in HIV-SN were loss of function in mechanical and vibration detection. Structured clinical examination was superior to QST or IENFD in HIV-SN diagnosis. HIV-SN participants had higher plasma triglyceride, concentrations depression, anxiety and catastrophizing scores, and prevalence of insomnia than HIV participants without HIV-SN.

Absence of clinical relationship between oxidized low density lipoproteins and diabetic peripheral neuropathy: a case control study

Background

The pathophysiology of diabetic peripheral neuropathy (DPN) is complex and uncertain. A potential comorbidity in diabetes mellitus (DM) that may contribute to greater severity of DPN is a lipid disorder, such as with elevated cholesterol, low density lipoproteins or triglycerides. Oxidized low density lipoprotein (oxLDL) is a form of cholesterol that exerts direct toxic effects and contributes to pathogenicity through ligating a receptor called lectin-like receptor (LOX-1).

Methods

We examined plasma oxLDL levels in cohorts of patients with DPN with neuropathic pain (NeP), DPN patients without NeP, DM patients without DPN, patients with idiopathic peripheral neuropathy, and control subjects without DM or neuropathy. Our outcome measure was extent of oxLDL elevation, measured as fasting with Enzyme-Linked ImmunoSorbant Assay (ELISA) studies. Severity of diabetes was assessed using hemoglobin A1C measurements. Neuropathic severity was measured with the Utah Early Neuropathy Score (UENS). We hypothesized that DPN presence would be associated with oxLDL elevations.

Results

A total of 115 subjects (47 with DPN and NeP, 23 with DPN without NeP, 12 with diabetes only, 13 with idiopathic peripheral neuropathy, and 20 control subjects without diabetes or neuropathy) were studied. Duration of diabetes and diabetic glycemic measures were similar between populations with DM. Severity of DPN was similar between cohorts with DPN and NeP and DPN without NeP. Plasma oxLDL levels were similar between all cohorts, without any elevation in the presence of DM noted in any cohort with DM.

Conclusions

oxLDL levels are not different in patients with DPN, and their lack of greater presence suggests that any pathogenic role in human DPN is likely limited.

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.

HIV peripheral neuropathy and foot care management: a review of assessment and relevant guidelines

Despite the decline in the incidence of central nervous system disease associated with HIV, distal sensory peripheral (DSP) neuropathy continues to be prevalent in this population, causing debilitating symptoms and affecting quality of life. Patients typically present with numbness, tingling, burning pain, and loss of sensation in the toes and soles of their feet. Although this complication causes loss of protective function and puts patients at elevated risk for injury, infection, and falls, foot care for people with HIV is often overlooked. This article reviews what is known about DSP neuropathy in HIV and discusses relevant foot care guidelines, adopted from the literature on other conditions associated with neuropathic foot disorders.

Diabetic ketoacidosis: an overlooked child killer in sub-Saharan Africa?

The true incidence of diabetic ketoacidosis (DKA) in sub-Saharan Africa is unknown but unlike in the Western countries, DKA is also uniquely frequent among type 2 diabetes patients of African origin. Increased hyperglycaemia and hepatic ketogenesis lead to osmotic diuresis, dehydration and tissue hypoxia. Acute complications of DKA include cerebral oedema, which may be compounded by malnutrition, parasitic and microbial infections with rampant tuberculosis and HIV. Overlapping symptoms of these conditions and misdiagnosis of DKA contribute to increased morbidity and mortality. Inability of the patients to afford insulin treatment leads to poor glycemic control as some patients seek alternative treatment from traditional healers or use herbal remedies further complicating the disease process. Standard treatment guidelines for DKA currently used may not be ideal as they are adapted from those of the developed world. Children presenting with suspected DKA should be screened for comorbidities which may complicate fluid and electrolyte replacement therapy protocol. Patient rehabilitation should take into account concurrent treatment for infectious conditions to avoid possible life-threatening drug interactions. We recommend that health systems in sub-Saharan Africa leverage the Expanded Immunization Programme or TB/HIV/AIDS programmes, which are fairly well entrenched to support diabetes services.

HIV-related neuropathy: current perspectives

Distal symmetric polyneuropathy (DSP) related to human immunodeficiency virus (HIV) is one of the most common neurologic complications of HIV, possibly affecting as many as 50% of all individuals infected with HIV. Two potentially neurotoxic mechanisms have been proposed to play a crucial role in the pathogenesis of HIV DSP: neurotoxicity resulting from the virus and its products; as well as adverse neurotoxic effects of medications used in the treatment of HIV. Clinically, HIV DSP is characterized by a combination of signs and symptoms that include decreased deep tendon reflexes at the ankles and decreased sensation in the distal extremities as well as paresthesias, dysesthesias, and pain in a symmetric stocking-glove distribution. These symptoms are generally static or slowly progressive over time, and depending on the severity, may interfere significantly with the patient's daily activities. In addition to the clinical picture, nerve conduction studies and skin biopsies are often pursued to support the diagnosis of HIV DSP. Anticonvulsants, antidepressants, topical agents, and nonspecific analgesics may help relieve neuropathic pain. Specifically, gabapentin, lamotrigine, pregabalin, amitriptyline, duloxetine, and high-dose topical capsaicin patches have been used in research and clinical practice. Further research is needed to elucidate the pathogenesis of HIV DSP, thus facilitating the development of novel treatment strategies. This review discusses the epidemiology, pathophysiology, clinical findings, diagnosis, and management of DSP in the setting of HIV.

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.

A Case of Possible Darunavir/Ritonavir-Induced Peripheral Neuropathy

A 65-year-old man, M.S.M., known as being HIV infected for 20 years, presented with muscle ache and progressive weakness 3 months after initiation of darunavir as a part of his antiretroviral therapy (ART). The patient's treatment included darunavir/ritonavir 600/100 mg twice daily, plus a backbone of didanosine and abacavir which were the backbone in his previous regimen for several years according to his drug resistance profile. Three months after initiation of darunavir/ritonavir the patient exhibited clinical symptoms of severe pain and progressive weakness of his lower limbs; he was unable to walk and was totally wheelchair-bound. Severe sensory peripheral polyneuropathy was revealed on electromyogram (EMG). All medications, including ART, were stopped. Within two months, concomitantly with initiation of raltegravir, etravirine and emcitricabine/tenofovir, the patient recovered, gained weight, resumed walking and his CD4 counts rose from 270 to 450 cells/mm3. A second EMG study 3 months after initiation of his new ART regimen showed compete recovery of the previously diagnosed peripheral neuropathy. In this report, we present a case of severe HIV-1-related acute demyelinating polyneuropathy which initiated after new generation PI darunavir/ritonavir was given and resolved after cessation of the drug without the use of immune-based therapies. The variety of HIV-related polyneuropathies will be discussed.

A clinically relevant rodent model of the HIV antiretroviral drug stavudine induced painful peripheral neuropathy

HIV-associated sensory neuropathy is the most frequent manifestation of HIV disease, afflicting 40-50% of patients whose HIV disease is otherwise controlled by antiretroviral therapy. It often presents with significant neuropathic pain and is consistently associated with previous exposure to nucleoside reverse transcriptase inhibitors including stavudine (d4T), which is widely used in resource-limited settings. Here we investigated complex pain-related behaviours associated with d4T treatment using ethologically relevant thigmotaxis and burrowing behaviours in adult rats. Detailed neuropathological response was also examined using neurochemistry, electron microscopy, and proteomics. After 2 intravenous injections of d4T (50 mg/kg, 4 days apart), rats developed hind paw mechanical hypersensitivity, which plateaued at 21 days after initial d4T injection, a time that these animals also had significant changes in thigmotaxis and burrowing behaviours when compared to the controls; reductions in hind paw intraepidermal nerve fibre density and CGRP/IB4 immunoreactivity in L5 spinal dorsal horn, suggesting injury to both the peripheral and central terminals of L5 dorsal root ganglion neurons; and increases in myelinated and unmyelinated axon diameters in the sural nerve, suggesting axonal swelling. However, no significant glial and inflammatory cell response to d4T treatment was observed. Sural nerve proteomics at 7 days after initial d4T injection revealed down-regulated proteins associated with mitochondrial function, highlighting distal axons vulnerability to d4T neurotoxicity. In summary, we have reported complex behavioural changes and a distinctive neuropathology in a clinically relevant rat model of d4T-induced sensory neuropathy that is suitable for further pathophysiological investigation and preclinical evaluation of novel analgesics.

Neuromuscular manifestations of HIV/AIDS

The human immunodeficiency virus (HIV) epidemic, now entering its fourth decade, affects approximately 33 million people living in both developed and resource-limited countries. Neurological complications of the peripheral nervous system are common in HIV-infected patients, and neuromuscular pathology is associated with significant morbidity. Peripheral neuropathy is the most common neuromuscular manifestation observed in HIV/AIDS, and in the antiretroviral era, its prevalence has increased. The purpose of this review was to describe the clinical spectrum of neuromuscular disorders in the setting of HIV infection and to provide an approach to diagnosis and management.

HIV-associated sensory neuropathy: still a problem in the post-stavudine era?

Sensory neuropathy (SN) is a common and difficult to manage cause of chronic pain in HIV. Recent recommendations for earlier HIV treatment and avoidance of neurotoxic antiretroviral drugs (such as stavudine) have led to optimism that HIV-SN rates may decline. We present several reasons as to why HIV-SN is likely to remain prevalent, despite improvements in HIV management, together with clinical evidence confirming high HIV-SN rates in cohorts never exposed to neurotoxic medications. A combination of epidemiologic studies, laboratory work and clinical trials are needed to understand the problem of HIV-SN in the post-stavudine era. Improved HIV-SN prevention and management strategies are needed if the morbidity associated with HIV infection is to improve along with life expectancy.

Peripheral neuropathy in HIV: prevalence and risk factors

OBJECTIVES

To estimate neuropathic sign/symptom rates with initiation of combination antiretroviral therapy (cART) in HIV-infected ART-naive patients, and to investigate risk factors for: peripheral neuropathy and symptomatic peripheral neuropathy (SPN), recovery from peripheral neuropathy/SPN after neurotoxic ART (nART) discontinuation, and the absence of peripheral neuropathy/SPN while on nART.

DESIGN

AIDS Clinical Trials Group (ACTG) Longitudinal Linked Randomized Trial participants who initiated cART in randomized trials for ART-naive patients were annually screened for symptoms/signs of peripheral neuropathy. ART use and disease characteristics were collected longitudinally.

METHODS

Peripheral neuropathy was defined as at least mild loss of vibration sensation in both great toes or absent/hypoactive ankle reflexes bilaterally. SPN was defined as peripheral neuropathy and bilateral symptoms. Generalized estimating equation logistic regression was used to estimate associations.

RESULTS

Two thousand, one hundred and forty-one participants were followed from January 2000 to June 2007. Rates of peripheral neuropathy/SPN at 3 years were 32.1/8.6% despite 87.1% with HIV-1RNA 400 copies/ml or less and 70.3% with CD4 greater than 350 cells/μl. Associations with higher odds of peripheral neuropathy included older patient age and current nART use. Associations with higher odds of SPN included older patient age, nART use, and history of diabetes mellitus. Associations with lower odds of recovery after nART discontinuation included older patient age. Associations with higher odds of peripheral neuropathy while on nART included older patient age and current protease inhibitor use. Associations with higher odds of SPN while on nART included older patient age, history of diabetes, taller height, and protease inhibitor use.

CONCLUSION

Signs of peripheral neuropathy remain despite virologic/immunologic control but frequently occurs without symptoms. Aging is a risk factor for peripheral neuropathy/SPN.