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

Neuropsychiatric Effects of Antiviral Drugs

The adverse events of antiviral drugs are dose-dependent and often reversible. The nervous system is often affected and to date, many studies have been published regarding the central nervous system toxicity of antiviral agents. They may cause significant neuropsychiatric complications, which range from mild symptoms such as irritability and difficulty sleeping to severe complications such as depression, psychosis, and painful peripheral neuropathy, side effects which may necessitate discontinuation of treatment. The pathogenetic mechanisms may involve molecular targets common to other centrally active drugs, including human monoamine oxidase‐A (MAO‐A), serotonin receptors, gamma-aminobutyric acid (GABA) GABA-A receptors, 5-HT2A and 5-HT2C receptors and others. Notable examples include oseltamivir which may act as MAO inhibitor and efavirenz, which has an affinity for serotonin 5-HT2 and GABA-A receptors, the serotonin transporter, the MAO enzyme, and the vesicular monoamine transporter, with subjective effects which may be similar to those of the psychedelic hallucinogen lysergic acid diethylamide (LSD). Other antiviral drugs with prominent nervous system effects include nucleoside reverse transcriptase inhibitors, which are associated with the development of peripheral neuropathy after prolonged use (an effect strongly associated with older drugs which have since fallen into disfavor such as stavudine) and interferons, which may cause depression. Clinicians should be familiar with such adverse effects in order to recognise them promptly once they occur and manage them appropriately.

Predictors of worsening neuropathy and neuropathic pain after 12 years in people with HIV

OBJECTIVE

Distal sensory polyneuropathy (DSP) and neuropathic pain are important clinical concerns in virally suppressed people with HIV. We determined how these conditions evolved, what factors influenced their evolution, and their clinical impact.

METHODS

Ambulatory, community-dwelling HIV seropositive individuals were recruited at six research centers. Clinical evaluations at baseline and 12 years later determined neuropathy signs and distal neuropathic pain (DNP). Additional assessments measured activities of daily living and quality of life (QOL). Factors potentially associated with DSP and DNP progression included disease severity, treatment, demographics, and co-morbidities. Adjusted odds ratios were calculated for follow-up neuropathy outcomes.

RESULTS

Of 254 participants, 21.3% were women, 57.5% were non-white. Mean baseline age was 43.5 years. Polyneuropathy prevalence increased from 25.7% to 43.7%. Of 173 participants initially pain-free, 42 (24.3%) had incident neuropathic pain. Baseline risk factors for incident pain included unemployment (OR [95% CI], 5.86 [1.97, 17.4]) and higher baseline body mass index (BMI) (1.78 [1.03, 3.19] per 10-units). Participants with neuropathic pain at follow-up had significantly worse QOL and greater dependence in activities of daily living than those who remained pain-free.

INTERPRETATION

HIV DSP and neuropathic pain increased in prevalence and severity over 12 years despite high rates of viral suppression. The high burden of neuropathy included disability and poor life quality. However, substantial numbers remained pain-free despite clear evidence of neuropathy on exam. Protective factors included being employed and having a lower BMI. Implications for clinical practice include promotion of lifestyle changes affecting reversible risk factors.

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.

Tenofovir disoproxil fumarate induces peripheral neuropathy and alters inflammation and mitochondrial biogenesis in the brains of mice

Mounting evidence suggests that antiretroviral therapy (ART) drugs may contribute to the prevalence of HIV-associated neurological dysfunction. The HIV envelope glycoprotein (gp120) is neurotoxic and has been linked to alterations in mitochondrial function and increased inflammatory gene expression, which are common neuropathological findings in HIV+ cases on ART with neurological disorders. Tenofovir disproxil fumarate (TDF) has been shown to affect neurogenesis in brains of mice and mitochondria in neurons. In this study, we hypothesized that TDF contributes to neurotoxicity by modulating mitochondrial biogenesis and inflammatory pathways. TDF administered to wild-type (wt) and GFAP-gp120 transgenic (tg) mice caused peripheral neuropathy, as indicated by nerve conduction slowing and thermal hyperalgesia. Conversely TDF protected gp120-tg mice from cognitive dysfunction. In the brains of wt and gp120-tg mice, TDF decreased expression of mitochondrial transcription factor A (TFAM). However, double immunolabelling revealed that TFAM was reduced in neurons and increased in astroglia in the hippocampi of TDF-treated wt and gp120-tg mice. TDF also increased expression of GFAP and decreased expression of IBA1 in the wt and gp120-tg mice. TDF increased tumor necrosis factor (TNF) α in wt mice. However, TDF reduced interleukin (IL) 1β and TNFα mRNA in gp120-tg mouse brains. Primary human astroglia were exposed to increasing doses of TDF for 24 hours and then analyzed for mitochondrial alterations and inflammatory gene expression. In astroglia, TDF caused a dose-dependent increase in oxygen consumption rate, extracellular acidification rate and spare respiratory capacity, changes consistent with increased metabolism. TDF also reduced IL-1β-mediated increases in IL-1β and TNFα mRNA. These data demonstrate that TDF causes peripheral neuropathy in mice and alterations in inflammatory signaling and mitochondrial activity in the brain.

Clinical diagnosis of sensory neuropathy in HIV patients treated with tenofovir: A 6-month follow-up study

BACKGROUND

Sensory neuropathy (SN) is a common and often painful neurological condition associated with HIV-infection and its treatment. However, data on the incidence of SN in neuropathy-free individuals initiating combination antiretroviral therapies (cART) that do not contain the neurotoxic agent stavudine are lacking.

AIMS

We investigated the 6-month incidence of SN in ART naïve individuals initiating tenofovir (TDF)-based cART, and the clinical factors associated with the development of SN.

METHODS

120 neuropathy-free and ART naïve individuals initiating cART at a single center in Johannesburg, South Africa were enrolled. Participants were screened for SN using clinical signs and symptoms at study enrolment and approximately every 2-months for a period of ~6-months. Diagnostic criteria for symptomatic SN was defined by the presence of at least one symptom (pain/burning, numbness, paraesthesias) and at least two clinical signs (reduced vibration sense, absent ankle reflexes or pin-prick hypoaesthesia). Diagnostic criteria for asymptomatic SN required at least two clinical signs only (as above).

RESULTS

A total of 88% of the cohort completed three visits within the 6-month period. The 6-month cumulative incidence of neuropathy was 140 cases per 1000 patients (95% CI: 80-210) at an incidence rate of 0.37 (95% CI: 0.2-0.5) per person year. Height and active tuberculosis (TB) disease were independently associated with the risk of developing SN (P < .05).

INTERPRETATION

We found that within the first 6 months of starting cART, incident SN persists in the post-stavudine era, with 11 (9%) of individuals developing asymptomatic SN, and 9 (8%) developing symptomatic SN.