Effect of hard-drug use on CD4 cell percentage, HIV RNA level, and progression to AIDS-defining class C events among HIV-infected women

Opioid-Mediated HIV-1 Immunopathogenesis

Despite the ability of combination antiretroviral therapy to dramatically suppress viremia, the brain continues to be a reservoir of HIV-1 low-level replication. Adding further complexity to this is the comorbidity of drug abuse with HIV-1 associated neurocognitive disorders and neuroHIV. Among several abused drugs, the use of opiates is highly prevalent in HIV-1 infected individuals, both as an abused drug as well as for pain management. Opioids and their receptors have attained notable attention owing to their ability to modulate immune functions, in turn, impacting disease progression. Various cell culture, animal and human studies have implicated the role of opioids and their receptors in modulating viral replication and virus-mediated pathology both positively and negatively. Further, the combinatorial effects of HIV-1/HIV-1 proteins and morphine have demonstrated activation of inflammatory signaling in the host system. Herein, we summarized the current knowledge on the role of opioids on peripheral immunopathogenesis, viral immunopathogenesis, epigenetic profiles of the host and viral genome, neuropathogenesis of SIV/SHIV-infected non-human primates, blood-brain-barrier, HIV-1 viral latency, and viral rebound. Overall, this review provides recent insights into the role of opioids in HIV-1 immunopathogenesis. Graphical abstract.

Substance use patterns and HIV-1 RNA viral load rebound among HIV-positive illicit drug users in a Canadian setting

BACKGROUND

Active illicit drug use can present a barrier to the medical management of HIV infection by complicating adherence to antiretroviral therapy (ART). Plasma HIV-1 RNA viral load (VL) rebound, defined as a period of detectable HIV VL following ART and VL suppression, can lead to the generation of viral resistance and potential treatment failure. We sought to investigate the contribution of substance use patterns on rates of VL rebound.

METHODS

We used data from the ACCESS study, a long-running community-recruited prospective cohort of HIV-positive people who use illicit drugs in Vancouver, Canada, a setting of universal no-cost HIV treatment. We analysed time to VL rebound (that is, two consecutive observations ≥1,000 copies/ml) after ART initiation and sustained viral suppression (that is, two consecutive observations <50 copies/ml) using extended Cox regression models with a recurrent events framework.

RESULTS

Between May 1996 and November 2013, 564 ART-exposed participants achieved at least one instance of VL suppression and contributed 1,893.8 person-years of observation. Over follow-up, 198 (35.1%) participants experienced ≥ one instance of VL rebound. In adjusted analyses, VL rebound was associated with younger age (adjusted hazard ratio [AHR] =0.97, 95% CI: 0.95, 0.98), heroin injection (≥ daily versus < daily, AHR =1.52, 95% CI: 1.01, 2.30), crack use (≥ daily versus < daily, AHR = 1.73, 95% CI: 1.08, 1.92) and heavy alcohol use (≥ four versus < four drinks/day, AHR =1.97, 95% CI: 1.17, 3.31).

CONCLUSIONS

The present study suggests that in addition to heavy alcohol use, high-intensity illicit drug use, particularly ≥ daily heroin injection and ≥ daily crack smoking are risk factors for VL rebound. In addition to the impact of high-intensity drug use on health-care engagement and ART adherence, some evidence exists on the direct impact of psychoactive substances on ART metabolism and the natural progression of HIV disease. At-risk individuals should be provided additional supports to preserve virological control and maintain the benefits of ART.

The impact of prescribed opioids on CD4 cell count recovery among HIV-infected patients newly initiating antiretroviral therapy

OBJECTIVES

Certain prescribed opioids have immunosuppressive properties, yet their impact on clinically relevant outcomes, including antiretroviral therapy (ART) response among HIV-infected patients, remains understudied.

METHODS

Using the Veterans Aging Cohort Study data, we conducted a longitudinal analysis of 4358 HIV-infected patients initiating ART between 2002 and 2010 and then followed them for 24 months. The primary independent variable was prescribed opioid duration, categorized using pharmacy data as none prescribed, short-term (< 90 days) and long-term (≥ 90 days). Outcomes included CD4 cell count over time. Analyses adjusted for demographics, comorbid conditions, ART type and year of initiation, and overall disease severity [ascertained with the Veterans Aging Cohort Study (VACS) Index]. Sensitivity analyses examined whether effects varied according to baseline CD4 cell count, achievement of viral load suppression, and opioid properties (i.e. dose and known immunosuppressive properties).

RESULTS

Compared to those with none, patients with short-term opioids had a similar increase in CD4 cell count (mean rise per year: 74 vs. 68 cells/μL; P = 0.11), as did those with long-term prescribed opioids (mean rise per year: 74 vs. 75 cells/μL; P = 0.98). In sensitivity analysis, compared with no opioids, the effects of short-term prescribed opioids were statistically significant among those with a baseline CD4 cell count ≥ 500 cells/μL (mean rise per year: 52 cells/μL for no opioids vs. 20 cells/μL for short-term opioids; P = 0.04); findings were otherwise unchanged.

CONCLUSIONS

Despite immunosuppressive properties intrinsic to opioids, prescribed opioids appeared to have no effect on CD4 cell counts over 24 months among HIV-infected patients initiating ART.

Heroin Use and HIV Disease Progression: Results from a Pilot Study of a Russian Cohort

Opioids have immunosuppressive properties, yet their impact on HIV disease progression remains unclear. Using longitudinal data from HIV-infected antiretroviral therapy-naïve Russian individuals (n = 77), we conducted a pilot study to estimate the effect of heroin use on HIV disease progression. Heroin use was categorized based on past 30 days self-reported use at baseline, 6 and 12 months as none, intermittent or persistent. We estimated the effect of heroin use on HIV disease progression, measured as change in CD4 count from baseline to 12 months, using multivariable linear regression. Those with intermittent (n = 21) and no heroin use (n = 39) experienced mean decreases in CD4 count from baseline to 12 months (-103 and -10 cells/mm(3), respectively; adjusted mean difference (AMD) -93; 95 % CI -245, 58). Those with persistent use (n = 17) showed a mean increase of 53 cells/mm(3) (AMD 63; 95 % CI -95, 220). Future studies exploring the effects of heroin withdrawal on HIV disease progression are warranted.

Crystal methamphetamine use and HIV medical outcomes among HIV-infected men who have sex with men accessing support services in New York

BACKGROUND

Drug use poses multiple challenges to maintaining physical health among HIV-infected individuals, particularly with regard to disease progression. Few studies, however, have examined the association between the use of crystal methamphetamine ("crystal meth") and HIV disease progression specifically among HIV-infected men who have sex with men (MSM). Understanding this relationship among HIV-infected MSM is particularly critical because of the high rates of crystal meth use reported in the population.

METHODS

Associations between recent crystal meth use and poor HIV medical outcomes (viral load>200 copies/mL, CD4 count <350 cells/mm(3)) were analyzed for 2896 HIV-infected MSM enrolled in Ryan White Part A programs in the greater New York metropolitan area between November 2010 and June 2012.

RESULTS

Crystal meth use (reported by 4%) was independently associated with unsuppressed viral load (AOR=1.8, CI=1.1-2.9) in multivariate analyses controlling for sociodemographic characteristics. There was no significant relationship between crystal meth use and low CD4 counts.

CONCLUSIONS

To date, little research has examined how crystal meth use influences HIV medical outcomes among HIV-infected MSM. This analysis showed a significant independent association between crystal meth use and unsuppressed viral load among MSM in an HIV service population. Future studies should examine biological and psychosocial mediators, moderators and confounders of this relationship to inform intervention development for MSM crystal meth users in HIV care settings.

Influence of noninjecting and injecting drug use on mortality, retention in the cohort, and antiretroviral therapy, in participants in the Swiss HIV Cohort Study

OBJECTIVES

We studied the influence of noninjecting and injecting drug use on mortality, dropout rate, and the course of antiretroviral therapy (ART), in the Swiss HIV Cohort Study (SHCS).

METHODS

Cohort participants, registered prior to April 2007 and with at least one drug use questionnaire completed until May 2013, were categorized according to their self-reported drug use behaviour. The probabilities of death and dropout were separately analysed using multivariable competing risks proportional hazards regression models with mutual correction for the other endpoint. Furthermore, we describe the influence of drug use on the course of ART.

RESULTS

A total of 6529 participants (including 31% women) were followed during 31 215 person-years; 5.1% participants died; 10.5% were lost to follow-up. Among persons with homosexual or heterosexual HIV transmission, noninjecting drug use was associated with higher all-cause mortality [subhazard rate (SHR) 1.73; 95% confidence interval (CI) 1.07-2.83], compared with no drug use. Also, mortality was increased among former injecting drug users (IDUs) who reported noninjecting drug use (SHR 2.34; 95% CI 1.49-3.69). Noninjecting drug use was associated with higher dropout rates. The mean proportion of time with suppressed viral replication was 82.2% in all participants, irrespective of ART status, and 91.2% in those on ART. Drug use lowered adherence, and increased rates of ART change and ART interruptions. Virological failure on ART was more frequent in participants who reported concomitant drug injections while on opiate substitution, and in current IDUs, but not among noninjecting drug users.

CONCLUSIONS

Noninjecting drug use and injecting drug use are modifiable risks for death, and they lower retention in a cohort and complicate ART.

The effects of opioids on HIV reactivation in latently-infected T-lymphoblasts

Background

Opioids may have effects on susceptibility to HIV-infection, viral replication and disease progression. Injecting drug users (IDU), as well as anyone receiving opioids for anesthesia and analgesia may suffer the clinical consequences of such interactions. There is conflicting data between in vitro experiments showing an enhancing effect of opioids on HIV replication and clinical data, mostly showing no such effect. For clarification we studied the effects of the opioids heroin and morphine on HIV replication in cultured CD4-positive T cells at several concentrations and we related the observed effects with the relevant reached plasma concentrations found in IDUs.

Methods

Latently-infected ACH-2 T lymphoblasts were incubated with different concentrations of morphine and heroine. Reactivation of HIV was assessed by intracellular staining of viral Gag p24 protein and subsequent flow cytometric quantification of p24-positive cells. The influence of the opioid antagonist naloxone and the antioxidants N-acetyl-cysteine (NAC) and glutathione (GSH) on HIV reactivation was determined. Cell viability was investigated by 7-AAD staining and flow cytometric quantification.

Results

Morphine and heroine triggered reactivation of HIV replication in ACH-2 cells in a dose-dependent manner at concentrations above 1 mM (EC₅₀ morphine 2.82 mM; EC₅₀ morphine 1.96 mM). Naloxone did not interfere with heroine-mediated HIV reactivation, even at high concentrations (1 mM). Opioids also triggered necrotic cell death at similar concentrations at which HIV reactivation was observed. Both opioid-mediated reactivation of HIV and opioid-triggered cell death could be inhibited by the antioxidants GSH and NAC.

Conclusions

Opioids reactivate HIV in vitro but at concentrations that are far above the plasma levels of analgesic regimes or drug concentrations found in IDUs. HIV reactivation was mediated by effects unrelated to opioid-receptor activation and was tightly linked to the cytotoxic activity of the substances at millimolar concentrations, suggesting that opioid-mediated reactivation of HIV was due to accompanying effects of cellular necrosis such as activation of reactive oxygen species and NF-κB.

HIV and recent illicit drug use interact to affect verbal memory in women

OBJECTIVE

HIV infection and illicit drug use are each associated with diminished cognitive performance. This study examined the separate and interactive effects of HIV and recent illicit drug use on verbal memory, processing speed, and executive function in the multicenter Women's Interagency HIV Study.

METHODS

Participants included 952 HIV-infected and 443 HIV-uninfected women (mean age = 42.8, 64% African-American). Outcome measures included the Hopkins Verbal Learning Test-Revised and the Stroop test. Three drug use groups were compared: recent illicit drug users (cocaine or heroin use in past 6 months, n = 140), former users (lifetime cocaine or heroin use but not in past 6 months, n = 651), and nonusers (no lifetime use of cocaine or heroin, n = 604).

RESULTS

The typical pattern of recent drug use was daily or weekly smoking of crack cocaine. HIV infection and recent illicit drug use were each associated with worse verbal learning and memory (P < 0.05). Importantly, there was an interaction between HIV serostatus and recent illicit drug use such that recent illicit drug use (compared with nonuse) negatively impacted verbal learning and memory only in HIV-infected women (P < 0.01). There was no interaction between HIV serostatus and illicit drug use on processing speed or executive function on the Stroop test.

CONCLUSIONS

The interaction between HIV serostatus and recent illicit drug use on verbal learning and memory suggests a potential synergistic neurotoxicity that may affect the neural circuitry underlying performance on these tasks.

Assessing the effects of drug misuse on HIV/AIDS prevalence

Drug misuse (injecting drug users-IDU) has been recognized to have a significant effect on the spread of HIV/AIDS epidemic. A deterministic model to assess the contribution of drug misuse and sex in the spread of HIV/AIDS is investigated. The threshold parameters of the model are determined and stabilities are analysed. Analysis of the reproduction number has shown that increase in drug misuse results in an increase in HIV infections. Furthermore, numerical simulations of the model show that drug misuse enhances HIV transmission and progression to AIDS. Thus, in a population with intravenous drug users, advocating for safe sex alone will not be enough to control the HIV/AIDS epidemic.

Substance Abuse, Hepatitis C, and Aging in HIV: Common Cofactors that Contribute to Neurobehavioral Disturbances

Although the prevalence of neurocognitive disturbances among individuals with HIV has decreased in recent years, rates of impairment still remain high. This review presents findings from comorbid conditions that may contribute to further neurocognitive impairments in this already vulnerable population. We will focus on three co-factors that have received substantial attention in the neuroAIDS literature: drug use, hepatitis C co-infection (HCV), and aging. All three conditions commonly co-occur with HIV and likely interact with HIV in complex ways. Collectively, the extant literature suggests that drug use, HCV, and aging serve to worsen the neurocognitive profile of HIV through several overlapping mechanisms. A better understanding of how specific comorbidities interact with HIV may reveal specific phenotypes of HIV-associated neurocognitive disorder that may aid in the development of more targeted behavioral and pharmacological treatment efforts.

Cocaine reduces thymic endocrine function: another mechanism for accelerated HIV disease progression

Thymulin is a thymic peptide important for the maturation and differentiation of immature thymocytes, which have been found to be depressed in patients with low-level CD4(+) cell recovery despite viral control. Substance use is associated with faster progression of HIV disease, which has been ascribed to poor adherence to antiretroviral medication. Recent findings of an association between cocaine use and decline in CD4(+) cell counts independent of antiretroviral adherence indicate alternative mechanisms for disease progression. We evaluated the relationship between thymulin activity, CD4(+) and CD8(+) cell counts and the CD4(+)/CD8(+) ratio, and the covariate effects of substance use cross-sectionally in 80 HIV(+) active substance users and over 12 months in 40 participants. Thymulin activity was analyzed in plasma using a modification of the sheep rosette bioassay. Thymulin activity was negatively associated with cocaine use (β = -0.908,95% CI: -1.704, -0.112; p = 0.026). Compared to those who do not use cocaine, cocaine users were 37% less likely to have detectable thymulin activity (RR = 0.634, 95% CI: 0.406, 0.989 p = 0.045) and were 75 times more likely to show a decrease in thymulin activity (OR = 74.7, 95% CI: 1.59, 3519.74; p = 0.028) over time. CD4(+) cell count was positively associated with thymulin activity (β = 0.127, 95% CI: 0.048,0.205; p = 0.002), detectable thymulin activity was 2.32 times more likely in those with a CD4 cell count ≥200 cells/μl (RR = 2.324, 95% CI: 1.196, 4.513, p = 0.013), and those with an increase in CD4 cell counts were more likely to show an increase in thymulin activity (OR = 1.02, 95% CI: 1.00, 1.034; p = 0.041) over time. Thymulin activity is predictive of HIV disease progression and is depressed in cocaine users independent of antiretroviral treatment (ART) and HIV viral load. Understanding the mechanisms for accelerated HIV disease progression provides opportunities to find alternative strategies to counteract immunosuppression.

Morphine potentiates neuropathogenesis of SIV infection in rhesus macaques

Despite the advent of antiretroviral therapy, complications of HIV-1 infection with concurrent drug abuse are an emerging problem. Opiates are well known to modulate immune responses by preventing the development of cell-mediated immune responses. Their effect on the pathogenesis of HIV-1 infection however remains controversial. Using the simian immunodeficiency virus/macaque model of HIV pathogenesis, we sought to explore the impact of morphine on disease progression and pathogenesis. Sixteen rhesus macaques were divided into two groups; four were administered saline and 12 others morphine routinely. Both groups of animals were then inoculated with SIVmacR71/17E and followed longitudinally for disease pathogenesis. The morphine group (M+V) exhibited a trend towards higher mortality rates and retardation in weight gain compared to the virus-alone group. Interestingly, a subset of M+V animals succumbed to disease within weeks post-infection. These rapid progressors also exhibited a higher incidence of other end-organ pathologies. Despite the higher numbers of circulating CD4+ and CD8+ T cells in the M+V group, CD4/CD8 ratios between the groups remained unchanged. Plasma and CSF viral load in the M+V group was at least a log higher than the control group. Similarly, there was a trend toward increased virus build-up in the brains of M+V animals compared with controls. A novel finding of this study was the increased influx of infected monocyte/macrophages in the brains of M+V animals.

Non-injection drug use and HIV disease progression in the era of combination antiretroviral therapy

Little is known about the effects of non-injection drug use (NIDU) on HIV antiretroviral treatment outcomes. We conducted a systematic literature search and identified nine publications from prospective cohort studies investigating the relationship between NIDU and clinical HIV disease progression. Hazard ratios from studies estimating the effect of drug use on time to AIDS-related mortality ranged from 0.89 to 3.61, and only two of these were statistically significant. Hazard ratios from studies assessing time to an AIDS-defining event ranged from 1.19 to 2.51, with 8 of the 14 estimates falling between 1.55 and 1.65 regardless of drug use definition and measurement of use or frequency. It is suggested that NIDU may have a moderate effect of increasing the risk of progression to AIDS, but its impact on AIDS-related mortality is uncertain. NIDU may affect HIV antiretroviral treatment outcomes primarily through interaction with antiretroviral therapy and, to a lesser extent, through immune modulation and deterioration of general health. The limitations about published studies are discussed, and future perspectives on research on this topic are provided.

The relationship between injection and noninjection drug use and HIV disease progression

BACKGROUND

Injection drug use is associated with poor HIV outcomes even among persons receiving highly active antiretroviral therapy (HAART), but there are limited data on the relationship between noninjection drug use and HIV disease progression.

METHODS

We conducted an observational study of HIV-infected persons entering care between January 1, 1999, and December 31, 2004, with follow-up through December 31, 2005.

RESULTS

There were 1,712 persons in the study cohort: 262 with a history of injection drug use, 785 with a history of noninjection drug use, and 665 with no history of drug use; 56% were White, and 24% were females. Median follow-up was 2.1 years, 33% had HAART prior to first visit, 40% initiated first HAART during the study period, and 306 (17.9%) had an AIDS-defining event or died. Adjusting for gender, age, race, prior antiretroviral use, CD4 cell count, and HIV-1 RNA, patients with a history of injection drug use were more likely to advance to AIDS or death than nonusers (adjusted hazard ratio [HR] = 1.97, 95% confidence interval [CI] = 1.43-2.70, p < .01). There was no statistically significant difference of disease progression between noninjection drug users and nonusers (HR = 1.19, 95% CI = 0.92-1.56, p = .19). An analysis among the subgroup who initiated their first HAART during the study period (n = 687) showed a similar pattern (injection drug users: HR = 1.83, 95% CI = 1.09-3.06, p = .02; noninjection drug users: HR = 1.21, 95% CI = 0.81-1.80, p = .35). Seventy-four patients had active injection drug use during the study period, 768 active noninjection drug use, and 870 no substance use. Analyses based on active drug use during the study period did not substantially differ from those based on history of drug use.

CONCLUSIONS

This study shows no relationship between noninjection drug use and HIV disease progression. This study is limited by using history of drug use and combining different types of drugs. Further studies ascertaining specific type and extent of noninjection drug use prospectively, and with longer follow-up, are needed.

Associations between use of crack cocaine and HIV-1 disease progression: research findings and implications for mother-to-infant transmission

Recent in vitro and in vivo research has suggested that cocaine has a direct effect on the pathogenesis of AIDS. These findings are confirmed by epidemiological studies linking the use of injected, inhaled, and smoked (crack) cocaine and indicators of HIV disease progression, even among adherent users of highly active antiretroviral therapy. Recent studies of vertical HIV transmission suggest that cocaine use may play a role in mother-to-child infection via alteration of maternal immune responses, enhanced viral replication in maternal immune cells, or alterations in the immune systems of neonates or infants. The purpose of this article is to review research conducted over the past several decades on associations between use of cocaine and HIV disease progression, especially among HIV+ women, and to explore its potential relevance for understanding mother-to-infant transmission of HIV.

Excess mortality among HIV-infected patients diagnosed with substance use dependence or abuse receiving care in a fully integrated medical care program

BACKGROUND

We examined the association between substance use (SU) disorder and mortality among HIV-infected patients in a large, private medical care program.

METHODS

In a retrospective cohort design, HIV-infected patients (≥14 years old) from a large health plan (Northern California) were studied to examine mortality associated with diagnosis of SU dependence or abuse over an 11-year period.

RESULTS

At study entry or during follow-up, 2,279 (25%) of 9,178 HIV-infected patients had received a diagnosis of SU disorder. Diagnoses were categorized as alcohol dependence/abuse only, illicit drugs only, or both. Cause of death differed by the category of SU diagnosis. Mortality rates ranged from 35.5 deaths per 1,000 person-years in patients with an SU disorder to 17.5 deaths among patients without an SU disorder. Regression results indicated mortality risk was significantly higher in all categories of SU disorder compared to no SU diagnosis (hazard ratios ranging from 1.65 to 1.67) after adjustment for SU treatment and confounders.

CONCLUSIONS

A diagnosis of SU dependence/abuse is associated with higher mortality among HIV-infected patients for whom access to medical services is not a significant factor.

Substance use and HIV disease progression in the HAART era: implications for the primary prevention of HIV

Prior to the era of highly active anti-retroviral therapy (HAART), cohort studies provided equivocal evidence to support the hypothesis that substance use predicts more rapid HIV disease progression. The present review examined the effects of substance use on HIV disease progression in cohort studies with follow-up that continued into the HAART era. Of the 20 studies included in this review, 16 observed that substance use predicted at least one indicator of HIV disease progression. Ten of the 11 studies that followed participants exclusively in the HAART era observed an effect of substance use on HIV disease progression. Findings across studies indicate that stimulant use promotes more rapid HIV disease progression and the effects of substance use on HIV disease progression can persist after controlling for self-reported HAART non-adherence. Future investigations that examine the bio-behavioral pathways whereby substance use promotes HIV disease progression should include: measures of HIV genotypic and phenotypic resistance, multi-method assessment of adherence, and assessment of co-morbid infections that are more prevalent among substance users. Although further mechanistic research is needed, findings from existing cohort studies have clear clinical implications. Implementing screening, brief intervention and referral to substance abuse treatment in HIV medical care could optimize health outcomes and decrease HIV transmission rates by boosting the effectiveness of "Test and Treat" approaches to HIV prevention.

Opioid pharmacotherapy for chronic non-cancer pain in the United States: a research guideline for developing an evidence-base

This document reports the consensus of an interdisciplinary panel of research and clinical experts charged with reviewing the use of opioids for chronic noncancer pain (CNCP) and formulating guidelines for future research. Prescribing opioids for chronic noncancer pain has recently escalated in the United States. Contrasting with increasing opioid use are: 1) The lack of evidence supporting long-term effectiveness; 2) Escalating misuse of prescription opioids including abuse and diversion; and 3) Uncertainty about the incidence and clinical salience of multiple, poorly characterized adverse drug events (ADEs) including endocrine dysfunction, immunosuppression and infectious disease, opioid-induced hyperalgesia and xerostomia, overdose, falls and fractures, and psychosocial complications. Chief among the limitations of current evidence are: 1) Sparse evidence on long-term opioid effectiveness in chronic pain patients due to the short-term time frame of clinical trials; 2) Insufficiently comprehensive outcome assessment; and 3) Incomplete identification and quantification of ADEs. The panel called for a strategic interdisciplinary approach to the problem domain in which basic scientists and clinicians cooperate to resolve urgent issues and generate a comprehensive evidence base. It offered 4 recommendations in 3 areas: 1) A research strategy for studying the effectiveness of long-term opioid pharmacotherapy; 2) Improvements in evidence-generation methodology; and 3) Potential research topics for generating new evidence.

PERSPECTIVE

Prescribing opioids for CNCP has outpaced the growth of scientific evidence bearing on the benefits and harms of these interventions. The need for a strong evidence base is urgent. This guideline offers a strategic approach to creating a comprehensive evidence base to guide safe and effective management of CNCP.

Rhesus macaque model of chronic opiate dependence and neuro-AIDS: longitudinal assessment of auditory brainstem responses and visual evoked potentials

Our work characterizes the effects of opiate (morphine) dependence on auditory brainstem and visual evoked responses in a rhesus macaque model of neuro-AIDS utilizing a chronic continuous drug delivery paradigm. The goal of this study was to clarify whether morphine is protective, or if it exacerbates simian immunodeficiency virus (SIV)-related systemic and neurological disease. Our model employs a macrophage tropic CD4/CCR5 coreceptor virus, SIV(mac)239 (R71/E17), which crosses the blood-brain barrier shortly after inoculation and closely mimics the natural disease course of human immunodeficiency virus infection. The cohort was divided into three groups: morphine only, SIV only, and SIV + morphine. Evoked potential (EP) abnormalities in subclinically infected macaques were evident as early as 8 weeks postinoculation. Prolongations in EP latencies were observed in SIV-infected macaques across all modalities. Animals with the highest cerebrospinal fluid viral loads and clinical disease showed more abnormalities than those with subclinical disease, confirming our previous work (Raymond et al., J Neurovirol 4:512-520, 1998; J Neurovirol 5:217-231, 1999; AIDS Res Hum Retroviruses 16:1163-1173, 2000). Although some differences were observed in auditory and visual evoked potentials in morphine-treated compared to morphine-untreated SIV-infected animals, the effects were relatively small and not consistent across evoked potential type. However, morphine-treated animals with subclinical disease had a clear tendency toward higher virus loads in peripheral and central nervous system tissues (Marcario et al., J Neuroimmune Pharmacol 3:12-25, 2008) suggesting that if had been possible to follow all animals to end-stage disease, a clearer pattern of evoked potential abnormality might have emerged.

Crack-cocaine use accelerates HIV disease progression in a cohort of HIV-positive drug users

BACKGROUND

HIV infection is prevalent among substance abusers. The effects of specific illicit drugs on HIV disease progression have not been established. We evaluated the relationship between substances of abuse and HIV disease progression in a cohort of HIV-1-positive active drug users.

METHODS

A prospective, 30-month, longitudinal study was conducted on 222 HIV-1 seropositive drug users in Miami, FL. History of illicit drug, alcohol, and medication use, CD4+ cell count, and viral load were performed every 6 months.

RESULTS

Crack-cocaine users were 2.14 times [95% confidence interval (CI): 1.08 to 4.25, P = 0.029] more likely to present a decline of CD4 to <or=200 cells/mL, independent of antiretroviral use. Viral load over 30 months was significantly higher in crack users (beta = 0.315, P = 0.037) independent of highly active antiretroviral therapy (HAART) over time. The only multidrug combination that significantly increased the risk of disease progression was crack cocaine with marijuana (hazard ratio = 2.42; 95% CI: 1.042 to 5.617, P = 0.04). Of those on HAART, a significantly lower proportion of crack-cocaine users versus nonusers had controlled viral load (P < 0.001), suggesting lower medication adherence, whereas crack-cocaine users not on HAART showed a greater risk for HIV disease progression than nonusers (hazard ratio = 3.946; 95% CI: 1.049 to 14.85, P = 0.042).

CONCLUSIONS

Crack-cocaine use facilitates HIV disease progression by reducing adherence in those on HAART and by accelerating disease progression independently of HAART.

Crack cocaine, disease progression, and mortality in a multicenter cohort of HIV-1 positive women

BACKGROUND

Longitudinal associations between patterns of crack cocaine use and progression of HIV-1 disease are poorly understood, especially among women. This study explores relationships between crack use and HIV-1 disease outcomes in a multicenter cohort of infected women.

METHODS

Subjects were 1686 HIV-seropositive women enrolled at six US research centers in the Women's Interagency HIV Study. Approximately 80% were non-white and 29% used crack during the study period. Cox survival and random regression analysis examined biannual observations made April 1996 through September 2004. Outcome measures included death due to AIDS-related causes, CD4 cell count, HIV-1 RNA level, and newly acquired AIDS-defining illnesses.

RESULTS

Persistent crack users were over three times as likely as non-users to die from AIDS-related causes, controlling for use of HAART self-reported at 95% or higher adherence, problem drinking, age, race, income, education, illness duration, study site, and baseline virologic and immunologic indicators. Persistent crack users and intermittent users in active and abstinent phases showed greater CD4 cell loss and higher HIV-1 RNA levels controlling for the same covariates. Persistent and intermittent crack users were more likely than non-users to develop new AIDS-defining illnesses controlling for identical confounds. These results persisted when controlling for heroin use, tobacco smoking, depressive symptoms, hepatitis C virus coinfection, and injection drug use.

CONCLUSION

Use of crack cocaine independently predicts AIDS-related mortality, immunologic and virologic markers of HIV-1 disease progression, and development of AIDS-defining illnesses among women.

Recreational drug use and T lymphocyte subpopulations in HIV-uninfected and HIV-infected men

The effects of recreational drugs on CD4 and CD8 T cells in humans are not well understood. We conducted a longitudinal analysis of men who have sex with men (MSM) enrolled in the Multicenter AIDS Cohort Study (MACS) to define associations between self-reported use of marijuana, cocaine, poppers and amphetamines, and CD4 and CD8 T cell parameters in both HIV-uninfected and HIV-infected MSM. For the HIV-infected MSM, we used clinical and laboratory data collected semiannually before 1996 to avoid potential effects of antiretroviral treatment. A regression model that allowed random intercepts and slopes as well as autoregressive covariance structure for within subject errors was used. Potential confounders adjusted for included length of follow-up, demographics, tobacco smoking, alcohol use, risky sexual behaviors, history of sexually transmitted infections, and antiviral therapy. We found no clinically meaningful associations between use of marijuana, cocaine, poppers, or amphetamines and CD4 and CD8 T cell counts, percentages, or rates of change in either HIV-uninfected or -infected men. The regression coefficients were of minimum magnitude despite some reaching statistical significance. No threshold effect was detected for frequent (at least weekly) or continuous substance use in the previous year. These results indicate that use of these substances does not adversely affect the numbers and percentages of circulating CD4 or CD8 T cells in either HIV-uninfected or -infected MSM.

Risk factors for death among patients in French Guiana: 1996-2005

Risk factors for death in an HIV-infected cohort in French Guiana were studied in 1374 patients between 1996 and 2005. Of these patients, 48.5% were male and 76% were immigrants. Covariates were measured at the time of consultation. There were 223 deaths. Addictions [adjusted hazard ratio (HR)=13; 95% confidence interval (CI) 5.5-30.6; P<0.001], age>60 years (HR=1.5; 95% CI 0.9-2.5; P=0.13), male gender (HR=1.5; 95% CI 1.03-2.5; P=0.03) and CD4 count<50 cells/microL (HR=9.1; 95% CI 5.1-16.3; P<0.001) were independently associated with death. These results suggest that strategies promoting early diagnosis and better follow-up of addicted patients would have a significant impact on mortality.

Effect of morphine on the neuropathogenesis of SIVmac infection in Indian Rhesus Macaques

Morphine is known to prevent the development of cell-mediated immune (CMI) responses and enhance expression of the CCR5 receptor in monocyte macrophages. We undertook a study to determine the effect of morphine on the neuropathogenesis and immunopathogenesis of simian immunodeficiency virus (SIV) infection in Indian Rhesus Macaques. Hypothetically, the effect of morphine would be to prevent the development of CMI responses to SIV and to enhance the infection in macrophages. Sixteen Rhesus Macaques were divided into three experimental groups: M (morphine only, n = 5), VM (morphine + SIV, n = 6), and V (SIV only, n = 5). Animals in groups M and VM were given 2.5 mg/kg of morphine sulfate, four times daily, for up to 59 weeks. Groups VM and V were inoculated with SIVmacR71/17E 26 weeks after the beginning of morphine administration. Morphine prevented the development of enzyme-linked immunosorbent spot-forming cell CMI responses in contrast to virus control animals, all of which developed CMI. Whereas morphine treatment had no effect on viremia, cerebrospinal fluid viral titers or survival over the time course of the study, the drug was associated with a tendency for greater build-up of virus in the brains of infected animals. Histopathological changes in the brains of animals that developed disease were of a demyelinating type in the VM animals compared to an encephalitic type in the V animals. This difference may have been associated with the immunosuppressive effect of the drug in inhibiting CMI responses.

Antiretroviral HIV treatment and care for injecting drug users: an evidence-based overview

AIDS-related mortality and the rate of progression to AIDS have dramatically decreased since the advent of highly active antiretroviral treatment (HAART). The overall benefit from antiretroviral HIV treatment has, however, been lesser in HIV-infected injecting drug users (IDUs) than in other patient groups (e.g. men who have sex with men). Poorer outcomes in HIV-infected IDUs are related to a variety of factors, including increased rates of non-HIV-related deaths, hepatitis C, delayed access to effective treatment, lower adherence to care and treatment regimens, continuation of illicit drug use, depression and negative life events. The available evidence strongly suggests the need for the large-scale implementation of comprehensive treatment and care strategies for IDUs that include both treatment of drug dependence and HAART.

Study on the blood-borne virus co-infection and T lymphocyte subset among intravenous drug users

AIM: To investigate the features of various blood-borne virus infections and co-infection in intravenous drug users (IDUs), and to examine the correlation of T lymphocyte subsets with virus co-infection.

METHODS: Four hundred and six IDUs without any clinical manifestation of hepatitis and 102 healthy persons were enrolled in this study. HBV-DNA and HCV-RNA were detected by fluorescence quantitative PCR. HBsAg, HBeAg, anti-HBc, anti-HCV, HDV-Ag, anti-HGV, anti-HIV, and HCMV-IgM were assayed by enzyme-linked immunosorbent assay (ELISA) and immunochromatographic tests. The levels of Th1 and Th2 cytokines were measured by ELISA and radioactive immune assay (RIA). The T lymphocyte subpopulation was detected by using fluorescence immunoassay. The similar indices taken from the healthy persons served as controls.

RESULTS: The viral infection rate among IDUs was 36.45% for HBV, 69.7% for HCV, 47.3% for HIV, 2.22% for HDV, 1.97% for HGV, and 3.45% for HCMV. The co-infection rate of blood-borne virus was detected in 255 of 406 (62.81%) IDUs. More than 80% (161/192) of subjects infected with HIV were co-infected with the other viruses, such as HBV, HCV. In contrast, among the controls, the infection rate was 17.65% for HBV and 0% for the other viruses. Our investigation showed that there was a profound decrease in the proportion of CD4/CD8 and the percentage of CD3 and CD4, but not in the percentage of CD8. The levels of PHA-induced cytokines (IFN-γ and IL-4) and serum IL-2 were obviously decreased in IDUs. On the other hand, the level of serum IL-4 was increased. The level of IFN-γ and the percentage of CD4 were continuously decreased when the IDUs were infected with HIV or HIV co-infection. IDUs with HIV and HBV co-infection was 15.1% (29/192). Of those 29 IDU with HIV and HBV co-infection, 51.72% (15/29) and 37.93% (11/29) were HBV-DNA-positive and HBeAg-positive, respectively. But, among IDUs without HIV infection, only 1.68% (2/119) of cases were HBV-DNA-positive.

CONCLUSION: HCV, HBV and HIV infections are common in this population of IDU, leading to a high incidence of impaired Th1 cytokine levels and CD4 lymphocyte. IDUs with HIV and HBV/HCV co-infection have lower expression of Th1 cytokine with enhancement of the Th2 response. HIV may be causing HBV replication by decreasing Th1 function.

Cocaine induced inflammatory response in human neuronal progenitor cells

We have employed a genomic approach in homogenous cell culture to investigate the fundamental transcriptional responses which occur in neurons over time as a consequence of a single 30-min exposure to cocaine. Data from 24 Affymetrix microarrays, representing eight treatment groups, were analyzed by GeneChip Operating Software and then further mined by hierarchical clustering, anova, and Ingenuity Pathway Analysis software to examine known molecular pathways impacted by the observed transcriptional changes. For each time point under investigation, the data sets of genes exhibiting altered expression in treated cells compared with control were interrogated with a specific focus on differential expression of genes involved in immunomodulation and inflammation. The existing literature on the effects of cocaine in a diverse array of experimental paradigms demonstrates a significant modulation of inflammation and immune mechanisms, but these have typically been studies of chronic exposure in immune-competent cells. Our data show a time-dependent up-regulation of genes associated with pro-inflammatory and immune responses, peaking at 24 h as confirmed by all methods of analysis, suggesting a specific neuronal immunomodulatory response to acute cocaine exposure.

Mortality in an urban cohort of HIV-infected and at-risk drug users in the era of highly active antiretroviral therapy

BACKGROUND

Mortality trends among drug users in the era of highly active antiretroviral therapy (HAART) remain unclear.

METHODS

We examined mortality rates, causes of death, and predictors of mortality in 398 human immunodeficiency virus (HIV)-infected and 656 at-risk drug users for the period of 1996-2001. National death index reports were used to confirm deaths, and causes of death were derived from medical records. Cox proportional hazards models were used to determine factors associated with mortality.

RESULTS

During 1996-2001, mortality rates in HIV-infected and HIV-uninfected participants were 7.3 and 1.5 deaths per 100 person-years, respectively (P<.001). The mean age at the time of death was 43.6 years for HIV-infected subjects and 47.7 years in HIV-uninfected subjects (P<.001). For 398 HIV-infected participants who were observed for 1443 person-years, death rates decreased from 11.4 to 5.4 deaths per 100 person-years over the 6-year period (P=.04). Among all participants, causes of death were as follows: HIV/AIDS, 27% of subjects; substance abuse, 31%; bacterial infection, 25%; other medical illness, 14%; and violence, 3%. Persons who initiated HAART at a CD4+ lymphocyte count of 201-350 cells/mm3 experienced improved survival, compared with those who initiated it at a CD4+ lymphocyte count of < or =200 cells/mm3 (P=.01). In a multivariate Cox model of HIV-infected subjects, factors independently associated with mortality included receipt of HAART (adjusted hazard ratio [HR(adj)], 0.44; 95% confidence interval [CI], 0.28-0.68) and CD4+ lymphocyte count of < or =200 cells/mm3 (HR(adj), 4.23; 95% CI, 2.24-7.60). Use of methadone or illicit drugs did not predict mortality.

CONCLUSIONS

To further reduce mortality among drug users, interventions aimed at improving HAART use are warranted. Preventive health and timely management of treatable conditions, such as bacterial infections, also needs emphasis.

Hepatitis C virus coinfection and HIV load, CD4+ cell percentage, and clinical progression to AIDS or death among HIV-infected women: Women and Infants Transmission Study

BACKGROUND

Despite previous study, it remains unclear whether hepatitis C virus (HCV) coinfection affects the progression of human immunodeficiency virus (HIV) type 1 infection. The Women and Infants Transmission Study provided an opportunity to assess this issue.

METHODS

Longitudinal data on 652 HIV-1-infected women enrolled in the study before the availability of highly active antiretroviral therapy (HAART; 1989-1995) were analyzed. Random effects models were used to determine whether HCV coinfection was associated with different CD4+ cell percentages and HIV-1 RNA levels over time, and Cox proportional hazards models were used to compare the rates of clinical progression to acquired immunodeficiency syndrome (AIDS) or death.

RESULTS

Of 652 women, 190 (29%) were HCV infected. During follow-up, 19% of women were exposed to HAART. After controlling for indicators of disease progression (CD4+ cell percentages and HIV-1 RNA levels determined closest to the time of delivery in pregnant women), ongoing drug use, receipt of antiretroviral therapy, and other important covariates, no differences were detected in the HIV-1 RNA levels, but the CD4+ cell percentages were slightly higher in HCV-infected women than in HCV-uninfected women. During follow-up, 48 women had progression to a first clinical AIDS-defining illness (ADI), and 26 died with no documented antecedent ADI. In multivariable analyses, HCV-infected participants did not have faster progression to a first class C AIDS-defining event or death (relative hazard, 0.75; 95% confidence interval, 0.37-1.53).

CONCLUSIONS

In this cohort, the rate of clinical progression of HIV-1 infection was not greater for HCV-infected women.