Comparison of progression and non-progression in injecting drug users and homosexual men with documented dates of HIV-1 seroconversion. European Seroconverter Study and the Tricontinental Seroconverter Study

Lower Broadly Neutralizing Antibody Responses in Female Versus Male HIV-1 Infected Injecting Drug Users

Understanding the factors involved in the development of broadly neutralizing antibody (bNAb) responses in natural infection can guide vaccine design aimed at eliciting protective bNAb responses. Most of the studies to identify and study the development of bNAb responses have been performed in individuals who had become infected via homo- or heterosexual HIV-1 transmission; however, the prevalence and characteristics of bNAb responses in injecting drug users (IDUs) have been underrepresented. We retrospectively studied the prevalence of bNAb responses in HIV-1 infected individuals in the Amsterdam Cohort, including 50 male and 35 female participants who reported injecting drug use as the only risk factor. Our study revealed a significantly lower prevalence of bNAb responses in females compared to males. Gender, transmission route and CD4+ count at set point, but not viral load, were independently associated with the development of bNAb responses in IDUs. To further explore the influences of gender in the setting of IDU, we also looked into the Swiss 4.5k Screen. There we observed lower bNAb responses in female IDUs as well. These results reveal that the emergence of bNAbs may be dependent on multiple factors, including gender. Therefore, the effect of gender on the development of bNAb responses is a factor that should be taken into account when designing vaccine efficacy trials.

Evaluation of Possible Effects of Continued Drug Use on HIV Progression among Women

Data from a prospective, multi-centred study of HIV infection in women (HIV Epidemiology Research Study [HERS)) was analysed to investigate the effect of continued injection drug use behaviours on progression to AIDS. All women enrolled in the HERS had at enrolment and at six-month intervals, a face-to-face interview which included specific injection drug use, a physical exam, and specimen collection that included T-cell subset analysis and HIV plasma RNA detection. Six hundred and thirty-nine HIV-infected women contributed 3021 person years of observation during 7.25 years of follow-up, and 299 of these women progressed to AIDS (46.8%). In multivariable analysis, there was no significantly increased risk of progression to AIDS for women reporting pre-baseline injection drug use [hazard ratio (HR)=1.07 (0.78, 1.47)] or reported injection drug use during follow-up [HR=0.89 (0.66, 1.21)] compared with never injecting. In a separate multivariable-model, comparing women who reported no injection in past six months to active injection drug users, the frequency of injection during the previous six months measured by daily injection [HR=0.97 (0.61, 1.55)] or less than daily injection [HR=O.84 (0.54, 1.33)] was not associated with progression to AIDS. Being in drug treatment was independently associated with a slower progression to AIDS [HR=0.41 (0.28,0.59)]. Neither injection drug use, nor frequency of injection drug use was associated with progression to AIDS among HIV infected women. Initiation of antiretroviral therapy among drug users should be based on readiness for treatment rather than concern about faster progression.

Modeling a dynamic bi-layer contact network of injection drug users and the spread of blood-borne infections

Injection drug users (IDUs) are at high risk of acquiring and spreading various blood-borne infections including human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV) and a number of sexually transmitted infections. These infections can spread among IDUs via risky sexual and needle-sharing contacts. To accurately model the spread of such contagions among IDUs, we build a bi-layer network that captures both types of risky contacts. We present methodology for inferring important model parameters, such as those governing network structure and dynamics, from readily available data sources (e.g., epidemiological surveys). Such a model can be used to evaluate the efficacy of various programs that aim to combat drug addiction and contain blood-borne diseases among IDUs. The model is especially useful for evaluating interventions that exploit the structure of the contact network. To illustrate, we instantiate a network model with data collected by a needle and syringe program in Chicago. We model sexual and needle-sharing contacts and the consequent spread of HIV and HCV. We use the model to evaluate the potential effects of a peer education (PE) program under different targeting strategies. We show that a targeted PE program would avert significantly more HIV and HCV infections than an untargeted program, highlighting the importance of reaching individuals who are centrally located in contact networks when instituting prevention programs.

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.

Injecting drug use is associated with a more rapid CD4 cell decline among treatment naïve HIV-positive patients in Indonesia

Background

It remains unclear whether the natural course of human immunodeficiency virus (HIV) differs in subjects infected through injecting drug use (IDU) and no data have been published from low- or middle-income countries. We addressed this question in an urban cohort in Indonesia, which is experiencing a rapidly growing HIV epidemic strongly driven by IDU.

Methods

All antiretroviral treatment (ART) naïve HIV-positive patients who had at least two subsequent CD4 cell counts available before starting ART were included in this study. We examined the association between IDU and CD4 cell decline using a linear mixed model, with adjustment for possible confounders such as HIV viral load and hepatitis C antibodies.

Results

Among 284 HIV-positive ART naïve patients, the majority were male (56%) with a history of IDU (79% among men). People with a history of IDU had a statistically significant faster decline in CD4 cells (p<0.001). Based on our data, patients with a history of IDU would have an average 33% decline in CD4 cells after one year without ART, compared with a 22% decline among non-users. At two years, the decline would average 66 and 40%, respectively. No other factor was significantly associated with CD4 cell decline.

Conclusions

We show that a history of IDU is associated with a more rapid CD4 cell natural decline among HIV-positive individuals in Indonesia. These findings have implications for monitoring ART naïve patients with a history of IDU and for starting ART in this group.

Slow immunological progression in HIV-1 CRF07_BC-infected injecting drug users

Human immunodeficiency virus type 1 (HIV-1) circulating recombinant form (CRF) 07_BC has caused serious HIV-1 epidemics among injecting drug users (IDUs) in East Asia. Little is known about the characteristics of the virus and its impact on disease progression among the infected individuals. In this study, we compared immunological progression between 423 IDUs infected with CRF07_BC and 194 men who have sex with men (MSM) with primary subtype B infection, and a representative full-length CRF07_BC molecular clone, pCRF07_BC, was constructed to characterize the virus. We found that IDUs infected with CRF07_BC had significantly slower immunological progression in the Cox proportional hazards model (hazard ratio: 0.30; 95% confidence interval: 0.13–0.69; P=0.004). The constructed recombinant CRF07_BC viruses had a reduced processing of the Gag/Gag-Pol polyproteins, a decreased incorporation of Vpr in the virus particle, tethering of virus particles on the plasma membrane and decreased virus growth kinetics. These phenotypes are related to the unique 7-amino acid deletion in the p6 of CRF07_BC, since complementation of the 7-amino acid in pCRF07_BC could improve the defective phenotypes. In summary, compared with MSM infected with HIV-1 subtype B, IDUs infected with CRF07_BC had slower immunological progression, which is likely correlated with interference of virus particle maturation by the 7-amino acid deletion in p6.

Disease progression by infecting HIV-1 subtype in a seroconverter cohort in sub-Saharan Africa

Objective:

To describe immunologic, virologic, and clinical HIV disease progression by HIV-1 subtype among Africans with well documented estimated dates of HIV infection (EDIs).

Design:

Prospective cohort.

Methods:

Adults and youth with documented HIV-1 infection in the past 12 months were recruited from seroincidence cohorts in East and Southern Africa and followed at 3–6 month intervals. Blood for lymphocyte subset and viral load determination was collected at each visit. Pol was sequenced from the first positive specimen to ascertain subtype. Preantiretroviral therapy disease progression was measured by three time-to-event endpoints: CD4⁺ cell count 350 cells/μl or less, viral load measurement at least 1 × 10⁵ copies/ml, and clinical AIDS.

Results:

From 2006 to 2011, 615 participants were enrolled at nine research centers in Kenya, Rwanda, South Africa, Uganda, and Zambia; 579 (94.1%) had viral subtyping completed. Predominant subtypes were C (256, 44.2%), A (209, 36.1%), and D (84, 14.5%). After adjustment for age, sex, and human leukocyte antigen alleles in Cox regression analyses, subtype C-infected participants progressed faster than subtype A to all three endpoints [CD4⁺ hazard ratio 1.60, 95% (confidence interval) CI 1.16, 2.20; viral load hazard ratio 1.59, 95% CI 1.12, 2.25; and AIDS hazard ratio 1.60, 95% CI 1.11, 2.31). Subtype D-infected participants reached high viral load more rapidly (hazard ratio 1.61, 95% CI 1.01, 2.57) and progressed nearly twice as fast to AIDS compared to subtype A (hazard ratio 1.93, 95% CI 1.21, 3.09).

Conclusion:

Subtype-specific differences in HIV disease progression suggest that the local subtype distribution be considered when planning HIV programs and designing and defining clinical endpoints for HIV prevention trials.

Rapid dissemination of SIV follows multisite entry after rectal inoculation

Receptive ano-rectal intercourse is a major cause of HIV infection in men having sex with men and in heterosexuals. Current knowledge of the mechanisms of entry and dissemination during HIV rectal transmission is scarce and does not allow the development of preventive strategies. We investigated the early steps of rectal infection in rhesus macaques inoculated with the pathogenic isolate SIVmac251 and necropsied four hours to nine days later. All macaques were positive for SIV. Control macaques inoculated with heat-inactivated virus were consistently negative for SIV. SIV DNA was detected in the rectum as early as four hours post infection by nested PCR for gag in many laser-microdissected samples of lymphoid aggregates and lamina propria but never in follicle-associated epithelium. Scarce SIV antigen positive cells were observed by immunohistofluorescence in the rectum, among intraepithelial and lamina propria cells as well as in clusters in lymphoid aggregates, four hours post infection and onwards. These cells were T cells and non-T cells that were not epithelial cells, CD68⁺ macrophages, DC-SIGN⁺ cells or fascin⁺ dendritic cells. DC-SIGN⁺ cells carried infectious virus. Detection of Env singly spliced mRNA in the mucosa by nested RT-PCR indicated ongoing viral replication. Strikingly, four hours post infection colic lymph nodes were also infected in all macaques as either SIV DNA or infectious virus was recovered. Rapid SIV entry and dissemination is consistent with trans-epithelial transport. Virions appear to cross the follicle-associated epithelium, and also the digestive epithelium. Viral replication could however be more efficient in lymphoid aggregates. The initial sequence of events differs from both vaginal and oral infections, which implies that prevention strategies for rectal transmission will have to be specific. Microbicides will need to protect both digestive and follicle-associated epithelia. Vaccines will need to induce immunity in lymph nodes as well as in the rectum.

AIDS denialism and public health practice

In this paper, we respond to AIDS denialist arguments that HIV does not cause AIDS, that antiretroviral drugs are not useful, and that there is no evidence of large-scale deaths from AIDS, and discuss the key implications of the relationship between AIDS denialism and public health practice. We provide a brief history of how the cause of AIDS was investigated, of how HIV fulfills Koch's postulates and Sir Bradford Hil's criteria for causation, and of the inconsistencies in alternatives offered by denialists. We highlight clinical trials as the standard for assessing efficacy of drugs, rather than anecdotal cases or discussions of mechanism of action, and show the unanimous data demonstrating antiretroviral drug efficacy. We then show how statistics on mortality and indices such as crude death rate, life expectancy, child mortality, and population growth are consistent with the high mortality from AIDS, and expose the weakness of statistics from death notification, quoted by denialists. Last we emphasize that when denialism influences public health practice as in South Africa, the consequences are disastrous. We argue for accountability for the loss of hundreds of thousands of lives, the need to reform public health practice to include standards and accountability, and the particular need for honesty and peer review in situations that impact public health policy.

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.

Human immunodeficiency virus controllers: mechanisms of durable virus control in the absence of antiretroviral therapy

Chronic viral infections can appear in two very different forms: those that are typically immunologically contained after acute symptomatic infection, such as Epstein-Barr virus (EBV), and those that predictably lead to persistent viremia and progressive clinical disease. Human immunodeficiency virus (HIV) infection is typical of the latter and has resulted in more than 20 million deaths worldwide. Here we review a remarkable subset of persons infected with HIV who are able to achieve long-term control of viremia and avoid immunodeficiency without the need for antiviral therapy. We review the contributing role of host genetic factors, innate and adaptive immune responses, and viral factors that may contribute to this phenotype. These individuals indicate that as with other potentially pathogenic chronic viral infections, the human immune system is able to fully control HIV and prevent HIV-associated disease, at least in some individuals. Further understanding of the mechanisms whereby this occurs should yield critical insights for prophylactic and therapeutic antiviral interventions.

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.

Predictors of disease progression in HIV infection: a review

During the extended clinically latent period associated with Human Immunodeficiency Virus (HIV) infection the virus itself is far from latent. This phase of infection generally comes to an end with the development of symptomatic illness. Understanding the factors affecting disease progression can aid treatment commencement and therapeutic monitoring decisions. An example of this is the clear utility of CD4+ T-cell count and HIV-RNA for disease stage and progression assessment. Elements of the immune response such as the diversity of HIV-specific cytotoxic lymphocyte responses and cell-surface CD38 expression correlate significantly with the control of viral replication. However, the relationship between soluble markers of immune activation and disease progression remains inconclusive. In patients on treatment, sustained virological rebound to >10,000 copies/mL is associated with poor clinical outcome. However, the same is not true of transient elevations of HIV RNA (blips). Another virological factor, drug resistance, is becoming a growing problem around the globe and monitoring must play a part in the surveillance and control of the epidemic worldwide. The links between chemokine receptor tropism and rate of disease progression remain uncertain and the clinical utility of monitoring viral strain is yet to be determined. The large number of confounding factors has made investigation of the roles of race and viral subtype difficult, and further research is needed to elucidate their significance. Host factors such as age, HLA and CYP polymorphisms and psychosocial factors remain important, though often unalterable, predictors of disease progression. Although gender and mode of transmission have a lesser role in disease progression, they may impact other markers such as viral load. Finally, readily measurable markers of disease such as total lymphocyte count, haemoglobin, body mass index and delayed type hypersensitivity may come into favour as ART becomes increasingly available in resource-limited parts of the world. The influence of these, and other factors, on the clinical progression of HIV infection are reviewed in detail, both preceding and following treatment initiation.

Comparative studies on mucosal and intravenous transmission of simian immunodeficiency virus (SIVsm): evolution of coreceptor use varies with pathogenic outcome

Coreceptor usage of isolates from 30 cynomolgus macaques infected intrarectally (n=22) or intravenously (n=8) with simian immunodeficiency virus of sooty mangabey origin (SIVsm) was evaluated in U87.CD4 and GHOST(3) cell lines. Based on progression rate, the animals were divided into progressors (18 animals), slow progressors (five animals) and long-term non-progressors (seven animals). There was no difference in how many or which coreceptors were used according to route of infection. All isolates but one used CCR5 for cell entry, and CCR5 was also the major coreceptor in 70 out of 105 isolates tested. In general, early isolates were multitropic, using CCR5, CXCR6 and/or gpr15. Interestingly, CXCR4-using viruses could be isolated on human peripheral blood mononuclear cells (PBMCs), but not on cynomolgus macaque PBMCs, suggesting that human PBMCs select for variants with CXCR4 use. Even though CXCR4-using SIV isolates have been reported rarely, we could recover CXCR4-using viruses from 13 monkeys. CXCR4 use either appeared early during the acute phase of infection and disappeared later or only appeared late in infection during immunodeficiency. Surprisingly, one late isolate from a progressor monkey did not use CCR5 at all and used the CXCR4 receptor with high efficiency. The ability to use many different receptors decreased over time in long-term non-progressor monkeys, whilst the majority of progressor monkeys showed broadening of coreceptor use, stable coreceptor use or fluctuation between the different coreceptor-usage patterns. The results indicate that, in the infected host, evolution of SIV coreceptor usage occurs, involving changes in the mode of coreceptor use.

Comparative studies on mucosal and intravenous transmission of simian immunodeficiency virus (SIVsm): the kinetics of evolution to neutralization resistance are related to progression rate of disease

The kinetics of appearance of autologous neutralizing antibodies were studied in cynomolgus macaques infected with simian immunodeficiency virus (SIVsm) by the intravenous (IV) route (six monkeys) or the intrarectal (IR) route (ten monkeys). The SIVsm inoculum virus and reisolates obtained at 2 weeks, 3 or 4 months and later than 1 year were tested in a GHOST(3) cell line-based plaque-reduction assay with autologous sera collected at the same sampling times. All monkeys developed a neutralizing-antibody response to the inoculum virus, those infected by the IV route earlier than monkeys infected by the IR route. Animals were divided into progressor (P), slow-progressor (SP) and long-term non-progressor (LTNP) monkeys, based on progression rate. In P monkeys, neutralization escape could be demonstrated by 3 months post-infection. Neutralization-resistant variants also emerged in SP and LTNP monkeys, but were much delayed compared with P monkeys. Evolution of neutralization resistance was also demonstrated by a positive-control serum in the heterologous reaction. Pooled sera from four LTNP monkeys showed a broad neutralizing capacity, including neutralization of escape variants. These results from a large group of infected monkeys showed that SIV evolves to neutralization resistance in the infected host and that the kinetics of this evolution are related to the route of transmission and the progression rate of SIV disease. The results suggest an important role for neutralizing antibodies in controlling viraemia. Although this control is transient in the infected host, neutralization resistance is relative and variant viruses may be neutralized by a broadly cross-neutralizing serum pool.

Higher set point plasma viral load and more-severe acute HIV type 1 (HIV-1) illness predict mortality among high-risk HIV-1-infected African women

BACKGROUND

There is limited information on the natural history of human immunodeficiency virus type 1 (HIV-1) infection in Africa, especially from individuals with well-defined dates of infection. We used data from a prospective cohort study of female sex workers in Mombasa, Kenya, who were followed up monthly from before the date of HIV-1 infection.

METHODS

Antiretroviral-naive women who had a well-defined date of HIV-1 infection were included in this analysis. The effects of set point plasma viral load (measured 4-24 months after infection), early CD4+ cell count, and symptoms of acute HIV-1 infection on mortality were assessed using Cox proportional hazards analysis.

RESULTS

Among 218 women, the median duration of follow-up after HIV-1 infection was 4.6 years. Forty women died, and at 8.7 years (the time of the last death), the cumulative survival rate was 51% by Kaplan-Meier analysis. Higher set point viral load, lower early CD4+ cell count, and more-symptomatic acute HIV-1 illness each predicted death. In multivariate analysis, set point viral load (hazard ratio [HR], 2.28 per 1 log10 copies/mL increase; P=.001) and acute HIV-1 illness (HR, 1.14 per each additional symptom; P=.05) were independently associated with higher mortality.

CONCLUSION

Among this group of African women, the survival rate was similar to that for HIV-1-infected individuals in industrialized nations before the introduction of combination antiretroviral therapy. Higher set point viral load and more-severe acute HIV-1 illness predicted faster progression to death. Early identification of individuals at risk for rapid disease progression may allow closer clinical monitoring, including timely initiation of antiretroviral treatment.

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

In vitro and animal studies suggest that cocaine and heroin increase HIV replication and suppress immune function, whereas epidemiologic studies are inconclusive regarding their effect on HIV infection progression. The authors prospectively examined the association between illicit-drug use and 4 outcome measures (CD4 cell percentage, HIV RNA level, survival to class C diagnosis of HIV infection, and death) in a national cohort of HIV-infected women. Women enrolled between 1989 and 1995 were followed for 5 years and repeatedly interviewed about illicit ("hard")--drug use. Up to 3 periodic urine screens validated self-reported use. Outcomes were compared between hard-drug users (women using cocaine, heroin, methadone, or injecting drugs) and nonusers, adjusting for age, antiretroviral therapy, number of pregnancies, smoking, and baseline CD4 cell percentage. Of 1148 women, 40% reported baseline hard-drug use during pregnancy. In multivariate analyses, hard-drug use was not associated with change in CD4 cell percentage (P = 0.84), HIV RNA level (P = 0.48), or all-cause mortality (relative hazard = 1.10; 95% confidence interval, 0.61-1.98). Hard-drug users did, however, exhibit a higher risk of developing class C diagnoses (relative hazard = 1.65; 95% confidence interval, 1.00-2.72), especially herpes, pulmonary tuberculosis, and recurrent pneumonia. Hard-drug-using women may have a higher risk for nonfatal opportunistic infections.

Do HIV Disease Progression and HAART Response Vary among Injecting Drug Users in Europe?

Prior to HAART availability, there was no evidence of a geographical variation in HIV disease progression among injecting drug users (IDU) from different European regions. Nowadays, factors of importance regarding HIV disease progression in the face of HAART availability, such as HAART access, adherence, and the organization of care for IDU may differ across Europe. Therefore we studied HIV disease progression in a European study of IDU with known dates of HIV-seroconversion. Results show that with ongoing HAART availability, the risk of HIV disease progression has continued to decrease. When accounting for pre-AIDS death (in AIDS analyses) and non-natural deaths (suicide, overdose, accidents and homicide, in analyses of death) which are common among IDU, the risk of AIDS and death has decreased by as much as 65% and 75%, respectively, in 2000/2001. Results show little geographic variation in progression to AIDS. All-cause mortality was higher in IDU from Glasgow than elsewhere, while in the Valencian region (Spain) IDU were at a significantly lower risk of non-natural deaths. The timing of HAART initiation by treatment-naïve IDU likewise differed across Europe: IDU in Amsterdam, Innsbruck, and Edinburgh started at significantly lower CD4 counts than IDU in Paris, Geneva, Glasgow, and the Valencian region, but the subsequent short-term immune response was similar. In conclusion, the risk in progression to AIDS or natural death is similar across western Europe although IDU across Europe differ in other factors, such as the risk of non-natural death and the timing of HAART initiation.

The role of substance abuse in HIV disease progression: reconciling differences from laboratory and epidemiologic investigations

From the onset of the HIV/AIDS epidemic, the use of licit and illicit drugs has been investigated for its potential impact on HIV disease progression. Findings from a large number of laboratory-based studies indicate that drug abuse may exacerbate HIV disease progression; however, epidemiological studies have shown mixed results. This article presents a review of findings from both laboratory-based and epidemiologic investigations. In addition, we provide a careful evaluation of methodological strengths and limitations inherent to both study designs in order to provide a more nuanced understanding of how these findings may complement one another.

The relationship between non-injection drug use behaviors on progression to AIDS and death in a cohort of HIV seropositive women in the era of highly active antiretroviral therapy use

AIMS

To evaluate the effects of longitudinal patterns and types of non-injection drug use (NIDU) on HIV progression in the highly active antiretroviral therapy (HAART) era.

DESIGN

Women's Interagency HIV Study (WIHS), a prospective cohort study conducted at six US sites.

METHODS

Data were collected semi-annually from 1994 to 2002 on 1046 HIV(+) women. Multivariate Cox proportional hazards modeling was used to estimate relative hazards for developing AIDS and for death by pattern and type of NIDU.

FINDINGS

During follow-up, 285 AIDS events and 287 deaths, of which 177 were AIDS-related, were reported. At baseline, consistent and former NIDU was associated with CD4(+) counts of < 200 cells/microl (43% and 46%, respectively) and viral load > 40,000 copies/ml (53% and 55%, respectively). Consistent NIDU reported less HAART use (53%) compared with other NIDU patterns. Stimulant use was associated with CD4(+) cell counts of < 200 cells/microl (53%) and lower HAART initiation (63%) compared with other NIDU types. In multivariate analyses, progression to AIDS was significantly higher among consistent (RH = 2.52), inconsistent (RH = 1.63) and former (RH = 1.56) users compared with never users; and for stimulant (RH = 2.04) and polydrug (RH = 1.65) users compared with non-users. Progression to all-cause death was higher only among former users (RH = 1.48) compared with never users in multivariate analysis. NIDU behaviors were not associated with progression to AIDS-related death.

CONCLUSIONS

In this study, pattern and type of NIDU were associated with HIV progression to AIDS and all-cause mortality. These differences were associated with lower HAART utilization among consistent NIDU and use of stimulants, and poor baseline immunological and virological status among former users.

Pre-seroconversion immune status predicts the rate of CD4 T cell decline following HIV infection

OBJECTIVE

To study whether immune status prior to HIV seroconversion predicts CD4 T cell decline during HIV infection.

DESIGN

Prospective cohort study including 51 injecting drug users (IDU) who were HIV negative at study entry and seroconverted for HIV during follow-up.

METHODS

Cryopreserved peripheral blood mononuclear cells obtained before HIV seroconversion were used to measure naive (CD45RO-CD27+), memory (CD45RO+CD27+), and total CD4 T cell numbers, the fraction of dividing Ki67+CD4+ T cells, and CD4 T cell receptor excision circles (TREC). The effect of pre-seroconversion immune status, as defined by these markers, on the rate of CD4 T cell decline during HIV infection was assessed using linear regression for repeated measurements.

RESULTS

IDU with low pre-seroconversion CD4 T cell TREC contents lost CD4 T cells at a significantly faster rate during HIV infection than those with a high CD4 T cell TREC content. IDU with higher pre-seroconversion CD4 T cell numbers had a significantly steeper CD4 T cell decline in the first 3 months of HIV infection, but their CD4 T cell counts remained higher throughout HIV infection. Intermediate levels of pre-seroconversion dividing Ki67+CD4+ T cells were associated with a significantly steeper CD4 cell decline than high levels. IDU with the highest pre-seroconversion drug-injecting frequencies showed slower CD4 T cell decline than those who injected less. No correlation was present between pre-seroconversion immune markers and the pre-seroconversion duration or intensity of drug use.

CONCLUSION

Among IDU, immune status prior to HIV infection as measured by TREC content affects the disease course after HIV seroconversion.

[Predictors of progression and death in patients with advanced HIV infection in the era of highly active antiretroviral therapy]

INTRODUCTION

To assess the factors associated with progression of infection and death in HIV-positive patients with severe immunodepression in the era of highly active antiretroviral therapy (HAART).

METHODS

We studied 146 HIV-infected patients with < 100 x 10(6)/L CD4+ lymphocytes and positive cytomegalovirus (CMV) serology enrolled between December 1997 and October 1998 and prospectively followed a median of 12.1 months. The main outcome measures were progression of HIV infection, defined as the appearance of a new AIDS-defining disease (CDC category C) or death. HIV viral load, lymphocyte count (CD4+ and CD8+), HAART administration and other clinical variables were evaluated at baseline. CMV viremia (determined by PCR) and HAART efficacy were recorded during follow-up.

RESULTS

Progression was observed in 40% of patients and 17% died. Factors associated with progression or death were CD4+ lymphocyte count less than 50 x 10(6)/L, CD8+ lymphocyte count less than 500 x 10(6)/L, HIV viral load more than 300,000 copies RNA/mL, CMV viremia, and absence or inefficacy of HAART. In the multivariate model, absence of HAART and low CD4+ and CD8+ counts remained statistically associated with progression, but the only variable associated with death was CMV viremia.

CONCLUSIONS

In patients with advanced HIV infection, CD4+ and CD8+ cell count and HAART were the most important factors related to progression, and CMV viremia was the strongest predictor of death.

Interaction between HIV and intravenous heroin abuse?

In this article I will review the findings of the potential interactive effects of HIV infection and heroin use as observed in both clinical and laboratory studies. Some of the findings are discrepant and I will endeavour to propose models that could accommodate these variant results as well as suggest factors that could be considered in analysing future investigations in order to resolve these apparent discrepancies.

Differences in CD4 cell counts at seroconversion and decline among 5739 HIV-1-infected individuals with well-estimated dates of seroconversion

We studied repeated measurements of CD4 cell counts on 5739 HIV-1-infected individuals with reliably estimated dates of seroconversion (SC) aged > or =15 years at SC prior to initiation of highly active antiretroviral therapy (HAART) or AIDS using random effects models. Estimated CD4 cell count at SC differed significantly by sex, exposure group, and age, being higher in women, hemophilic men, and injection drug users (IDUs) as well as in those aged >40 years at SC. The rate of CD4 cell count decline did not differ significantly by sex; thus, differences between men and women were stable throughout the HIV-1 incubation period. There was a monotonic relationship between CD4 slopes and age at SC, with steeper slopes in older subjects. At 5 years after SC, the median difference in CD4 cell counts between the oldest (>40 years at SC) and youngest (16-20 years at SC) subjects was around 90 cells/microL. Mean rate of CD4 decline was significantly steeper in subjects diagnosed during acute infection. There was no evidence of a faster loss of CD4 cells in subjects who seroconverted after 1994. Apart from hemophilic men, who tended to have a steeper rate of CD4 decline on average, mean CD4 slopes did not differ by exposure category. These results suggest that before the initiation of HAART or other interventions based on immune status, consideration of demographic factors may be worthwhile.

Does access to health care impact survival time after diagnosis of AIDS?

Lack of access to health care is often blamed for poor health outcomes, but this effect is not supported by existing HIV/AIDS literature. The authors examined the association between access to care and survival time after progression to AIDS, using survival analysis methods. This study combined data from two CDC sponsored studies of HIV-infected persons, a cross-sectional interview study and a longitudinal medical record review study. Study subjects included 752 persons who progressed to AIDS before December 31, 1999, and were patients at either of two major HIV care facilities in Detroit, MIchigan. Separate statistical models were used to test associations between survival time after meeting the criteria for AIDS and two indicators of access to health care: (1) perceived access to health care and (2) health care utilization patterns. Perceived access was not associated with survival time after AIDS, but patterns of health care utilization were significantly associated with survival time after AIDS (HR = 2.04, p < 0.001). Individuals who received a greater proportion of their care in the ER had a worse survival prognosis than those who received more of their health care in an outpatient clinic setting. It is crucial that we provide HIV-infected populations with tools that enable them to access a regular source of health care.

Methods for estimating the AIDS incubation time distribution when date of seroconversion is censored

In most cohort studies on HIV infection and AIDS, data on time from seroconversion to AIDS or death are doubly censored, both at the time origin and at the endpoint of interest. In epidemiological research, the most frequently adopted approach is to restrict the analysis to persons with narrow seroconversion intervals and to impute the midpoint of this interval as date of seroconversion. For many cohort studies, the consequence is that a substantial proportion of the data is not used. We consider four methods that are expected to be less biased when all cohort data are used: two imputation methods, conditional mean and multiple imputation, and two likelihood maximization methods. We derive the likelihood structure of the cohort data and clarify its dependence on study design. All methods are applied to data from the Amsterdam cohort study among injection drug users. In a simulation study the data generation process of this cohort study is imitated. The performance of midpoint, conditional mean and multiple imputation are compared. With midpoint imputation, both an analysis using the full data set, as well as one restricted to the cases with small seroconversion intervals, is performed. Conditional mean imputation comes out as the preferred method. It gives best results with respect to mean squared error. Moreover, when confidence intervals are computed through standard methods that ignore the uncertainty in the imputed date of seroconversion, coverage probabilities are almost correct.

Pre-AIDS mortality and its association with HIV disease progression in haemophilic men, injecting drug users and homosexual men

OBJECTIVE

To study pre-AIDS mortality and its association with HIV disease progression in different exposure groups with known intervals of HIV seroconversion.

DESIGN AND METHODS

The type and rate of pre-AIDS deaths were assessed in 111 HIV-infected haemophilic men followed in London, and 118 injecting drug users and 158 homosexual men followed in Amsterdam. In each group, the association between CD4+ T-cell count, HIV RNA and pre-AIDS mortality was studied using proportional hazards analysis.

RESULTS

By 10 years after seroconversion 7.3% of the haemophilic men had died without AIDS and 38.2% had developed AIDS. These figures were 20.2 and 30.5% for injecting drug users, and 8.0 and 55.0% for homosexual men. The major causes of pre-AIDS mortality appear to differ in the three exposure groups. The risk of pre-AIDS death tended to increase with decreasing CD4 cell count and increasing HIV RNA levels in injecting drug users and homosexual men. In men with haemophilia the associations were less obvious, although the log-transformed CD4 cell count was predictive for pre-AIDS death.

CONCLUSIONS

Pre-AIDS deaths occur and are at least partially related to HIV disease progression irrespective of how individuals became infected. Because of the longer life expectancy due to highly active antiretroviral therapy (HAART), pre-AIDS deaths are likely to show a further increase. Methods to incorporate these intermediate outcomes should be considered in the estimation of the size of the HIV epidemic and in the survival analysis of HIV-infected individuals. Prevention and treatment of non-AIDS infections, especially hepatitis C virus infection, and cancers will become increasingly important in HIV-infected individuals. The interaction between these therapies and HAART should be closely monitored.

Stress and coping: the psychoneuroimmunology of HIV/AIDS

A considerable body of evidence, reviewed in this chapter, suggests that psychosocial factors play an important role in progression of HIV infection, its morbidity and mortality. Psychosocial influences relating to faster disease progression include life-event stress, sustained depression, denial/avoidance coping, concealment of gay identity (unless one is rejection-sensitive), and negative expectancies. Conversely, protective psychosocial factors include active coping, finding new meaning, and stress management. In studying long survivors of HIV/AIDS, our group has found protective effects on health of life involvement, collaborative relationship with doctor, emotional expression, depression (conversely), and perceived stress (conversely). Reviewed and discussed are psychoneuroimmunological pathways by which immune and neuroendocrine mechanisms might link psychosocial factors with health and long survival. Finally, biological factors are also a major determinant of disease progression and include genetics and age of the host, viral strain and virulence, medication and several immune response factors on which psychosocial influences could impact.

HIV-infected long-term nonprogressors: epidemiology, mechanisms of delayed progression, and clinical and research implications

Long-term nonprogressors (LTNPs) should be defined as untreated HIV-infected persons without AIDS and with high CD4(+) counts and low plasma viral loads 10 or more years after infection. Although no demographic or behavioral variables distinguish LTNPs, studies should be expanded to include geographically and ethnically diverse groups. Underlying mechanisms for delayed progression appear to include strong CD8(+) cytotoxic T-lymphocyte and noncytolytic suppressive activity, host genetic factors including chemokine receptor polymorphisms, and infection with attenuated viral strains.

Stavudine, lamivudine and indinavir in drug abusing and non-drug abusing HIV-infected patients: adherence, side effects and efficacy

OBJECTIVES

To compare adherence and clinical outcome with highly active antiretroviral therapy (HAART) in intravenous drug users (IDUs) and subjects with other HIV risk behaviours (non-IDUs).

METHODS

A total of 133 non-naive HIV-infected patients, 95 (71%) IDUs and 38 (29%) non-IDUs received triple drug therapy with stavudine, lamivudine, and indinavir. Adherence, side effects, and immunological and virological efficacy of treatment were assessed every 3 months.

RESULTS

During a median follow-up of 12 months, 43 patients (32% of the total) showed adequate adherence in all clinical appointments. Adherence was superior in non-IDUs than in IDUs in every visit, but a significant difference was found only at 6 months, when 22 (58%) non-IDUs versus 37 (39%) IDUs were adherent (P = 0.047). Mildly increased bilirubin was observed in 69 (52%) patients, and renal colic in 34 (26%). No difference in side effects was found between IDUs and non-IDUs. After 6 months of treatment, 35 (43%) participants presented a CD4 cell count increase >100x10(6)/l, and 47 (58%) achieved undetectable HIV RNA (lower limit of detection: 200 copies/ml). CD4 cell count and HIV RNA responses were similar in both groups.

CONCLUSIONS

Adherence to the employed HAART regimen was poor. Non-IDUs were more adherent than IDUs, but the difference between both groups was small. Side effects and efficacy were similar in IDUs and non-IDUs.

[AIDS-free time and survival of an injecting drug users HIV seroconvertors cohort]

OBJECTIVE

To analyze AIDS free time, survival and the pre-AIDS survival for a injecting drug users cohort (IDU) of HIV seroconvertors.

SUBJECT AND METHODS

Interval for seroconversion was available for 276 IDUs from Centers for AIDS Information and Prevention (CIPS) recruited between 1987 and until June of 1996. AIDS diagnosis and vital status dates were obtained by follow up at hospitals, mortality and AIDS registries, and CIPS visits. The end of follow up was December of 1996. Seroconversion date was estimated as the middle point between last HIV- and first HIV+. Kaplan-Meier extension and Cox regression for truncated data were fitted to estimate AIDS-free and survival times and to observe differences by sex, age consumption time and year of seroconversion. Weibull, and Log-normal parametric models were fitted to estimate median and percentiles of AIDS-free and survival times distribution.

RESULTS

34 cases have been identified as AIDS, 24 as deaths, 9 of them being before AIDS. 63.5% of the individuals were AIDS-free 7 years after seroconversion, and the probability of death was 25.50. Pre-AIDS mortality is around 8.7%. There were not significant differences by sex, age, consumption time and year of seroconversion. Log-normal model fitted better estimating an AIDS-free median time of 10.93 years and 13.67 survival years.

CONCLUSION

The incubation period of HIV infection in a cohort of seroconvertors in our environment was around 11 years, not different from that observed out of the Mediterranean area as Holland, Scotland or United States

Survival and progression of HIV disease in women attending GUM/HIV clinics in Britain and Ireland. Study Group for the MRC Collaborative Study of HIV Infection in Women

OBJECTIVES

To describe the pattern of clinical disease in women with HIV infection and to examine the effect of potential cofactors, including oral contraceptive use, alcohol and smoking, ethnic group, and route of HIV transmission, on progression to AIDS and death.

DESIGN

Prospective observational cohort study.

SETTING

15 HIV and genitourinary medicine (GUM) clinics in Britain and Ireland.

PARTICIPANTS

505 women aged over 18 years with a positive HIV antibody test entered the study between June 1992 and August 1995, with outcome data available for 503 women, and 1208 woman years of follow up to April 1996.

MAIN OUTCOME MEASURES

AIDS defining conditions, incidence of AIDS, and death.

RESULTS

120 women (24%) had AIDS at entry to the study. There were 99 incident AIDS cases and 132 deaths during 1208 woman years of follow up. Pneumocystis carinii pneumonia (PCP) was the commonest first AIDS defining condition in white women (31% of AIDS cases), followed by oesophageal candidiasis (19%) while tuberculosis was the most common first AIDS defining condition among black African women (24% of AIDS cases), followed by oesophageal candidiasis (19%). In multivariate analyses, rate of progression to AIDS was significantly related to CD4 lymphocyte count at entry and PCP prophylaxis, but not to ethnic group, route of HIV transmission, alcohol, smoking, or oral contraceptive use. Mortality from all causes was not significantly different in women infected through injecting drugs (adjusted ratio 1.1, 95% confidence interval 0.7-1.8) compared with those infected through sexual intercourse, and non-significantly lower in black African women (0.7, 0.3-1.2) compared with white women. Survival was not significantly related to smoking, alcohol, or oral contraceptive use.

CONCLUSIONS

In women attending GUM/HIV clinics, the pattern of AIDS defining conditions differs by ethnic group, but progression of HIV disease is not importantly related to smoking, alcohol, oral contraceptive use, route of HIV transmission, or ethnic group.

Relationship between HIV-1 viral load and continued drug use in untreated infected injection drug users

The role of continued drug use in development of AIDS has been investigated, using mainly CD4(+) cells as outcome variable. The objective of this study was to verify whether continued drug use can influence HIV-1 plasma viral load.We used cross-sectional enrolment data of the HIV-infected IDUs cohort study Manif 2000 (October 1995-October 1996), recruiting patients in hospital departments of Marseilles, Nice and Paris suburbs. To minimize biases due to differential access to health care, only patients receiving outpatient care for at least 2 years but with no antiretroviral treatment were selected for analysis (n = 108). Available information regarding clinical and laboratory information from medical records and clinical examination as well as drug use and HIV-related risk practices were obtained by a face-to-face and a self-administered questionnaire. Patients denying recent heroin injection were cross-validated by a serological assay to detect morphine. Forty-two patients (39%) reported recent heroin injection; among those denying recent use (n=66), eight (positive for serum morphine assay) were re-classified as IDUs. A difference of 0.35 log in viral load was observed between active and ex-IDUs which increases (0.6 log, p=0.03) in those who have been using drugs for 10 years or more.This result persisted when adjusted for CD4(+) counts, clinical stage or years since diagnosis. Continued drug use may have a significant but limited impact on HIV viral load only in patients with a longer history of drug use. Consequences of persisting drug use on long-term progression to AIDS has to be investigated further.

New evidence to reconcile in vitro and epidemiologic data on the possible role of heroin on CD4+ decline among HIV-infected injecting drug users

Long-term effects of drug type and other drug use related risk factors on CD4+ cell decline were assessed in 224 HIV-infected injecting drug users (IDUs) from Baltimore (ALIVE), USA, and 63 IDUs from Amsterdam, The Netherlands. Higher frequencies of borrowing used injection equipment since 1980 resulted in a higher CD4+ count already present before seroconversion (P = 0.049). Use of mainly heroin in the seroconversion interval resulted in a sharper CD4+ decline until the first 6 months after seroconversion (P = 0.004), but CD4+ values converged later on. This finding might reconcile earlier discordant epidemiological and laboratory study results regarding the possible effects of heroin.