The effect of cigarette smoking on the development of AIDS in HIV-1-seropositive individuals

A Novel mHealth App for Smokers Living With HIV Who Are Ambivalent About Quitting Smoking: Formative Research and Randomized Feasibility Study

BACKGROUND

More people who smoke and are living with HIV now die from tobacco-related diseases than HIV itself. Most people are ambivalent about quitting smoking and want to quit someday but not yet. Scalable, effective interventions are needed to motivate and support smoking cessation among people ambivalent about quitting smoking (PAQS) who are living with HIV.

OBJECTIVE

This study aims to develop an app-based intervention for PAQS who are living with HIV and assess its feasibility, acceptability, and potential impact. Results of this study will inform plans for future research and development.

METHODS

In phase 1, PAQS living with HIV (n=8) participated in user-centered design interviews to inform the final intervention app design and recruitment plan for a subsequent randomized pilot study. In phase 2, PAQS living with HIV were randomized to either a standard care control app or a similar experimental app with additional content tailored for PAQS and those with HIV. Participants were followed for 3 months. Feasibility focused on recruitment, retention, and participants' willingness to install the app. The study was not powered for statistical significance. Indices of acceptability (satisfaction and use) and impact (smoking behavior change and treatment uptake) were assessed via automated data and self-report among those who installed and used the app (n=19).

RESULTS

Recruitment for both study phases was a challenge, particularly via web-based and social media platforms. Enrollment success was greater among people living with HIV recruited from a health care provider and research registry. Once enrolled, retention for the phase 2 randomized study was good; 74% (14/19) of the participants completed the 3-month follow-up. Phase 1 findings suggested that PAQS living with HIV were receptive to using an app-based intervention to help them decide whether, when, and how to stop smoking, despite not being ready to quit smoking. Phase 2 findings further supported this conclusion based on feedback from people who agreed to use an app, but group differences were observed. Indices of acceptability favored the experimental arm, including a descriptively higher mean number of sessions and utilization badges. Similarly, indices of potential impact were descriptively higher in the experimental arm (proportion reducing smoking, making a quit attempt, or calling free tobacco quitline). No participants in either arm quit smoking at the 3-month follow-up.

CONCLUSIONS

On the basis of this formative work, PAQS living with HIV may be receptive to using a mobile health-based app intervention to help them decide whether, when, or how to stop using tobacco. Indices of acceptability and impact indicate that additional research and development are warranted.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05339659; https://clinicaltrials.gov/study/NCT05339659.

Design and rationale of the Botswana Smoking Abstinence Reinforcement Trial: a protocol for a stepped-wedge cluster randomized trial

BACKGROUND

With expanded and sustained availability of HIV treatment resulting in substantial improvements in life expectancy, the need to address modifiable risk factors associated with leading causes of death among people living with HIV/AIDS (PLWH), such as tobacco smoking, has increased. Tobacco use is highly prevalent among PLWH, especially in southern Africa, where HIV is heavily concentrated, and many people who smoke would like to quit but are unable to do so without assistance. SBIRT (Screening, Brief Intervention and Referral to Treatment) is a well-established evidence-based approach successful at supporting smoking cessation in a variety of settings. Varenicline is efficacious in supporting smoking cessation. We intend to assess the effectiveness of SBIRT and varenicline on smoking cessation among PLWH in Botswana and the effectiveness of our implementation.

METHODS

BSMART (Botswana Smoking Abstinence Reinforcement Trial) is a stepped-wedge, cluster randomized, hybrid Type 2 effectiveness-implementation study guided by the RE-AIM framework, to evaluate the effectiveness and implementation of an SBIRT intervention consisting of the 5As compared to an enhanced standard of care. SBIRT will be delivered by trained lay health workers (LHWs), followed by referral to treatment with varenicline prescribed and monitored by trained nurse prescribers in a network of outpatient HIV care facilities. Seven hundred and fifty people living with HIV who smoke daily and have been receiving HIV care and treatment at one of 15 health facilities will be recruited if they are up to 18 years of age and willing to provide informed consent to participate in the study.

DISCUSSION

BSMART tests a scalable approach to achieve and sustain smoking abstinence implemented in a sustainable way. Integrating an evidence-based approach such as SBIRT, into an HIV care system presents an important opportunity to establish and evaluate a modifiable cancer prevention strategy in a middle-income country (MIC) setting where both LHW and non-physician clinicians are widely used. The findings, including the preliminary cost-effectiveness, will provide evidence to guide the Botswanan government and similar countries as they strive to provide affordable smoking cessation support at scale.

CLINICAL TRIAL REGISTRATION

NCT05694637 Registered on 7 December 2022 on clinicaltrials.gov, https://clinicaltrials.gov/search?locStr=Botswana&country=Botswana&cond=Smoking%20Cessation&intr=SBIRT.

Optimizing behavioral and pharmacological smoking cessation interventions among people with HIV

BACKGROUND

People with HIV/AIDS (PWH) smoke at nearly three times the rate of the general population. Interventions to promote sustained quitting among PWH are urgently needed.

METHODS

Our study used a randomized factorial design to evaluate the effects of varenicline, compared with placebo, and behavioral cessation therapy, positively smoke free (PSF), compared with standard of care (SOC) among PWH who smoke. The study was designed with power to detect a small effect (Cohen's h of 0.28-0.36) with 240 participants. The primary outcome was the 7-day point prevalence abstinence (PPA) confirmed by exhaled carbon monoxide (ECO) less than 10 ppm for both main effects at 36 weeks. The study was conducted from June 2016 to November 2020. During the study's last year, recruitment was halted because of COVID-19.

RESULTS

The study randomized 184 participants with power to detect a medium effect (Cohen's h of 0.41). Participants were mostly African American (89.7%), men (62.8%) who smoked mentholated cigarettes (96.7%). Nearly all received antiretroviral medication (96.2%). Quit rates for the entire sample were 7.5% at 36 weeks. Compared with those who received placebo, neither those who received varenicline [36 weeks; OR (95% CI), 1.31 (0.33-5.22), P  = 0.70] nor PSF [36 weeks; OR (95% CI), 0.26 (0.03-2.44), P  = 0.24) were more likely to quit smoking.

CONCLUSION

Among an urban living, primarily African American sample of PWH who smoke neither varenicline nor PSF was found to be efficacious at 36 weeks. Our study was not powered to detect small effects sizes. Larger trials are needed to establish tobacco treatment standards for PWH who smoke.

HIV-associated lung disease

Lung disease encompasses acute, infectious processes and chronic, non-infectious processes such as chronic obstructive pulmonary disease, asthma and lung cancer. People living with HIV are at increased risk of both acute and chronic lung diseases. Although the use of effective antiretroviral therapy has diminished the burden of infectious lung disease, people living with HIV experience growing morbidity and mortality from chronic lung diseases. A key risk factor for HIV-associated lung disease is cigarette smoking, which is more prevalent in people living with HIV than in uninfected people. Other risk factors include older age, history of bacterial pneumonia, Pneumocystis pneumonia, pulmonary tuberculosis and immunosuppression. Mechanistic investigations support roles for aberrant innate and adaptive immunity, local and systemic inflammation, oxidative stress, altered lung and gut microbiota, and environmental exposures such as biomass fuel burning in the development of HIV-associated lung disease. Assessment, prevention and treatment strategies are largely extrapolated from data from HIV-uninfected people. Smoking cessation is essential. Data on the long-term consequences of HIV-associated lung disease are limited. Efforts to continue quantifying the effects of HIV infection on the lung, especially in low-income and middle-income countries, are essential to advance our knowledge and optimize respiratory care in people living with HIV.

Cigarette smoke and nicotine effects on behavior in HIV transgenic rats

HIV-related neurocognitive impairment can be worsened by cigarette smoking and be more severe in women. Therefore, we analyzed the effects of sex on behavioral function in HIV transgenic (Tg) rats that were exposed to either nicotine alone, to smoke from either nicotine-containing or nicotine-free cigarettes, or non-exposed. The animals were then assessed on the open field test for the total distance traveled and for the fraction of the total distance traveled and the total time spent in the center of the field, and the results then compared to WT rats subjected to the same exposures and testing. Higher total distances indicate greater locomotor activity and a higher center field measures imply a lower anxiety state. Total distances were overall higher for female and for Tg rats exposed to nicotine-free CS. Also, the total distance and both center field measures were overall higher for female rats in the control and nicotine-free CS-exposed groups. This was observed specifically for WT females as compared to WT males and, for the center field measures, for WT females as compared to Tg males. No genotype or sex-related differences were found for rats in the nicotine-free cigarette smoke (CS) and nicotine-containing CS exposed groups. Therefore, nicotine exposure did not impact genotype- and sex-related differences in motor responses and anxiety levels that were found in the control state. However, exposure to the non-nicotine components of CS resulted in locomotor activation in the presence of the HIV genes and was anxiogenic in WT and Tg male animals.

Design and methods of a randomized trial testing the novel Wellness Intervention for Smokers Living with HIV (WISH)

Smoking rates are disproportionately high among people living with HIV. Smokers living with HIV (SLWH) are also largely unaware of the HIV-specific deleterious effects of smoking and often lack motivation and confidence in their ability to quit tobacco. To address these issues, we developed the Wellness Intervention for Smokers Living with HIV (WISH). WISH is grounded in the Information-Motivation-Behavioral Skills (IMB) Model and is designed for all SLWH, regardless of their initial motivation to quit. It follows evidence-based, best practice guidelines for nicotine dependence treatment, but is innovative in its use of a comprehensive wellness approach that addresses smoking within the context of HIV self-management including treatment adherence and engagement, stress management, substance use, and other personally relevant health behavior goals. The described randomized trial will enroll SLWH who are receiving care at Veterans Affairs (VA) medical centers and compare WISH's impact on smoking behavior to standard care services offered through the National VA Quitline and SmokefreeVET texting program. It will also assess intervention impact on markers of immune status and mortality risk. If effective, WISH could be disseminated to Veterans nationwide and could serve as a model for designing quitline interventions for other smokers who are ambivalent about quitting. The current paper outlines the rationale and methodology of the WISH trial, one of a series of studies recently funded by the National Cancer Institute to advance understanding of how to better promote smoking cessation among SLWH.

Smoking as a Risk Factor of Invasive Fungal Disease: Systematic Review and Meta-Analysis

To investigate the association between smoking and invasive fungal disease (IFD), we searched MEDLINE and Web of Science for studies published until September 2018. Two authors independently performed study selection and data extraction. Relative risks (RRs) were pooled using random-effects meta-analysis. We included 25 studies (18 171 participants; 2527 IFD cases). The meta-analysis showed an increased risk of IFD in smokers (RR 1.41 [95% confidence interval 1.09-1.81]; P = .008). The risk of IFD was higher in retrospective than in prospective studies (RR 1.93 [1.28-2.92] vs. 1.02 [0.78-1.34]; P = .04), in studies with multivariate adjustment compared to studies with univariate analysis (RR 2.15 [1.27-3.64] vs. 1.15 [0.88-1.51]; P = .06), and in studies published after 2002 (RR 2.08 [1.37-3.15] vs. 0.95 [0.75-1.22]; P = .008); other subgroup characteristics did not significantly influence the association in metaregression. Smoking cessation strategies should be implemented, especially in patients who are already at risk for IFD.

Feasibility of implementing a novel behavioural smoking cessation intervention amongst human immunodeficiency virus-infected smokers in a resource-limited setting: A single-arm pilot trial

BACKGROUND

Tobacco use is prevalent amongst individuals infected with human immunodeficiency virus (HIV). In resource-constrained settings, pharmacological smoking cessation interventions are unfeasible because of their high cost. There is a need to develop and evaluate behavioural interventions to address the unique challenges of tobacco use in the HIV-infected populations in these settings.

OBJECTIVES

The authors aimed to assess the feasibility and acceptability of the Behavioural Activation/Problem Solving for Smoking Cessation (BAPS-SC) intervention programme to determine whether it should be tested in an adequately powered randomised controlled trial.

METHOD

The authors merged behavioural activation therapy (BAT) with the principles of problem-solving therapy to create a novel five-session counselling model to address the unique challenges of tobacco cessation amongst those infected with HIV. Feasibility measures included the rate of enrolment amongst those eligible and the retention rate and descriptive analysis of intervention acceptability. The authors' secondary outcome was 7-day point smoking prevalence abstinence, confirmed with breath carbon monoxide.

RESULTS

A total of 128 individuals were screened over 8 weeks with 50 deemed eligible and 40 enrolled (80%). Retention at week 12 was 53% (21/40). The 7-day point prevalence abstinence, co-confirmed, at week 12 was 37.5% (15/40). All respondents indicated that they would recommend BAPS-SC to other smokers who want to quit, and would be willing to participate in the programme again up to the point of exit if they did not stop smoking.

CONCLUSION

A full-scale randomised control trial comparing BAPS-SC with usual practice is warranted to evaluate the efficacy of this novel intervention in these settings.

Pathogenesis of HIV-Related Lung Disease: Immunity, Infection, and Inflammation

Despite anti-retroviral therapy (ART), human immunodeficiency virus-1 (HIV)-related pulmonary disease continues to be a major cause of morbidity and mortality for people living with HIV (PLWH). The spectrum of lung diseases has changed from acute opportunistic infections resulting in death to chronic lung diseases for those with access to ART. Chronic immune activation and suppression can result in impairment of innate immunity and progressive loss of T cell and B cell functionality with aberrant cytokine and chemokine responses systemically as well as in the lung. HIV can be detected in the lungs of PLWH and has profound effects on cellular immune functions. In addition, HIV-related lung injury and disease can occur secondary to a number of mechanisms including altered pulmonary and systemic inflammatory pathways, viral persistence in the lung, oxidative stress with additive effects of smoke exposure, microbial translocation, and alterations in the lung and gut microbiome. Although ART has had profound effects on systemic viral suppression in HIV, the impact of ART on lung immunology still needs to be fully elucidated. Understanding of the mechanisms by which HIV-related lung diseases continue to occur is critical to the development of new preventive and therapeutic strategies to improve lung health in PLWH.

Tobacco and Antiretrovirals Modulate Transporter, Metabolic Enzyme, and Antioxidant Enzyme Expression and Function in Polarized Macrophages

BACKGROUND

Cigarette smoking increases systemic oxidative stress, inflammation, and viral replication in individuals with HIV. Macrophages are infected during HIV infection and serve as an important reservoir throughout the process. Macrophages exist in two phenotypes, the classically activated M1 macrophage and alternatively activated M2 macrophage. The expression of drug efflux transporters and metabolic enzymes, which have direct effects on intracellular drug concentrations, differ between the pro-inflammatory M1 macrophage and the anti-inflammatory M2 macrophage.

OBJECTIVE

To further explain the role of tobacco use in worsened outcomes in the HIV + population receiving antiretroviral therapy.

METHODS

Western blotting was used to examine macrophage polarization and expression of drug efflux transporters, CYP enzymes, and antioxidant enzymes. The arginase assay was used to measure arginase activity. Cytokine production was measured using the human multiplex inflammatory cytokine assay kit. The 8-OHdG DNA Damage Quantification Direct Kit was used to quantify DNA damage. Viral replication under the influence of tobacco and antiretroviral drug use was measured by p24 Elisa.

RESULTS

We observed phenotypic shifts from M1 to M2 with both individual and combination treatments with cigarette smoke condensate and the protease inhibitor antiretroviral drug lopinavir. These shifts lead to changes in cytokine production, the expression of CYP enzymes, anti-oxidant enzymes, and drug efflux transporters, as well as changes in viral replication.

CONCLUSION

This data suggest a mechanism by which tobacco use impairs HIV antiretroviral therapy to increase intracellular drug concentrations in this important cellular reservoir.

Treating bacterial pneumonia in people living with HIV

Introduction: Bacterial pneumonia remains an important cause of morbidity and mortality in people living with HIV (PLWH) in the antiretroviral therapy (ART) era. In addition to being immunocompromised, as reflected by low CD4 cell counts and elevated HIV viral loads, PLWH often have other behaviors associated with an increased risk of pneumonia including smoking and injected drug use. As PLWH are aging, comorbid conditions such as chronic obstructive pulmonary disease (COPD), cancers, and cardiovascular, renal and liver diseases are emerging as additional risk factors for pneumonia. Pathogens are often similar to those in HIV-uninfected individuals; however, PLWH are at risk for unusual and/or multi-drug resistant organisms causing bacterial pneumonia based, in part, on their CD4 cell counts and other exposures. Areas covered: In this review, we focus on the recognition and management of bacterial community-acquired pneumonia (CAP) in PLWH. Along with antimicrobial treatment, we discuss prevention strategies such as vaccination and smoking cessation. Expert opinion: Early initiation of ART after HIV infection can decrease the risk of pneumonia. Improved efforts at vaccination, smoking cessation, and reduction of other substance use are urgently needed in PLWH to decrease the risk for bacterial pneumonia. As PLWH are aging, comorbidities are additional risk factors for bacterial CAP.

Tobacco Use and Sustained Viral Suppression in Youth Living with HIV

Tobacco has been associated with worse HIV disease progression in adult samples of people living with HIV; however, studies have yet to examine these effects in youth living with HIV (YLWH). This study examined the association between tobacco smoking behaviors and sustained viral suppression among a sample of 820 YLWH who were recruited through the Adolescent Medicine Trials Network for HIV Interventions. Participants completed a cross-sectional survey and then staff abstracted viral suppression data from medical records for up to 26 weeks prior to enrollment. Overall, 20.4% of youth reported daily or almost daily tobacco use. In multivariable analyses, older age and daily or almost daily tobacco smoking, and ART adherence remained statistically significant in predicting sustained viral suppression over the study period. These findings underscore the need for tobacco screening and interventions in HIV care settings in order to identify youth in need of additional smoking cessation services.

Cigarette smoke and nicotine effects on brain proinflammatory responses and behavioral and motor function in HIV-1 transgenic rats

Cognitive impairment in HIV-1 infection is associated with the induction of chronic proinflammatory responses in the brains of infected individuals. The risk of HIV-related cognitive impairment is increased by cigarette smoking, which induces brain inflammation in rodent models. To better understand the role of smoking and the associated immune response on behavioral and motor function in HIV infection, wild-type F344 and HIV-1 transgenic (HIV1Tg) rats were exposed to either smoke from nicotine-containing (regular) cigarettes, smoke from nicotine-free cigarettes, or to nicotine alone. The animals were then tested using the rotarod test (RRT), the novel object recognition test (NORT), and the open field test (OFT). Subsequently, brain frontal cortex from the rats was analyzed for levels of TNF-α, IL-1, and IL-6. On the RRT, impairment was noted for F344 rats exposed to either nicotine-free cigarette smoke or nicotine alone and for F344 and HIV1Tg rats exposed to regular cigarette smoke. Effects from the exposures on the OFT were seen only for HIV1Tg rats, for which function was worse following exposure to regular cigarette smoke as compared to exposure to nicotine alone. Expression levels for all three cytokines were overall higher for HIV1Tg than for F344 rats. For HIV1Tg rats, TNF-α, IL-1, and IL-6 gene expression levels for all exposure groups were higher than for control rats. All F344 rat exposure groups also showed significantly increased TNF-α expression levels. However, for F344 rats, IL-1 expression levels were higher only for rats exposed to nicotine-free and nicotine-containing CS, and no increase in IL-6 gene expression was noted with any of the exposures as compared to controls. These studies, therefore, demonstrate that F344 and HIV1Tg rats show differential behavioral and immune effects from these exposures. These effects may potentially reflect differences in the responsiveness of the various brain regions in the two animal species as well as the result of direct toxicity mediated by the proinflammatory cytokines that are produced by HIV proteins and by other factors that are present in regular cigarette smoke.

Behavioral Interventions for Tobacco Use in HIV-Infected Smokers: A Meta-Analysis

CONTEXT

Smoking is responsible for increased morbidity and mortality in HIV-infected smokers.

OBJECTIVE

To assess the efficacy of behavioral interventions for smoking cessation among HIV-infected smokers compared with the standard care.

DATA SOURCES

PubMed, Cochrane, CINHAL, PsychINFO, and Google Scholar were searched for randomized controlled trials published in English.

STUDY SELECTION

Eligibility criteria were randomized controlled trials with targeted behavioral interventions compared with standard of care (or enhanced standard of care) aimed at promoting abstinence in HIV-infected smokers. A total of 17,384 articles were found and 17,371 were excluded; 13 full text articles were obtained and reviewed, and 8 met the eligibility criteria (Κ = 0.94).

DATA EXTRACTION

The primary outcome was expired carbon monoxide-verified 7-day point prevalence abstinence rates. Adequate sequence generation and freedom from incomplete or selective outcome reporting was used to assess study quality.

RESULTS

A total of 1822 subjects from 8 studies yielded a statistically significant effect of behavioral interventions in increasing abstinence in HIV-infected smokers with a moderate effect size (relative risk: 1.51; 95% confidence interval: 1.17 to 1.95). Those studies with interventions of 8 sessions or more had a large effect size for abstinence (relative risk: 2.88; 95% confidence interval: 1.89 to 4.61). When stratified by the number of sessions, there was no heterogeneity.

CONCLUSIONS

Targeted behavioral smoking cessation interventions are efficacious. Interventions consisting of 8 sessions or more had the greatest treatment efficacy.

A semivarying joint model for longitudinal binary and continuous outcomes

Semivarying models extend varying coefficient models by allowing some regression coefficients to be constant with respect to the underlying covariate(s). In this paper we develop a semivarying joint modelling framework for estimating the time-varying association between two intensively measured longitudinal response: a continuous one and a binary one. To overcome the major challenge of jointly modelling these responses, namely, the lack of a natural multivariate distribution, we introduce a Gaussian latent variable underlying the binary response. Then we decompose the model into two components: a marginal model for the continuous response, and a conditional model for the binary response given the continuous response. We develop a two-stage estimation procedure and discuss the asymptotic normality of the resulting estimators. We assess the finite-sample performance of our procedure using a simulation study, and we illustrate our method by analyzing binary and continuous responses from the Women's Interagency HIV Study.

Impact of HIV infection and smoking on lung immunity and related disorders

HIV-infected persons not only have higher rates of smoking than the general population, but are also unusually vulnerable to the associated adverse health effects, both infective and noninfective in origin. Indeed, in the setting of well-organised care and availability of highly active antiretroviral therapy, HIV-infected smokers lose more life-years to smoking than to HIV infection per se, presenting a major challenge to healthcare providers. Not surprisingly, the respiratory system is particularly susceptible to the damaging interactive chronic inflammatory and immunosuppressive effects of HIV and smoking, intensifying the risk of the development of opportunistic infections, as well as lung cancer and obstructive lung disorders. The impact of smoking on the immunopathogenesis and frequencies of these respiratory conditions in the setting of HIV infection, as well as on the efficacy of antiretroviral therapy, represent the primary focus of this review.

Intra-ventral tegmental area HIV-1 Tat1-86 attenuates nicotine-mediated locomotor sensitization and alters mesocorticolimbic ERK and CREB signaling in rats

Cigarette smoking prevalence in the HIV-positive individuals is profoundly higher than that in the HIV-negative individuals. We have demonstrated that HIV-1 transgenic rats exhibit attenuated nicotine-mediated locomotor activity, altered cAMP response element binding protein (CREB) and extracellular regulated kinase (ERK1/2) signaling in the mesocorticolimbic regions. This study investigated the role of HIV-1 transactivator of transcription (Tat) protein in the alterations of nicotine-mediated behavior and the signaling pathway observed in the HIV-1 transgenic rats. Rats received bilateral microinjection of recombinant Tat1-86 (25 μg/side) or vehicle directed at ventral tegmental area (VTA) followed by locomotor testing in response to 13 daily intravenous injections of nicotine (0.05 mg/kg, freebase, once/day) or saline. Further, we examined the phosphorylated levels of CREB (pCREB) and ERK1/2 (pERK1/2) in the prefrontal cortex (PFC), nucleus accumbens (NAc) and VTA. Tat diminished baseline activity in saline control rats, and attenuated nicotine-induced behavioral sensitization. Following repeated saline injection, the basal levels of pERK1 in the NAc and VTA and pERK2 in VTA were lower in the vehicle control group, relative to the Tat group. After repeated nicotine injection, pERK1 in NAc and VTA and pERK2 in VTA were increased in the vehicle group, but not in the Tat group. Moreover, repeated nicotine injections decreased pCREB in the PFC and VTA in the Tat group but not in the vehicle group. Thus, these findings indicate that the direct injection of Tat at the VTA may mediate CREB and ERK activity in response to nicotine-induced locomotor activity.

A Review of the Literature Concerning HIV and Cigarette Smoking: Morbidity and Mortality, Associations with Individual- and Social-Level Characteristics, and Smoking Cessation Efforts

Cigarette smoking is endemic among many populations, but is especially prevalent among people living with HIV, and is consequently associated with a variety of types of morbidity as well as mortality. Despite this knowledge, relatively little research has been conducted among smokers living with HIV. Extant research has focused on examining individual-level characteristics associated with smoking behaviors, to the neglect of examining social-level factors. This manuscript represents a critical literature review of the intersecting research fields of HIV and cigarette smoking. Topics considered within this review include: morbidity, mortality, as well as treatment and medication adherence outcomes; individual- and social-level characteristics associated with various smoking behaviors; evidence-based smoking cessation interventions; and findings from cessation interventions among smokers living with HIV. Additionally, gaps in the existing literature, as well as directions for future research were identified and discussed.

Prevalence and socioeconomic factors associated with smoking in people living with HIV by sex, in Recife, Brazil

INTRODUCTION

Smoking is the leading cause of preventable death in the world. The prevalence of smoking is higher in people infected with HIV than in the general population. Although it is biologically plausible that smoking increases the morbidity and mortality of people living with HIV/AIDS, few studies in developing countries have analyzed the determinants and consequences of smoking in HIV infected people.

OBJECTIVE

To estimate the prevalence of smoking and identify the socioeconomic factors associated with smoking and smoking cessation in patients with HIV by sex.

METHODS

A cross-sectional study was conducted with baseline data, obtained from an ongoing prospective cohort study of patients with HIV attending two referral centers in Recife, Northeast Region of Brazil, between July 2007 and October 2009.

RESULTS

The prevalence of current smoking was 28.9%. For both sexes, smoking was independently associated with heavy alcohol drinking and marijuana use. Among women, smoking was associated with living alone, not being married and illiteracy; and among men, being 40 years or older, low income and using crack. Compared with ex-smokers, current smokers were younger and more likely to be unmarried, heavy drinkers and marijuana users.

CONCLUSIONS

It is important to incorporate smoking cessation interventions for the treatment of heavy alcohol drinkers and marijuana users with HIV/AIDS, which may increase life expectancy and quality of life, as smoking is related to risk of death, relapse of tuberculosis, and non communicable diseases.

Utilization of cessation resources among HIV-positive and HIV-negative men who smoke and who have sex with men in Chengdu, China

INTRODUCTION

Given the implications for smoking among individuals living with HIV and the high rates of smoking and HIV among men who have sex with men (MSM) in China, we examined differences in prior use of and future interest in various cessation resources among MSM smokers with or without HIV.

METHODS

We conducted a cross-sectional survey of 381 MSM; HIV status was provided by 350 MSM, and complete data was provided by a total of 344 (188 HIV-positive and 156 HIV-negative) current smokers (past 30 days) recruited by a nongovernmental organization in Chengdu in 2012-2013. Participants reported tobacco and alcohol use; psychosocial factors; past-year quit attempts; health care provider interactions on smoking; and prior use of and interest in cessation resources.

RESULTS

Smokers living with HIV were more likely to have used behavioral interventions (p < .001) and pharmacotherapy (p = .033). Those who were HIV-positive were also more interested in behavioral interventions (p = .002) and pharmacotherapy (p = .008). Correlates of interest in behavioral interventions in the regression model included lower cigarette consumption (p = .011), higher confidence in quitting (p = .035), greater likelihood of attempting to quit in the past year (p = .026), and being HIV-positive (p = .008). Correlates of interest in pharmacotherapy included greater depressive symptoms (p = .047) and being HIV-positive (p = .015).

CONCLUSIONS

Smokers living with HIV were more likely to have ever attempted to quit smoking, to have used cessation resources, and to be interested in using cessation aids. These findings indicate the promise of greater dissemination of cessation resources, particularly if Chinese clinical practices are strengthened to offer cessation support.

Healthcare provider intervention on smoking and quit attempts among HIV-positive versus HIV-negative MSM smokers in Chengdu, China

Given the implications for smoking among HIV-positive individuals and high smoking and HIV rates among men who have sex with men (MSM) in China, we examined sociodemographic, smoking-related, psychosocial, and substance use factors in relation to HIV status; receiving some sort of healthcare provider intervention regarding smoking; and having made a quit attempt in the past year in a sample of MSM smokers in Chengdu. We conducted a cross-sectional survey of 381 MSM smokers recruited by a nongovernmental organization in Chengdu in 2012-2013. Of these, 350 disclosed their HIV status and 344 (188 HIV-positive and 156 HIV-negative) provided completed data. Half (50.0%) reported at least one quit attempt in their lifetime; 30.5% reported a quit attempt in the past year. The majority (59.4%) reported that a healthcare provider had intervened in some way (assessed smoking, advised quitting, provided assistance), most commonly by assessing smoking status (50.0%). HIV-positive individuals were more likely to report a healthcare provider intervening on their smoking (p < .001). Those who received provider intervention were more likely to have attempted to quit ever (p = .009) and in the past year (p < .001). Those HIV-positive were more likely to have attempted to quit since diagnosis if a provider had intervened (p = .001). Multivariate regression documented that being HIV-positive (p < .001), greater cigarette consumption (p = .02), less frequent drinking (p = .03), and greater depressive symptoms (p = .003) were significant correlates of healthcare provider intervention. Multivariate regression also found that healthcare provider intervention (p = .003), older age (p = .01), and higher autonomous motivation (p = .007) were significant correlates of attempting to quit in the past year. Given the impact of healthcare provider intervention regarding smoking on quit attempts among MSM, greater training and support is needed to promote consistent intervention on smoking in the clinical setting among HIV-positive and HIV-negative MSM smokers.

Smoking and HIV-related health issues among older HIV-positive gay, bisexual, and other men who have sex with men

The prevalence of cigarette smoking and the relations between smoking and HIV clinical markers, HIV medication adherence, and opportunistic infections (OIs) were examined in a sample of 199 HIV-positive, gay, bisexual, and other men who have sex with men (MSM) aged 50 and older. Overall, 35.7% were current smokers, 35.7% were former smokers, and 28.6% were never smokers. In the final multivariable polytomous logistic regression model controlling for age, income, and illicit drug use, current smokers were less likely to report an undetectable viral load as compared to never and former smokers. Relative to never smokers, former smokers were more likely to report respiratory OIs, and current smokers were more likely to report gastrointestinal OIs. This study demonstrates high prevalence of cigarette smoking among aging, HIV-positive MSM and provides additional evidence for a relationship between smoking and poorer HIV clinical markers. Targeted and tailored smoking cessation programs within the context of HIV care services are warranted.

Psychological Distress, Coping, and Disease Progression in HIV-positive Homosexual Men

The objectives of the study were (1) to examine the role of coping styles in disease progression in models controlling for initial CD4+ cell counts, distress, and health behavior in a sample of HIV- positive homosexual men (n = 65), and (2) to investigate the relationship between coping styles and distress (e.g. depression, anxiety, negative ruminations). A consistent association between planful problem-solving coping and disease progression was demonstrated. Distress was positively correlated with indicators of passive-defensive coping style (e.g. self- controlling, escape-avoidance), and negatively correlated with planful problem-solving and positive reappraisal. The results suggest that coping styles may merit a specific focus in future research of psychological factors in HIV infection, particularly as they may relate both to medical outcome and to the social/emotional aspects of being HIV-infected.

Cigarette smoking in the HIV-infected population

As mortality due to AIDS-related causes has decreased with the use of antiretroviral therapy, there has been a rise in deaths related to non-AIDS-defining illnesses. Given the exceedingly high prevalence of cigarette smoking among individuals living with HIV infection, tobacco has been implicated as a major contributor to this paradigm shift. Evidence suggests that smoking-related illnesses, such as cardiovascular disease, respiratory illnesses, and certain malignancies, contribute substantially to morbidity and mortality among HIV-infected persons. In this review, we summarize the adverse health consequences of smoking relevant to HIV-infected individuals and discuss smoking cessation in this unique population, including a discussion of barriers to quitting and a review of studies that have examined smoking cessation interventions.

Projected effects of tobacco smoking on worldwide tuberculosis control: mathematical modelling analysis

OBJECTIVES

Almost 20% of people smoke tobacco worldwide--a percentage projected to rise in many poor countries. Smoking has been linked to increased individual risk of tuberculosis infection and mortality, but it remains unclear how these risks affect population-wide tuberculosis rates.

DESIGN

We constructed a state transition, compartmental, mathematical model of tuberculosis epidemics to estimate the impact of alternative future smoking trends on tuberculosis control. We projected tuberculosis incidence, prevalence, and mortality in each World Health Organization region from 2010 to 2050, and incorporated changing trends in smoking, case detection, treatment success, and HIV prevalence.

RESULTS

The model predicted that smoking would produce an excess of 18 million tuberculosis cases (standard error 16-20) and 40 million deaths from tuberculosis (39-41) between 2010 and 2050, if smoking trends continued along current trajectories. The effect of smoking was anticipated to increase the number of tuberculosis cases by 7% (274 million v 256 million) and deaths by 66% (101 million v 61 million), compared with model predictions that did not account for smoking. Smoking was also expected to delay the millennium development goal target to reduce tuberculosis mortality by half from 1990 to 2015. The model estimated that aggressive tobacco control (achieving a 1% decrease in smoking prevalence per year down to eradication) would avert 27 million smoking attributable deaths from tuberculosis by 2050. However, if the prevalence of smoking increased to 50% of adults (as observed in countries with high tobacco use), the model estimated that 34 million additional deaths from tuberculosis would occur by 2050.

CONCLUSIONS

Tobacco smoking could substantially increase tuberculosis cases and deaths worldwide in coming years, undermining progress towards tuberculosis mortality targets. Aggressive tobacco control could avert millions of deaths from tuberculosis.

Recent cigarette smoking and HIV disease progression: no evidence of an association

The association between smoking and HIV disease progression has been examined in several studies; however, findings have been inconsistent. We examined the effect of recent cigarette smoking on CD4(+) T cell count/µl (CD4 count) and HIV RNA concentration (HIV viral load (VL)) among two HIV-infected cohorts with alcohol problems in Massachusetts in the periods 1997-2001 and 2001-2006 using a prospective cohort design and linear mixed models. Smoking groups were defined as: minimal or non-smokers, light smokers, moderate smokers, and heavy smokers. Age, alcohol use, injection drug use, depressive symptoms, gender, annual income, and antiretroviral therapy adherence were considered as potential confounders. Among 462 subjects, no significant differences in CD4 count or VL were found between smoking groups. Using minimal or non-smokers as the reference group, the adjusted mean differences in CD4 count were: 8.2 (95% confidence interval (CI): -17.4, 33.8) for heavy smokers; -0.1 (95% CI: -25.4, 5.1) for moderate smokers; and -2.6 (95% CI: -28.3, 3.0) for light smokers. For log10 VL, the adjusted differences were: 0.03 (95% CI: -0.12, 0.17) for heavy smokers; -0.06 (95% CI: -0.20, 0.08) for moderate smokers; and 0.14 (95% CI -0.01, 0.28) for light smokers. This study did not find an association between smoking cigarettes and HIV disease progression as measured by CD4 cell count and VL.

Present and past influences on current smoking among HIV-positive male veterans

INTRODUCTION

Cigarette smoking has become an important influence of morbidity and mortality for HIV-positive individuals in the era of highly active antiretroviral therapy. Although smoking is common among military personnel and veterans, the lasting impact of military service on smoking at a later stage of life has not been examined. The current study investigated present and past influences on current smoking among HIV-positive male veterans.

METHODS

Participants were 200 HIV-positive men served by the Veterans Affairs Medical Center. A survey was administered via audio-enhanced computer-assisted self-interview, and additional information was extracted from the computerized patient record system.

RESULTS

Logistic regression was performed to test hypotheses concerning the participants' current situations as well as characteristics of their past military service. Having smokers in one's environment, being more depressed, and having used alcohol or drugs were associated with having smoked in the previous 30 days, whereas stronger endorsement of attitudes stating adverse effects of smoking was linked to lower likelihood of smoking. Neither having been in a military conflict nor the length of the military service was significantly related to current smoking.

CONCLUSIONS

Remote experiences in the military did not have a sustained effect on smoking behavior years later. Implications of this study for the development of smoking cessation programs targeting HIV-positive veterans include the importance of altering attitudes about tobacco, treating underlying depression, addressing social influence, decreasing substance use, and increasing awareness of the heightened vulnerability to a variety of negative consequences of smoking among infected individuals.

Genetically expressed HIV-1 viral proteins attenuate nicotine-induced behavioral sensitization and alter mesocorticolimbic ERK and CREB signaling in rats

The prevalence of tobacco smoking in HIV-1 positive individuals is 3-fold greater than that in the HIV-1 negative population; however, whether HIV-1 viral proteins and nicotine together produce molecular changes in mesolimbic structures that mediate psychomotor behavior has not been studied. This study determined whether HIV-1 viral proteins changed nicotine-induced behavioral sensitization in HIV-1 transgenic (HIV-1Tg) rats. Further, we examined cAMP response element binding protein (CREB) and extracellular regulated kinase (ERK1/2) signaling in the prefrontal cortex (PFC), nucleus accumbens (NAc) and ventral tegmental area (VTA). HIV-1Tg rats exhibited a transient decrease of activity during habituation, but showed attenuated nicotine (0.35mg/kg, s.c.)-induced behavioral sensitization compared to Fisher 344 (F344) rats. The basal levels of phosphorylated CREB and ERK2 were lower in the PFC of HIV-1Tg rats, but not in the NAc and VTA, relative to the controls. In the nicotine-treated groups, the levels of phosphorylated CREB and ERK2 in the PFC were increased in HIV-1Tg rats, but decreased in F344 animals. Moreover, repeated nicotine administration reduced phosphorylated ERK2 in the VTA of HIV-1Tg rats and in the NAc of F344 rats, but had no effect on phosphorylated CREB, indicating a region-specific change of intracellular signaling. These results demonstrate that HIV-1 viral proteins produce differences in basal and nicotine-induced alterations in CREB and ERK signaling that may contribute to the alteration in psychomotor sensitization. Thus, HIV-1 positive smokers are possibly more vulnerable to alterations in CREB and ERK signaling and this has implications for motivated behavior, including tobacco smoking, in HIV-1 positive individuals who self-administer nicotine.

Smoking and the outcome of infection

Smoking has substantial local and systemic adverse effects on the immune system, respiratory tract and skin and soft tissues. Smokers are at increased risk of invasive pneumococcal disease, pneumonia, periodontitis, surgical infections, tuberculosis, influenza and meningococcal disease. The results of several studies indicate that smokers with periodontitis or tuberculosis suffer more severe disease. Data on the impact of smoking on sepsis and pneumonia are controversial and limited, and systematic data regarding the outcome of the majority of infections in smokers are scarce. Abundant data indicate that children exposed to environmental tobacco smoke (ETS) suffer from more severe infections. However, information regarding the effects of ETS on the outcome of infections in adults is limited. Various aspects of the relation between smoking and the outcome of bacterial infection (e.g. potential dose-dependent effects and the interactions between smoking and other environmental factors that may affect the course of infectious diseases) remain to be established.

Mechanisms and genes involved in enhancement of HIV infectivity by tobacco smoke

HIV infection is more common among smokers than nonsmokers, and, remarkably, HIV-infected individuals are about 3 times more likely to smoke than the uninfected general population. However, the relationship between tobacco smoking and HIV/AIDS disease progression remains controversial. In this study, we demonstrate a potent enhancing effect of aqueous tobacco smoke extract (TSE) on HIV infectivity that is nicotine-independent. This increased infectivity is neither NF-κB mediated nor a direct result of oxidative stress, as it cannot be blocked by antioxidants. On the contrary, TSE itself was found to possess significant antioxidant potential, enabling it to protect the viability of both infected cells and HIV virions in the presence of peroxide. Assessment of TSE-induced alterations in cellular gene expression that may be involved in increasing HIV infectivity in T cells showed that TSE up-regulates some genes known to be capable of enhancing HIV and HCV infection, or protecting HIV, but down-regulates several genes involved in cellular defense and antigen presentation. These results demonstrate that tobacco smoke can enhance HIV infectivity, possibly by a combination of direct (antioxidant) and indirect (gene-based) mechanisms. This raises the concern that smoking may thereby increase the risk of acquisition or progression of HIV infection.

The convergence of the global smoking, COPD, tuberculosis, HIV, and respiratory infection epidemics

At the beginning of the 21st century, we are facing the convergence of several epidemics. These include tobacco smoking, tuberculosis, HIV infection, influenza, and chronic obstructive pulmonary disease. These epidemics interact by way of increasing disease susceptibility and worsening outcomes. To control these interacting epidemics, we need to better understand each infection and how it influences the others. Multifaceted approaches will be necessary to reduce the impact on those in developing nations most likely to be affected by the convergence of all epidemics.

Prevalence and management of intestinal helminthiasis among HIV-infected patients at Muhimbili National Hospital

OBJECTIVE

A cross-sectional study was conducted at Muhimbili National Hospital (Tanzania) to determine prevalence of helminthiasis among in-patients with HIV/AIDS.

METHODOLOGY

After signing an informed consent form, participants answered a sociodemographic and risk factor questionnaire. Fecal specimens from patients with HIV-infected and uninfected patients were screened for intestinal helminthiasis (IHLs) using coprological methods.

RESULTS

A total of 146 patients were recruited, of those 66 were HIV-negative while 80 were HIV-negative patients. Thirty-five patients (12 HIV/AIDS and 23 non-HIV/AIDS) had helminthic infections. Hookworms were the most frequently detected helminths among patients living with HIV/AIDS (13.6%) and HIV-negative patients (17.5%), followed by schistosomiasis (9%) detected among HIV-negative individuals only.

CONCLUSION

Prevalence of helminthiases (HLs) was observed to be relatively lower among HIV-infected than uninfected patients, which is ascribable to prophylactic measures adopted for patients with HIV/AIDS. Thus, it is recommended that routine screening for HLs and prophylactic measures should be adopted for the improvement of patients' health status.

Global lung health: the colliding epidemics of tuberculosis, tobacco smoking, HIV and COPD

Tuberculosis (TB), smoking, HIV and chronic obstructive pulmonary disease (COPD) are burgeoning epidemics in developing countries. The link between TB and HIV is well established. Less well recognised is the strong relationship between tobacco smoking and the development and natural history of TB. These associations are of considerable relevance to public health and disease outcomes in individuals with TB. Moreover, tobacco smoking, a modifiable risk factor, is associated with poorer outcomes in HIV-associated opportunistic infections, of which TB is the commonest in developing countries. It is now also becoming clear that TB, like tobacco smoke, besides its known consequences of bronchiectasis and other pulmonary morbidity, is also a significant risk factor for the development of COPD. Thus, there is a deleterious and synergistic interaction between TB, HIV, tobacco smoking and COPD in a large proportion of the world's population. Further work, specifically mechanistic and epidemiological studies, is required to clarify the role of tobacco smoke on the progression of TB and HIV infection, and to assess the impact of smoking cessation interventions. These interactions deserve urgent attention and have major implications for coordinated public health planning and policy recommendations in the developing world.

Effect of cigarette smoking on HIV acquisition, progression, and mortality

Cigarette smoking is more common among those with HIV compared with the general population. However, it remains unclear whether smoking alters the natural history of HIV infection or if unique health consequences related to smoking occur in the context of HIV. In this article, we review the literature on the effect of smoking on acquisition of HIV, progression of HIV to AIDS, and mortality. Although there was significant heterogeneity in the study populations evaluated, we found little evidence that cigarette smoking increases the risk for acquiring HIV. Two studies observed that smoking was associated with more rapid CD4 cell count declines, but most data suggest that smoking does not accelerate progression to clinical AIDS. The most consistent finding was an increased risk for respiratory infections in smokers. Although no effect of smoking was seen with AIDS-related mortality, findings related to all-cause mortality were inconclusive. Owing to an increase in chronic non-AIDS outcomes in the post-highly active antiretroviral therapy (HAART) era, smoking is likely an increasingly important contributor to morbidity and mortality in HIV-infected populations. Future investigation of the biological and clinical effects of smoking, and of preventive approaches to reduce the heavy burden among individuals with HIV is warranted.

Smoking and predictors of pneumonia among HIV-infected patients receiving care in the HAART era

BACKGROUND

Smoking tobacco is disproportionably common among HIV-infected patients in the highly active antiretroviral therapy (HAART) era.

METHODS

An observational cohort study of 300 HIV-positive patients receiving care between 1996 and 2005 examined the effect of smoking on pneumonia risk. Multivariable analyses assessed the association between smoking and pneumonia risk and identified independent predictors of pneumonia during the HAART era.

RESULTS

Current smoking was common (67%). Eighty-two patients (27%) experienced 119 pneumonia episodes during 2151 patient-years of follow-up, with 7.2 episodes/100 person-years among smokers and 2.9 episodes/100 person-years among non-smokers (unadjusted incidence rate ratio (IRR): 2.50 (95% CI: 1.58, 4.09). Adjustment for age and HIV RNA level resulted in an IRR of 1.77 (95% CI: 0.98, 3.21). No prior antiretroviral therapy use (P-value <0.001), higher HIV RNA level (P-value = 0.01), lower CD4 count (P-value = 0.01), younger age (P-value = 0.01), and alcohol use (P-value = 0.04) were independent predictors of pneumonia. HAART use decreased pneumonia risk (IRR 0.28, 95% CI: 0.18, 0.44).

CONCLUSIONS

While HIV-positive smokers had over a 2-fold increase in the rate of pneumonia, the trend did not reach statistical significance in multivariable models. Clinical factors such as HAART, alcohol use and immunological status are important in pneumonia risk.

Neuroimmunity, drugs of abuse, and neuroAIDS

It has long been postulated that drugs of abuse may represent significant cofactors in the progression of human immunodeficiency virus (HIV)-induced disease. Both HIV infection and drugs of abuse have significant effect on the immune system as well as on the nervous system. In HIV infection, abnormalities in these systems intersect to lead to a constellation of symptoms known as neuroAIDS. Drugs of abuse may synergize with such damage, acting on immune and/or neural cells. However, definitive epidemiological evidence for such an interaction is lacking. Here we review such studies as well as the use of the nonhuman primate/simian immunodeficiency virus system to investigate the interaction of neuroAIDS with drugs of abuse. Furthermore, recent findings on mechanisms of actions of selected drugs reveal the possibility of protective as well as detrimental effects on the central nervous system damage induced by HIV.

Cigarette smoking among HIV+ men and women: examining health, substance use, and psychosocial correlates across the smoking spectrum

The prevalence of cigarette smoking among HIV+ individuals is greater than that found in the general population. However, factors related to smoking within this population are not well understood. This study examined the associations between smoking and demographic, medical, substance use, and psychosocial factors in a clinic-based sample of HIV+ men and women. Two hundred twelve participants completed self-report measures of tobacco use, HIV-related symptoms, viral load, CD4, alcohol and illicit drug use, depression, and social support. Multinomial logistic regression (MLR) analyses modeled the independent associations of the cross-sectional set of predictors with smoking status. Results indicated that 74% of the sample smoked at least one cigarette per day; using standard definitions, 23% of the sample were light smokers, 22% were moderate smokers, and 29% smoked heavily. Smoking was associated with more HIV-related symptoms, greater alcohol and marijuana use, and less social support. Light smoking was related to minority race/ethnicity and less income; moderate smoking was associated with less education; and heavy smoking was related to less education and younger age. Viral load, CD4 count, and depression were not associated with smoking status. Psychosocial interventions targeting this population should consider the relationships between biopsychosocial factors and smoking behavior.

Morphine modulates gammadelta lymphocytes cytolytic activity following BCG vaccination

Chronic opioid administration modulates lymphocytes' functional capabilities increasing susceptibility to infectious diseases. Bacille-Calmette-Guérin (BCG) vaccination initiates a non-specific and specific cell-mediated immunity orchestrated by T lymphocytes including gammadelta T lymphocytes. gammadelta T lymphocytes increase in natural killer and antigen-directed cytolytic response following BCG vaccination. The objective of this study was to determine morphine effects on gammadelta T lymphocytes' cytolytic activity. Pigs were chronically administered morphine and subsequently vaccinated with Mycobacterium bovis BCG. By administering morphine prior to BCG vaccination, natural killer response was significantly suppressed (p=.034). Furthermore, innate cytolytic response against M. bovis-infected monocytes (p=.002) as well as antigen specific cytolytic functions (p=.04) were significantly altered due to morphine administration. It was concluded that administering morphine prior to BCG vaccination significantly altered gammadelta T lymphocyte cytolytic responses.

Is smoking tobacco an independent risk factor for HIV infection and progression to AIDS? A systemic review

OBJECTIVES

To systematically review the evidence of the relation between smoking tobacco and HIV seroconversion and progression to AIDS.

METHODS

A systematic review was undertaken of studies to look at tobacco smoking as a risk factor for either HIV seroconversion or progression to AIDS.

RESULTS

Six studies were identified with HIV seroconversion as an outcome measure. Five of these indicated that smoking tobacco was an independent risk factor after adjusting for important confounders with adjusted odds ratios ranging from 1.6 to 3.5. 10 studies were identified using progression to AIDS as an end point of which nine found no relation with tobacco smoking.

CONCLUSIONS

Tobacco smoking may be an independent risk factor for HIV infection although residual confounding is another possible explanation. Smoking did not appear to be related to progression to AIDS although this finding may not be true in developing countries or with the longer life expectancies seen with highly active antiretroviral therapy.

Addictive drugs and their relationship with infectious diseases

The use of drugs of abuse, both recreationally and medicinally, may be related to serious public health concerns. There is a relationship between addictive drugs of abuse such as alcohol and nicotine in cigarette smoke, as well as illegal drugs such as opiates, cocaine and marijuana, and increased susceptibility to infections. The nature and mechanisms of immunomodulation induced by such drugs of abuse are described in this review. The effects of opiates and marijuana, using animal models as well as in vitro studies with immune cells from experimental animals and humans, have shown that immunomodulation induced by these drugs is mainly receptor-mediated, either directly by interaction with specific receptors on immune cells or indirectly by reaction with similar receptors on cells of the nervous system. Similar studies also show that cocaine and nicotine have marked immunomodulatory effects, which are mainly receptor-mediated. Both cocaine, an illegal drug, and nicotine, a widely used legal addictive component of cigarettes, are markedly immunomodulatory and increase susceptibility to infection. The nature and mechanism of immunomodulation induced by alcohol, the most widely used addictive substance of abuse, are similar but immunomodulatory effects, although not receptor-mediated. The many research studies on the effects of these drugs on immunity and increased susceptibility to infectious diseases, including AIDS, are providing a better understanding of the complex interactions between immunity, infections and substance abuse.

Association of cigarette smoking with HIV prognosis among women in the HAART era: a report from the women's interagency HIV study

OBJECTIVE

We assessed the association of cigarette smoking with the effectiveness of highly active antiretroviral therapy (HAART) among low-income women.

METHODS

Data were analyzed from the Women's Interagency HIV Study, a multisite longitudinal study up to 7.9 years for 924 women representing 72% of all women who initiated HAART between July 1, 1995, and September 30, 2003.

RESULTS

When Cox's regression was used after control for age, race, hepatitis C infection, illicit drug use, previous antiretroviral therapy, and previous AIDS, smokers on HAART had poorer viral responses (hazard ratio [HR]=0.79; 95% confidence interval [CI]=0.67, 0.93) and poorer immunologic response (HR=0.85; 95% CI=0.73, 0.99). A greater risk of virologic rebound (HR=1.39; 95% CI=1.06, 1.69) and more frequent immunologic failure (HR=1.52; 95% CI=1.18, 1.96) were also observed among smokers. There was a higher risk of death (HR=1.53; 95% CI=1.08, 2.19) and a higher risk of developing AIDS (HR=1.36; 95% CI=1.07, 1.72) but no significant difference between smokers and nonsmokers in the risk of death due to AIDS.

CONCLUSIONS

Some of the benefits provided by HAART are negated in cigarette smokers.

Tobacco use and readiness to quit smoking in low-income HIV-infected persons

The study aim was to identify covariates of smoking status and readiness to quit that encompassed key sociodemographic and health status variables, health-related quality of life, drug use and unprotected sex, and tobacco use variables in a cohort of low-income persons living with HIV. We also examined the impact of HIV diagnosis on smoking cessation. The sample (N = 428) was mostly male (59%) and Black (53%) or Hispanic (30%), and had a high school education or less (87%). Mean age was 40 years. Two-thirds of participants were current smokers, 19% former smokers, and 16% never smokers. Current smokers smoked a mean of 16 cigarettes/day for 22 years; 42% were in the precontemplation stage of readiness to quit smoking, 40% were contemplators, and 18% were in preparation. Most current smokers (81%) reported receiving medical advice to quit smoking. Multivariate logistic regression analyses indicated that current smokers, compared with former smokers, were more likely to use illicit drugs, perceive a lower health risk for continued smoking, and report less pain. Current smokers, compared with nonsmokers (former and never smokers), were more likely to report greater illicit drug use in their lifetime, current illicit drug use, and less pain. A multiple linear regression indicated that greater current illicit drug use, greater emotional distress, and a lower number of quit attempts were associated with lower stage of readiness to quit smoking. These findings confirm a high prevalence of smoking among HIV-infected persons and suggest a complex interplay among drug use, pain, and emotional distress that impact smoking status and, among smokers, readiness to quit. Tobacco control programs for HIV-infected persons should build motivation to quit smoking and address salient barriers to cessation--such as comorbid drug use, emotional distress, pain, and access to and coverage for treatment--and should educate smokers regarding the HIV-specific health benefits of cessation.

The impact of cigarette smoking on mortality, quality of life, and comorbid illness among HIV-positive veterans

BACKGROUND

The impact of smoking on outcomes among those with HIV infection has not been determined in the era of highly active antiretroviral therapy (HAART).

STUDY OBJECTIVE

Determine the impact of smoking on morbidity and mortality in HIV-positive patients post-HAART.

DESIGN

Prospective observational study.

PARTICIPANTS

Eight hundred and sixty-seven HIV-positive veterans enrolled in the Veterans Aging Cohort 3 Site Study.

MEASUREMENTS

Clinical data were collected through patient questionnaire, International Classification of Diseases--9th edition codes, and standardized chart extraction, and laboratory and mortality data through the national VA database. Quality of life was assessed with the physical component summary (PCS) of the Short-Form 12.

RESULTS

Current smokers had increased respiratory symptoms, chronic obstructive pulmonary disease (COPD), and bacterial pneumonia. In analyses adjusted for age, race/ethnicity, CD4 cell count, HIV RNA level, hemoglobin, illegal drug and alcohol use, quality of life was substantially decreased (beta=-3.3, 95% confidence interval [CI] -5.3 to -1.4) and mortality was significantly increased (hazard ratio 1.99, 95% CI 1.03 to 3.86) in current smokers compared with never smokers.

CONCLUSIONS

HIV-positive patients who currently smoke have increased mortality and decreased quality of life, as well as increased respiratory symptoms, COPD, and bacterial pneumonia. These findings suggest that smoking cessation should be emphasized for HIV-infected patients.

Prevalence and clinical predictors of Pneumocystis colonization among HIV-infected men

BACKGROUND

The epidemiology and transmission of Pneumocystis are poorly understood. The incidence of colonization, or detection of organisms without signs of disease, has been debated, and risk factors for colonization are largely unknown.

OBJECTIVE

To determine the rate of Pneumocystis colonization among HIV-infected patients at autopsy and analyze associated clinical variables.

METHODS

Subjects were selected from the Multicenter AIDS Cohort Study. Subjects who died from causes other than Pneumocystis pneumonia and consented to autopsy were included in analysis. DNA was extracted from lung tissue, and nested PCR was performed to detect the presence of Pneumocystis. Clinical data were obtained from the Multicenter AIDS Cohort database. Univariate and multivariate analyses were performed to determine predictors of Pneumocystis colonization.

RESULTS

Pneumocystis DNA was detected in 42 of 91 (46%) subjects by nested PCR. Clinical variables such as CD4 cell count, use of Pneumocystis prophylaxis or antiretroviral drugs, and history of previous Pneumocystis pneumonia were not related to risk of colonization. Multivariate analysis demonstrated that cigarette smoking was related to an increased risk of colonization [odds ratio (OR), 4.5; 95% confidence interval (CI), 1.27-15.6; P = 0.02] and risk also varied by city of residence (OR, 0.12; 95% CI, 0.03-0.45; P = 0.002 for living in Los Angeles).

CONCLUSIONS

This study found a high rate of Pneumocystis colonization among HIV-infected patients. We also identified cigarette smoking and city of residence as novel, independent risk factors for colonization. The role of subclinical colonization in disease transmission and the effects of Pneumocystis colonization on the lung require further study.

Hydroquinone and catechol interfere with T cell cycle entry and progression through the G1 phase

Cigarette smoking causes profound suppression of pulmonary T cell responses, which is associated with increased susceptibility to respiratory tract infections and decreased tumor surveillance. Hydroquinone (HQ) and catechol, at concentrations comparable to those found in cigarette smoke, are potent inhibitors of T cell activation and proliferation. We have previously shown that HQ and catechol inhibit ribonucleotide reductase, the rate-limiting enzyme in DNA synthesis. In this report we demonstrate that HQ and catechol also inhibit blastogenesis by interfering with T cell cycle entry and progression through the G(1) phase. In an attempt to localize the point in the cell cycle where arrest occurred, a set of key markers of activation and cell cycle progression were examined, including induction of c-Myc, up regulation of RNA synthesis, surface expression of CD71, and induction of E2F-dependent gene expression. Addition of HQ or catechol prior to stimulation inhibited each of these events without decreasing cell viability. However, production of IL-2 and surface expression of CD69 and CD25 were not affected, indicating that HQ and catechol inhibit only certain cell cycle events. These studies provide further indication of the regulatory pathways by which cigarette smoke inhibits T cell responses in the lungs of smokers.

Microbial infections, immunomodulation, and drugs of abuse

The use of recreational drugs of abuse has generated serious health concerns. There is a long-recognized relationship between addictive drugs and increased levels of infections. Studies of the mechanisms of actions of these drugs became more urgent with the advent of AIDS and its correlation with abused substances. The nature and mechanisms of immunomodulation by marijuana, opiates, cocaine, nicotine, and alcohol are described in this review. Recent studies of the effects of opiates or marijuana on the immune system have demonstrated that they are receptor mediated, occurring both directly via specific receptors on immune cells and indirectly through similar receptors on cells of the nervous system. Findings are also discussed that demonstrate that cocaine and nicotine have similar immunomodulatory effects, which are also apparently receptor mediated. Finally, the nature and mechanisms of immunomodulation by alcohol are described. Although no specific alcohol receptors have been identified, it is widely recognized that alcohol enhances susceptibility to opportunistic microbes. The review covers recent studies of the effects of these drugs on immunity and on increased susceptibility to infectious diseases, including AIDS.