Cocaine blunts human CD4+ cell activation

Cocaine-mediated impact on HIV infection in humanized BLT mice

Cocaine abuse has been shown to have broad-ranging effects on human immunity. With regards to HIV infection, in vitro studies have shown that cocaine enhances infection of stimulated lymphocytes. Moreover, cohort studies in the pre- and post-HAART era have linked stimulant abuse with increased HIV pathogenesis. The latter data, however, have been undermined by a series of confounding factors underscoring the importance of controlled in vivo models to fully assess the impact of cocaine use and abuse on HIV infection and pathogenesis. Here, we have infected humanized mice with HIV-1 following acute cocaine exposure to assess the impact on infection. Stimulant exposure resulted in increased inflammatory cytokine expression, accelerated HIV infection, while blunting effector function of cytotoxic T lymphocytes. These data demonstrate cocaine’s multifactorial impact on HIV infection that extends beyond high-risk behavior.

Natural killer cell activity and function in chronic HCV-infected patients during peg interferon and ribavirin: early effects of active substance use

In Western countries, chronic hepatitis C virus (HCV)-infection mostly affects former and active substance users. The effect of active substance use on interferon (IFN)-responsiveness and therapy efficacy is not well understood. In this study, we compared natural killer (NK) cell activity and function in healthy controls and chronic HCV-infected patients with and without active substance use, as well as the early effects of antiviral therapy with peg-IFN and ribavirin. No differences were observed between chronic HCV patients and healthy individuals in the number and frequencies of CD56(dim) and CD56(bright) NK cells. Also, IL-12/18-induced IFN-gamma production by NK cells was comparable between all groups, whereas the cytotoxic ability of NK cells (granzyme and CD107a levels) was more potent in HCV-infected patients as compared to healthy controls, and highest in non-substance users. Moreover, at baseline, the activation of NK cells was significantly lower in HCV-infected patients who used substances, when compared to healthy individuals. Therapy-induced viral load reduction assessed early at day 7 showed a similar decline in substance users and non-substance use HCV patients, with 25% substance users and 17% non-substance users testing HCV-RNA negative at day 7. Furthermore, early during IFN-based therapy, NK cells from HCV patients remained responsive to IFN, and only a minor decline in the degree of STAT-1 phosphorylation was observed irrespective of substance use. These findings were further supported by comparable in vitro p-STAT-1 induction in all three experimental groups. Despite subtle differences at baseline between healthy individuals and chronic HCV patients, we observed that active substance use in chronic HCV-infected patients did not affect the immune responsiveness to IFN early after start of treatment, and thus, we found no evidence - from an immunological point of view - that antiviral therapy of our cohort of HCV-infected patients with active substance use is less efficient.

Cumulative exposure to stimulants and immune function outcomes among HIV-positive and HIV-negative men in the Multicenter AIDS Cohort Study

We examined associations between stimulant use (methamphetamine and cocaine) and other substances (nicotine, marijuana, alcohol and inhaled nitrites) with immune function biomarkers among HIV-seropositive (HIV +) men taking highly active antiretroviral therapy (ART) and HIV-seronegative (HIV-) men in the Multicenter AIDS Cohort Study. Among HIV + men, cumulative adherence to ART (4.07, 95% confidence interval [CI]: 3.52, 4.71, per 10 years of adherent ART use), and recent cohort enrolment (1.38; 95% CI: 1.24, 1.55) were multiplicatively associated with increase in CD4+/CD8+ ratios. Cumulative use of methamphetamine (0.93; 95% CI: 0.88, 0.98, per 10 use-years), cocaine (0.93; 95% CI: 0.89, 0.96, per 10 use-years) and cumulative medical visits (0.99; 95% CI: 0.98, 0.99, per 10 visit-years), each showed small negative associations with CD4+/CD8+ ratios. Among HIV- men, cumulative medical visits (0.996; 95% CI: 0.993, 0.999), cumulative number of male sexual partners (0.999; 95% CI: 0.998, 0.9998, per 10 partner-years) and cigarette pack-years (1.10; 95% CI: 1.02, 1.18, per 10 pack-years) were associated with CD4+/CD8+ ratios over the same period. ART adherence is associated with a positive immune function independent of stimulant use, underscoring the influence of ART on immune health for HIV+ men who engage in stimulant use.

Alcohol, drugs, sexual behavior, and HIV in Trinidad and Tobago--the way forward

The HIV epidemic in Trinidad and Tobago is primarily heterosexual, fueled by a high level of risky sex, gender inequality, and alcohol and drug use; however, the influence of alcohol and drugs has been neglected in the literature. Research shows that current HIV prevention approaches have failed to substantially impact sexual behavior change. This may be so because they do not incorporate a comprehensive understanding of the sociocultural factors underlying sexual behavior. There is an urgent need to understand how socially accepted patterns of alcohol and drug use contribute to sexual behaviors and HIV risk in Trinidad and Tobago. Moreover, specialized, evidence-based interventions are needed for HIV-infected substance abusers. Using an adaptation of the cognitive behavioral stress management (CBSM) protocol, this intervention project aimed to assess effectiveness in reducing relapse and risky behaviors among recovering HIV-infected substance abusers in Trinidad and Tobago.

Methadone, buprenorphine, and street drug interactions with antiretroviral medications

While street drugs appear unlikely to alter the metabolism of antiretroviral (ARV) medications, several ARVs may induce or inhibit metabolism of various street drugs. However, research on these interactions is limited. Case reports have documented life-threatening overdoses of ecstasy and gamma-hydroxybutyrate after starting ritonavir, an ARV that inhibits several metabolic enzymes. For opioid addiction, methadone or buprenorphine are the treatments of choice. Because a number of ARVs decrease or increase methadone levels, patients should be monitored for methadone withdrawal or toxicity when they start or stop ARVs. Most ARVs do not cause buprenorphine withdrawal or toxicity, even if they alter buprenorphine levels, with rare exceptions to date including atazanavir/ritonavir associated with significant increases in buprenorphine and adverse events related to sedation and mental status changes in some cases. There are newer medications yet to be studied with methadone or buprenorphine. Further, there are many frequently used medications in treatment of complications of HIV disease that have not been studied. There is need for continuing research to define these drug interactions and their clinical significance.

Impaired cytokine production and suppressed lymphocyte proliferation activity in HCV-infected cocaine and heroin ("speedball") users

HCV-infected "speedball" users (n = 30) were selected from an original cohort of 400 intravenous drug users for cytokine analysis. Cytokine concentrations (TNF-alpha, IL-1beta, IL-6, IFN-gamma, IL-2, IL-4, IL-10 and IL-12) were determined in plasma and peripheral blood mononuclear cells (PBMC) cultures derived ex vivo from these patients. In addition, lymphocyte proliferation was measured in 49 HCV-positive "speedball" users. TNF-alpha, IL-6, IFN-gamma, IL-2, IL-4, IL-10, IL-12 cytokines and not IL-1beta were significantly increased in plasma from HCV-positive "speedball" users compared with healthy controls. Except for IL-10, all other cytokines measured were augmented in phytohemagglutinin-stimulated PBMC cultures from HCV-positive "speedball" users. Likewise, overproduction of cytokines TNF-alpha, IL-1beta, IL-6 and IFN-gamma, was consistently detected when PBMC cultures from HCV-positive "speedball" users were stimulated with a biological response modifier. However, HCV-infected "speedball" users showed significant reduction in lymphoproliferative activity. Compared with healthy subjects, there was a consistent overproduction of both TH1 and TH2 type cytokines in the plasma and PBMC's of HCV-infected "speedball" users. Furthermore, there was a persistent reduction of lymphoproliferative activity in this group. These immunologic abnormalities, coupled with the range of response between the two TH-types in HCV-infected "speedball" users, suggest impairment in the regulatory mechanism of the TH1-TH2 system.

CD4 cell recovery during successful antiretroviral therapy in naive HIV-infected patients: the role of intravenous drug use

We evaluated the impact of HIV risk practice on immune reconstitution in a prospective cohort of 288 patients (176 former injecting drug users) who maintained complete virus suppression for more than 24 months. Significant differences in CD4 cell counts at 6 and 24 months were detected. Multivariate analysis showed that drug use was an independent predictor of poor immunological recovery. Injection drug abuse impairs short and long-term CD4 cell recovery in HIV-positive patients initiating successful highly active antiretroviral therapy.

Peripheral human T lymphocyte maintenance of immune functional capacity and phenotypic characteristics following in vivo cocaine exposure

The effects of cocaine exposure upon the host's immune response is equivocal since a variety of studies have generated conflicting conclusions, often as the result of differences between in vitro and/or animal models and the actual conditions experienced in humans who are acutely abusing this drug. To further address this issue, we have studied a group of patients who were positive for cocaine or cocaine metabolites and we evaluated a variety of functional parameters of T-lymphocytes and other peripheral lymphoid cell populations, as well as immunophenotypic characteristics of these cells. When compared to normal controls and patients who were negative for cocaine, we found that the cocaine-positive patients had T-cell functional assays which were essentially normal, with the exception of a slight depression in PHA stimulation. Likewise, the immunophenotype of the peripheral blood lymphocytic populations showed normal percentages and numbers of their T cell subsets (CD4, CD8), NK cells, and B cells. Multicolor flow cytometry analysis revealed no difference in T cell subpopulations positive for the "memory" marker, CD62L. No correlation could be established between levels of cocaine or cocaine metabolites and any phenotypic, demographic, or functional parameter. In summary, these results demonstrate that individuals acutely exposed to cocaine do not show markedly altered T cell function or fluctuations in phenotypically identified cell populations. These studies imply that acute cocaine exposure does not predispose individuals to grossly apparent immunosuppression. However, the possibility that subtle, transient, or more specific changes in the immune system may be incurred by use of cocaine, particularly with chronic exposure, remains to be determined.

Cellular immune correlates of clinical severity in oral lichen planus: preliminary association with mood states

OBJECTIVES

We investigated cellular immune and psycho-immune dysfunctions in patients with erosive and non-erosive oral lichen planus (OLP) lesions.

METHODS

Patients with erosive or non-erosive OLP were screened at the UCLA Dental Clinic. The profile of mood states (POMS) was administered. T lymphocyte subpopulations were monitored by dual fluorescence. T lymphocytes were stimulated with phytohemagglutinin (PHA) for assessment of markers of activation by flow cytometry and of interleukin (IL)-2 production by ELISA. Plasma cortisol and neopterin levels were assessed by radioimmunoassay.

RESULTS

Circulating T cells that express the cluster of differentiation no. 4 (CD4+) but devoid of the CD45RA marker, and POMS score were significantly associated (r = 0.83, P < 0.05) in the patients we studied. We found a significantly higher (P < 0.05) per cent and absolute lymphocyte numbers of circulating CD4+CD45RA- cells in the OLP patients with erosive lesions, compared to OLP patients with non-erosive lesions. The ratio of CD4+ CD45RA+ over CD4+CD45RA- cells was significantly (P < 0.05) biased toward the CD4+CD45RA- subpopulation in OLP patients with erosive lesions (ratio = 0.19 +/- 0.09) compared to patients with non-erosive OLP lesions (ratio = 0.47 +/- 0.15). The expression of CD54, but not that of CD69, was significantly blunted (P < 0.05) in OLP patients following CD3+ cell stimulation. IL-2 production and plasma neopterin were normal in these patients. There was no correlation between plasma cortisol and T cell populations.

CONCLUSIONS

We find fine differences in psycho-immune interactions between patients afflicted with non-erosive OLP lesions compared to those with erosive OLP lesions.

Alcohol modulation of human normal T-cell activation, maturation, and migration

We are interested in the characterization of the effects of alcohol on human T-cell activation, maturation, and migration, because this cell population is crucial in the initiation, regulation, and propagation of cellular immunity. We and others have described the effects of both acute and chronic exposure of human immune cells to ethanol (EtOH) in vitro. Herein, we briefly, review these reports and expand this body of literature with the inclusion of new data recently obtained in our laboratory. We confirm the blunting effects of EtOH on the production of interleukin-2 and mitogen proliferative response following T-cell mitogen stimulation, and on the expression of membrane markers of activation. We show that EtOH significantly alters the expression of the CD4 cell-associated marker of activation, CD26. We report the effect of EtOH on the expression of the homing receptor CD62L by CD4+ cells, and on their ability to adhere by a CD18-mediated process to a defined cellular substratum. Furthermore, we demonstrate the effects of EtOH and EtOH and beta-endorphin pretreatment on the activation of CD4+ lymphocytes endowed with the homing receptor CD62L.