Potential interventions for HIV/AIDS wasting: an overview

Interferon-α-Mediated Activation of T Cells from Healthy and HIV-Infected Individuals Is Suppressed by Δ9-Tetrahydrocannabinol

Patients with HIV routinely use medicinal cannabinoids to treat neuropathic pain, anxiety, and human immunodeficiency virus (HIV)-associated wasting. However, Δ⁹-tetrahydrocannabinol (THC), the primary psychoactive cannabinoid in cannabis, suppresses T-cell function and secretion of interferons, both critically important in the antiviral immune response. Interferon-α (IFNα), a key cytokine in T-cell activation and peripheral control of HIV infection, can potentiate responsiveness to interleukin-7 (IL-7), a crucial homeostatic cytokine for peripheral T-cell maintenance. The objective of this investigation was to compare the response of T cells to stimulation by IFNα and IL-7 in T cells from healthy and HIV⁺ donors in the absence and presence of THC. To compare T-cell responses between healthy and HIV⁺ donors signaling through IFNα receptor, IFNα-induced expression of IL-7α receptor (IL-7Rα), cognate signaling through IL-7R, and on IL-7-mediated T-cell proliferation were measured by flow cytometry and real-time quantitative polymerase chain reaction. CD8⁺ T cells from HIV⁺ donors showed a diminished response to IFNα-induced phosphorylated signal transducer and activator of transcription-1 activation compared with CD8⁺ T cells from healthy donors, whereas CD4⁺ T cells from HIV⁺ donors and healthy donors were comparable. Treatment with IFNα promoted IL-7R expression and potentiated IL-7-induced STAT5 phosphorylation to augment IL-7-mediated proliferation by T cells from healthy and HIV⁺ donors. Finally, HIV⁺ donors exhibited reduced sensitivity to THC-mediated suppression by IFNα- and IL-7-mediated stimulation compared with healthy donors. These results further support THC as being immune suppressive while identifying putatively beneficial aspects of cannabinoid-based therapies in HIV⁺ patients.

HIV-infected cannabis users have lower circulating CD16+ monocytes and IFN-γ-inducible protein 10 levels compared with nonusing HIV patients

OBJECTIVE

Chronic immune activation and elevated numbers of circulating activated monocytes (CD16) are implicated in HIV-associated neuroinflammation. The objective was to compare the level of circulating CD16 monocytes and IFN-γ-inducible protein 10 (IP-10) between HIV-infected cannabis users (HIV+MJ+) and noncannabis users (HIV+MJ-) and determine whether in-vitro Δ-Tetrahydrocannabinol (THC), a constituent of cannabis, affected CD16 expression as well as IP-10 production by monocytes.

DESIGN

The levels of circulating CD16 monocytes and IP-10 from HIV+MJ- and HIV+MJ+ donors were examined. In-vitro experimentation using THC was performed on primary leukocytes isolated from HIV-MJ-, HIV+MJ- and HIV+MJ+ donors to determine if THC has an impact on CD16 monocyte and IP-10 levels.

METHODS

Flow cytometry was used to measure the number of blood CD16 monocytes and plasma IP-10 from HIV+MJ- and HIV+MJ+ donors. Peripheral blood mononuclear cells were isolated from HIV-MJ- and HIV+ (MJ- and MJ+) donors for in-vitro THC and IFNα treatment, and CD16 monocytes and supernatant IP-10 were quantified.

RESULTS

HIV+MJ+ donors possessed a lower level of circulating CD16 monocytes and plasma IP-10, compared with HIV+MJ- donors. Further, monocytes from HIV+MJ+ donors were unable to induce CD16 expression when treated with in-vitro IFNα, whereas HIV-MJ- and HIV+MJ- donors displayed pronounced CD16 induction, suggesting anti-inflammatory effects by cannabis. Lastly, in-vitro THC treatment impaired CD16 monocyte transition to CD16 and monocyte-derived IP-10.

CONCLUSION

Components of cannabis, including THC, may decelerate peripheral monocyte processes that are implicated in HIV-associated neuroinflammation.

Δ9-Tetrahydrocannabinol Suppresses Secretion of IFNα by Plasmacytoid Dendritic Cells From Healthy and HIV-Infected Individuals

Plasmacytoid dendritic cells (pDCs) play a crucial role in host antiviral immune response through secretion of type I interferon. Interferon alpha (IFNα), a type I IFN, is critical for mounting the initial response to viral pathogens. A consequence of Human Immunodeficiency Virus-1 (HIV) infection is a decrease in both pDC number and function, but prolonged pDC activity has been linked with progression from HIV infection to the development of AIDS. Patients with HIV in the United States routinely use cannabinoid-based therapies to combat the side effects of HIV infection and antiretroviral therapy. However, cannabinoids, including Δ-tetrahydrocannabinol (THC), are well-characterized immunosuppressants. Here, we report that THC suppressed secretion of IFNα by pDC from both healthy and HIV+ donors through a mechanism involving impaired phosphorylation of interferon regulatory factor 7. These results suggest that THC can suppress pDC function during the early host antiviral response by dampening pDC activation.

Use of Dronabinol Improves Appetite and Reverses Weight Loss in HIV/AIDS-Infected Patients

Objective: To determine whether dronabinol affects appetite and weight status in patients living with HIV/AIDS. Methods: A retrospective chart review was conducted to analyze weight and appetite changes and nausea status in patients with HIV/AIDS who received dronabinol for 3 to 12 months from January 11, 1993, to March 17, 2003. Results: Of the 117 patients who lost weight before baseline, 63% maintained or gained weight. In patients receiving dronabinol for 1 year, the mean weight gain (± SD) was 3.7 ± 10.6 lb. The percentage of patients experiencing loss of appetite decreased significantly from 71% at baseline to 26% at 1 month (P < .001) and continued to decline throughout the trial. The percentage of patients experiencing nausea at baseline (38%) decreased consistently from week 2 on; this change from baseline was significant at month 6 (P = .031). Conclusion: When taken for 3 months to 1 year, dronabinol significantly improves appetite and reverses weight loss in patients living with HIV/AIDS.

Substance use in older HIV-infected patients

PURPOSE OF REVIEW

Substance use may persist throughout the life course and has a substantial impact on health outcomes globally. As HIV-infected individuals are disproportionately impacted by substance use and living longer, it is critical that providers and researchers alike understand the impact of substance use on older, HIV-infected patients and potential treatment options. To this end, we conducted a review of the literature focusing on the most commonly used substances to outline the epidemiology, health consequences, treatment options and latest research relevant to older, HIV-infected patients.

RECENT FINDINGS

Substance use impacts older, HIV-infected patients with regards to HIV-related and non-HIV-related outcomes. Counseling strategies are available for marijuana and stimulant use disorders. Brief counseling is useful alongside medications for alcohol, tobacco and opioid use disorders. Many medications for alcohol, tobacco and opioid use disorders are safe in the setting of antiretroviral therapy. Unfortunately, few interventions targeting substance use in older, HIV-infected patients have been developed and evaluated.

SUMMARY

As older, HIV-infected patients continue to experience substance use and its related health consequences, there will be a growing need for the development of safe and effective interventions, which address the complex needs of this population.

Efficacy and tolerability of high-dose dronabinol maintenance in HIV-positive marijuana smokers: a controlled laboratory study

RATIONALE

Dronabinol (Δ(9)tetrahydrocannabinol) is approved for HIV-related anorexia, yet, little is known about its effects in HIV-positive marijuana smokers. HIV-negative marijuana smokers require higher than recommended dronabinol doses to experience expected effects.

OBJECTIVES

Employing a within-subjects, double-blind, placebo-controlled design, we assessed the effects of repeated high-dose dronabinol in HIV-positive marijuana smokers taking antiretroviral medication.

METHODS

Participants (N = 7), who smoked marijuana 4.2 ± 2.3 days/week, resided in a residential laboratory for two 16-day stays, receiving dronabinol (10 mg QID) in one stay and placebo in the other. Efficacy was assessed with objectively verified food intake and body weight. Tolerability was measured with sleep, subjective, and cognitive assessments. For analyses, each inpatient stay was divided into two phases, days 1-8 and 9-16; we compared dronabinol's effects with placebo in each 8-day phase to investigate tolerance.

RESULTS

Despite sustained increases in self-reported food cravings, dronabinol only increased caloric intake in the initial 8 days of dosing. Similarly, sleep quality was improved only in the first 8 days of dosing. Dronabinol's mood-enhancing effects were sustained across the 16-day inpatient stay. Dronabinol was well tolerated, causing few negative subjective or cognitive effects.

CONCLUSIONS

In HIV-positive marijuana smokers, high dronabinol doses safely and effectively increased caloric intake. However, repeated high-dose dronabinol appeared to result in selective tolerance to these effects. These findings indicate that HIV-positive individuals who smoke marijuana may require higher dronabinol doses than are recommended by the FDA. Future research to establish optimal dosing regimens, and reduce the development of tolerance, is required.

Health-related quality of life in HIV-infected patients: the role of substance use

HIV infection and substance use disorders are chronic diseases with complex contributions to health-related quality of life (HRQOL). We conducted a cross-sectional survey of 951 HIV-infected adults receiving care at 14 HIV Research Network sites in 2003 to estimate associations between HRQOL and specific substance use among HIV-infected patients. HRQOL was assessed by multi-item measures of physical and role functioning, general health, pain, energy, positive affect, anxiety, and depression. Mental and physical summary scales were developed by factor analysis. We used linear regression to estimate adjusted associations between HRQOL and current illicit use of marijuana, analgesics, heroin, amphetamines, cocaine, sedatives, inhalants, hazardous/binge alcohol, and drug use severity. Current illicit drug use was reported by 37% of subjects. Mental HRQOL was reduced for current users [adjusted beta coefficient -9.66, 95% confidence interval [(CI]) -13.4, -5.94] but not former users compared with never users. Amphetamines and sedatives were associated with large decreases in mental (amphetamines: beta = -22.8 [95% CI -33.5, -12.0], sedatives: beta = -18.6 [95% CI -26.2, -11.0]), and physical HRQOL (amphetamines: beta = -11.5 [95% CI -22.6, -0.43], sedatives: beta = -13.2 [95% CI -21.0, -5.36]). All illicit drugs were associated with decreased mental HRQOL: marijuana (beta = -7.72 [95% CI -12.0, -3.48]), non-prescription analgesics (beta = -13.4 [95% CI -20.8, -6.07]), cocaine (beta = -10.5 [95% CI -16.4, -4.67]), and inhalants (beta = -14.0 [95% CI -24.1, -3.83]). Facilitating sobriety for patients with attention to specific illicit drugs represents an important avenue for elevating HRQOL in patients living with HIV.

Evaluation of oral cannabinoid-containing medications for the management of interferon and ribavirin-induced anorexia, nausea and weight loss in patients treated for chronic hepatitis C virus

OBJECTIVES

The systemic and cognitive side effects of hepatitis C virus (HCV) therapy may be incapacitating, necessitating dose reductions or abandonment of therapy. Oral cannabinoid-containing medications (OCs) ameliorate chemotherapy-induced nausea and vomiting, as well as AIDS wasting syndrome. The efficacy of OCs in managing HCV treatment-related side effects is unknown.

METHODS

All patients who initiated interferon-ribavirin therapy at The Ottawa Hospital Viral Hepatitis Clinic (Ottawa, Ontario) between August 2003 and January 2007 were identified using a computerized clinical database. The baseline characteristics of OC recipients were compared with those of nonrecipients. The treatment-related side effect response to OC was assessed by c2 analysis. The key therapeutic outcomes related to weight, interferon dose reduction and treatment outcomes were assessed by Student's t test and c2 analysis.

RESULTS

Twenty-five of 191 patients (13%) initiated OC use. Recipients had similar characteristics to nonrecipients, aside from prior marijuana smoking history (24% versus 10%, respectively; P=0.04). The median time to OC initiation was seven weeks. The most common indications for initiation of OC were anorexia (72%) and nausea (32%). Sixty-four per cent of all patients who received OC experienced subjective improvement in symptoms. The median weight loss before OC initiation was 4.5 kg. A trend toward greater median weight loss was noted at week 4 in patients eventually initiating OC use (-1.4 kg), compared with those who did not (-1.0 kg). Weight loss stabilized one month after OC initiation (median 0.5 kg additional loss). Interferon dose reductions were rare and did not differ by OC use (8% of OC recipients versus 5% of nonrecipients). The proportions of patients completing a full course of HCV therapy and achieving a sustained virological response were greater in OC recipients.

CONCLUSIONS

The present retrospective cohort analysis found that OC use is often effective in managing HCV treatment-related symptoms that contribute to weight loss, and may stabilize weight decline once initiated.