Brief Report: Impact of Methamphetamine Use and Rectal STIs on Systemic and Rectal Mucosal Inflammation

Cannabis Use and Biomarkers of Inflammation, Immune Activation, and Microbial Translocation in Persons with HIV

Background: The relationship between cannabis and inflammation among persons with HIV (PWH) remains unclear. We examined whether the cannabis metabolite 11-nor-9-carboxy THC (THC-COOH) is associated with lower levels of plasma biomarkers of inflammation, immune activation, and microbial translocation in PWH. We hypothesized that cannabis use would be associated with lower levels of plasma inflammatory biomarkers than noncannabis use. Methods: We quantified THC-COOH in plasma, with THC-COOH levels between 5.1-69.9 μg/L and ≥70 μg/L being classified as moderate and heavy cannabis use, respectively, with noncannabis use defined as undetected THC-COOH. We measured a panel of plasma biomarkers of inflammation (interleukin [IL]-1-β, tumor necrosis factor-alpha, IL-18, IL-6, and C-reactive protein), immune activation (CD14 and CD163), and microbial translocation (iFABP2 and lipopolysaccharide binding protein [LBP]), with all biomarkers collected on the same day. We used a cross-sectional design and linear regression models to test whether cannabis use is associated with lower biomarker levels. Results: Participants were (N=107) sexual minority men with HIV (median age=32 years, IQR=28, 38), of whom 65% were virally suppressed; 36%, 44%, and 20% were classified as nonuse, moderate, and heavy cannabis, respectively. In linear regression models adjusted for viral suppression, stimulant use, and CD4 counts, heavy cannabis use was significantly associated with lower levels of log10 LBP (β=-0.14, 95% confidence interval: -0.24 to -0.04; false discovery rate=0.0029; partial eta squared=0.07) than noncannabis users. No precise associations were observed for other biomarkers (all p>0.05). Conclusions: Our findings suggest that cannabis use may be associated with lower plasma LBP. Further work is needed to clarify the relationship between cannabis use and biomarkers of microbial translocation in PWH.

Overamped: Stimulant Use and HIV Pathogenesis

PURPOSE OF REVIEW

In the era of HIV treatment as prevention (TasP), more clarity is needed regarding whether people with HIV who use stimulants (i.e., methamphetamine, powder cocaine, and crack cocaine) display elevated HIV viral load and greater immune dysregulation.

RECENT FINDINGS

Although rates of viral suppression have improved in the TasP era, stimulant use was independently associated with elevated viral load in 23 of 28 studies included in our review. In the 12 studies examining other HIV disease markers, there was preliminary evidence for stimulant-associated alterations in gut-immune dysfunction and cellular immunity despite effective HIV treatment. Studies generally focused on documenting the direct associations of stimulant use with biomarkers of HIV pathogenesis without placing these in the context of social determinants of health. Stimulant use is a key barrier to optimizing the effectiveness of TasP. Elucidating the microbiome-gut-brain axis pathways whereby stimulants alter neuroimmune functioning could identify viable targets for pharmacotherapies for stimulant use disorders. Examining interpersonal, neighborhood, and structural determinants that could modify the associations of stimulant use with biomarkers of HIV pathogenesis is critical to guiding the development of comprehensive, multi-level interventions.