Daily Cannabis Use is Associated With Lower CNS Inflammation in People With HIV

Abstract

Objective: Recent cannabis exposure has been associated with lower rates of neurocognitive impairment in people with HIV (PWH). Cannabis's anti-inflammatory properties may underlie this relationship by reducing chronic neuroinflammation in PWH. This study examined relations between cannabis use and inflammatory biomarkers in cerebrospinal fluid (CSF) and plasma, and cognitive correlates of these biomarkers within a community-based sample of PWH.

Methods: 263 individuals were categorized into four groups: HIV- non-cannabis users (n = 65), HIV+ non-cannabis users (n = 105), HIV+ moderate cannabis users (n = 62), and HIV+ daily cannabis users (n = 31). Differences in pro-inflammatory biomarkers (IL-6, MCP-1/CCL2, IP-10/CXCL10, sCD14, sTNFR-II, TNF-α) by study group were determined by Kruskal-Wallis tests. Multivariable linear regressions examined relationships between biomarkers and seven cognitive domains, adjusting for age, sex/gender, race, education, and current CD4 count.

Results: HIV+ daily cannabis users showed lower MCP-1 and IP-10 levels in CSF compared to HIV+ non-cannabis users (p = .015; p = .039) and were similar to HIV- non-cannabis users. Plasma biomarkers showed no differences by cannabis use. Among PWH, lower CSF MCP-1 and lower CSF IP-10 were associated with better learning performance (all ps < .05).

Conclusions: Current daily cannabis use was associated with lower levels of pro-inflammatory chemokines implicated in HIV pathogenesis and these chemokines were linked to the cognitive domain of learning which is commonly impaired in PWH. Cannabinoid-related reductions of MCP-1 and IP-10, if confirmed, suggest a role for medicinal cannabis in the mitigation of persistent inflammation and cognitive impacts of HIV.

Keywords: HIV/AIDS; NeuroAIDS; Neuroinflammation; cannabinoids; cerebrospinal fluid; cognition; marijuana; neurocognitive impairment.

Figure 1.. HIV+ daily cannabis users display lower levels of MCP-1 and IP-10 in CSF compared to HIV+ non-cannabis users

Abbreviations: MCP-1 = monocyte chemoattractant protein-1; IP-10 = interferon-gamma-inducible protein-10; CSF = cerebrospinal fluid; HIV = human immunodeficiency virus In panel (a), there was significant omnibus difference across the four HIV/Cannabis groups in the level of MCP-1 in CSF (p = 0.027). MCP-1 in CSF was significantly lower in HIV+ daily cannabis users compared to HIV+ non-cannabis users (p = 0.015). MCP-1 in CSF was significantly higher in HIV+ non-cannabis users compared to the HIV− non-cannabis users (p = 0.005). In panel (b), there was significant omnibus difference across the four HIV/Cannabis groups in the level of IP-10 in CSF (p = 0.001). IP-10 in CSF was significantly lower in HIV+ daily cannabis users compared to HIV+ non-cannabis users (p = 0.039). IP-10 in CSF was significantly higher in HIV+ non-cannabis and moderate cannabis users compared to the HIV− non-cannabis users (p < 0.001, p = 0.003).