Central Markers of Neuroinflammation in Alcohol Use Disorder: A Meta-analysis of Neuroimaging, Cerebral Spinal Fluid, and Postmortem Studies

Introduction And Aims: There is emerging evidence that heavy long-term alcohol consumption may alter the neuroimmune profile. We conducted a meta-analysis of the association between alcohol use disorder (AUD) and the extent of neuroinflammation using cerebrospinal (CSF), PET (Positron Emission Tomography), and postmortem studies.

Design And Methods: A comprehensive search of electronic databases was conducted using the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) for AUD-related terms in combination with neuroinflammatory markers and cytokine- and chemokine-related terms for CSF, PET, and postmortem studies. Participants had to meet established criteria for AUD and/or heavy alcohol consumption with dependence features and be compared with healthy controls. Papers retrieved were assessed for inclusion criteria and a critical appraisal was completed using the Newcastle-Ottawa Scale. A meta-analysis was conducted on postmortem and PET studies.

Results: Eleven papers met the inclusion criteria with CSF, PET, and postmortem studies included in the final analysis. Postmortem studies demonstrate significant heterogeneity (???? (14) = 62.02, ???? < 0.001), with the alcohol group showing higher levels of neuroimmune markers than controls (???? = 1.50 [95% CI 0.56, 2.45]). PET studies demonstrated a lower [ C] PBR28 total volume of distribution (V ) for translocator protein in the hippocampus (g = -1.95 [95% CI -2.72, -1.18], p < 0.001) of the alcohol group compared to controls.

Conclusion: There is emerging evidence across multiple diagnostic modalities that alcohol impacts neuroimmune signaling in the human brain.