Neuroimmunology of Huntington’s Disease: Revisiting Evidence from Human Studies

Figure 1

Inflammatory/immune changes observed in patients with Huntington’s disease. Postmortem studies have shown increased microglia activation and astrocytosis in brain from patients who suffered from HD. In addition, increased expression of inflammatory mediators, such as cytokines and proteins related to intracellular pathways, was found in brains from patients with HD. Studies using PET also demonstrated increased microglial activation in HD. Cerebrospinal fluid samples from patients with HD presented increased levels of inflammatory mediators. In addition to changes in the central nervous system, patients with HD also display increased peripheral levels of inflammatory mediators, such as cytokines, chemokines, and complement factor proteins, besides alteration in monocyte activity and intracellular signaling proteins. A2M = alpha-2-macroglobulin; Akt = protein kinase B; APOA4 = apolipoprotein A4; CRP = C-reactive protein; HD = Huntington’s disease; Ig = immunoglobulin; IL = interleukin; JAK/STAT = janus kinase/signal transducer and activator of transcription; MCP = monocyte chemoattractant protein; MIP = macrophage inflammatory protein; MMP = matrix metalloproteinase; NF-κB = nuclear factor kappa; PET = positron emission tomography; PGLYRP2 = peptidoglycan recognition protein 2; sTNFR1 = soluble TNF receptor type I; TNF = tumor necrosis factor. study found no change in circulating levels of TNF-α in HD. study found that patients with HD presented higher serum levels of IgA than controls. = increase; = decrease; = no change.