APOE-induced microglial activation: an in vitro assay to screen sera from Alzheimer's disease patients and novel therapeutic compounds

Histamine and Immune Biomarkers in CNS Disorders

Neuroimmune dysregulation is a common phenomenon in different forms of central nervous system (CNS) disorders. Cross-links between central and peripheral immune mechanisms appear to be disrupted as reflected by a series of immune markers (CD3, CD4, CD7, HLA-DR, CD25, CD28, and CD56) which show variability in brain disorders such as anxiety, depression, psychosis, stroke, Alzheimer's disease, Parkinson's disease, attention-deficit hyperactivity disorder, migraine, epilepsy, vascular dementia, mental retardation, cerebrovascular encephalopathy, multiple sclerosis, brain tumors, cranial nerve neuropathies, mental retardation, and posttraumatic brain injury. Histamine (HA) is a pleiotropic monoamine involved in several neurophysiological functions, neuroimmune regulation, and CNS pathogenesis. Changes in brain HA show an age- and sex-related pattern, and alterations in brain HA levels are present in different CNS regions of patients with Alzheimer's disease (AD). Brain HA in neuronal and nonneuronal compartments plays a dual role (neurotrophic versus neurotoxic) in a tissue-specific manner. Pathogenic mechanisms associated with neuroimmune dysregulation in AD involve HA, interleukin-1β, and TNF-α, whose aberrant expression contributes to neuroinflammation as an aggravating factor for neurodegeneration and premature neuronal death.

Microglia, amyloid and dementia in alzheimer disease. A correlative study

To elucidate the role of microglia in Alzheimer's disease, a clinicopathological study was performed involving 26 cases, the mental status of which had been studied pre mortem by the Blessed test score (BTS). We measured the volume density of CD 68 immunoreactive (IR) microglia, congophilic plaques and Abeta deposits, and the numerical density of neurofibrillary tangles (NFT) in a sample of Area 9 (middle frontal gyrus). Dementia was significantly correlated only with the volume density of Abeta deposits and the numerical density of NFT. The volume densities of microglia and congophilic plaques were strongly correlated. With the intellectual status used as a time scale, IR microglia and amyloid deposits appeared almost simultaneously at an early stage in the pathological cascade and decreased, whereas Abeta and NFT were still accumulating. The intellectual deficit seemed to be more significantly related to the latter two lesions than to the microglia-amyloid complex, that was visible at an earlier stage (around BTS = 15).