Role of inflammatory and hemostatic biomarkers in Alzheimer's and vascular dementia - A pilot study from a tertiary center in Northern India.

INTRODUCTION: A reliable plasma biomarker in differentiating between Alzheimer's disease (AD) and Vascular dementia (VaD) is the need of the hour, in most memory clinics. Even though there is no disease modifying treatment, it is important to know the type of dementia for both symptomatic treatment and prognostication.

METHODS: Neuropsychological assessment, MRI brain, FDG-PET brain and CSF biomarkers of AD (Aβ42 and total tau) were used for establishing the diagnosis of Mild Cognitive Impairment (MCI), AD or VaD.

RESULTS: 68 diagnosed patients of AD/MCI/VaD were included. FDG PET brain, plasma fibrinogen, d dimer, IL6 and CRP were done in all 68 patients while 48 patients underwent CSF biomarker analysis. Sixteen patients had MCI, of which 11 were MCI-AD and 5 were MCI-VaSC. There were 41 patients with AD (Mild AD-9, Mod AD-23, Severe AD-9) and 11 patients with VaD. Alzheimer group (MCI-AD and AD) and Vascular group (MCI VaSC & VaD) consisted of 52 and 16 patients respectively. Alzheimer and Vascular groups did not exhibit significant difference in IL6 and CRP levels. Plasma fibrinogen levels were significantly higher in VaD and vascular group as compared to Alzheimer group. But MCI-VaSC was not significantly different from MCI-AD. Plasma d dimer levels were significantly higher in all vascular subgroups compared to Alzheimer subgroups except between MCI-VaSC and MCI-AD.

CONCLUSION: Hemostatic biomarkers were higher in Vascular group compared to Alzheimer group whereas there was no difference in inflammatory biomarkers. But the sensitivity and specificity of fibrinogen and d-dimer were not high enough for routine clinical use. Further studies in a larger sample are required to confirm these results.