The neutrophil and platelet to lymphocyte ratios in people with subjective, mild cognitive impairment and early Alzheimer's disease

Background In this study we aimed to explore the role of inflammation in subjects with mild Alzheimer dementia (AD), mild cognitive impairment (MCI) and subjective cognitive decline (SCD) via new potential inflammation markers of Neutrophil-lymphocyte ratio (NLR) and Platelet-lymphocyte ratio (PLR). NLR and PLR are useful and cost-effective biomarkers, showing peripheral systemic inflammation, were previously shown in neuropsychiatric disorders [1] . Methods In screening phase the patients were assessed with mini-mental state examination, clinical dementia rating scale (CDR), geriatric depression scale (GDS) and Hachinski Ischemic Scale (HIS) after unstructured psychiatric interview according to diagnostic and statistical manual of mental disorder, Text Revised (DSM-IV, TR). Spectrum of cognitive decline includes 31 patients with mild Alzheimer's disease, 30 subjects with mild cognitive impairment, 31 individuals with subjective cognitive decline. Thirty-one healthy controls enrolled to the study. Results NLR value of patients with AD was 2.38 ± 0.81, subjects with MCI was 2.48 ± 1.19, SCD group was 2.24 ± 1.11 and control group was 1.85 ± 0.80. NLR was significantly higher in AD and MCI groups when compared with control group ( P  = 0.006, P  = 0.03, respectively). Platelet-lymphocyte ratio was not correlated with cognitive impairment. Neutrophil counts were indifferent when comparing either of groups. Lymphocyte levels were significantly lower in each of cognitive decline groups when compared to healthy controls. Conclusion The present findings suggest that systemic inflammation may have a role in developing Alzheimer's Disease.