The evaluation of neutrophil-lymphocyte ratio in Alzheimer's disease.

Background/aim: There is growing consensus in the literature that inflammation plays a significant role in the pathophysiology of Alzheimer's disease (AD). The blood neutrophil-lymphocyte ratio (NLR) is a new, inexpensive and easily applicable marker of inflammation. The aim of this study was to investigate the association between NLR, as an inflammatory biomarker, and AD.

Methods: 241 AD patients and 175 patients with normal cognitive function were evaluated in this study.

Results: The mean ± SD NLR of AD patients was significantly higher than that of patients with normal cognitive function (3.21 ± 1.35 vs. 2.07 ± 0.74, p < 0.001, respectively). Receiver operating characteristic curve analysis suggested that the optimum NLR cutoff point for AD was 2.48 with 69.29% sensitivity, 79.43% specificity, 82.30% positive predictive values and 65.30% negative predictive values. Logistic regression analysis showed that elevated NLR (OR: 4.774, 95% CI: 2.821-8.076, p < 0.001) was an independent variable for predicting AD.

Conclusion: Elderly people with AD have higher NLR than healthy controls. Elevated NLR levels are usually considered as an inflammatory marker. The results of this study suggested that inflammation plays a role in the pathogenesis of AD.