Combining serum and urine biomarkers in the early diagnosis of mild cognitive impairment that evolves into Alzheimer’s disease in patients with the apolipoprotein E ε4 genotype

Abstract

Possession of the apolipoprotein E (APOE) ε4 genotype is a major predictor of progression to Alzheimer’s disease (AD), particularly in patients with mild cognitive impairment (MCI). However, the use of APOE genotyping in the diagnosis of MCI is limited due to its low sensitivity and specificity, which often results in a high false-positive rate. In this study, we found that there was a significant decrease in serum BDNF and notable increase in urine AD7c-NTP in MCI patients who harbored the APOE ε4 allele. Both serum BDNF and urine AD7c-NTP had higher positive predictive values and were more sensitive biomarkers of MCI. Additionally, a testing strategy employing serum BDNF and urine AD7c-NTP revealed increases in sensitivity, positive and negative predictive values, and predictive ability compared with the use of either biomarker alone, suggested that combinatorial detection might have great potential for translation to the clinic.

• Alzheimer’s disease
• apolipoprotein E ε4
• mild cognitive impairment
• serum BDNF
• urine AD7c-NTP

Acknowledgements

The authors thank Wenlong Tan for assisting in the preparation of this manuscript.

Declaration of interest

The authors declare no conflict of interest. This work was supported by the Hebei Medical Science Research Program (20130345) of the Health Department of Hebei Province and the Technology Support Program (201202) of the Harrison International Peace Hospital.

Supplementary material available online.