Development of a Novel Urine Alzheimer‐Associated Neuronal Thread Protein ELISA Kit and Its Potential Use in the Diagnosis of Alzheimer's Disease

Background Alzheimer's disease (AD) is an age‐related chronic degenerative disease that damages the nervous system. A noninvasive and simple method for early detection of AD is extremely important for the diagnosis and prognosis of AD. Thus, we aimed to develop an enzyme‐linked immunosorbent assay (ELISA) kit to detect urine Alzheimer‐associated neuronal thread protein (AD7C‐NTP), and to evaluate its clinical value for the diagnosis of AD. Methods Immunogenic AD7C‐NTP peptide fragments were synthesized by the solid‐phase method and used for immunizing mice or rabbits to generate anti‐AD7C‐NTP antibodies. The urine AD7C‐NTP ELISA kit was then established; the generated mouse anti‐AD7C‐NTP antibody was used as a capture antibody, the biotin‐labeled rabbit anti‐AD7C‐NTP antibody was used as a detection antibody, and avidin labeled by horseradish peroxidase was used as a substrate. The first morning urine specimens of 121 AD patients and 118 age‐matched controls were collected, and the urine AD7C‐NTP levels were detected by the above ELISA kit. Results Mouse and rabbit anti‐AD7C‐NTP antibody ELISA titer was found to be 1:8,000 and 1:32,000, respectively. A single band with a relative molecular mass of 41 kDa was found in human brain specimens by Western blot assay, which was identified as AD7C‐NTP antibody. The urine AD7C‐NTP concentration of the AD patients was higher than that of the age‐matched controls, the sensitivity was 89.3% and the specificity was 84.7%. Conclusions Our study demonstrated that our newly developed urine AD7C‐NTP ELISA kit has suggested potential for diagnosing AD in a Chinese population, suggesting it may be a useful diagnostic kit for detecting early AD.