Biochemical assay for AD7C-NTP in urine as an Alzheimer's disease marker

✍ Scribed by Hossein Ghanbari; Kasra Ghanbari; Iraj Beheshti; Michael Munzar; Audrey Vasauskas; Paul Averback

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 36 KB
• Volume: 12
• Category: Article
• ISSN: 0887-8013
• DOI: 10.1002/(sici)1098-2825(1998)12:5<285::aid-jcla6>3.0.co;2-5

✦ Synopsis

A reliable and specific immunoassay has been developed to detect and measure AD7C-NTP, a biochemical marker for Alzheimer's disease, in urine. The urine samples are first processed by centrifugation and ultrafiltration to fractionate and concentrate AD7C-NTP. The urinary AD7C-NTP has the same molecular weight as AD7C-NTP in brain and cerebrospinal fluid by size exclusion chromatography. It has also retained the binding properties to the monoclonal and polyclonal antibodies developed against recombinantly produced AD7C-NTP. This assay is an enzyme linked sandwich immunoassay (ELSIA) using 96 well microtiter plates. The plate surface is coated with a monoclonal antibody (N3I4) which has a high affinity and specificity for AD7C-NTP, capturing it effectively from the samples. The detection was achieved using a polyclonal antibody (ADRI). The utility of the assay has been demonstrated using urine specimens from Alzheimer's disease (AD) patients and non-Alzheimer's controls. Urinary AD7C-NTP in the AD group (2.5 ng/mL, n=66) was significantly higher than the non-AD group (0.8 ng/mL, n=134).Using 1.5 ng/mL as cut off, in this patient population, specificity and sensitivity of urinary AD7C-NTP were comparable to CSF AD7C-NTP.