Crosswalk study on blood collection-tube types for Alzheimer's disease biomarkers

• Introduction Blood-based Alzheimer's disease (AD) biomarkers show promise, but pre-analytical protocol differences may pose problems. We examined seven AD blood biomarkers (amyloid beta [A beta]42${\rm{A\beta }}]{_{42}}$, A beta 40${\rm{A}}{{{\beta}}_{40}}$, phosphorylatedtau[p-tau181${\rm{phosphorylated\;tau\;[p - ta}}{{\rm{u}}_{181}}$, total tau [t-tau], neurofilament light chain [NfL], A beta 4240,${\rm{A}}{{{\beta}}_{\frac{{42}}{{40}}}},$ and p-tau181A beta 42$\frac{{{\rm{p - ta}}{{\rm{u}}_{181}}}}{{{\rm{A}}{{{\beta}}_{42}}}}$) in three collection tube types (ethylenediaminetetraacetic acid [EDTA] plasma, heparin plasma, serum). Methods Plasma and serum were obtained from cerebrospinal fluid or amyloid positron emission tomography-positive and -negative participants (N = 38) in the Wisconsin Registry for Alzheimer's Prevention. We modeled AD biomarker values observed in EDTA plasma versus heparin plasma and serum, and assessed correspondence with brain amyloidosis. Results Results suggested bias due to tube type, but crosswalks are possible for some analytes, with excellent model fit for NfL (R2${{\rm{R}}<^>2}\;$= 0.94), adequate for amyloid (R2${{\rm{R}}<^>2}\;$= 0.40-0.69), and weaker for t-tau (R2${{\rm{R}}<^>2}\;$= 0.04-0.42) and p-tau181${\rm{p - ta}}{{\rm{u}}_{181}}$ ( R2${{\rm{R}}<^>2}\;$= 0.22-0.29). Brain amyloidosis differentiated several measures, especially EDTA plasma pTau181A beta 42$\frac{{{\rm{pTa}}{{\rm{u}}_{181}}}}{{{\rm{A}}{\beta _{42}}}}$ (d$d\;$= 1.29). Discussion AD biomarker concentrations vary by tube type. However, correlations for some biomarkers support harmonization across types, suggesting cautious optimism for use in banked blood.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Neurovetenskaper (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Neurosciences (hsv//eng)

Keyword

Alzheimer's disease

amyloid beta

cognitively unimpaired

neurofilament

light

plasma

p-tau181

t-tau

sas procedure

Neurosciences & Neurology

Publication and Content Type

ref (subject category)

art (subject category)