“Biological variation estimates of Alzheimer’s disease plasma biomarkers in healthy individuals.”
Wagner S. Brum, et al. – European Federation of Clinical Chemistry and Laboratory Medicine Working Group on Biological Variation.
In this study, plasma biomarkers for AD were collected in 10 weekly measurements from cognitively normal individuals to assess levels of biological and technical variation. Phospho-tau levels were relatively stable compared to the robust increases seen in AD, making them promising biomarkers for the clinic. However, the small decrease in plasma Aβ42/Aβ40 observed in patients is similar enough to the fluctuations seen in this study that it may not be sufficiently robust for clinical use. Understanding the margin of error introduced by biological and analytical variability is essential for proper clinical and research practices, where individuals are often assessed using single tests spaced months or years apart.
