WEDNESDAY, Jan. 7, 2026 (HealthDay News) -- Dried blood collection derived from capillary blood shows potential for Alzheimer disease (AD) biomarker testing, according to a study published online Jan. 5 in Nature Medicine.In a study including 337 participants from seven centers, Hanna Huber, Ph.D., from The Sahlgrenska Academy at the University of Gothenburg in Sweden, and colleagues examined the potential of dried plasma spot (DPS) and dried blood spot (DBS) analysis, derived from capillary blood, for detecting AD biomarkers, including phosphorylated tau at amino acid 217 (p-tau217), glial fibrillary acidic protein, and neurofilament light. Overall, 304 participants provided paired capillary DPS or DBS and venous plasma samples.The researchers identified strong correlations between DPS p-tau217 and venous plasma p-tau217. There was a progressive increase in DPS p-tau217 with increasing disease severity, with good accuracy for predicting cerebrospinal fluid biomarker positivity (area under the curve, 0.864). Using paired venous plasma samples, glial fibrillary acidic protein and neurofilament light were successfully detected, with strong correlations between DBS and DPS, respectively. In individuals with Down syndrome, who have a high genetic risk for AD but in whom standard blood sampling by venipuncture may be more complicated, the method was also effective, with elevated biomarkers seen in those with dementia versus asymptomatic individuals."Despite the promise shown, we do not currently recommend the use of dried blood analysis for clinical use, decision-making, or patient management, because of observed differences in analytical performance and diagnostic accuracy between capillary-derived and venous blood samples," the authors write. "Further methodological refinement and validation will be essential before clinical translation can be considered."Several authors disclosed ties to the biopharmaceutical industry.Abstract/Full Text.Sign up for our weekly HealthDay newsletter