Plasma p-tau217 shows no correlation with age or comorbidity in adolescents

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medRxiv Published April 5, 2026 Medically reviewed April 26, 2026 Study authors: Stancil, S. L.; Brewe, M.; Mayfield, H.; Morris, J. DOI ↗ By Dr. Sofia Müller, MD · Lifespan & Whole-Person Care

Key Takeaway

Note: p-tau217 levels in adolescents show no correlation with age or comorbidity but vary significantly by collection method.

An observational cohort study examined plasma p-tau217 levels in 41 adolescents (mean age 16±2.6 years). The study assessed whether p-tau217 varied with age, comorbidity, medication use, or biospecimen collection method, comparing venous plasma to Tasso+ capillary plasma collection.

The analysis found no correlation between p-tau217 and age or BMI z-score in adolescents. There were no differences in p-tau217 levels based on psychiatric, cardiometabolic, or gastrointestinal comorbidities, nor based on corresponding medication use. A key methodological finding was that p-tau217 concentrations were >10-fold higher in Tasso+ capillary plasma compared to venous plasma.

Safety and tolerability data were not reported. The study was limited by its small sample size of 41 adolescents and lack of reported statistical measures. The authors note venous and Tasso+ capillary plasma should not be directly compared or pooled until methodological differences are resolved. This preliminary evidence suggests p-tau217 may be stable across adolescence but requires validation in larger studies.

Study Details

Study typeCohort

Sample sizen = 41

EvidenceLevel 3

PublishedMar 2026

View Original Abstract ↓

BackgroundAdolescence is a critical period of neurodevelopment with the emergence of chronic medical conditions and increasing exposure to long-term medications. P-tau217 is a sensitive blood-based biomarker of neuropathology in older adults, yet its developmental behavior and susceptibility to common clinical factors in youth are unclear. Here we tested whether p-tau217 varies with age, comorbidity, or medication use during adolescence; and whether collection method (venous vs Tasso+ capillary) yields comparable concentrations. MethodsIn an adolescent cohort, plasma p-tau217 was measured by Simoa HD-X. Paired venous and Tasso+ capillary samples were also analyzed from adult volunteers for methodological comparison ResultsIn adolescents (n=41; mean age 16{+/-}2.6 years), p-tau217 did not correlate with age or BMI z-score and did not differ by psychiatric, cardiometabolic, or gastrointestinal comorbidity, nor by corresponding medication use. In contrast, p-tau217 concentrations were >10-fold higher in Tasso+ capillary plasma than venous plasma, a discordance replicated in paired adult samples. ConclusionPlasma p-tau217 appears physiologically stable across common clinical variables in adolescence, but highly sensitive to biospecimen collection method. Venous and Tasso+ capillary plasma should not be directly compared or pooled until methodological differences are resolved. These data provide a developmental baseline and critical methodological caution for pediatric neuroscience and decentralized biomarker studies.