Tau 2.0 kit

Non-fasting blood samples were collected for all participants. Blood was
collected into plastic dipotassium ethylene diaminetetraacetic acid tubes, and
processed according to standard procedures, with plasma aliquoted and frozen at
−80°C. Frozen plasma aliquots were shipped on dry ice to the
University of Gothenburg (Sweden) for batch analysis. Plasma p-tau₁₈₁concentration was measured using an in-house single molecule array method on an
HD-X analyzer (Quanterix), as previously described in detail.^{11 (link)} The lower limit of
quantification (LLoQ) was 1.0 pg/mL, with a dynamic range of 1.0 to 128.0 pg/mL.
An in-house Simoa method was used to measure plasma NfL concentration
(Quanterix), as described by Gisslén et al.^{44 (link)} The LLoQ was 1.9 pg/mL, with a dynamic
range of 1.9 to 1800 pg/mL. Plasma T-tau concentration was measured using Tau
2.0 kit and the HD-1 analyzer (Quanterix) with an LLoQ of 0.061 pg/mL and a
dynamic range of 0.061 to 360 pg/mL. The measurements were performed in one
round of experiments, using one batch of reagents. Intra-assay coefficients of
variation were below 10% for all the biomarkers.

Non-fasting blood samples were collected for all participants. Blood was collected into plastic dipotassium EDTA tubes, and processed according to standard procedures, with plasma aliquoted and frozen at −80°C. Frozen plasma aliquots were shipped on dry ice to the University of Gothenburg (Sweden) for batch analysis. Plasma NfL concentration was measured using an ultrasensitive in-house Simoa method on an HD-1 Analyzer (Quanterix, Billerica, Massachusetts), as previously described in detail (Gisslen et al., 2016 (link)). This in-house Simoa assay is very similar to commercial Simoa methods (only minor variations) and this same method was previously found to have a high correlation (r = .89) with CSF NfL in a sample of patients with HIV infections (Gisslen et al., 2016 (link)). The LLOQ was 1.9 pg/mL, with a dynamic range of 1.9-1800 pg/mL. T-tau concentrations were measured using the commercially available Tau 2.0 kit and the HD-1 Analyzer (Quanterix, Billerica, Massachusetts) with an LLOQ of 0.061 pg/mL and a dynamic range of 0.061-360 pg/mL. The measurements were performed by board-certified laboratory technicians who were blinded to clinical data. All samples were detectable with an average coefficient of variation (CV) of 4%.