Table 4.
Performance of plasma P-tau181 for Aβ+ detection with regard to renal function (creatinine and eGFR)
| Population with CSF biomarkers available | Total | Creatinine <68 First tertile |
Creatinine 69–82 Second tertile |
Creatinine ≥82 Third tertile |
| Creatinine (μmol/L) | 74 (71–77) | 61 (57–64) | 73 (71–80) | 95 (84–111) |
| Plasma P-tau 181(pg/mL) | 3.0 (2.8–3.4) | 2.3 (1.8–3.3) | 2.9 (2.5–3.9) | 3.7 (2.7–5.2) |
| Plasma P-tau 181 in Aβ− | 2.2 (1.9–2.4) | 1.9 (1.5–2.4) | 2.3 (1.6–2.7) | 2.9 (1.9–4.0) |
| Plasma P-tau 181 in Aβ+ | 3.7 (2.8–4.5) | 3.1 (2.2–4.3) | 3.6 (2.9–4.0) | 4.2 (3.6–5.4) |
| AUC Plasma P-tau 181 Aβ+ | 0.783 | 0.763 | 0.872 | 0.733 |
| Plasma P-tau 181 cutpoints (pg/mL) | 2.77 | 2.31 | 2.77 | 3.52 |
| Sensitivity (%) | 80.9 | 75.0 | 89.5 | 80.0 |
| Specificity (%) | 69.6 | 73.0 | 80.0 | 70.0 |
| Population with CSF biomarkers available | Total |
eGFR <74
first tertile |
eGFR 74–86
second tertile |
eGFR >86
third tertile |
| eGFR (mL/min/1.73 m2) | 79 (68–89) | 64 (54–69) | 79 (76–84) | 91 (89–93) |
| Plasma P-tau 181(pg/mL) | 3.0 (2.1–3.9) | 3.5 (2.4–4.2) | 3.1 (2.1–3.9) | 2.7 (1.8–3.9) |
| Plasma P-tau 181 in Aβ− | 2.2 (1.7–3.0) | 2.7 (1.7–3.4) | 2.0 (1.7–2.6) | 2.0 (1.6–2.9) |
| Plasma P-tau 181 in Aβ+ | 3.7 (2.8–4.5) | 3.8 (3.1–5.4) | 3.8 (2.8–4.5) | 3.3 (2.7–4.2) |
| AUC Plasma P-tau 181 Aβ+ | 0.783 | 0.763 | 0.872 | 0.733 |
| Plasma P-tau 181 cutpoints (pg/mL) | 2.77 | 2.81 | 2.71 | 2.44 |
| Sensitivity (%) | 80.9 | 86.4 | 84.2 | 78.8 |
| Specificity (%) | 69.6 | 60.0 | 77.8 | 68.6 |
Values of creatinine and plasma P-tau181 are express as median (25–75th percentile). Cutpoints correspond to the best Youden index on the ROC curves.
AUC, area under the curve; Aβ+, amyloid positive; CSF, cerebrospinal fluid; eGFR, estimated glomerular filtration rate; ROC, receiving operator characteristic.