Table 4

Added value of CSF and blood KLK8 on diagnostic accuracy of CSF AD biomarkers

AD versus CONMCI versus CON
CSF KLK8Blood KLK8CSF KLK8Blood KLK8
AUC (95% CI)P valueAUC (95% CI)P valueAUC (95% CI)P valueAUC (95% CI)P value
42 0.94 (0.87 to 1.0)0.96 (0.92 to 1.0)0.88 (0.78 to 0.98)0.90 (0.82 to 0.98)
42+KLK80.97 (0.94 to 1.0)0.97 (0.92 to 1.0)0.99 (0.96 to 1.0)0.96 (0.92 to 1.0)
AUC difference0.04 (−0.02 to 0.09)0.200.01 (−0.03 to 0.05)0.590.11 (0.01 to 0.21)0.030.06 (−0.01 to 0.13)0.06
T-tau0.94 (0.89 to 0.99)0.95 (0.91 to 0.99)0.94 (0.87 to 1.0)0.95 (0.90 to 1.0)
T-tau +KLK80.96 (0.91 to 1.0)0.97 (0.93 to 1.0)1.0 (1.0 to 1.0)1.0 (1.0 to 1.0)
AUC difference0.02 (−0.02 to 0.05)0.320.01 (−0.01 to 0.04)0.360.06 (−0.01 to 0.13)0.110.05 (−0.01 to 0.1)0.07
P-tau0.98 (0.93 to 1.0)0.97 (0.93 to 1.0)0.88 (0.72 to 1.0)0.91 (0.81 to 1.0)
P-tau +KLK81.0 (1.0 to 1.0)0.97 (0.93 to 1.0)1.0 (1.0 to 1.0)0.98 (0.95 to 1.0)
AUC difference0.02 (−0.02 to 0.07)0.30−0.003 (−0.02 to 0.01)0.690.12 (−0.04 to 0.28)0.150.07 (−0.03 to 0.18)0.18
42+T tau+P-tau0.97 (0.91 to 1.0)0.98 (0.96 to 1.0)0.91 (0.76 to 1.0)0.92 (0.81 to 1.0)
42+T tau+P tau+KLK81.0 (1.0 to 1.0)1.0 (1.0 to 1.0)1.0 (1.0 to 1.0)1.0 (1.0 to 1.0)
AUC difference0.03 (−0.03 to 0.09)0.290.02 (−0.01 to 0.04)0.250.09 (−0.06 to 0.24)0.230.08 (−0.02 to 0.19)0.10
  • AUCs of CSF AD core biomarkers (ie, CSF Aβ42, CSF T-tau, CSF P-tau each and combination of all three) are compared with AUCs of CSF AD biomarker of interest with added value of CSF or blood KLK8. Data were adjusted for gender, age and study group as well as for biomarker of interest. p values were determined by DeLong test.

  • 42, β-amyloid 42; AD, Alzheimer’s disease; AUC, area under the curve; CON, controls; CSF, cerebrospinal fluid; MCI, mild cognitive impairment due to AD; P, p value; P-tau, phosphorylated tau; T-tau, total tau.