Figure 4

Diagnostic performance of EZR-autoantibodies captured by ELISA. (A) Scatter plots show the reactivity of PDAC (n = 69), healthy subject (HS, n = 45), non-PDAC (n = 28), autoimmune disease (AD, n = 12) and chronic pancreatitis (CP, n = 37) patient sera to EZR recombinant protein as assessed by ELISA: PDAC vs. HS, non-PDAC and CP P < 0.0001; PDAC vs. AD P = 0.0006. (B) Scatter plots show the reactivity of prediagnostic PDAC patient (n = 16) and matched control (n = 32) sera from the EPIC cohort to EZR recombinant protein as assessed by ELISA: PDAC vs. controls P = 0.0002. Reactivity is expressed as optical density (O.D.) read at 450 nm, P-values were calculated by Student's t-test. (C) ROC analysis of EZR-autoantibody sensitivity and specificity using O.D. obtained in ELISA as a continuous variable (cut-off value: O.D. = 0.1183). (D) Classification and regression tree (CART) analysis of CA19.9 serum levels (≥ 37 IU/ml), EZR-autoantibody reactivity (O.D. ≥ 0.1183) and ENOA1,2-autoantibody reactivity (expressed as 2DE WB positivity) with 93 PDAC patients and controls where all parameters were available. The number and percentage of PDAC patients and controls are shown for each node. (E) ROC analysis of sensitivity and specificity of EZR-autoantibody detection in combination with CA19.9 and ENOA1,2-autoantibodies in the cohort of samples where all three parameters were available (PDAC patients: n = 45; benign controls: HS, AD, CP, n = 48). The applied diagnostic algorithm assigns patients to the PDAC group when both EZR-autoantibodies and CA19.9 are positive, and separates discordant cases into PDAC or controls based on the presence or absence of ENOA1,2-autoantibodies.