Figure 1.

Plot of dd-cfDNA quantity (cp/ml) by dd-cfDNA(%). Green, pink, and blue data points show patients with biopsy proven antibody-mediated rejection, mixed, and T cell–mediated rejection, respectively. Black data points show patients with no evidence of AR at biopsy. The vertical dashed line shows the cutoff point for dd-cfDNA(%) (≥1%); the horizontal dashed line shows the cutoff for the new quantity of dd-cfDNA threshold (≥78 cp/ml). The samples to the right of the vertical dashed line, with dd-cfDNA(%) values ≥1%, are considered high risk according to the original single-threshold algorithm. The samples in the upper left quadrant, with dd-cfDNA <1% and dd-cfDNA ≥78 cp/ml, are considered low risk for rejection by the single threshold algorithm, and high risk for rejection by the two-threshold algorithm. The two data points in the red oval show the patients with AR identified by the new algorithm. The samples in the lower left quadrant are considered at low risk for rejection by both algorithms.