Utility and limitations of the use of donor-derived cell-free DNA in kidney transplantation

Table 2 Studies assessing plasma donor-derived cell-free DNA for the diagnosis of rejection using commercially available assays

Ref.	Assay used	Patient number	Threshold (%)	Sensitivity/specificity	PPV/NPV
Bloom et al[7]	AlloSure	102	1	59/85	61/84
Sigdel et al[8]	Prospera	193	1	88.7/72.6	52/95
Huang et al[9]	AlloSure	63	0.74	79/72	77/75
Bu et al[42]	AlloSure	1092	0.5	78/71	50/90
Bromberg et al[32]	Prospera	424	1	79/85.3	32.6/97.9

PPV: Positive predictive value; NPV: Negative predictive value.