Table 4.

Association of donor YKL-40 with risk of recipient DGF, stratified by AKI status

Tertile of YKL-40 (Range [ng/ml])	N	Rate of DGF (%)	RR (95% CI)
			Unadjusted	Adjusted for Donor Variablesa	Adjusted for Donor, Transport, and Recipient Variablesb	Adjusted for Donor, Transport, Recipient Variables, and Donor NGALc
Donors without AKI
T1 (<0.61)	n1=853	240 (28)	1.0 (referent)	1.0 (referent)	1.0 (referent)	1.0 (referent)
T2 (0.61–3.31)	n2=796	226 (28)	1.01 (0.86 to 1.20)	0.93 (0.80 to 1.09)	0.92 (0.79 to 1.08)	0.88 (0.75 to 1.03)
T3 (3.33–432.78)	n3=592	187 (32)	1.13 (0.95 to 1.34)	0.96 (0.82 to 1.14)	0.91 (0.77 to 1.07)	0.79 (0.65 to 0.97)
Donors with AKI
T1 (<0.61)	n1=23	16 (70)	1.0 (referent)	1.0 (referent)	1.0 (referent)	1.0 (referent)
T2 (0.61–3.31)	n2=32	14 (44)	0.64 (0.39 to 1.06)	0.63 (0.39 to 1.01)	0.59 (0.38 to 0.91)	0.57 (0.37 to 0.89)
T3 (3.33–432.78)	n3=139	73 (53)	0.76 (0.53 to 1.08)	0.65 (0.46 to 0.93)	0.66 (0.47 to 0.91)	0.51 (0.32 to 0.80)

Donor AKI was defined as at least a doubling of serum creatinine from admission to the terminal value. There was a significant interaction between the highest urinary YKL-40 tertile and AKI (P=0.05) in unadjusted analyses.

^aDonor variables used for adjustment: age (years), height (cm), weight (kg), black race, history of hypertension, history of diabetes, terminal serum creatinine, stroke as cause of death, and donation after circulatory determination of death status.

^bIncludes all variables listed above plus the following transport and recipient variables: cold ischemia time (hours), age (years), black race, gender, previous kidney transplant, diabetes as the cause of ESRD, number of human leukocyte antigen mismatches, body mass index (kg/m²), duration of dialysis before transplant (months), and panel reactive antibody (%).

^cIncludes all variables listed above plus log base 2–transformed donor urine NGAL.