Table 3.

Association between individual biomarker concentration and renal recovery and mortality

Biomarker	(95% CI)
	Renal recovery		Mortality
	OR for renal recovery	HR for time to renal recovery	OR for death	HR for time to death
Inflammation
IL-6	0.91 (0.81–1.01)	0.93 (0.86–1.01)	1.19 (1.07–1.32)*	1.19 (1.12–1.27)*
IL-8	0.74 (0.65–0.85)*	0.81 (0.73–0.89)*	1.50 (1.32–1.71)*	1.36 (1.27–1.46)*
IL-10	0.88 (0.77–1.01)	0.92 (0.83–1.03)	1.30 (1.14–1.49)*	1.24 (1.16–1.33)*
IL-18	0.82 (0.70–0.96)***	0.87 (0.78–0.97)***	1.35 (1.16–1.58)*	1.27 (1.15–1.40)*
MIF	0.86 (0.76–0.97)***	0.92 (0.85–1.01)	1.37 (1.22–1.54)*	1.26 (1.17–1.35)*
Apoptosis
TNFR-I	0.62 (0.46–0.84)**	0.70 (0.60–0.82)*	1.61 (1.16–2.24)**	1.47 (1.16–1.86)**
TNFR-II	0.88 (0.64–1.23)	0.90 (0.70–1.16)	1.17 (0.85–1.60)	1.16 (0.95–1.43)
DR-5	0.91 (0.74–1.12)	0.91 (0.78–1.06)	1.36 (1.10–1.67)**	1.24 (1.09–1.41)$

Multivariable logistic regression models with corresponding OR were constructed to examine association between each individual biomarker concentration (per natural log unit) and renal recovery and mortality. All models were adjusted for differences in age; race; sex; Charlson comorbidity score without age; history of chronic hypoxemia, liver disease and immunocompromised state; premorbid serum creatinine; nephrotoxic cause of AKI; diagnosis of sepsis; presence of oliguria at initiation of RRT; use of mechanical ventilation; APACHE-II score, and intensity of RRT. Models were not adjusted for other biomarkers.

For the recovery model, an OR of >1 indicates that higher biomarker concentration is associated with increased renal recovery, and an OR <1 indicates nonrecovery. For the mortality model, OR >1 indicates that higher biomarker concentration is associated with increased mortality and OR <1 indicates lower mortality.

Multivariable Cox models with corresponding HR were constructed to examine association between individual biomarker concentration and time to event outcomes. Models were adjusted for baseline covariates as above. For time to renal recovery model, a HR >1 indicates that higher marker concentration is associated with faster recovery and <1 indicates slower recovery. For time to death, a HR of >1 indicates that higher marker concentration is associated with shorter time to death and <1 indicates longer time to death. The models included 682 subjects due to missing premorbid creatinine data in 134 subjects and DR-5 marker levels in 1 subject. Models were not constructed for IL-1 β, TNF, and GM-CSF due to high censoring of biomarker data.

*P < 0.001; **P < 0.01; ***P < 0.05; ^$P = 0.001.

IL, interleukin; MIF, macrophage migration inhibitory factor; TNFR, tumor necrosis factor receptor; DR, death receptor.