Table 2.

Presence of elevated biomarkers in high-ALT human serum. ALT and five candidate biomarkers were assayed in human serum by quantitative immunoblotting using recombinant human protein standards. None were detectable in the serum from subjects with normal ALT levels. The five biomarkers were all elevated in subjects experiencing hepatotoxicity, with the levels correlating to ALT measurements. ALT was also measured by the more sensitivity enzymatic activity assay which was converted to absolute concentration using calibration standards. Four of the five are much more abundant in blood than ALT.

	APAP hepatotoxicity				Control
Sample	H1	H2	H3	H4	C1	C2	C3	C4
Gender	Female	Female	Male	Male	Female	Female	Male	Male
Age (year)	32	68	44	57	32	54	45	75
Weight (kg)	55	50	60	74	52	49	70	63
Height (cm)	160	159	175	176	163	158	177	165
ALT(IU/L)	632	424	345	182	18	35	32	27
ALT(µg/ml)*	1.26	0.84	0.69	0.36	0.04	0.07	0.06	0.05
ALT(µg/ml)	0.55	0.22	ND	ND	ND	ND	ND	ND
BHMT (µg/ml)	64.9	60.7	31.3	17.8	ND	ND	ND	ND
FAH (µg/ml)	53.8	49.8	38.7	ND	ND	ND	ND	ND
FBP1 (µg/ml)	38.3	33.1	10.3	12.2	ND	ND	ND	ND
DPYS (µg/ml)	20.7	18.3	5.1	6.4	ND	ND	ND	ND
HPD (µg/ml)	0.32	0.27	0.02	0.09	ND	ND	ND	ND

*Estimated based on enzymatic activity. ND: Not detectable.