Mechanistic biomarkers provide early and sensitive detection of acetaminophen-induced acute liver injury at first presentation to hospital

Abstract

Acetaminophen overdose is a common reason for hospital admission and the most frequent cause of hepatotoxicity in the Western world. Early identification would facilitate patient-individualized treatment strategies. We investigated the potential of a panel of novel biomarkers (with enhanced liver expression or linked to the mechanisms of toxicity) to identify patients with acetaminophen-induced acute liver injury (ALI) at first presentation to the hospital when currently used markers are within the normal range. In the first hospital presentation plasma sample from patients (n = 129), we measured microRNA-122 (miR-122; high liver specificity), high mobility group box-1 (HMGB1; marker of necrosis), full-length and caspase-cleaved keratin-18 (K18; markers of necrosis and apoptosis), and glutamate dehydrogenase (GLDH; marker of mitochondrial dysfunction). Receiver operator characteristic curve analysis and positive/negative predictive values were used to compare sensitivity to report liver injury versus alanine transaminase (ALT) and International Normalized Ratio (INR). In all patients, biomarkers at first presentation significantly correlated with peak ALT or INR. In patients presenting with normal ALT or INR, miR-122, HMGB1, and necrosis K18 identified the development of liver injury (n = 15) or not (n = 84) with a high degree of accuracy and significantly outperformed ALT, INR, and plasma acetaminophen concentration for the prediction of subsequent ALI (n = 11) compared with no ALI (n = 52) in patients presenting within 8 hours of overdose.

Conclusion: Elevations in plasma miR-122, HMGB1, and necrosis K18 identified subsequent ALI development in patients on admission to the hospital, soon after acetaminophen overdose, and in patients with ALTs in the normal range. The application of such a biomarker panel could improve the speed of clinical decision-making, both in the treatment of ALI and the design/execution of patient-individualized treatment strategies.

Figure 1

Plasma biomarker values at presentation to the hospital emergency department correlate with peak ALT activity. (A) miR-122, (B) total HMGB1, (C) apoptosis K18, (D) necrosis K18, and (E) GLDH activity were correlated against peak ALT activity in patients who presented early after acetaminophen overdose (<24 hours, n = 129).

Figure 2

Plasma biomarker values at presentation to the hospital emergency department correlate with peak INR. (A) miR-122, (B) total HMGB1, (C) apoptosis K18, (D) necrosis K18, and (E) GLDH activity were correlated against peak INR in patients who presented early after acetaminophen overdose (<24 hours, n = 129).

Figure 3

Correlation of admission and 4-hour back-extrapolated plasma acetaminophen concentration with peak ALT and INR. Plasma (A) peak ALT activity and (B) peak INR were correlated with admission acetaminophen concentration for all patients (n = 129). Plasma (C) peak ALT activity and (D) peak INR were correlated with 4-hour back-extrapolated acetaminophen concentration for all patients (n = 129). Correlation coefficient, Pearson R values, and statistical significance are indicated.

Figure 4

Plasma biomarker values are elevated in patients with normal liver function tests who subsequently develop ALI. (A) miR-122, (B) total HMGB1, (C) apoptosis K18, (D) necrosis K18, (E) GLDH activity, and (F) ALT activity were quantified in plasma from patients who presented within 24 hours of a acetaminophen overdose and had an ALT activity level within the normal range (<50 IU/L) at presentation (n = 98). Presentation values for miR-122, total HMGB1, apoptosis K18, necrosis K18, GLDH, and ALT are compared between patients who do not (n = 83) and do (n = 15) develop ALI, as defined by an ALT activity rising above 3× ULN. Data are given as median (IQR) and statistical significance is recorded on each figure as required for each biomarker.

Figure 5

ROC curve analysis supports the potential for novel biomarkers to predict the development of ALI. ROC analysis was calculated to determine the potential for plasma (A) miR-122, (B) total HMGB1, (C) apoptosis K18, (D) necrosis K18, (E) GLDH activity, and (F) ALT activity to predict the development of ALI following presentation <24 hours following acetaminophen overdose. All patients (n = 98) presented with ALT activity within the normal range (<50 IU/L) and then either subsequently stayed within the normal range (n = 83) or developed ALI as defined by an ALT activity rising above 3× ULN (n = 15). AUC, statistical significance, and sensitivity (SENS) at 90% specificity is recorded on each figure as required.