Evaluation of the liver injury unit scoring system to predict survival in a multinational study of pediatric acute liver failure

Abstract

Objective: To examine the predictive value of the Liver Injury Units (LIU) and admission values (aLIU) of bilirubin and prothrombin time and international normalized ratio scores in a large cohort from the Pediatric Acute Liver Failure (PALF) Study Group, a multinational prospective study.

Study design: LIU and aLIU scores were calculated for 461 and 579 individuals, respectively, enrolled in the PALF study from 1999 to 2008. Receiver operator characteristic curves were used to evaluate the scores with respect to survival without liver transplantation (LT), death, or LT by 21 days after enrollment.

Results: At 21 days, 50.3% of participants were alive without LT, 36.2% underwent LT, and 13.4% died. The c-indices for transplant-free survival were 0.81 based on the LIU score with the international normalized ratio (95% CI, 0.78-0.85) and 0.76 based on the aLIU score (95% CI, 0.72-0.79). The LIU score predicted LT better than it predicted death (c-index for LT 0.84, c-index for death 0.76).

Conclusion: Based on data from a large, multicenter cohort of patients with PALF, the LIU score was a better predictor of transplant-free survival than was the aLIU score. The LIU score might be a helpful, dynamic tool to predict clinical outcomes in patients with PALF.

Figure 1

A, Distribution of the LIU score by previously derived quartiles using INR for participants from the PALF Study Group. Survival without LT with native liver is stratified by quartiles of the LIU score. LIU = 3.507 × peak total bilirubin (mg/dL) + 45.51 × peak INR (seconds) + 0.254 × peak ammonia (μmol/L). B, Distribution of the aLIU score by previously derived quartiles using INR for participants from the PALF Study Group. Survival without LT with native liver stratified by quartiles of the aLIU score. aLIU = 8.4 × admission bilirubin (mg/dL) + 50.0 × admission peak INR.

Figure 2

A, Distribution of the LIU score by previously derived quartiles using PT on participants from the PALF Study Group. Survival without LT with native liver is stratified by quartiles of the LIU score. LIU = 3.584 × peak total bilirubin (mg/dL) + 1.809 peak × PT (seconds) + 0.307 × peak ammonia (μmol/L). B, Distribution of the aLIU score by previously derived quartiles using PT for participants from the PALF Study Group. Survival without LT with native liver stratified by quartiles of the aLIU score. aLIU = 6.9 × admission bilirubin (mg/dL) + 4.0 × admission peak PT (seconds).

Figure 3

A, ROC curve of LIU score using INR for predicting 21-day outcome of death or LT versus LT-free survival (n = 461). B, ROC curve of LIU score using INR for predicting 21-day outcome of LT versus LT-free survival (n = 399). C, ROC curve of LIU score using INR for predicting 21-day outcome of death versus LT-free survival (n = 294).

Figure 4

A, Likelihood of LT divided by quartiles of the LIU score using INR in participants with PALF with an indeterminate diagnosis. B, Likelihood of death without LT divided by quartiles of the LIU score using INR in participants with PALF with an indeterminate diagnosis. C, Likelihood of transplantation divided by quartiles of the LIU score using INR in participants with PALF with a specified diagnosis. D, Likelihood of death without LT divided by quartiles of the LIU score using INR in participants with PALF with a specified diagnosis.