ALT-LDH Index of Kotoh et al for Evaluating a Patient with Acute Liver Injury

Patient selection: serum ALT > 1,000 U/L and/or INR > 1.5

Parameters:

(1) serum ALT in U/L

(2) serum LDH in U/L

(3) median of the normal LDH range (halfway between LLN and ULN)

ALT-LDH index =

= (serum ALT) / ((serum LDH) - (median of the normal LDH range))

where:

• Testing was performed on an Hitachi 7500 Clinical Analyzer.

• The reference range for serum ALT was 6 to 30 U/L and for serum LDH was 119 to 229/U/L. This means that the median LDH is 174 U/L.

• The half-life for ALT is given as 48 hours in the previous section.

• According to www.clinlabnavigator.com the half-life for LDH isoenzymes from liver and skeletal muscle is 10 hours (versus 100-110 hours for LD1 from the heart).

Interpretation:

• Survivors with conservative management tended to show a rapid increase in the index during the hospitalization. This may relate to the half-life of the enzymes and the level of ongoing liver injury.

• An index after 48 hours (third day in the ICU) > 3.0 was 75% sensitive and 100% specific for predicting survival with conservative management.

Limitations:

• To transport this score to a different location the assays for ALT and LDH must behave comparably.