Definition and risk factors for chronicity following acute idiosyncratic drug-induced liver injury.

BACKGROUND & AIMS: Chronic outcome following acute idiosyncratic drug-induced liver injury (DILI) is not yet defined. This prospective, long-term follow-up study aimed to analyze time to liver enzyme resolutions to establish the best definition and risk factors of DILI chronicity. METHODS: 298 out of 850 patients in the Spanish DILI registry with no pre-existing disease affecting the liver and follow-up to resolution or ⩾1year were analyzed. Chronicity was defined as abnormal liver biochemistry, imaging test or histology one year after DILI recognition. RESULTS: Out of 298 patients enrolled 273 (92%) resolved ⩽1year from DILI recognition and 25 patients (8%) were chronic. Independent risk factors for chronicity were older age [OR: 1.06, p=0.011], dyslipidemia [OR: 4.26, p=0.04] and severe DILI [OR: 14.22, p=0.005]. Alanine aminotransferase (ALT), alkaline phosphatase (ALP) and total bilirubin (TB) median values were higher in the chronic group during follow-up. Values of ALP and TB >1.1 x upper limit of normal (xULN) and 2.8 xULN respectively, in the second month from DILI onset, were found to predict chronic DILI (p<0.001). Main drug classes involved in chronicity were statins (24%) and anti-infectives (24%). Histological examination in chronic patients demonstrated two cases with ductal lesion and seven with cirrhosis. CONCLUSIONS: One year is the best cut-off point to define chronic DILI or prolonged recovery, with risk factors being older age, dyslipidemia and severity of the acute episode. Statins are distinctly related to chronicity. ALP and TB values in the second month could help predict chronicity or very prolonged recovery. LAY SUMMARY: Drug-induced liver injury (DILI) patients who do not resolve their liver damage during the first year should be considered chronic DILI patients. Risk factors for DILI chronicity are older age, dyslipidemia and severity of the acute episode. Chronic DILI is not a very common condition; normally featuring mild liver profile abnormalities and not being an important clinical problem, with the exception of a small number of cases of early onset cirrhosis.

The value of serum aspartate aminotransferase and gamma-glutamyl transpetidase as biomarkers in hepatotoxicity.

BACKGROUND & AIMS: The current definition of the pattern of liver injury in hepatotoxicity (DILI) is given by the R (ratio) value, dividing alanine aminotransferase (ALT) and alkaline phosphatase (ALP) in upper limits of normal at DILI onset. We aimed to explore the validity of using aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT) as biomarkers of hepatocelullar and cholestatic damage, respectively, when calculating the R value. METHODS: Clinical, laboratory and histological data from 588 DILI episodes included in the Spanish DILI Registry were analyzed. Linear regression analysis was performed to establish the most appropriate cut-off points for hepatocellular and cholestatic patterns when calculating R with AST and GGT. RESULTS: The overall agreement between ALT/ALP and AST/ALP was 76%, with 96%, 61% and 41% agreement in the hepatocellular (R ≥ 5), cholestatic (R ≤ 2) and mixed groups respectively (P < 0.001). Classified by the causative drug, the agreement was higher (87-95%) among drug classes that mainly present with hepatocellular damage and lower (48-58%) for those in which cholestatic-mixed injury predominate (P < 0.001)). The overall agreement between ALT/ALP and ALT/GGT was weak (59%), except for in hepatocellular cases that showed a good agreement (94%) (P = 0.001). Pattern of injury according to liver histology demonstrated 65%, 68% and 47% agreement for ALT/ALP, AST/ALP and ALT/GGT ratios respectively. CONCLUSIONS: AST can reliably replace ALT when calculating pattern of liver injury in DILI, while GGT can only substitute ALP when the R value scores as hepatocellular. The biochemical signature of causative drugs does influence the validity of the ratios with AST or GGT.