title: LDH to AST ratio in biliary pancreatitis--a possible indicator of pancreatic necrosis: preliminary results.
abstract: OBJECTIVE
  Lactate dehydrogenase (LDH) has been reported to be a sensitive indicator of pancreatic necrosis (PN). In patients with biliary pancreatitis (BP), however, liver enzymes are generally elevated early in the course of the disease because of acute inflammatory liver cell injury caused by ampullary stones impacted during their transpapillary passage. Accordingly, the identification of PN using the initial high LDH activity as an indicator of PN in BP may not be accurate. In patients with ongoing PN, LDH would be expected to increase thereafter. We hypothesized that an elevation of the ratio of LDH to aspartate aminotransferase (AST) (LDH/AST) would better reflect PN in BP.
  
  
  METHODS
  The plasma concentrations of the LDH/AST ratio over a 3-wk postadmission period were evaluated and compared with serial computed tomograpy (CT) scans of the abdomen in two groups of patients with BP, consisting of 5 PN patients and 17 non-PN patients. A group of 50 healthy adults served as controls for the LDH/AST ratio measurement.
  
  
  RESULTS
  On postadmission days 1 and 2, the LDH/AST ratios in both groups of patients were low, with no significant difference. In the PN patients, the LDH/AST ratio increased thereafter, reached peak values, and decreased. In the non-PN patients, the LDH/AST ratio increased gradually, but remained within the control range. In the PN patients, the LDH/AST ratios on postadmission days 3, 5, and 7 were significantly higher than those of the non-PN patients. The CT scans of the abdomen of the PN patients showed an initial edematous pancreas with the development of late PN. The peak values of the LDH/AST ratio correlated well with the extent of PN.
  
  
  CONCLUSIONS
  An elevated LDH/AST ratio identifies patients who develop PN. The LDH/AST ratio could be used as an indicator of PN in BP patients.
authors.affiliation: Department of Surgery, Ogaki Municipal Hospital, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Isogai
authors.forename: A
authors.initials: A
authors.lastname: Yamaguchi
authors.forename: A
authors.initials: A
authors.lastname: Hori
authors.forename: Y
authors.initials: Y
authors.lastname: Kaneoka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001219:Aspartate Aminotransferases / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D010195:Pancreatitis / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed
chemical_list: D015415:Biomarkers; D007770:L-Lactate Dehydrogenase; D001219:Aspartate Aminotransferases