Use of Amylase and Alanine Transaminase to Predict Acute Gallstone Pancreatitis in a Population with High HIV Prevalence

BACKGROUND: The etiology of acute pancreatitis can be difficult to determine early in the course of the disease. The aim of the present study was to determine the relationship between biochemical parameters and the cause of acute pancreatitis. METHODS: A prospectively collected database of patients admitted with acute pancreatitis between 2001 and 2008 was analyzed. The relationships between etiology and age, sex, admission serum amylase level, and admission alanine transaminase (ALT) level were evaluated. RESULTS: Acute pancreatitis was diagnosed in 464 patients. The disease was related to alcohol in 275 cases, gallstones in 81 cases, HIV in 49 cases, dyslipidemia in 42 cases, and it was idiopathic in 17 cases. Alcoholic pancreatitis was more common in men, whereas the other identifiable causes were more common in women (P < 0.001). Mean age at presentation was 39 years with no difference in age in relation to etiology (P = 0.057). When compared to patients with non-biliary causes of pancreatitis, patients with gallstone pancreatitis had greater median (range) serum amylase activity [1,423 U/l (153-7,500 U/l) versus 589 U/l (58-11,144 U/l); P < 0.001] and ALT activity [153 U/l (8-13,233 U/l) versus 31 U/l (6-421 U/l); P < 0.001]. No significant differences in amylase or ALT activity were found between non-biliary etiologies (P > 0.05). Alanine transaminase was the only factor independent of sex to predict gallstone etiology, with activity >150 U/l having a specificity of 97 %. CONCLUSIONS: In patients with acute gallstone pancreatitis, the serum amylase and ALT activities were more than double those of other etiologies. An ALT level of >150 U/l was highly predictive of gallstone etiology independent of gender. Neither amylase nor ALT could differentiate non-biliary etiologies. The combination of amylase and ALT offered no improvement in predicting etiology over each alone.