Studies on improving the predictive markers for the diagnosis of acute pancreatitis after Endoscopic Retrograde Cholangiopancreatography (ERCP)

Endoscopic Retrograde Cholangiopancreatography (ERCP) is a widely performed gastroenterological procedure often accompanied by the development of acute pancreatitis post-ERCP - the current literature quoting an incidence between 0% and 39.5%. Because acute pancreatitis can be a very serious outcome, sometimes leading to death, a method for predicting poor outcomes post-ERCP would be an advantage to the clinicians and patients. Described below is the development of two algorithms with a strong capacity to predict poor outcomes post-ERCP. In addition to assessing a battery of common laboratory blood tests, this study also took the opportunity to study a recently described but still research-based analyte, the enzymatic activity of the trypsin bound to the serine protease inhibitor alpha- 2- macroglobulin ( a2M) complex called Macroglobulin-Trypsin complex-Like Substance (MTLS), high levels of MTLS have been identified in patients who developed acute pancreatitis post-ERCP. It was hypothesized that MTLS might be a useful, novel indicator of patients at risk of development of post-ERCP pancreatitis. Three separate studies were carried out. The first was a retrospective study of 72 patients presenting for ERCP to the collaborating gastroenterologist, and the second was a prospective study involving 29 more patients. The retrospective study involved the analysis of previously collected blood specimens pre-ERCP and post-ERCP. On the pre-ERCP specimens 22 laboratory tests were performed to test the haematological, biochemical and coagulation status of the patients. Lipase, a classical diagnostic marker for acute pancreatitis, was measured on the patient's post-ERCP samples. From this study sophisticated statistical analysis was based on a 2-step process - Factor Analysis with Principal Component Extraction followed by Discriminant Analysis on the key components identified by Factor Analysis - in order to develop a predictive algorithm for poor outcomes post-ERCP. The objective of the second, prospective, trial was to ...