Acute Pancreatitis. Biomarkers and radiology assessment

Sammanfattning: Background: Acute pancreatitis (AP) is a common and potentially severe disease. Early identification of severity grade is crucial for the outcome of the patient. For study approaches and comparison of inter-institutional data the AP patients need to be uniformly classified.The aims of this thesis were to investigate the early stratifiation capacity of biomarkers in AP and to assess the morphological criteria of the revised Atlanta classification (RAC).Methods: The studies are based on two cohorts. The first cohort encompasses 285 AP patients from six European centers. All patients had at least one CT performed during the first three months after onset of disease. In total 388 CTs were scored by six local radiologists and one central expert radiologist according to the morphological criteria of the RAC. The results were compared using interobserver agreement levels.The second cohort was enrolled at Skåne University Hospital Malmö. Blood samples from 232 AP patients were collected upon admission and daily as long as the pancreatic amylase was elevated. Exact time for onset of pain was requested at inclusion. From the serum samples selected biomarkers were analysed and compared with severity outcome of the patients.Results: In general the interobserver agreement between the local radiologists and the central expert radiologist was good regarding clinically important radiological features. Two areas of interpretation inconsistensies were identified: presence of extrapancreatic necrosis and necrotic debris of peripancreatic or pancreatic collections.In biomarker analysis we found that cut-off levels for severe disease established by previous studies did not reach sufficient stratification capacity in our cohort. However, a combination of IL-6 and CRP (with cut-off levels 23.6 pg/ml and 57 mg/L respectively) demonstrated good potential in differentiating mild from non-mild (moderately severe and severe AP according to the RAC) disease. When investigating the temporal development of biomarkers we found that the mean values of IL-6 and IL-1β increased significantly in the severe group between 0-24 and 25-48 hours after onset of disease. Additionally, differences in mean values (i.e. delta-values) varied significantly between the mild and severe group for IL-6, IL-1β and IL-10.Conclusions: Our results indicate that radiologists are unfamiliar with some of the new morphological categories of the RAC, potentially resulting in inconsistent reporting of necrotising pancreatitis. Among prognostic biomarkers in AP, in general CRP, IL-6, IL-1β and IL-10 demonstrated superior stratification capacity in our cohort.