Markers for predicting severity and progression of acute pancreatitis

Several tools have been developed for severity stratification in acute pancreatitis. They include single biochemical markers, imaging methods, and complex scoring systems, all of which aim at an early detection of severe acute pancreatitis to optimise monitoring and treatment of patients as early as possible. Among single biochemical markers, C-reactive protein (CRP) remains the most useful. Despite its delayed increase, peaking not earlier than 72 h after the onset of symptoms, it is accurate and widely available. Many other markers have been evaluated for their usefulness, and for some of them very promising data could be shown. Among them interleukin 6 seems to be the most promising parameter for use in clinical routine. For the detection of pancreatic infection, procalcitonin is the most sensitive, and can be used as an indicator for the need for fine-needle aspiration of pancreatic necrosis.

Regarding imaging, contrast-enhanced computed tomography is still the reference method for the detection of necrotising acute pancreatitis. Pancreatitis-specific scoring systems have been shown to be of value for the prediction of severity and progression of acute pancreatitis, but cannot be applied any earlier than 48 h after admission to hospital. The APACHE-II score has not been developed specifically for acute pancreatitis and is rather complex to assess, but has been proven to be an early and reliable tool. Indication, timing and consequences of the methods applied need to be carefully considered and incorporated into clinical assessments to avoid costs and harm to the patient.

Introduction

Acute pancreatitis (AP) can still – despite optimised treatment – be a life-threatening illness. Although in the majority of cases the disease is relatively mild and associated with low mortality, 10–25% of patients present with a severe course of the disease and significant mortality. In 1992 the Atlanta classification of acute pancreatitis distinguished and defined mild and severe acute pancreatitis, based on clinical, laboratory and anatomical/pathological changes of the pancreatic gland.¹ Distant extrapancreatic organ failure and the development of local or systemic complications determine the course and outcome of severe acute pancreatitis.

Two peaks of mortality in acute pancreatitis are recognised: early (within the first 2 weeks) and late. The mortality rate is strongly associated with the degree of multi-organ failure, but the causes in early and late mortality are distinct. The reported relative mortality rates in the early phase of AP range from about one third to more than a half of the deaths,2, 3, 4 and are due to the systemic inflammatory response. Complications due to sepsis, in most cases caused by infection of pancreatic necrosis, also result in multi-organ dysfunction syndrome (MODS) and are the major cause of deaths in the late course of the disease.2, 3, 5, 6, 7 It is crucial to recognise patients at risk of developing severe acute pancreatitis at an early stage in order to optimise therapy and intensive monitoring. Several tools have been introduced and tested for early and easy stratification of severity in acute pancreatitis; they include clinical signs, biochemical markers, imaging methods, and complex scoring systems.

This review gives a critical up-to-date overview on current knowledge on markers for predicting severity and progression of acute pancreatitis, with special emphasis on those applicable in current clinical routine.