Free serum DNA is an early predictor of severity in acute pancreatitis Ivan Gornik a , Jasenka Wagner b , Vladimir Gašparović a , Gordan Lauc c,d , Olga Gornik c, ⁎ a Division of Emergency and Intensive Care Medicine, Department of Medicine, Rebro University Hospital, Kišpatićeva 12, Zagreb, Croatia b Department of Chemistry and Biochemistry, University of Osijek, Medical School, Huttlerova 4, Osijek, Croatia c Department of Biochemistry and Molecular Biology, University of Zagreb, Faculty of Pharmacy and Biochemistry, Ante Kovačića 1, 10 000 Zagreb, Croatia d Genos d.o.o., Trg. Lj Gaja 6, 31000 Osijek, Croatia Received 4 May 2008; received in revised form 9 September 2008; accepted 26 September 2008 Available online 1 November 2008 Abstract Objectives: Cell-free DNA has been investigated as a diagnostic marker in many diseases, including acute conditions. Our hypothesis was that in acute pancreatitis free serum DNA correlates with the extent of pancreatic necrosis and that it may be an early marker of severity. Design and methods: Free DNA was measured in sera from 30 patients with acute pancreatitis at admission, on the first, fourth and seventh day following admission. Results: On the first day following admission patients who would develop severe pancreatitis had significantly higher serum DNA levels than those with mild disease (median 0.271 ng/μL vs. 0.059 ng/μL respectively; P b 0.001). This parameter showed very good characteristics as a potential severity predictor (area under ROC curve 0.97). Free serum DNA was in correlation with the extent of pancreatic necrosis. Conclusions: Free serum DNA correlates with the extent of pancreatic necrosis and is a potential early marker of severe acute pancreatitis. © 2008 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved. Keywords: Acute pancreatitis; Cell-free DNA; Prognostic marker; Pancreatic necrosis Introduction Acute pancreatitis (AP) is usually a self limiting, short lasting mild disease, but in some 20% of cases the disease takes a severe course with systemic inflammatory response, local and systemic complications and high mortality rates despite treatment. Early identification of severe AP is still one of the main problems in clinical practice [1]. Clinical judgment alone has good specificity, but low sensitivity, since it misses many severe cases. Development of a method for early recognition of severe cases is a major issue, since early treatment may reduce morbidity and mortality [2]. Ranson and colleagues developed the first scoring system that was used for predicting severity of AP more than 30 years ago [3]. Since than, other multifactorial systems, like Glasgow (Imrie) [4] score, have been developed specifically for that purpose. Some non-specific scores, like acute physiology and chronic health evaluation (APACHE) II [5] have also been used as predictors of disease course as well as single biochemical parameters [6]. These mainly include markers of inflammation such as C-reactive protein (CRP), interleukin (IL) 6, IL-8, TNF-alpha, and HLA-DR expression on monocytes [7,8]. Of those, CRP measurement is the most widely accepted single test severity marker [9], but it usually rises only after second day of disease and is not specific. Abdominal CT, performed during first days of disease also has predictive significance in AP [10]. Other parameters and scoring systems have also been investigated, usually with small additional predictive value or none at all. Circulating (cell-free) DNA in serum or plasma has been investigated as a non-invasive diagnostic tool in a variety of clinical conditions [11]. The investigations have mainly been focused on autoimmune diseases [12], cancer research [13,14] and prenatal diagnostics of foetal diseases [15–17]. However, elevated levels of circulating DNA have also been reported in acute medical conditions such as trauma [18], stroke [19], myocardial infarction [20] and sepsis [21] and explored as indicators of disease severity and predictors of mortality. New molecular methods, primarily quantitative real time PCR make Available online at www.sciencedirect.com Clinical Biochemistry 42 (2009) 38 – 43 ⁎ Corresponding author. Fax: +385 1 4856 201. E-mail address: ogabela@pharma.hr (O. Gornik). 0009-9120/$ - see front matter © 2008 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved. doi:10.1016/j.clinbiochem.2008.09.121