Concentración De Dna Del Plasma Como Predictor De Mortalidadr

Available online http://ccforum.com/content/10/2/R60

Research
Vol 10 No 2

Open Access

Plasma DNA concentration as a predictor of mortality and sepsis in critically ill patients
Andrew Rhodes1, Stephen J Wort1, Helen Thomas2, Paul Collinson2 and E David Bennett1
1Intensive

2Department

Care Unit, St Georges's Hospital, London, UK of Chemical Pathology, St Georges's Hospital,London, UK

Corresponding author: Andrew Rhodes, arhodes@sghms.ac.uk Received: 30 Nov 2005 Revisions requested: 6 Jan 2006 Revisions received: 13 Mar 2006 Accepted: 16 Mar 2006 Published: 13 Apr 2006 Critical Care 2006, 10:R60 (doi:10.1186/cc4894) This article is online at: http://ccforum.com/content/10/2/R60 © 2006 Rhodes et al., licensee BioMed Central Ltd. This is an open access articledistributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract
Introduction Risk stratification of severely ill patients remains problematic, resulting in increased interest in potential circulating markers, such ascytokines, procalcitonin and brain natriuretic peptide. Recent reports have indicated the usefulness of plasma DNA as a prognostic marker in various disease states such as trauma, myocardial infarction and stroke. The present study assesses the significance of raised levels of plasma DNA on admission to the intensive care unit (ICU) in terms of its ability to predict disease severity or prognosis.Methods Fifty-two consecutive patients were studied in a general ICU. Blood samples were taken on admission and were stored for further analysis. Plasma DNA levels were estimated by a PCR method using primers for the human β-haemoglobin gene. Results Sixteen of the 52 patients investigated died within 3 months of sampling. Nineteen of the 52 patients developed either severe sepsis or septic shock.Plasma DNA was higher in ICU patients than in healthy controls and was also higher in patients who developed sepsis (192 (65–362) ng/ml versus 74 (46–156) ng/ml, P = 0.03) or who subsequently died either in the ICU (321 (185–430) ng/ml versus 71 (46–113) ng/ml, P < 0.001) or in hospital (260 (151–380) ng/ml versus 68 (47– 103) ng/ml, P < 0.001). Plasma DNA concentrations were found to besignificantly higher in patients who died in the ICU. Multiple logistic regression analysis determined plasma DNA to be an independent predictor of mortality (odds ratio, 1.002 (95% confidence interval, 1.0–1.004), P = 0.05). Plasma DNA had a sensitivity of 92% and a specificity of 80% when a concentration higher than 127 ng/ml was taken as a predictor for death on the ICU.

Conclusion Plasma DNA may bea useful prognostic marker of mortality and sepsis in intensive care patients.

Introduction
Prognosis of patients is important in risk stratification and for efficient use of hospital resources. Predicting the outcome of patients in the intensive care environment is of particular significance, to ensure that resources are used appropriately. Numerous biomarkers have been evaluated to predictmorbidity and mortality in the intensive care setting, although none have proved entirely useful. Examples of such biomarkers include cytokines [1], procalcitonin [2], C-reactive protein [3], brain natriuretic peptide [4] and cardiac troponin I [5]. Interest has recently developed in the use of plasma DNA, or cell-free nucleic acid, as a prognostic marker [6]. Plasma DNA can be defined as fragmentsof DNA that are detectable in the extracellular fluid. There are two types of DNA present in the

circulation; 'free' DNA present in the plasma (which includes DNA packed into nucleosomes from apoptotic cells) or DNA associated with circulating lymphocytes (considered a minor component) [7]. Relatively little is known about free circulating DNA, but numerous studies have established that...