Evaluation of New Diagnostic Biomarkers in Pediatric Sepsis: Matrix Metalloproteinase-9, Tissue Inhibitor of Metalloproteinase-1, Mid-Regional Pro-Atrial Natriuretic Peptide, and Adipocyte Fatty-Acid Binding Protein

RESEARCH ARTICLE Evaluation of New Diagnostic Biomarkers in Pediatric Sepsis: Matrix Metalloproteinase-9, Tissue Inhibitor of Metalloproteinase-1, MidRegional Pro-Atrial Natriuretic Peptide, and Adipocyte Fatty-Acid Binding Protein Mashael F. Alqahtani1, Craig M. Smith1,2,3, Scott L. Weiss4, Susan Dawson5, Hantamalala Ralay Ranaivo3, Mark S. Wainwright1,2,3* a11111 OPEN ACCESS Citation: Alqahtani MF, Smith CM, Weiss SL, Dawson S, Ralay Ranaivo H, Wainwright MS (2016) Evaluation of New Diagnostic Biomarkers in Pediatric Sepsis: Matrix Metalloproteinase-9, Tissue Inhibitor of Metalloproteinase-1, Mid-Regional Pro-Atrial Natriuretic Peptide, and Adipocyte Fatty-Acid Binding Protein. PLoS ONE 11(4): e0153645. doi:10.1371/ journal.pone.0153645 Editor: Zaccaria Ricci, Bambino Gesù Children's Hospital, ITALY Received: November 9, 2015 Accepted: April 2, 2016 Published: April 18, 2016 Copyright: © 2016 Alqahtani et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper. Funding: This study was supported by a grant from the Medical Research Junior Board Foundation of Ann & Robert H. Lurie Children's Hospital of Chicago. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. 1 Department of Pediatrics, Divisions of Critical Care, Ann & Robert. H. Lurie Children’s Hospital of Chicago, Northwestern Feinberg School of Medicine, Chicago, Illinois, United States of America, 2 Department of Pediatrics, Divisions of Neurology, Ann & Robert. H. Lurie Children’s Hospital of Chicago, Northwestern Feinberg School of Medicine, Chicago, Illinois, United States of America, 3 Ruth D. & Ken M. Davee Pediatric Neurocritical Care Program, Ann & Robert. H. Lurie Children’s Hospital of Chicago, Northwestern Feinberg School of Medicine, Chicago, Illinois, United States of America, 4 Department of Anesthesiology and Critical Care Medicine, The Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America, 5 Department of Pathology and Laboratory Medicine, Swedish Covenant Hospital, Chicago, Illinois, United States of America * Abstract Elevated plasma concentrations of matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), mid-regional pro-atrial natriuretic peptide (mrProANP), and adipocyte fatty-acid-binding proteins (A-FaBPs) have been investigated as biomarkers for sepsis or detection of acute neurological injuries in adults, but not children. We carried out a single-center, prospective observational study to determine if these measures could serve as biomarkers to identify children with sepsis. A secondary aim was to determine if these biomarkers could identify children with neurologic complications of sepsis. A total of 90 patients  18 years-old were included in this study. 30 with severe sepsis or septic shock were compared to 30 age-matched febrile and 30 age-matched healthy controls. Serial measurements of each biomarker were obtained, beginning on day 1 of ICU admission. In septic patients, MMP9-/TIMP-1 ratios (Median, IQR, n) were reduced on day 1 (0.024, 0.004–0.174, 13), day 2 (0.020, 0.002–0.109, 10), and day 3 (0.018, 0.003–0.058, 23) compared with febrile (0.705, 0.187–1.778, 22) and healthy (0.7, 0.4–1.2, 29) (p< 0.05) controls. A-FaBP and mrProANP (Median, IQR ng/mL, n) were elevated in septic patients compared to control groups on first 2 days after admission to the PICU (p <0.05). The area under the curve (AUC) for MMP-9/TIMP-1 ratio, mrProANP, and A-FaBP to distinguish septic patients from healthy controls were 0.96, 0.99, and 0.76, respectively. MMP-9/TIMP-1 ratio was inversely and mrProANP was directly related to PIM-2, PELOD, and ICU and hospital LOS (p<0.05). A-FaBP level was associated with PELOD, hospital and ICU length of stay PLOS ONE | DOI:10.1371/journal.pone.0153645 April 18, 2016 1 / 11 Pilot Study of Diagnostic Biomarkers in Pediatric Sepsis Competing Interests: The authors have declared that no competing interests exist. (p<0.05). MMP-9/TIMP-1 ratio associated with poor Glasgow Outcome Score (p<0.05). AFaBP levels in septic patients with neurological dysfunction (29.3, 17.2–54.6, 7) were significantly increased compared to septic patients without neurological dysfunction (14.6, 13.3– 20.6, 11). MMP-9/TIMP-1 ratios were significantly lower, while A-FaBP and mrProANP were higher in septic patients compared to the control groups. Each biomarker was associated with hospital morbidity and length of stay. These results suggest that these biomarkers merit further prospective study for the early identification of children with sepsis. Introduction Sepsis remains a major cause of morbidity and mortality in pediatrics, with over 75,000 hospital admissions and $4.8 billion in health care costs in the United States annually [1]. The prevalence of pediatric severe sepsis in intensive care units in the United States has increased over the last decade from 6% in 2004 to ~8% in 2012, with a point prevalence of 8% globally [2,3]. The use of biomarkers has the potential to improve early recognition of patients with sepsis. Matrix metalloproteinases (MMPs) are a family of zinc-containing metalloendopeptidases involved in cell remodeling, adhesion, and apoptosis [4]. MMPs are secreted as pro-MMPs, which are activated by a variety of proteinases. MMP activity is highly regulated by interaction with tissue inhibitors of metalloproteinase (TIMPs) and by α-macroglobulins [5]. MMP-9, TIMP-1levels, and MMP-9/TIMP-1 ratio have previously been studied as biomarkers in adult severe sepsis and septic shock [6–8]. Pro-atrial natriuretic peptide (ProANP), the precursor of ANP and primary form of ANP storage in atrial cardiomyocytes, participates in the innate and adaptive immune response. ProANP levels in adults with sepsis are significantly higher in nonsurvivors than in survivors [9]. Circulating levels of adipocyte fatty acid–binding protein (A-FaBP), an intracellular lipid-binding protein, have been linked to severity of atherosclerosis, cardiovascular disease events, ischemic stroke, and sepsis [10]. None of these biomarkers have been evaluated for identification of sepsis in children. Studies in adults have also proposed these biomarkers for the detection of neurologic injury. Increases in MMP-9 and TIMP-1 have been associated with compromise of the blood brain barrier (BBB) [11–15]. MrProANP and A-FaBP have been associated with identification of ischemic stroke and prognosis for recovery [16–18]. The objectives of this study were to investigate the utility of MMP9, TIMP1, mrProANP, and A-FaBP as diagnostic biomarkers in pediatric patients (...truncated)