Letter to the Editor Biol Neonate 2005;87:19 DOI: 10.1159/000080890 Cardiac Troponin I Should Be Interpreted with Caution in Paediatric Neonatal Patients Concerning Turker et al.: ‘Cord Blood Cardiac Troponin I as an Early Predictor of Short-Term Outcome in Perinatal Hypoxia’ [Biol Neonate 2004;86:131–137] David C. Gaze Paul O. Collinson Chemical Pathology, St. George’s Healthcare NHS Trust, London, UK Published online: September 14, 2004 Dr. David C. Gaze Chemical Pathology, St George’s Healthcare NHS Trust London, SW17 0RE (UK) Tel. +44 20 8725 5878, Fax +44 20 8682 0744 E-Mail david.gaze@stgeorges.nhs.uk ABC Fax + 41 61 306 12 34 E-Mail karger@karger.ch www.karger.com © 2005 S. Karger AG, Basel 0006–3126/05/0871–0019$22.00/0 Accessible online at: www.karger.com/bon There have been recent reports of using cardiac troponin I (cTnI) as a marker in myocardial damage in neonates [1, 2]. These reports have provided controversial data. During development, a foetal isoform of car- diac troponin T (cTnT) is transiently ex- pressed in skeletal muscle [3], but is down- regulated in adult skeletal muscle tissue [4]. In foetal cardiac tissue, 5 isoforms of cTnT are expressed; however, no skeletal TnT is expressed [5]. During the development of the foetus, the dominant form of troponin I appears as slow muscle skeletal TnI (sTnI), which is down-regulated with concurrent up- regulation of cTnI expression during the first 9 months of life [6]. Therefore, cTnI is not a suitable candidate biomarker of cardiomyo- cyte damage in the neonatal period [7]. This concept has not been addressed by some authors [1, 2]; however, their data may either challenge this notion or may be attrib- utable to an infiltration of maternal blood carrying cTnI into the placenta during partu- rition. It has been shown that circulating maternal cTnI is detectable in mothers who suffer myocardial ischaemia during post- partum haemorrhage [8], but levels of mater- nal cTnI are not affected by either vaginal or caesarean modes of delivery [9]. References 1 McAuliffe F, Mears K, Fleming S, Grimes H, Morrison JJ: Fetal cardiac troponin I in rela- tion to intrapartum events and umbilical artery pH. Am J Perinatol 2004;21:147–152. 2 Turker G, Babaoglu K, Gokalp AS, Sarper N, Zengin E, Arisoy AE: Cord blood cardiac tro- ponin I as an early predictor of short-term out- come in perinatal hypoxia. Biol Neonate 2004; 86:131–137. 3 Sutherland CJ, Esser KA, Elsom VL, Gordon ML, Hardeman EC: Identification of a pro- gram of contractile protein gene expression ini- tiated upon skeletal muscle differentiation. Dev Dyn 1993;196:25–36. 4 Anderson PA, Malouf NN, Oakeley AE, Pagani ED, Allen PD: Troponin T isoform expression in humans: A comparison among normal and failing adult heart, fetal heart, and adult and fetal skeletal muscle. Circ Res 1991;69:1226– 1233. 5 Collinson PO, Boa FG, Gaze DC: Measure- ment of cardiac troponin. Ann Clin Biochem 2001;38:423–449. 6 Sasse S, Brand NJ, Kyprianou P, Dhoot GK, Wade R, Arai M, et al: Troponin I gene expres- sion during human cardiac development and in end-stage heart failure. Circ Res 2003;72:932– 938. 7 Higgins JP, Higgins JA: Elevation of cardiac troponin I indicates more than myocardial ischemia. Clin Invest Med 2003;26:133–147. 8 Karpati PCJ, Rossignol M, Pirot M, Cholley B, Vicaut E, Henry P, Kevorkian JP, Schurando P, Peynet J, Jacob M, Payen D, Mebazaa A: High incidence of myocardial ischemia during postpartum hemorrhage. Anesthesiology 2004; 100:30–36. 9 Koscica KL, Bebbington M, Bernstein PS: Are maternal serum troponin I levels affected by vaginal or caesarean delivery? Am J Perinatol 2004;21:31–34. Downloaded by: McMaster University 198.143.60.1 - 1/19/2016 9:22:47 AM