Diagnostic Use of Serum Deoxyribonuclease I Activity as a Novel Early-Phase Marker in Acute Myocardial Infarction

Abstract

Background-The delayed release of serum cardiac markers such as creatine kinase isoenzyme MB and equivocal early electrocardiographic changes have hampered a diagnosis of acute myocardial infarction (AMI) in the early phase after its onset. Therefore, a reliable serum biochemical marker for the diagnosis of AMI in the very early phase is desirable. Methods and Results-Serum samples were collected from the patients with AMI, unstable angina pectoris, stable angina pectoris, and other diseases. Levels of serum deoxyribonuclease I (DNase I) activity in the patients were determined. An abrupt elevation of serum DNase I activity was observed within approximately 3 hours of the onset of symptoms in patients with AMI, with significantly higher activity levels (21.7Ϯ5.10 U/L) in this group compared with the other groups with unstable angina pectoris (10.4Ϯ4.41 U/L), angina pectoris (10.8Ϯ3.70 U/L), and other diseases (9.22Ϯ4.16 U/L). Levels of the DNase I activity in serum then exhibited a marked time-dependent decline within 12 hours and had returned to basal levels within 24 hours. Conclusions-We suggest that serum DNase I activity could be used as a new diagnostic marker for the early detection of AMI. Key Words: myocardial infarction Ⅲ enzymes Ⅲ diagnosis I n patients with acute myocardial infarction (AMI), the infarct size is an important determinant of both mortality and morbidity. 1 When revascularization and thrombolytic therapies are initiated rapidly, there is a greater potential for reduction in the infarct size. The release of cardiac proteins from injured cardiac tissue into plasma has been used as a diagnostic marker for the exclusion or confirmation of AMI. 2 However, it is often difficult to make a diagnosis of AMI in the very early phase, ie, within 3 hours of onset. This is partly due to a delay in the appearance in the serum of the biochemical markers specific for myocardial damage. 2,3 Deoxyribonuclease I (DNase I, EC 3.1.21.1), one of the well-known enzymes, was the first enzyme to be recognized as specific for DNA. 4 One of its proposed roles is DNA breakdown during apoptosis. 5 DNase I has been detected in human myocardium, and it has been reported that the activity level increases in heart failure due to idiopathic dilated cardiomyopathy. 6 However, the association between serum DNase I activity level and coronary heart disease (CHD) has not yet been clarified. In the present study, we assessed the serum DNase I activity in patients with AMI and related CHD and found that there is a specific elevation of serum DNase I activity in the very early stages of AMI. Methods Patients and Sample CollectionWe assessed 53 consecutive Japanese patients with AMI admitted to our hospitals between September 2002 and May 2003. The clinical diagnosis of AMI and unstable angina pectoris (UAP) was made according to the European Society of Cardiology/American College of Cardiology Committee criteria. 7 The mean lapse time between the onset of symptoms and hospital admission was 10.7Ϯ13.8 hours. Emergent coronary ang...

Low Circulating Levels of Mitochondrial and High Levels of Nuclear DNA Predict Mortality in Chronic Heart Failure

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Coronary Neutrophil Extracellular Trap Burden and Deoxyribonuclease Activity in ST-Elevation Acute Coronary Syndrome Are Predictors of ST-Segment Resolution and Infarct Size

“…39 DNase activity is upregulated within the first 3 hours of ACS. 40 A single-nucleotide polymorphism in the DNase-1 gene, which leads to impaired DNase activity, was independently associated with a higher incidence of myocardial infarction. 41 In animal models, medicinal DNase was successfully used to prevent venous thrombogenesis.…”

Ultrasound-Responsive Polymer-Coated Microbubbles That Bind and Protect DNA

“…As described in the Materials and Methods section, the microbubble dispersions were exposed to 200 U/L rhDNase-I, which is about 20-fold higher than the DNase activity found in human blood. 32 Figure 7 shows the gel electrophoresis results on pDNA released from pDNA-loaded microbubbles (by NaCl) that were exposed to DNase-I. As shown in Figure 7A, DNase-I degrades both free pDNA (lane 3) and pDNA in the presence of uncoated microbubbles (lane 6).…”