Dityrosine, a protein product of oxidative stress, as a possible marker of acute myocardial infarctions

The verification of acute and lethal myocardial infarctions remains a crucial problem in the daily routine work of legal medicine. In order to enhance the possibilities in micromorphologic diagnostics, we investigated if dityrosine as a protein product of oxidative stress can be detected in myocardial tissue after an infarction and, if so, if it occurs early enough to be used in the diagnosis of infarctions with a short survival time. We examined tissue samples from 61 autopsy cases (37 male, 24 female) with verified or suspected infarctions as well as 11 control cases (7 male, 4 female). Immunohistochemical staining was performed for dityrosine and the established markers fibronectin and C_5b-9. Positive staining for dityrosine was obtained in nearly all cases with infarctions aged 4 h to 2 weeks. Single positive results were obtained in cases with older (up to 2 months) or assumedly very fresh (up to 4 h) infarctions. Furthermore, single positive results with a different staining pattern were obtained in the control group. We concluded that dityrosine as a marker of oxidative stress can be detected after infarctions and might occur early enough to be helpful in the diagnosis of infarctions with a short survival time. Though dityrosine does not seem to be specific for infarctions, the different staining patterns enable a differentiation.