Classification of contraction bands using immunohistochemistry.

Pathological contraction bands (CBs) are a type of necrosis pattern found in the myocardium. The composition of CB is not well studied. This is because CBs have diverse forms and can be observed in various causes of death. In pathology fields, CBs are classified artifactual CB and CB necrosis. We have identified different forms of CB by examining the expression and distribution of complement component C9 (CCC9) and Sirtuin1 by immunohistochemistry in the myocardium of patients who died because of different causes of death. We used cardiac tissues with CB from 30 forensic autopsy cases in our department from the last 2 years. We excluded the cases that had very little CB. We found that our CB classification based on expression levels of both CCC9 and Sirtuin1 correlated well with the agonal situation, including high temperature, myocardial infarction, cardiopulmonary resuscitation, and hypothermia. On the basis of these results, we here advocate a classification scheme based on immunohistochemistry. Furthermore, we found that CB necrosis could be detected using immunostaining with CCC9. Using our classification scheme, it will be possible to more accurately research each type of CB and the causative mechanisms.