Abstract

Background: Morphological diagnosis of advanced myocardial infarction is not difficult; however its early phases usually remain indistinguishable in a macroscopic examination, and are often invisible under the microscope or hard to interpret unequivocally. The aim of this paper is to determine the usefulness of immunohistochemical staining to detect C1q, C9 and C5b-9, in the morphological diagnosis of an early myocardial infarction. Data and methodology: The experimental group consisted of tissue samples with suspected myocardial infarction unconfirmed in a routine morphological diagnosis (n=22). The control group consisted of myocardium samples without salient pathologies (n=10). Immunohistochemical reactions were conducted using a detection system based on enzymatic peroxidase reaction. The IHC reaction assessment was conducted based on halfquantitative Immunoreactive Score scale. Results: Morphological analysis of preparations based on haematoxylin and eosin staining in the experimental group did not show important changes that would denote myocardial infarction. The immunohistochemical reaction for C1q and C9 was intense, whereas in case of C5b-9 it was weak in all examined myocardium samples of the experimental group. In the control group no positive immunohistochemical reaction was observed. Conclusion: The results can indicate that immunohistochemical reactions to detect C1q and C9 can be a morphological indicator of early myocardial infarction. Reactions to detect C5b-9 are not specific to early myocardial infarction.

Keywords: Myocardial infarction; Morphological diagnosis; Complement components