Elevação da isoenzima mb da creatinaquinase fora de um contexto de enfarte agudo do miocárdio.

Abstract

The increased serum level of the MB isoenzyme of creatine kinase is a very useful test for the diagnosis of acute myocardial infarction. However, there are several situations of false positives for this test that are scarcely mentioned in the standard medical references. We report a case of prostate carcinoma with a high serum creatine kinase BB fraction. The immunoinhibition method may cause a false increase in creatine kinase MB in this situation, which in the case presented suggested the diagnosis of myocardial infarction. We discuss patient diagnosis, laboratory methods for the determination of creatine kinase and the technical reasons for the false positives.