To the Editor.—
Mitochondrial creatine kinase (CK-MIT) is an isoenzyme of creatine kinase thought to be of mitochondrial origin that migrates cathodically to the MM fraction on electrophoresis. Bark, in his report entitled "Mitochondrial Creatine Kinase" (1980;243:2058), observed CK-MIT in eight patients, most of whom suffered acute myocardial infarction. All experienced shock with poor tissue perfusion, and six of the eight died within a brief period. He concluded that the presence of CK-MIT indicated severe tissue damage, particularly myocardial, and poor prognosis.We recently detected apparent CK-MIT in two patients without heart disease or shock, both of whom had metastatic carcinoma.
Report of Cases.—Case 1.—
A 63-year-old man complained of low-back pain, night sweats, weakness, and a 12-kg (27-lb) weight loss over several weeks. An examination led to an exploratory laparotomy, at which time multiple nodules were found in the liver. Biopsy findings indicated malignant lymphoma. Although his
Stewart TW, Roper BK. Mitochondrial Creatine Kinase in Cancer Patients. JAMA. 1983;249(9):1148. doi:10.1001/jama.1983.03330330030011