Serum type-2 macro-creatine kinase isoenzyme is not a useful marker of severe liver diseases or neoplasia.

We studied the creatine kinase (CK) isoenzyme pattern in sera from 332 patients affected by hepatic cirrhosis and several neoplastic diseases (102 cirrhosis, 36 hepatocarcinoma, 16 metastatic liver tumor, 40 breast cancer, 18 other neoplastic diseases and 120 cases of leukemia or lymphoma) to evaluate both its diagnostic utility for cancer diagnosis and its power as a prognostic index. Type-2 macro CK (mitochondrial creatine kinase) was detected, with no statistical difference in cirrhosis (14%), hepatocarcinoma (16%), metastatic liver tumor (31%), breast cancer (5%) and other tumors (6%). It was not detected in any patient with leukemia or lymphoma. The presence of type-2 macro CK was unrelated to the stage of either cirrhosis or hepatocarcinoma, according to Child and Okuda, respectively, nor was it correlated to serum cytolytic enzyme levels or to gamma-globulin levels. In cirrhotics, type-2 macro CK was not linked to serum levels of the following tumor markers: alpha-fetoprotein, pseudouridine and gamma-glutamyltransferase isoenzymes complexed to low-density lipoprotein. In addition, the atypical band persisted in several patients with cirrhosis monitored for six months who did not show any evidence of evolution toward hepatocarcinoma. Thus, type-2 macro CK has poor diagnostic sensitivity for neoplastic diseases, and lacks prognostic value both in cirrhosis and neoplastic diseases.