Modifications of lactate-dehydrogenase-isoenzyme serum levels in breast diseases
Mazzarino, C.; Pisana, C.; Morello, G.; Di Benedetto, A.
Bollettino della Societa Italiana di Biologia Sperimentale 53(7): 569-574
1977
ISSN/ISBN: 0037-8771 PMID: 911514 Document Number: 123411
While in the human mammary carcinoma there is no significant increase in total serum lactic dehydrogenase [LDH] activity until advanced stages, there are early net increases in serum LDH isoenzyme subtypes 4 and 5. These are macromolecules made up of type M chains and migrate electrophoretically toward the cathode. Isoenzyme 5 values are more than triple those of controls. In cases of fibrocystic mastopathy a lower increase in the same isoenzymes is noted. It appears that this enzyme pattern, which can be demonstrated by a technique perfected by M. Kahn in 1971, is of significant therapeutic and prognostic value, even after surgery or chemotherapy. LDH is composed of 4 polypeptide chains. Each monomer comes from 1 or 2 genetic sites called M and H. Isoenzyme 1 (H4) predominates in the heart, while isoenzyme 5 (M4) is derived from muscle tissue. In neoplasia the pattern of the 5 isoenzymes in the serum is modified. In mammary cancer there is an increase in the isoenzymes with a greater percentage of chain M (LDH5, LDH4 and LDH3). These can be separated by electrophoresis, using a special technique.