[Serum lactate dehydrogenase isoenzyme spectrum in malignant neoplasm patients].

The isoenzymic spectrum of lactate dehydrogenase of blood sera was studied in 170 patients with malignant and benign tumors, chronic inflammatory lesions and in healthy persons. The characteristic changes in patients with malignant tumors were as follows: an increased activity of slow fractions and a decreased one in rapidly migrating fractions. The level of the 5th isoenzyme activity and the frequency of its increased activity in serum correlated well with the degree of cancer spread. The determination of a percentual content of the isoenzyme may be used as a supplementary test for diagnosing metastic involvement of the liver. The examination of the serum lactate dehydrogenase spectrum in patients with benign tumors and chronic inflammatory disease revealed no changes characteristic of malignant neoplasms.