Abstract

Background: Lactate dehydrogenase (LDH, L-lactate, NAD+ oxidoreductase, EC1.1.1.27) is a
family of at least six NAD + -dependent isoenzymes (LD1-LD5 and LD6/LDX). It is recognized
as being one of the most common enzymes in nature. It belongs to the class of oxidoreductases
and it is characteristic for the final stage of anaerobic glycolysis. Aim of the study: To evaluate
the efficacy of lactate dehydrogenase as an indicator of liver tumors. Materials and methods:
The present study was performed in the Department of Biochemistry, Kidwai Institute of
Oncology, Bengaluru, Karnataka, India. For the study, a total of 100 patients were selected. The
age of the patients ranged from 18 to 40 years. Briefly, 20 μL of each patient serum was mixed
first with 1000 μL of buffer (pH 7.35) supplied by the manufacturing company and incubated for
1-5 min at 25 °C. A volume of 250 μL of substrate that composed of nicotinamide-adenine
dinucleotide (0.75 mmol/L) and sodium azide (0.095%) was added to the mixture. After mixing,
the absorbance at 340 nm was read by UV-visible spectrophotometer (CECiL, CE 1021,
England) after 1 min. CK levels were assayedaccording to Humazym M-test as described by the
instructions of the produced company. Results: It was observed that number of male patients
was 45 and number of female patients was 55. The mean age of the participating patients was
31.35 years. High LDH level are observed in large number in females (30 patients) than in males
(24 patients). Increased LDH levels in blood could not be indicator for liver diseases only, but it
may be resulted from damage in muscular tissues. 30 females and 24 males who possessed high
level of LDH were investigated for CK, as monitor for muscular injury. Additionally, 6 male
patients and 9 female patients showed increased levels of LDH and CK in their blood which
means they may sever from muscular damage. Conclusion: From the results of the present study,
this can be concluded that LDH can be used as a good biomarker for diagnosis of liver,
muscular and even cancer diseases. There is little variable between males and females in the
elevated values of LDH. Patients with normal values of CK and high level of LDH suggested to
have unidentified cancer disease, except liver cancer, and for that other specific tests are
required.