A study of salivary lactate dehydrogenase isoenzyme levels in patients with oral leukoplakia and squamous cell carcinoma by gel electrophoresis method

CONTEXT: The enzyme lactate dehydrogenase (LDH), which is found in almost all the cells of body tissues, can be separated into five fractions and the isoenzyme pattern is believed to vary according to the metabolic requirement of each tissue. LDH concentration in saliva, as an expression of cellular necrosis, could be considered to be a specific indicator for oral lesions that affect the integrity of the oral mucosa. AIM: The present study was designed to evaluate salivary LDH isoenzyme pattern in oral leukoplakia (OL) and oral squamous cell carcinoma (OSCC) and to correlate between LDH isoenzyme levels and histopathologic grading in selected cases of OL and OSCC. MATERIALS AND METHODS: Clinically diagnosed 30 cases each of OL and OSCC were selected for the study and 30 healthy individuals of comparable age served as control. Unstimulated whole saliva was aseptically collected and was processed immediately for LDH isoenzymes measurement by agarose gel electrophoresis. Biopsy specimen obtained was processed and stained by hematoxylin and eosin. Sections of OL and OSCC cases were scrutinized histopathologically and appropriately graded for epithelial dysplasia and differentiation of carcinoma respectively. STATISTICAL ANALYSIS USED: Two sample t test for testing the significance of difference between two group means was used. RESULTS AND CONCLUSION: The present salivary analysis for LDH isoenzyme reveals an overall increased salivary LDH isoenzyme level in OL and OSCC cases and a significant correlation between levels of salivary LDH isoenzymes and histopathologic grades of dysplasia in OL and OSCC. Salivary analysis of LDH will definitely provide the clinician and/or the patient himself with an efficient, non invasive and friendly new tool for diagnosis and monitoring of oral precancer and cancer.