tissue breakdown releases LDH, and therefore LDH can be measured as a surrogate for tissue breakdown such as occurs in haemolytic anaemia, rhabdomyolysis and tumour necrosis and is also raised in many other conditions
In rare cases, a mutation in the genes controlling the production of lactate dehydrogenase will lead to a medical condition known as lactate dehydrogenase deficiency
LDH is involved in tumor initiation and metabolism
LDH expression can act as a general marker in the prognosis of cancers. Expression of LDH5 and VEGF in tumors and the stroma has been found to be a strong prognostic factor for diffuse or mixed-type gastric cancers
elevated LDH can be an early marker of dysgerminoma
HIV / AIDS patients as a non-specific marker for pneumonia due to Pneumocystis jirovecii (PCP) or histoplasmosis
lung disease
pleural fluid LDH levels to differentiate exudate vs transudate
usual criterion (included in Light's criteria) is that a ratio of fluid LDH versus upper limit of normal serum LDH of more than 0.6 or 2⁄3 indicates an exudate, while a ratio of less indicates a transudate