Increased levels of CSF LDH are associated with several pathologies affecting the brain and CNS notably:-
Trauma – brain haemorrhagic necrosis
Infection – encephalitis, meningitis (significantly elevated in bacterial meningitis), progressive leukoencephalopathy
Neoplastic disorders – metastatic brain disease, metastases to spinal cord, meningioma
Auto-immunity – e.g multiple sclerosis
Lactate dehydrogenases exist in four distinct enzyme classes. Two of them are cytochrome c-dependent enzymes the other two are NAD (P)-dependent enzymes with each acting on either D-lactate or L-lactate. Lactate dehydrogenase catalyzes the interconversion of pyruvate and lactate with concomitant interconversion of NADH and NAD+. It converts pyruvate, the final product of glycolysis to lactate when oxygen is absent or in short supply and it performs the reverse reaction during the Cori cycle in the liver. At high concentrations of lactate, the enzyme exhibits feedback inhibition and the rate of conversion of pyruvate to lactate is decreased.
150 – 500 U/L
CSF sample collected into a plain universal container.
Charing Cross Hospital