Lactate Dehydrogenase (LD) Isoenzymes
This test measures the relative percentage of isoenzymes (LD1-5).
Lactate dehydrogenase (LD) is an enzyme found in almost all of the body’s cells, but only a small amount of it is usually detectable in the blood. LD is released from the cells into the bloodstream when cells are damaged or destroyed. Because of this, the LD test can be used as a general marker of injury to cells. In general, the isoenzyme locations are as follows:
- LD-1:heart, red cells, kidney
- LD-2: heart, red blood cells, kidney (lesser amounts than LD-1)
- LD-3:lungs and other tissues
- LD-4:white blood cells, lymph nodes, muscle, liver (lesser amounts than LD-5)
- LD-5:liver, skeletal muscle
Fasting is not required for this test. Take all medications as prescribed.