CLL and Lactate dehydrogenase (LDH)

CLL cells are abnormal B-cells. Part of their DNA instructions that tell the cell to die are mutated, and they don’t work as they should to protect the body from bad bacteria or viruses in the body’s fluids like the bloodstream. CLL is typically slow growing. If the type of CLL is more fast-growing, there will often be higher amounts of LDH in the blood sample.

'"Lactate dehydrogenase (LDH) is a protein that is in almost all cells. It can be released into the blood when a cell is damaged. A high level of LDH is an important sign of cell damage. High levels can be caused by a fast-growing cancer or other health problems. If the LDH level is high, treatment of CLL may be needed soon" (NCCN). 

Other causes of high LDH

As LDH is present in multiple types of cells, high levels of LDH can also be related to other illnesses and not necessarily CLL cells. The patient's doctor will combine other types of tests to review if the levels of LDH are connected to the patient's CLL or not. The other conditions that high LDH levels may indicate include: hemolytic anemia, infections, muscle injury, stroke, heart attack, liver disease, muscular dystrophy, or pancreatitis.

Do I need to prepare for the test? 

Patients don't need to fast or stop any types of medicines before the test like they may be asked to do for other types of blood tests. If there are any specific things the patient needs to do before the test, their doctor will let them know. 

Steps of the LDH test

The test takes a few minutes. It involves taking a small sample of the patient's blood. This is typically done using a needle and syringe, and the blood is usually drawn from a vein in the patient's arm. Before the needle is inserted, the healthcare professional will clean the area with an antiseptic and apply pressure to the vein to help make it easier to access. Once the blood has been collected, it is transferred to a sterile tube and sent to a laboratory for analysis.

After the test

The patient can go home once the test is over and conduct their daily activities as normal. 

The laboratory technician will conduct a Lactate Dehydrogenase assay to measure the amount of LDH in the blood sample. This works by mixing LDH with a dye called WST (water-soluble tetrazolium). The chemical reaction creates a yellow color. The more intense the color, the higher the number of destroyed cells.   

The results of an LDH test can typically be obtained within a few days. The healthcare professional who ordered the test will review the results with the patient and explain what they mean. If the LDH levels are elevated, further testing may be needed to determine the underlying cause.

"For adults, normal LDH levels in the blood are usually 140–280 units per liter (U/L). Doctors use a person’s symptoms to help interpret the data" (Medical News). 

Overall, an LDH test is a simple procedure that can provide important information about a patient's health. By measuring LDH levels in the blood, healthcare professionals can review the state of the CLL and develop appropriate treatment plans for the CLL patient.