Leukemoid reaction and chronic myeloid leukemia (CML) can both cause a high white blood cell count. However, they typically increase the levels of different types of white blood cells.
Granulocytes provide a broad immune defense for the body. In comparison, neutrophils are a type of granulocyte that focuses on fighting infections and healing wounds.
Keep reading to learn more about the similarities and differences between leukemoid reaction and CML.
A leukemoid reaction involves having an elevated white blood cell count, ranging from 50,000–100,000 white blood cells per cubic millimeter. This count is due to an increased number of neutrophils, which help the body fight bacterial, viral, and fungal infections. They also support the body to heal wounds.
The causes of the high white blood cell count can
The symptoms will vary depending on the cause.
Older research reports that the condition is rare and requires careful diagnosis. This process involves ruling out blood cancers, such as CML.
A thorough check of a person’s medical history may highlight a factor that increases their risk of leukemoid reaction, such as a recent infection. Further testing is sometimes necessary to differentiate a leukemoid reaction from CML. Such tests may include:
- white blood cell count and differential count
- leukocyte alkaline phosphatase score
- peripheral blood smear
- vitamin B12 level
- bone marrow biopsy
CML is a blood cancer in which having excess stem cells in the bone marrow increases white blood cell counts to abnormal levels. Leukemoid reaction also involves a high white blood cell count, which is a similarity between the two conditions.
Leukemoid reaction and CML both elevate white blood cells levels, but each condition affects a different type of white blood cell. Leukemoid reactions cause an increase in neutrophils, whereas CML
Additionally, the excess neutrophils in a leukemoid reaction are mostly mature cells that can function normally. The granulocytes in CML are abnormal and unable to function properly.
Another difference between these conditions is their symptoms. A person with a leukemoid reaction does not typically experience the symptoms of leukemia. However, someone with CML can experience these symptoms, which include:
- loss of appetite
- bleeding gums
- unexplained weight loss
- night sweats
- breathing problems
- bone and joint pain
- swollen lymph nodes
- frequent infections
A further difference between these conditions is their causes.
Leukemoid reactions stem from medical conditions outside of the bone marrow and are not necessarily the result of cancer. However, CML is the result of cancer that starts in the bone marrow.
There are also several differences in how doctors interpret laboratory results for each condition.
According to older research, the primary difference appears in the peripheral blood test. A leukemoid reaction may be present if the test shows mature neutrophils with a marked left shift. A left shift indicates the presence of immature neutrophils in the blood.
A diagnosis of CML may cause the peripheral blood test to show increased immature basophils and eosinophils.
Leukemoid reactions and CML are serious conditions that always require medical attention. People who experience signs or symptoms of either condition should contact a doctor right away.
Doctors use diagnostic tests to identify the cause of the symptoms. In some cases, they will prescribe treatments for the underlying cause, which could be cancer.
The American Cancer Society reports that, in a large trial,
Leukemoid reaction and CML both lead to increases in the number of white blood cells in the blood. However, they affect different white blood cell types. Leukemoid reactions cause an increase in neutrophils, whereas CML increases granulocytes. These cells have similar but different functions.
A key distinction is that CML is the result of blood cancer, which typically begins in the bone marrow. However, leukemoid reactions can have several causes, such as infections. These differing causes produce different symptoms and require different treatment approaches by doctors.