With the exception of blood from neonates or pregnant women, the appearance of immature granulocytes in the peripheral blood indicates an early-stage response to infection, inflammation or other stimuli of the bone marrow. Being able to detect IG quickly and reliably opens doors to new diagnostic possibilities for related disorders.
Current areas of research regarding the diagnostic significance of circulating immature granulocytes focus on the early and rapid discrimination of bacterial from viral infections, particularly in children (e.g. recognising bacterial infection in neonates), and the early recognition of bacterial infection and sepsis in adults, which is of particular importance for intensive care patients.
Valuable information for immediate action – at no additional cost
IG counts are relevant especially for patients who are highly susceptible to infections because of a suppressed immune system and because the increased IG count indicates the severity of the early innate immune response. In addition to patients with general infections and inflammations, clinicians will pay particular attention to:
- Patients from the intensive care unit,
- Patients undergoing chemotherapy,
- Patients suffering from HIV/AIDS.
The high accuracy of our IG counting method provides a valuable tool for physicians for concluding diagnoses or requesting further patient investigation. On conventional haematology analysers, the presence of immature granulocytes is usually flagged and requires a microscopic review. Our automatic IG counting reduces this review rate significantly. Moreover, results including the presence and concentration of IGs become available within minutes – and are included in the complete CBC+DIFF analysis, making it a valuable sixth subpopulation of the white blood cells.
Benefits
Sysmex devices are especially powerful as we provide an actual IG count [# and %] and not just a ‘flag’ for immature granulocytes. Automated IG counts generally mean you can reduce the number of blood smears and the workload by manual counting.
Using IG
The IG count alone does not let you predict sepsis or infection. However, it can support diagnosis and prediction together with other parameters such as cytokines, interleukins and CRP. It is more useful as a monitoring parameter when the patient has already been diagnosed correctly and is under treatment.
For blood samples of unknown patients with an increased IG count, blood smear preparation is still recommended. In known patients, an automated IG count can avoid the manual review while therapy monitoring infections or inflammation.
The IG count of paediatric patients, especially premature neonates or neonates younger than seven days, has to be taken with care due to their immature immune systems and the greater number of immature cells in the circulating blood.
Granulocytes are white blood cells (WBCs) that have small granules or particles. These granules contain numerous proteins that are responsible for helping the immune system fight off bacteria and viruses.
Granulocytosis occurs when there are too many granulocytes in the blood.
An abnormally high WBC count usually indicates an infection or disease. An increase in the number of granulocytes occurs in response to infections, autoimmune diseases, and blood cell cancers.
Granulocytosis is closely related to chronic myeloid leukemia (CML) and other bone marrow disorders.
Granulocytes form and mature in the bone marrow — the spongy tissue found inside many of your bones.
Bone marrow contains stem cells, which eventually develop into different types of blood cells, including granulocytes.
When granulocytes leave the bone marrow, they circulate through the bloodstream and respond to signals from the immune system. Their role is to attack foreign substances that cause inflammation or infection.
Neutrophils, eosinophils, and basophils are the key types of granulocytes.
Neutrophils typically account for 40 to 70 percent of all WBCs. Up to 4 percent of your WBCs may be eosinophils, while basophils account for under 2 percent.
The presence of granulocytes in the bloodstream is normal. These WBCs are part of your immune system and help defend your body against harmful bacteria and viruses.
However, a high number of granulocytes in the blood isn’t normal and usually indicates a health problem.
Bone marrow disorders are a major cause of granulocytosis. The following bone marrow disorders can cause granulocytosis:
- CML, a cancer of the white blood cells
- primary myelofibrosis, a blood cancer that causes a buildup of scar tissue in the bone marrow
- polycythemia vera, a disorder in which the body produces too many red blood cells (RBCs)
- primary thrombocythemia, a disorder in which the body produces too many platelets
Granulocytosis can also be seen in combination with:
- a bacterial or bloodstream infection
- sepsis
- kidney failure
- heart attack
- inflammatory bowel disease (IBD)
- some autoimmune diseases, including rheumatoid arthritis
- metastatic cancer
- extreme physical or emotional stress
- a burn injury
- smoking
- the use of certain medications, including corticosteroids
Granulocytosis is the main feature of CML, a rare blood cell cancer that begins in the bone marrow.
CML causes a buildup of underdeveloped granulocytes in the bone marrow and bloodstream.
Normally, bone marrow produces immature stem cells in a controlled way. These cells then mature and turn into RBCs, WBCs, or platelets. Your RBCs carry oxygen and nutrients, your WBCs help fight infection and inflammation, and your platelets enable the blood to clot.
In people with CML, this process doesn’t work correctly. Immature granulocytes and other WBCs begin to form and multiply uncontrollably, crowding out all the other types of necessary blood cells.
People with CML may experience the following symptoms:
- abnormal bleeding
- frequent infections
- fatigue
- loss of appetite
- pale-looking skin
- pain below the ribs on the left side of the body
- excessive sweating during sleep
CML is most common among older adults, but it can occur in people of any age. It also affects men more than women.
People who have been exposed to radiation, such as radiation therapy for the treatment of cancer, have a higher risk of developing CML.
Granulocytosis is normally diagnosed with a physical examination and a complete blood count (CBC). The CBC is a test that measures the amount of RBCs, WBCs, and platelets in your blood.
Abnormal numbers of these cells can indicate that you have an underlying medical condition.
The CBC involves giving a sample of blood. You’ll have blood drawn from a vein in your arm. The blood sample will then be sent to a lab for analysis. As with any blood draw, there’s a small chance of discomfort, bleeding, or infection.
Reference ranges will vary by lab. However, you typically have the following amount of granulocytes in your blood, according to Lab Tests Online:
- Neutrophils: 1,800–7,800 cells per microliter (mcl) of blood
- Eosinophils: 0–450/mcl of blood
- Basophils: 0–200/mcl of blood
Amounts that are higher than this may indicate granulocytosis.
Granulocytosis is a symptom of other conditions. It’s not considered a separate disease, and it usually isn’t treated directly.
Instead, treatment addresses the underlying condition causing granulocytosis. Treating any underlying conditions should also reduce the number of granulocytes in your blood.
Your treatment will depend on the condition causing your granulocytosis.
If your condition is related to cancer, your treatment may include the following:
- Bone marrow transplant. During a bone marrow transplant, your bone marrow will be removed and replaced with healthy stem cells. These stem cells may come from your body or from a donor’s body.
- Chemotherapy. Chemotherapy is an aggressive form of chemical drug therapy that helps destroy cancerous cells in the body.
- Radiation therapy. This treatment uses high-energy radiation to shrink tumors and kill cancerous cells.
- Splenectomy. An enlarged spleen is a common complication of CML. Surgery to remove the spleen may be recommended.
Some conditions respond well to medications, and other conditions can be treated with blood transfusions. Your doctor will determine the best treatment plan for you.