From the Guidelines
Elevated immature granulocytes (IG) in a blood test is a significant finding that warrants medical evaluation to determine the underlying cause, which could be an infection, inflammation, or a blood disorder such as leukemia, as indicated by the presence of immature cells in the blood count and differential 1. The presence of immature granulocytes in the blood suggests that the bone marrow is responding to an increased demand for white blood cells, which could be due to various causes such as:
- Bacterial infections
- Inflammation
- Tissue damage
- Certain medications
- Pregnancy
- Blood disorders or leukemia According to the European LeukemiaNet (ELN) recommendations, the presence of immature granulocytes is one of the criteria for the diagnosis of accelerated phase (AP) or blast phase (BP) in chronic myeloid leukemia (CML) 1. The diagnosis of CML should be confirmed by cytogenetics showing t(9;22)(q34;q11), and by multiplex RT-PCR showing BCR–ABL1 transcripts, as recommended by the ESMO clinical practice guidelines for diagnosis, treatment, and follow-up of CML 1. Treatment of elevated immature granulocytes focuses on addressing the underlying cause, such as:
- Antibiotics for infections
- Anti-inflammatory medications for inflammation
- Targeted therapy for blood disorders such as leukemia It is essential to note that persistent elevation of immature granulocytes requires medical investigation to determine the underlying cause, as it could be a sign of an underlying blood disorder or leukemia 1. In terms of prognosis and treatment, the recognition of disease progression from chronic phase (CP) to blast phase (BP) is crucial, and immunocytology by flow cytometry and histochemistry can help assess immature cells and distinguish between myeloid and lymphoid blast crisis 1.
From the Research
Significance of Elevated Immature Granulocytes
Elevated immature granulocytes (IG) have been associated with various clinical conditions, including:
- Infections, such as otitis media, upper and lower respiratory infections, and gastroenteritis, particularly in outpatients up to the age of 10 years 2
- Hematologic malignancies, drug therapy (glucocorticoids, chemotherapy), severe infections, and pregnancy (young females) in outpatients above the age of 10 years 2
- Sepsis, with IG count being a useful early diagnostic marker to discriminate between systemic inflammatory response syndrome (SIRS) and sepsis 3
- Microbial infection and its adverse sequelae in the intensive care unit, with IG percentage being a useful marker to predict infection, its invasiveness, and severity 4
- Acute pelvic-inflammatory-disease (PID), with IG counts and percentages being significantly effective in predicting acute PID and associated with severity 5
Diagnostic Value of Immature Granulocytes
The diagnostic value of IG has been compared to other markers, such as:
- Band percentage, with no significant associations found between IG percentage and band percentage or other SIRS criteria 6
- C-reactive protein (CRP) and white blood cell counts (WBC), with IG percentage being a useful marker to predict infection, its invasiveness, and severity, and adding value to WBC and CRP in the early exclusion of infection 4
- IG counts and percentages being useful for discriminating mild/moderate and severe PID, and predicting the need for surgical intervention 5
Clinical Applications of Immature Granulocytes
The clinical applications of IG include:
- Routine automated quantification of IG in peripheral blood samples as a powerful clinical parameter 2
- Early diagnostic marker of sepsis, particularly within the first 48 hours after SIRS onset 3
- Predictive value for microbial infection and its adverse sequelae in critically ill patients 4
- Adjunctive marker for the diagnosis of acute PID and discrimination between mild/moderate and severe PID 5