From the Guidelines
Immature granulocytes (abs) are considered abnormal when their count exceeds 0.1 × 10^9/L or 1% of total white blood cells, as indicated by a study on chronic myelogenous leukemia diagnosis, treatment, and follow-up 1. According to the study, a complete hematologic response (CHR) is achieved when there are no immature granulocytes and <5% basophils, among other criteria 1. This suggests that the presence of immature granulocytes is a significant indicator of bone marrow activity and potential disease. Key points to consider when evaluating immature granulocyte counts include:
- Normal values: less than 0.1 × 10^9/L or less than 1% of total white blood cells
- Elevated counts: often indicate active bone marrow response to infection, inflammation, or other stressors
- Clinical utility: identifying early bacterial infections, monitoring response to antibiotics, evaluating bone marrow disorders, and assessing recovery from chemotherapy The study from Annals of Oncology provides valuable insights into the clinical significance of immature granulocyte counts in the context of hematologic disorders 1. In clinical practice, it is essential to consider these counts in conjunction with other laboratory and clinical findings to make accurate diagnoses and develop effective treatment plans.
From the Research
Definition of Immature Granulocytes (IGs)
- Immature granulocytes (IGs) include metamyelocytes, myelocytes, and promyelocytes, and are the precursors of neutrophils 2.
- Increased IG counts found in peripheral blood indicate an enhanced bone marrow activity 2.
Clinical Significance of Immature Granulocytes
- IGs have been evaluated in numerous clinical conditions, such as severe acute pancreatitis, systemic inflammatory response syndrome, and infectious complications following open-heart surgery under cardiopulmonary bypass 2.
- IG count was found to be associated with disease severity, patient outcomes, duration of hospitalization, and development of complications in patients with COVID-19 infection 2.
- IG measurement is an easily accessible, cost-effective potential marker for screening bacteremia 3.
- IG% and IGC were positively correlated with hs-CRP, WBC, and neutrophil counts, and NLR in patients with predialysis chronic kidney disease 4.
- IG percentage is a useful marker to predict infection, its invasiveness, and severity in critically ill patients 5.
- IG% can present a high SYNTAX score with 76.2% sensitivity and 75.4% specificity at a cut-off value of 0.7 in patients with acute coronary syndrome 6.
Immature Granulocytes as Biomarkers
- IG count was a significantly associated with the severity of COVID-19 infection, with greater IG count values being detected in severe and critical cases 2.
- IG% and IGC had predictive value for the presence of inflammation in children with predialysis CKD 4.
- IG percentage adds to WBC and CRP in the early exclusion of infection and can be obtained routinely without extra blood sampling or costs 5.
- IG can be used as a parameter to predict high SYNTAX score in ACS patients in daily clinical practice 6.