Immature Granulocyte %

Would you like to know what lab results mean? Medical Tests Analyzer Software will explain and clarify your lab test report.

Granulocytes are a category of white blood cells characterized by the presence of granules in their cytoplasm. They are also called polymorphonuclear leukocytes (PMN or PML) because of the varying shapes of the nucleus, which is usually lobed into three segments. In common parlance, the term polymorphonuclear leukocyte often refers specifically to neutrophil granulocytes, the most abundant of the granulocytes. Granulocytes or PMN are released from the bone marrow by the regulatory complement proteins.

An immature granular leukocyte; includes neutrophilic, acidophilic, and basophilic types of polymorphonuclear leukocytes; respectively, neutrophils, eosinophils, and basophils.
A type of white blood cell that fights bacterial infection. Neutrophils, eosinophils, and basophils are granulocytes.
Leukocytes with abundant neutrophilic, eosinophilic or basophilic granules in the cytoplasm; mature granulocytes are the neutrophils, eosinophils, and basophils.
Leukocytes with abundant granules in the cytoplasm. They are divided into three groups according to the staining properties of the granules: neutrophilic, eosinophilic, and basophilic.

Immature granulocytes (metamyelocytes, myelocytes, and even promyelocytes) may be observed on the blood smear: total number < 2% is devoided of any significance; values over 2% and observed in at least two separated instances need explorations.

The immature granulocytes (IG), normally absent from peripheral blood, are increased in conditions such as bacterial infections, acute inflammatory disorders, cancer (particularly with marrow metastasis), tissue necrosis, acute transplant rejection, surgical and orthopedic trauma, myeloproliferative disorders, excessive bleeding, steroid use, and pregnancy (mainly during the third trimester). Usually, automated instruments can enumerated only the five-type white blood cells (WBC) found in the peripheral blood. With improved technology, users and manufactures have started looking at new applications, including enumeration of cell types normally not found in the blood, or present at very low level as immature granulocytes. Published studies agree that IG counts have a high specificity for infectious conditions (from 83% to 97%) but are accompanied by low sensitivity (between 35% and 40%). This low sensitivity does not allow to use the counting with the purpose of screening or early infection detection, while the clinical use in the evaluation of therapeutic response (e.g. to antibiotic therapy) seems more appropriate. At present, IG counting should not appear in the haematological report and must be used as a benchmark instrument-specific decision-making rules for reviewing or to be used in interpretative reporting for patients with clinically recognized infections.

All information on this page is intended for your general knowledge only and does not provide medical advice, diagnosis or treatment.