Hematology: Leukocytes Classification

Neutrophil Functions and Characteristics

• Neutrophils play a crucial role in the innate immune response by combating infections, particularly bacterial pathogens.
• They are the most abundant type of white blood cells, making up 55-70% of total leukocytes.
• Toxic neutrophil production is often caused by severe infections, inflammation, or stress.

Easy Identification of Leukocytes

• Neutrophils, the most easily identifiable leukocyte, are larger than red blood cells (RBCs) and possess a multi-lobed nucleus.

Eosinophil Characteristics and Functions

• Eosinophils are characterized by large granules that stain orange-red with eosin dye.
• They primarily target parasitic infections and play a role in allergic responses.

Neutrophil Appearance and Indicators

• Hyper-segmented neutrophils exhibit an increased number of lobes in the nucleus, with five or more lobes, often indicating megaloblastic anemia.
• A left shift in neutrophils indicates an increased number of immature neutrophils in circulation, typically associated with acute infections or stress.

Neutrophilia and Right Shift

• Neutrophilia refers to an elevated neutrophil count in response to infections or inflammatory conditions.
• A right shift in neutrophils signifies an increase in mature neutrophils and is often associated with chronic infections or steroid use.

Basophils and Heterophils

• Basophils are characterized by large granules that stain dark blue or purple, containing histamine and heparin, and are involved in allergic responses.
• Heterophils, found in some species (like birds and reptiles), have a distinctive appearance, with a segmented nucleus and granules that are similar to mammalian neutrophils but differ in size and staining characteristics.

Neutropenia Causes

• Neutropenia, or low neutrophil count, can commonly result from conditions such as bone marrow disorders, autoimmune diseases, or the effects of chemotherapy.

Test your knowledge about the classification and functions of leukocytes in hematology. Learn about the different pools in which leukocytes are found and their roles in the body.