Impacts and Significance of white blood cell counts in lymphocytic and Neutrophilic species
Contents
Introduction
Blood Cells
Blood cells are cell that are mainly found in blood, and produced via hematopoiesis. While the liquid component of blood, plasma, make up 55% of the blood, blood cells make up 45% , and can be categorized into 3 different groups (1). Erythrocytes, Thrombocytes, and Leukocytes. Leukocytes are white blood cells that are in charge for immunological response, and can be differentiated to granulocytes and agranulocytes. *
Granulocytes are characterized by the presence of granules in their cytoplasm (2). The most abundant type of granulocytes are neutrophil granulocytes, then low number of eosinophil granulocytes, basophil granulocytes, and monocytes comprises granulocytes. Granulocytes are also known as polymorphonuclear leukocytes for their varying shape of nucleus
Agranulocytes, which only contain a single nucleus in its cell, has its varying name mononuclear leukocytes. Opposite to granulocytes, they’re characterized by the absence of granules in the cytoplasm. There are two types of agranulocytes: lymphocytes and monocytes.
Neutrophil Granulocytes
Normal neutrophil morphology is similar in common domestic mammalian species. The chromatin of the nucleus is condensed and segmented and stains blue to purple. Nuclear lobes may be joined, but generally there is simply a narrowing of the nucleus between lobes without true filament formation (3).
Band neutrophils, which are the most common type of immature neutrophil seen in blood, is one stage less mature compared to segmented neutrophils. They can be distinguished from matures by the shape of their nucleus, lacking the clear segmentation (5).
Heterophils are are the most common leukocyte in avian blood and are analogous with mammalian neutrophils, however their nuclei aren't as lobulated (8).
Lymphocytes
Lymphocyte morphology can be characterized by its pale blue color of the cytoplasm and their nuclei are usually round or oval, allowing some slight indentation. Most of the lymphocytes that circulate in healthy dogs, cats, camelids and horses are small cells that have round nuclei with dense chromatin and a small rim of light blue cytoplasm. The chromatin is so dense because it is mostly heterochromatin (the cell is not actively transcribing DNA) (3).