Neutropenia:Not enough neutrophils, neutrophils being a type ofwhite blood cell(specifically a form ofgranulocyte) filled with neutrally-staining granules, tiny sacs ofenzymesthat help thecellto kill and digest microorganisms it has engulfed byphagocytosis. The matureneutrophilhas a segmentednucleus(it is called a seg or poly) while the immature neutrophil has band-shape nucleus (it is called a band). The neutrophil has a lifespan of about 3 days.
Neutropenia may be seen withviralinfections and afterradiotherapyand chemotherapy. Neutropenia lowers the immunologic barrier tobacterialandfungalinfection.
Granulocytopeniaor, as it is also called,agranulocytosisresultsinasyndromeof frequentchronicbacterial infectionsof theskin,lungs, etc. Although "agranulocytosis" literally means nogranulocytes, there may, in fact, be some granulocytes but too few of them, i.e. granulocytopenia. Granulocytopenia can begeneticand inherited or it can beacquiredas, for example, an aspect of leukemia.
Neutrophils, eosinophils and basophils are all types of granulocytes. They are named by the staining features of their granules in thelaboratory:
- Neutrophils have "neutral" subtle granules;
- Eosinophils have prominent granules that stain readily with the acid dye eosin; and
- Basophils have prominent granules that stain readily basic (nonacidic) dyes.
This classification dates back to a time when certain structures could be identified in cells by histochemistry, but the functions of theseintracellularstructures were still not yet fathomed. However, the classification of granulocytes into neutrophils, eosinophils and basophils is still widely used (and quite useful).
Granulocytopenia can therefore more specifically involve neutropenia (shortage of neutrophils), eosinopenia and/or basopenia. The term "neutropenia" is sometimes used interchangeably with granulocytopenia or agranulocytosis.
