Definition of Agranulocytosis

Agranulocytosis refers to a significant reduction in the number of granulocytes, a type of white blood cell containing microscopic granules. These granules are tiny sacs filled with enzymes that break down microorganisms. Granulocytes are part of the body's innate immune system, which fights infections in a somewhat non-specific manner. Unlike B-cells and T-cells, granulocytes do not target specific antigens.This condition leads to a syndrome characterized by frequent chronic bacterial infections affecting areas such as the skin and throat. Although "agranulocytosis" literally means the absence of granulocytes, it is often the case that there are some present, but in insufficient numbers. Agranulocytosis can be inherited genetically or can occur as a component of other conditions.There are three types of granulocytes: neutrophils, eosinophils, and basophils. They are categorized based on the staining properties of their granules in a laboratory setting. Neutrophils have granules that appear "neutral," eosinophils have granules that stain easily with the acid dye eosin, and basophils have granules that stain readily with basic (non-acidic) dyes. This classification, established when only certain cellular structures could be identified through histochemistry, remains widely used and practical today.

Medical Definition & Meaning