TOXIC CHANGES in neutrophils are morphologic
abnormalities acquired during maturation under conditions that intensely stimulate neutrophil
production and shorten the maturation time in marrow. On the standard hemogram, their presence
is reported under the WBC morphology section.
Most of the toxic changes reflect
asychrony of maturation between nucleus and cytoplasm. During normal
granulocytopoiesis, the lengthening and pinching in of the nucleus are coordinated with
progressive condensation of the chromatin and loss of cytoplasmic basophilia. Therefore,
normally matured segmented and late band neutrophils, shown in panels A and C, have
white cytoplasm with pink granules, long and fairly narrow nuclei and tightly condensed
chromatin.
Segmented and band neutrophils with toxic change (examples shown in panels B and D) have less condensed chromatin than their normal counterparts and bluer cytoplasm due to retention of ribosomal RNA. The cytoplasmic basophilia can be focal, streaked, or diffuse. Focal basophilia appears as pale blue spots, called Doehle bodies, that represent aggregated ribosomes and whorls of rough endoplasmic reticulum. Additionally, many cells with toxic change are larger than normal and have frothy or vacuolated cytoplasm, which represents degranulation of lysosomes. Specific granules are less visible than in normally matured cells. Doehle bodies in otherwise normal segmented neutrophils are not a significant abnormality. Contrary to what has been written in many books, toxic change in neutrophils is not necessarily associated with "toxemia". The term derives from the fact that these abnormalities were first noticed in human patients with gram negative sepsis and endotoxemia. Toxic change in neutrophils can be associated with inflammation of any cause if severe enough to intensely accelerate neutrophil production. |
Last Updated:Thursday, February 08, 1996