This band reflects all the "toxic changes" seen in reactive neutrophils:
A neutrophilic response to pyogenic bacteria can be seen within hours. The primary granules contain lysozymes - hydrolytic enzymes, defensins and peroxidase. Döhle bodies represent disintegrating endoplasmic reticulum. Vacuoles show where cytokines were released from storage vesicles. A very lacey or moth-eaten neutrophilic cytoplasm is seen with overwhelming infection. Occasionally the neutrophilic response is vigorous enough to elevate significantly the WBC to 30,000/µL or more, called a leukemoid reaction. A reactive left-shift includes myelocytes and meta-myelocytes, a few promyelocytes, but should not include blasts.
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