An increased number of band neutrophils in peripheral blood indicates which phenomenon?

• A. Leukemia
• B. Autoimmune hemolytic anemia
• C. Neutropenia
• D. Left shift

Answer: (D)

When the body faces infection or significant inflammation, the bone marrow releases neutrophils faster than they can fully mature. This spillover brings in more immature neutrophils, called bands, into the bloodstream. The presence of these increased band neutrophils is termed a left shift. It signals that the body is mounting an active, acute neutrophilic response to stress, often from bacterial infection or other inflammatory conditions.

This is why the option describing a left shift is the best choice: it directly reflects an increased number of immature neutrophils in peripheral blood. In contrast, leukemia involves malignant proliferation of white blood cells, autoimmune hemolytic anemia concerns red blood cells, and neutropenia is a low neutrophil count rather than an increase in immature forms.