A 2-day-old infant born at 30 weeks' gestation has an immature-to-total neutrophil ratio (I:T) of 0.40. This finding may indicate which condition?

• A. Neutropenia
• B. Leukocytosis
• C. Thrombocytopenia
• D. Sepsis

Answer: (D)

A high immature-to-total neutrophil ratio signals a left shift, meaning the bone marrow is releasing more immature neutrophils in response to infection or inflammation. In newborns, especially preterm infants, an I:T ratio as high as 0.40 indicates the circulation contains a large proportion of immature neutrophils, which is commonly seen with neonatal sepsis or early infection.

This makes sepsis the best answer because the question is about neutrophil maturation patterns rather than absolute counts. Neutropenia refers to very low neutrophil numbers, which isn’t directly implied by a high I:T ratio. Leukocytosis would describe high total white cells, not the maturation state of neutrophils. Thrombocytopenia involves platelets, not neutrophils.