1. What is Left Shift?

Left shift refers to the presence of increased band neutrophils (immature white blood cells) in the peripheral blood, indicating increased bone marrow production of neutrophils, typically in response to infection or inflammation.

2. How Does the Calculator Work?

The calculator uses the left shift formula:

Where:

• \( \text{Bands} \) — Number of band neutrophils (immature neutrophils)
• \( \text{Total Neutrophils} \) — Total number of neutrophils (segmented + bands)

Interpretation:

• >10%: Significant left shift (suggests acute bacterial infection)
• 5-10%: Mild left shift
• <5%: Normal

3. Importance of Left Shift Calculation

Details: Left shift assessment helps differentiate bacterial from viral infections, evaluate severity of infection, and monitor response to treatment.

4. Using the Calculator

Tips: Enter band count and total neutrophil count (required). WBC count is optional but can provide additional context. Values must be positive numbers with bands ≤ total neutrophils.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between left shift and leukocytosis?
A: Leukocytosis is increased total WBC count, while left shift specifically refers to increased immature neutrophils (bands).

Q2: Can you have left shift without leukocytosis?
A: Yes, this "left shift without leukocytosis" pattern can occur in early infection or in immunocompromised patients.

Q3: What conditions cause left shift?
A: Mainly bacterial infections, but also inflammation, stress, corticosteroid use, and myeloproliferative disorders.

Q4: How is left shift different from toxic granulation?
A: Left shift refers to immature neutrophils, while toxic granulation refers to morphological changes in mature neutrophils.

Q5: Is left shift always pathological?
A: Mild left shift can occur in pregnancy, exercise, or stress, but significant left shift (>10%) usually indicates pathology.