1. What is the I/T Ratio?

The I/T (Immature to Total neutrophil) ratio is a calculation used to assess the proportion of immature neutrophils relative to the total neutrophil count. It's particularly useful in neonatal sepsis evaluation and other infectious conditions.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( Immature\_neutrophils \) — Count of immature neutrophils (bands and earlier forms)
• \( Total\_neutrophils \) — Count of all neutrophils (mature + immature)

Explanation: The ratio provides a standardized way to quantify the left shift in neutrophil maturation.

3. Importance of I/T Ratio

Details: The I/T ratio is clinically significant as it helps in early detection of infections, especially in neonates where clinical signs may be subtle. Higher ratios often correlate with more severe infections.

4. Using the Calculator

Tips: Enter both immature and total neutrophil counts as whole numbers. The immature count cannot exceed the total count. Results are presented as a decimal between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal I/T ratio?
A: In healthy term neonates, the normal I/T ratio is typically <0.2. Values >0.2-0.3 may suggest infection.

Q2: How is this different from absolute neutrophil count?
A: While ANC gives total neutrophil numbers, I/T ratio provides information about neutrophil maturity which may change earlier in infection.

Q3: When should I/T ratio be measured?
A: Most commonly used in evaluation of neonatal sepsis, but may also be helpful in other populations with suspected acute infection.

Q4: Are there limitations to I/T ratio?
A: Interpretation varies by age (especially gestational age in neonates) and may be affected by stress, steroids, or other conditions.

Q5: How often should it be repeated?
A: Serial measurements may help track response to therapy in severe infections, typically every 12-24 hours during acute illness.