Immature Platelet Fraction Normal Range
The normal reference range for immature platelet fraction (IPF) in adults is 1.1-6.1% (mean 3.4%), or expressed as 0.7-5.7% depending on the analyzer and methodology used. 1, 2
Reference Ranges by Population
Adults
- IPF percentage: 1.1-6.1% with a mean of 3.4% established using the Sysmex XE-2100 analyzer 2
- Alternative reference range: 0.7-5.7% reported in other validation studies 1
- Absolute immature platelet count (AIPC): 2-12.6 × 10⁹/L with a mean of 5.15 × 10⁹/L 3
Neonates (Age-Dependent)
The IPF reference range in neonates varies significantly by gestational age, with younger gestational ages showing higher values 4:
- Term neonates (>37 weeks): 3.58% (95% CI: 3.29-3.87%) 4
- Late preterm (34-37 weeks): 4.14% (95% CI: 3.82-5.0%) 4
- Moderate preterm (32-34 weeks): 4.14% (95% CI: 3.46-4.82%) 4
- Very preterm (28-32 weeks): 5.51% (95% CI: 3.95-7.07%) 4
Clinical Interpretation
Elevated IPF Values
IPF values above the normal range indicate increased platelet production and help differentiate thrombocytopenia causes 1, 2:
- Optimal cutoff of 5.95% distinguishes increased peripheral platelet destruction from decreased production with 88% sensitivity and 75.9% specificity 1
- Markedly elevated IPF (>9%) strongly suggests peripheral destruction:
Normal or Low IPF Values
- IPF <6% with thrombocytopenia suggests bone marrow failure or suppression with mean values around 4.6% 1
- Normal IPF in the setting of thrombocytopenia indicates inadequate compensatory platelet production 2
Important Clinical Caveats
The IPF must be interpreted in context of the platelet count, as physiologically elevated IPF can occur with normal or high platelet counts during recovery from thrombocytopenia 3, 5. Studies evaluating IPF in infection specifically excluded patients with platelet counts <150 × 10⁹/L to avoid this confounding factor 3.
IPF rises 1-2 days before platelet count recovery in patients undergoing hematopoietic stem cell transplantation or chemotherapy, making it a useful predictive marker for platelet engraftment 5. This temporal relationship is critical for optimizing platelet transfusion strategies.
The method demonstrates good reproducibility and stability over 48 hours, making it suitable for routine clinical laboratory use 2. However, reference ranges may vary slightly between different automated hematology analyzers, so laboratory-specific validation is recommended 1, 4.