Reticulocyte Production Index

 

Input
 

Hct		% fraction ratio
Retic		% fraction ratio

 

Results
 

RPI		% fraction ratio
Decimal Precision   0 1 2 3

 

Notes

• The Maturation term represents the maturation time of RBC's (in days) at various levels of anemia.
• Maturation = 1.0 for Hct ≥40%.
• Maturation = 1.5 for Hct 30-39.9%.
• Maturation = 2.0 for Hct 20-29.9%.
• Maturation = 2.5 for Hct <20%.
• An RPI >3 shows a normal marrow response to anemia. An RPI <2 is an inadequate response to anemia.
• With a normal H&H, an RPI of 1 is normal.

 
Equations used
 

RPI = (Hct / 45) * Retic / Maturation

 

 

References

1. Hutchinson RE, Davey FR. Hematopoiesis. In: Henry JB, ed. Clinical Diagnosis and Management by Laboratory Methods 19th edition. WB Saunders 1996. NLMN ID: 9513812