RBC-to-Reticulocyte Hemoglobin Concentration Ratio

 

hemoglobin concentration in reticulocytes in g/L =

= (absolute reticulocyte count per µL) * (reticulocyte hemoglobin content in picograms per cell) * 10^6 * 10^(-12)

 

where:

• pico = 10^(-12)

• 10^6 indicates the number of microliters in a liter

 

hemoglobin concentration in mature red cells in g/L =

= (hemoglobin concentration in total red cells in g/L) - (concentration of hemoglobin in reticulocytes in g/L)

 

ratio of (mature red cell hemoglobin) to (reticulocyte hemoglobin) =

= (concentration of hemoglobin in mature red cells in g/L) / (concentration of hemoglobin in reticulocytes in g/L)

 

Interpretation:

• The normal ratio of mature red cell to reticulocyte hemoglobin concentration in adults is 76.58 +/- 21.93, giving a lower limit of normal of 54.55.

• Adult patients with hemoglobinopathies and decreased red cell survival will have a ratio less than normal; one method (unverified) of grading the ratio would be < 15 severe, 15 - 36 moderate, 37 - 54 mild.

• In healthy children the ratio is 78.5 +/- 30.4, giving a lower limit of 48.1

• For children with iron deficiency the ratio overlaps the normal range (59 +/- 21.9, or 37.1 to 80.9).

• Patients with hemoglobinopathy and hemolytic anemia who are treated successfully will show an increase in the ratio.

Genotype (Adult Population)	percent reticulocytes	reticulocyte hemoglobin in g/L	mature red cell hemoglobin content in g/L	ratio
AA (normal)	1.33 +/- 0.39	1.76 +/- 0.59	124.61 +/- 15.05	76.58 +/- 21.93
SC (4 alpha)	3.57 +/- 3.02	3.33. +/- 1.52	100.98 +/- 18.7	36.56 +/- 17.75
SS (4 alpha)	10.52 +/- 4.14	6.47 +/- 3.05	54.69 +/- 14	9.79 +/- 4.08
SS (3 alpha)	6.94 +/- 3.08	5.27 +/- 1.51	73.33 +/- 16.34	16.15 +/- 10.08
SS (2 alpha)	6.88 +/- 2.24	5.48 +/- 1.06	77.13 +/- 14.96	14.70 +/- 4.95

Table 1, page 135, Brugnara 1997; alpha indicates the number of alpha chains in hemoglobin, with patients having alpha thalassemia possessing less than 4