<unk> s are newly-produced red blood cells. They are slightly larger than totally mature red blood cells, and have some residual ribosomal RNA. The presence of RNA allows a visible blue stain to bind or, in the case of fluorescent dye, result in a different brightness. This allows them to be detected and counted as a distinct population.
The<unk>  production<unk>  (RPI, also called a corrected<unk>  count) is a calculated value used in the diagnosis of anemia.
This calculation is necessary because the raw<unk>  count is misleading in anemic patients.
The problem arises because the<unk>  count is not really a count but rather a percentage: it reports the number of<unk> s as a percentage of the number of red blood cells.
In anemia, the patient's red blood cells are depleted, creating an erroneously elevated<unk>  count.
The idea of the RPI is to assess whether the bone marrow is producing an appropriate response to an anemic state.<unk>  production should increase in response to any loss of red blood cells.
It should increase within 2-3 days of a major acute hemorrhage, for instance, and reach its peak in 6-10 days.
If<unk>  production is not raised in response to anemia, then the anemia may be due to an acute cause with insufficient time to compensate, or there is a defect with red blood cell production in the bone marrow.
Marrow defects include nutritional deficiencies (i.e. iron, folate, or B12) or insufficient erythropoietin, the stimulus for  red blood cell production.<unk>  Production<unk>  is calculated as follows:
The degree of anemia (done by normalizing hematocrit of 45%)<unk>  maturation time (RMT)
The<unk>  maturation time is 1.0 days for a hematocrit of 45 % to 2.5 days for a hematocrit of 15 %:<unk>  production<unk>  =<unk> s %  x  (HCT / 45)  x  (1 / RMT)
The<unk>  (RI) should be between 1.0 and 2.0 for a healthy individual.
RI < 2 with anemia indicates decreased production of<unk> s and therefore red blood cells.
RI > 2 with anemia indicates loss of red blood cells (destruction, bleeding, etc) leading to increased compensatory production of<unk> s to replace the lost red blood cells.** Value of 45 is usually used as a normal hematocrit.
So,in a person whose<unk>  count is 5%, hemoglobin 7.5 g/dL, hematocrit 25%, the RPI would be:
So,in a person whose<unk>  count is 5%, hemoglobin 7.5 g/dL, hematocrit 25%, the RPI would be:
5 x [corrected retic count]/[maturation correction] = 5 x (25/45) /2 = 1.4
Reticulocyte index
Absolute neutrophil count
Mean corpuscular hemoglobin
Mean corpuscular hemoglobin concentration
Hematocrit
Leukocyte alkaline phosphatase
Glycosylated hemoglobin
Differential blood count