1. MLAB 1315- Hematology Keri Brophy-Martinez
Unit 7: Anemia

2. Anemia
Anemia is the inability of the blood to supply the tissue with adequate oxygen for proper metabolic function.
Clinically, anemia is defined as a decrease in normal concentration of hemoglobin or erythrocytes.
Anemia is not a disease, but an expression of an underlying disorder or disease.

3. Development of Anemia Anemia occurs if:
Erythrocyte loss or destruction exceeds the maximum capacity of bone marrow erythrocyte production
Bone marrow erythrocyte production is impaired.

4. Anemia Two laboratory tests used to measure anemia Hemoglobin
Normal values
Male: g/dl
Female: g/dl
Moderate anemia: 7-10 g/dl
Severe anemia: <7 g/dl
Hematocrit - the proportion of red cells in whole blood expressed as a percentage (packed red cell volume)
Male: %
Female: 37-47%

5. Causes of anemia Acute blood loss (hemorrhage)
Accelerated destruction of RBC’s (immune or non-immune)
Nutritional deficiency (iron, folate or B12)
Bone marrow replacement (e.g. cancer)
Infection
Toxicity
Hematopoietic stem cell arrest or damage
Hereditary or acquired defect

6. Diagnosis of anemia Clinical history
Physical signs such as pallor, fatigue, weakness and shortness of breath
Laboratory tests
CBC
Examination of the blood smear
Reticulocyte - measures effective erythropoiesis
Bone marrow examination
Iron studies - iron, total iron-binding capacity (TIBC), ferritin
Vitamin B12 and folate
Erythropoietin level

7. Parameters of the CBC (complete blood count) used to diagnose anemia
Hemoglobin
Hematocrit
Note: the approximate relationship of the hemoglobin to the hematocrit is 1:3. This may vary with the cause of the anemia and the effect on the RBC indices, especially the MCV.
RBC indices
MCV - mean cell volume
Normal: male fl, female fl)
Indicates the average size (volume) of the red cells
Calculation: Hct x 10
RBC

8. RBC Indices con’t MCH - mean cell hemoglobin weight
Normal: pg
A measurement of the hemoglobin content in RBC’s
Calculation: Hgb x 10
RBC
MCHC - mean cell hemoglobin concentration
Normal: %
A measure of the concentration of hemoglobin in the average RBC
Calculation: Hgb x 100
Hct

9. Examination of the RBC’s in the peripheral blood smear
Alteration in size of the RBC is called anisocytosis.
Alteration in shape of the RBC is called poikilocytosis.
An RBC with normal hemoglobin content will appear normochromic (MCHC 32-36).
An RBC with decreased hemoglobin content will appear hypochromic (MCHC <32).
RBC size is designated as microcytic (small MCV <80), normocytic (normal size MCV ), or macrocytic (large MCV >100).

10. Classification of anemia by RBC indices
Normal size and color: normocytic/normochromic
Causes: bone marrow failure, hemolytic anemia, chronic renal failure, leukemia, metastatic malignancy
Increased size, normal color: macrocytic/normochromic
Causes: Folate or B12 deficiency, liver disease
Decreased size, decreased color: microcytic/hypochromic
Most common anemia
Causes: iron deficiency, sideroblastic anemia, thalassemia, chronic diseases

11. RBC inclusions are seen on Wright-stained smears in certain anemias
RBC inclusions are seen on Wright-stained smears in certain anemias. Discussion to follow.

12. Reticulocyte Adult normal: 0.5 - 1.5%
Useful in determining the response to the anemia and the potential of the bone marrow to manufacture RBC’s. Expressed as a percentage of the RBC’s.
When anemia is present, it is helpful to correct the retic using the patient’s hematocrit in order to assess appropriate bone marrow response
A supravital stain called New Methylene Blue is used to stain reticulocytes. On a Wright’s stained smear, reticulocytes appear as bluish red cells. The term used for retics on Wright’s stain is polychromasia.
Corrected retic% = retic % X Patient hct
Normal hct* based on age and sex
[*Normal female hct = 42%]
[*Normal male hct = 45%]

13. maturation time in days
Reticulocyte
Prematurely released retics remain in the blood and take from ½ to 1 ½ days longer to mature. This will cause even the “corrected” retic to be elevated, so a calculation must be performed to correct for this situation to obtain the reticulocyte production index (RPI). A maturation time table is used for this calculation.
RPI = corrected retic
maturation time in days

14. Normal Adult Values Red Blood Cells Male: 4.7-6.1 x 106 /µl
Female: x 106 /µl
Hemoglobin
Male: g/dl
Female: g/dl
Hematocrit
Male: %
Female: %
MCV
Male: fl
Female: fl
MCH
27-31 pg
MCHC
32-36 %
Reticulocyte %
RDW %