MLAB 1415: HematologyMLAB 1415: HematologyKeri Brophy-MartinezKeri Brophy-Martinez

Chapter 8: AnemiaPart Two

The “Normal” RBCThe “Normal” RBCBiconcave disc

Area of central pallor

Approx. size 7 µm

RBC Size VariationsRBC Size VariationsAlterations in the size of the RBC

is called anisocytosis.

Correlate with MCV and RDW

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NormocyticNormocytic

MCV 80-100 fL

MacrocytesMacrocytes

8 μm or larger in diameter MCV of greater than 100 fL Evaluate macrocytic cells for:

◦ shape (round versus oval)◦ color (red versus blue)◦ pallor (if present)◦presence or absence of inclusions

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MacrocytesMacrocytes

Macrocytes arrive in peripheral circulation by three main ways:◦ Impaired DNA synthesis leading to decreased

number of cellular divisions, resulting in a larger cell Vitamin B12/Folate deficiency

◦ Accelerated erythropoiesis ending in a premature release of reticulocytes

◦Conditions in which membrane cholesterol and lecithin are increased obstructive liver disease 6

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MicrocytesMicrocytes

Diameter less than 7 μm MCV less than 80 fL. Any defect impairing

hemoglobin synthesis results in microcytic, hypochromic RBCs.

Decrease in hemoglobin synthesis results in increased cellular division and, consequently, small cells.

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MicrocytesMicrocytes

Causes◦Ineffective iron utilization, absorption, utilization, or release.

◦Decreased or ineffective globin synthesis.

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MicrocyteMicrocyte

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RBC Color VariationsRBC Color VariationsCorrelates with MCHCReference range for MCHC= 32-

36%

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NormochromicNormochromicNormal

hemoglobin content

MCHC 32-36 %

HypochromiaHypochromia

Any RBC having area of central pallor greater than 3 μm.

Direct relationship between amount of hemoglobin in red cell and appearance of red cell when stained.

Any problem with hemoglobin synthesis results in some degree of hypochromia.

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Hypochromia Hypochromia

MCHC <32Most frequently seen in iron deficiency

anemia.  See in thalassemias, hemoglobinopathies, and sideroblastic anemias.  May also see hypochromia in lead poisoning.

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HypochromiaHypochromia

Do NOT attempt to determine the presence of hypochromia based ONLY on RBC indices – must look at peripheral smear!

Hypochromia usually graded (1+ to 4+).

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Hypochromia GradingHypochromia Grading

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PolychromasiaPolychromasia

Occurs when immature RBCs are released into peripheral blood stream. 

Blue-gray in color Larger than normal RBCs Basophilia is a result of

residual RNA fragments involved in hemoglobin synthesis.

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PolychromasiaPolychromasia

Cells are actually reticulocytes. Not uncommon to find a few

polychromatic cells on a normal peripheral blood smear.

Reticulocyte count should reflect the degree of polychromasia present.

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PolychromasiaPolychromasia

Causes of:◦ acute and chronic hemorrhage◦ hemolysis◦ regenerative red cell process◦newborns

Excellent indicator of therapeutic effectiveness for correcting iron deficiency anemia or vitamin therapy.

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Polychromasia GradingPolychromasia Grading

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HyperchromasiaHyperchromasia

Does not exist!!!!!!

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ReferencesReferencesHarmening, D. M. (2009). Clinical

Hematology and Fundamentals of Hemostasis. Philadelphia: F.A Davis.

McKenzie, S. B., & Williams, J. L. (2010). Clinical Laboratory Hematology . Upper Saddle River: Pearson Education, Inc.