Objectives

• Detail the morphologic features observed during erythrocyte maturation.

• Associate erythrocyte shapes and inclusions with biochemical and physical processes.

• Predict a disease process related to erythrocytes when given unfamiliar clinical data. Abnormalities of RBC distribution

RBC maturation

Abnormalities of RBC shape

Erythrocytic inclusions

Abnormalities of RBC size

RBC anatomy and physiology • A 48 yr old female was admitted to a hospital because of difficulty in breathing, wheezing, cough and fatigue. Her history included diabetes and hypertension.

– RBC count = 1.73 x 1012/L – Hgb = 8.2 g/dL – Hct = 19% – MCV = 109.8 fL – MCH = 47 pg – MCHC = 43.1 g/dL – Her WBC count and platelet count were within the reference intervals

• Evaluate the CBC information for this patient • Because of the abnormal values found in the CBC, the laboratory professional made a blood smear and performed a WBC differential and complete evaluation of the RBCs and platelets.

• What should be reported about the RBCs in the critical area of this smear?

• Which results of the CBC might be affected by the findings on the smear? • RBC = measured – 1.73 x 1012/L Hct = 19% • MCV = measured – 109.8 fL • Hgb = measured – 8.2 g/dL MCH = 47 pg

MCHC = 43.1 g/dL • The EDTA sample was warmed at 37 oC for 15 minutes. The CBC was repeated. The new smear appeared as below.

– RBC count = 2.63 x 1012/L – Hgb = 8.2 g/dL – Hct = 24% – MCV = 91 fL – MCH = 31.2 pg – MCHC = 34.2 g/dL Abnormalities of RBC Distribution

Rouleaux Agglutination Description Linear “coin stack” arrangement - Irregular clumping, “grape-like” - clusters

Mechanism Increased plasma proteins Antibody-mediated of Formation (fibrinogen or immunoglobulin)

• Plasma cell neoplasms • Usually cold-reactive, anti-red Clinical • Infectious, inflammatory or cell antibodies Correlation autoimmune diseases with • Some warm reactive, anti-red acute phase response cell antibodies Neg charge from RBCs normally membrane sialic acid 25 nm apart z

Abnormal or increased plasma proteins IgM antibodies Abnormalities of RBC Distribution

Proteins change surface charge, IgM antibodies reducing zeta span the zeta potential, and potential gap allowing cells to forming a loosely join in rows latticework that links the RBCs • A 20-year-old African-American male presented to the emergency room because of the onset of severe abdominal pain while on vacation skiing in Colorado.

– RBC = 2.95 x 1012/L – Hgb = 9.2 g/dL – Hct = 26.8 % – MCV = 84 fL – MCH = 31.2 pg – MCHC = 36.2 g/dL – PLT = 205 x 109/L – WBC = 11.8 x 109/L • WBC differential: Normal • 12 NRBCs/100 WBCs • Is the white count valid?

• Why does the patient have so many NRBCs in the peripheral blood?

• What is the most likely diagnosis? Pronormoblast

Basophilic normoblast

Polychromatophilic normoblast

Orthochromic normoblast

Reticulocyte • Cell size decreases 25 µm à 7 µm • Cytoplasm ratio increases • Nuclear size decreases • Chromatin pattern matures and Mature RBC nucleus is expelled • Cytoplasm stains progressively acidophilic Pronormoblast

Basophilic normoblast

Polychromatophilic normoblast

Orthochromic normoblast • Erythroleukemia • HDN Reticulocyte • Anemia – Acute blood loss – Heme synthesis – Hemoglobinopathies – Thalassemia Mature RBC – Hemolytic

Polychromasia: Many colors; residual RNA • Observed on Wright’s stained smears • Supravital stains reveal reticulocytes • Associated with: ² Acute and chronic hemorrhage ² Hemolytic anemia ² Effective anemia treatment ² Neonates

• Supravital Stain reveals reticulocytes

Acanthocytes

Dacryocytes

Drepanocytes Spiculated RBCS Echinocytes

Keratocytes

Schistocytes Terminology Description Occurrence

Acanthocyte Spicules of varying Liver disease, post- length irregularly splenectomy, (spike) distributed abetalipoproteinemia

Dacryocyte Single elongated or Myelofibrosis, metastatic (tear) pointed extremity cancer, thalassemia

Polymerized Drepanocyte Sickle cell anemia; Sickle cell hemoglobin: sickle, (sickle) trait with low O tension crescent, or boat shaped 2

Artifact, post-transfusion, Short equally spaced heparin therapy, renal failure, Echinocyte (sea projections; Burr cells; liver disease, post- urchin) crenated cell splenectomy, hyperlipidemia, MDS

Keratocyte One or more notches; (horn) horn-like projections Microangiopathic anemias, DIC, TTP, HUS, abnormal heart Red cell fragments; Schistocyte valves, vascular anomalies triangles, comma (cut) shaped; microcytic Sickle cell (drepanocyte) Hemoglobinopathy (Hgb S)

• Polymerized Hgb S (low pO2) causes RBC rigidity • Cells occlude small capillaries and cause infarctions Qualitative Hgb defect Higher surface area/volume ratio increases gas diffusion

Flexible structure allows passage through capillaries

Permits survival in smallest capillaries

Basophilic stippling

Cabot rings

RBC Inclusions Heinz bodies

Howell-Jolly bodies

Pappenheimer Terminology Description Occurrence

Round granules; variable Accelerated number / size; distributed Basophilic erythropoiesis, Impaired throughout the cell; erythropoiesis, lead stippling aggregates of ribosomes poisoning (RNA)

Figure-8, or incomplete Myelodysplastic Cabot ring ring; microtubules of the syndrome, Pernicious mitotic spindle Anemia, Thalassemia

Denatured or precipitated Unstable hemoglobins; hemoglobin; with supravital Thal; G-6-PD deficiency Heinz bodies stain, round-shaped, varying oxidative stress; Post- size, close to cell membrane splenectomy

Increased or abnormal Small, round bodies Howell-Jolly erythropoiesis: thal, PA, composed of DNA usually erythrodysplasia; bodies eccentric; usually single Post-splenectomy Clusters of iron granules; Post-splenectomy, Pappenheimer usually at cell periphery; diseases with accelerated, bodies visible with Prussian blue disordered, or impaired and Wright’s stain erythropoiesis Pappenheimer bodies (siderotic granules) • Small irregular purple granules (clusters) • Presumptive evidence of excess iron (ferritin and precipitated iron phosphate) • Confirmed with an iron stain (Prussian blue) • A 38-year-old female who complained of a heavy menstrual cycle for the past two years and increasing fatigue in the last several weeks.

– RBC = 2.1 x 1012/L – Hgb = 5.6 g/dL – Hct = 18.9% – MCV = 60 fL – MCH = 17.8 pg – MCHC = 29.5 g/dL – RDW = 19.0 – PLT = 364 x 109/L – WBC = 3.1 x 109/L Normocytes Macrocytes Microcytes

• MCV = 80 - 100 fL • MCV > 100 fL • MCV < 80 fL • Diameter of average • Diameter of average • Diameter of average cell cell 7-8 um cell >8 um <6 um • Associated with: • Associated with: Liver • Associated with: IDA; Ventilation disease; Megaloblastic Sideroblastic anemia; Lead anemia; Neonates poisoning, Myelodysplastic Syndromes; Thalassemia; ACD Megaloblastic Anemias Iron Deficiency Anemia MCV usually >120 fL MCV = 64 fL Anisocytosis

Normal Anisocytosis Normochromic: ~ 33% of the cell is filled with hemoglobin, there is central pallor

Hypochromic: central area larger and paler than normal, decreased hemoglobin • Iron Deficiency Anemia • Thalassemia • Sideroblastic conditions • Anemia of Chronic Inflammation Hemoglobin A a a

b b

Protoporphyrin

Globin

Heme

Fe • A 4-year-old male has been complaining of being too tired to play outdoors. The physician prescribed a multi- vitamin for the child, but the symptoms continued.

– RBC = 4.7 x 1012/L – Hgb =8.3 g/dL – Hct = 24 % – MCV = 70.1 fL – MCH = 21.0 pg – MCHC = 29.2 g/dL – PLT = 205 x 109/L – RDW = 17.6 x 109/L – PLT = 255 x 109/L – WBC = 10.1 x 109/L Blister

Codocytes

Knizocytes Non-spiculated RBCs Ovalocytes

Spherocytes

Stomatocytes Terminology Description Occurrence

Blister/Bite Membrane content Traumatic damage or removed by macrophages as inclusion; G-6-PD deficiency, cell cell passes through spleen hemoglobinopathies

Post-splenectomy, Codocyte Thin bell-shaped; increased thalassemia, (target cell) surface-to-volume ratio hemoglobinopathies, liver disease, lipid diseases

More than two concavities; Hemolytic anemias, Knizocyte dark band of hemoglobin hereditary spherocytosis across center

Ovalocyte Oval to elongated; with Many diseases, severe in central pallor and hereditary diseases of RBC (elliptocyte) hemoglobin at ends membrane

Dense hemoglobin content; Many diseases, severe in Spherocyte lack central pallor hereditary spherocytosis

Stomatocyte Uniconcave; very thick cup; Many diseases, severe in (mouth cell) oval or slitlike central pallor hereditary stomatocytosis Target cell (Codocyte) • Extreme membrane:cytoplasm ratio increase • Deficient hemoglobin production in hemoglobinopathies, thalassemia, iron deficiency, liver disease β-Thalassemia Intermedia

• Quantitative disorder of globin chains

• β+/ β+, β0/ β+, β0/ β a b b a • Laboratory results – Microcytic hypochromic anemia (Hb 7-10 g/dL) – RBC count is ↑ – Peripheral blood smear: codocytes, basophilic stip, NRBCs References

• Bessis, M. Blood Smears Reinterpreted, 1973, p. 61 • Color Atlas of Hematology: An Illustrated Field Guide Based on Proficiency Testing, CAP Press, 1998. • Clinical Laboratory Hematology, McKenzie, S. and Williams, L., Pearson, 2014. • John Landis: [email protected]