Interpretations of Peripheral Blood Smear

What sample is needed for the Peripheral Blood Smear?

• The blood sample may be in the EDTA or make a fresh blood smear.

What are the indications for Peripheral Blood Smear?

1. Peripheral blood smear gives very significant findings of RBC and white cells.
2. To see the effects of drugs on RBC and white cells.
3. To find the congenital abnormalities of the cells.
4. To find the acquired abnormalities of the cells.
5. A peripheral blood smear can give information about acute and chronic infection, infestation, leukemia, etc.

What is the function of Peripheral Blood Smear?

1. The differential count on the peripheral blood smears gives us information about anemias, leukemias, and any other abnormality of the blood cells.
2. DLC and CBC are less expensive, easy to perform, and can be done in a short time.
3. Peripheral blood smears under the expert eye can reveal information about the three cellular components: RBCs, white cells, and platelets.
4. All the types of leukocytes can be differentiated, and any abnormality can be found.

What are the RED Blood Cells abnormalities?

RBC size abnormality;

1. Microcytes are small in size.
   1. These are seen in iron deficiency anemia, hereditary spherocytosis, and thalassemia.
2. Macrocytes are large and seen in:
   1. Vit B12 or folic acid deficiency.
   2. Liver disorders.
   3. Post Splenectomy anemia.

RBC shape abnormality:

1. Spherocytes are small and round. Also, these are thick red blood cells.
   1. Hereditary spherocytosis.
   2. Acquired immune hemolytic anemia.

2. Elliptocytes: These are sickle-shaped or oval-shaped RBCs, also called pencil-shaped cells; these are seen in:
   1. Hereditary elliptocytosis.
   2. Sickle cell anemia.

3. Target cells have a dark spot in the center, and these are seen in the following:
   1. Thalassemia.
   2. Hemoglobinopathies.

4. Spiculated RBC has a rough surface or crenated in shape and is seen in:
   1. Uremia.
   2. Liver diseases.
   3. In bleeding ulcers.
5. Spur cell is seen in severe liver diseases
6. Burr cells These are irregularly contracted red cells. These are seen in :
   1. Renal diseases.
7. Fragmented cells are seen in :
   1. DIC.
   2. Post-splenectomy.
   3. Patient with a heart valve prosthesis.

What are the RBC staining or color abnormalities?

1. This will show the staining character of the cells.
2. Hypochromasia,  when the RBC are pale in color e.g.
   1. Iron deficiency anemia.
   2. Thalassemia.
3. Hyperchromasia is increased in color intensity, e.g.
   1. Seen in dehydration.
   2. The increased concentration of hemoglobin.

What are the Red blood cell intracellular abnormalities?

1. Normoblast is not seen normally on peripheral smears. These are seen in the following:
   1. Normoblast may be seen in the newborn.
   2. Hemolytic anemias.
   3. Sickle cell crises.
   4. Transfusion reaction.
   5. Erythroblastosis fetalis.
   6. Marrow space-occupying lesions like Myeloma, leukemia, and fibrosis.
   7. In physiologic response to hypoxia as in congenital heart disease and congestive heart failure.
2. Basophilic stippling: These are the inclusion in the cytoplasm of RBC seen in the following:
   1. Lead poisoning.
   2. Reticulocytosis.
3. Howell-Jolly bodies: These are remnants of nuclear material in the RBC  and are seen in the following:
   1. In patients with splenectomy.
   2. Hemolytic anemia.
   3. Megaloblastic anemia.
4. Heinz bodies are small irregular parts of hemoglobin seen in the following:
   1. Hemoglobinopathies.
   2. Hemolytic anemia.
   3. G 6 PD deficiency.
   4. Drug-induced injury to RBC.
5. Dimorphic red cells This is a feature of sideroblastic anemia.
   1. Also seen in a patient with post-transfusion.

How will you evaluate White blood cells?

1. It can be estimated in number, differential count, and any abnormality of the maturity can be evaluated.
2. For leukemia, one will see more immature cells.
3. The decreased count will indicate bone marrow depression.
   1. This may be due to drugs.
   2. Fibrosis of the marrow.
   3. Neoplasm.

How will you evaluate Platelet count?

1. This can also be estimated from the smear.
2. Thrombocytopenia is when the platelets are seen in less number on the smear.
   1. Idiopathic thrombocytopenic purpura ( ITP ).
   2. Hypersplenism.
   3. Hemorrhage.
   4. Leukemia.
   5. Myelofibrosis.
   6. Cancer chemotherapy.
   7. Inherited disorders like Wiskott-Aldrich syndrome.
   8. D I C.
   9. Systemic lupus erythematosus.
   10. Infections may be bacterial or viral.
3. Thrombocytosis when there is an increased number of platelets on smears.
   1. This may be seen in the following:
   2. Infection.
   3. Some leukemias and lymphomas.
   4. In splenectomy.
   5. Polycythemia vera.
   6. Rheumatoid arthritis.

• Please see the differential count ( CBC ) and RBC morphology for more details.

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