Red Blood Cell (RBC):- Part 2 – Peripheral blood smear, Normal Picture and RBC Morphology

Sample

• To assess RBC morphology make fresh smears and smears from the blood in EDTA.

Precautions

1. A well-made smear is needed.
2. A well-stained smear is also important.
3. Otherwise, the analysis of cell morphology may be greatly distorted by poorly made and poorly stained smears.

Indications

1. This is done to see the morphology of RBC as variation and abnormality in size, shape, structure, Hb contents and, staining characteristics.
2. Can diagnose the type of Anaemia.
3. Can diagnose Thalassemia.
4. Also, can find other abnormalities like hemoglobinopathies.
5. This also helps to see the effect of chemotherapy and radiation.
6. Special stains can find infections, infestation, leukemia, and other diseases.
   

   Peripheral blood smear evaluation

Pathophysiology

1. There are various sizes and shapes of RBC seen in the peripheral blood smear like:
   1. Normocytic when the size is normal (7 to 8 µm).
   2. Normochromic when the color is normal.
   3. Microcytic when the size is smaller than normal RBC and these are less than 6 µm.
      1. In iron deficiency anemia and thalassemia and hemoglobinopathies.
   4. Macrocytic when the size is larger than > 8 µm.
      1. Found in liver diseases, alcoholism, and oval in megaloblastic anemia.
   5. Anisocytosis is an abnormal variation in size from the normal diameter of 6 to 8 µm,  seen in severe anemia like iron deficiency, hemolytic anemia, and hypersplenism.
   6. Hypochromasia when the RBCs are pale with decreased Hb concentration.
   7. Poikilocytes when RBCs have variation in shapes.
   8. Spherocytes when RBCs are round without the central pale area.

1. 9. Elliptocytes are oval or elongated RBC.
      1. Found in hereditary elliptocytosis.

1. 10. Sickle cell is a crescent-shaped RBC seen in sickle cell anemia.
   11. The target cell is RBC with a dark central area and clear space between this dark area and periphery.
       1. Found in iron deficiency anemia, liver disease, post-splenectomy, and hemoglobinopathies.

1. 12. Schistocytes or helmet shape RBCs Are irregularly contracted cells or fragmented RBCs.
   13. Burr cells are RBCs with spinous processes.

1. 14. Acanthocytes are RBCs with small cells with thorny projections.
       1. found in liver disease, renal failure, and abetalipoproteinemia.

1. 15. Teardrop cell is RBCs with a tear like an appearance.
   16. The nucleated cell is RBCs with the presence of a nucleus. These are normoblast or megaloblastic cells.

2. In the peripheral smears also note for Inclusion:
   1. Howell-Jolly bodies. These are spherical purple bodies within RBCs, these are nuclear debris.
   2. Heinz inclusion bodies. These are small round inclusion of denatured hemoglobin, seen with supravital stain or under phase microscopy.
   3. Siderocytes are the RBCs containing siderotic granules which stain blue with Prussian blue stain.
   4. Basophilic stippling is the presence of punctate stippling seen with Wright stain.
      

      Red blood cell inclusion

3. Reticulocytes are also seen. These are RBCs containing RNA and stain pinkish-blue in color. With methylene blue show a reticular network.
4. Rouleaux formation is the pilling of RBCs on each other or aggregated RBCs.
   

   Red Blood cell rouleaux

Normal cells in the Peripheral blood

• Band form neutrophils = 2 to 6%
• Neutrophils = 50 to 70%
• Eosinophils  = 1 to 5%
• Basophils = 0 to 2%
• Lymphocytes = 20 to 44%
• Monocytes = 2 to 10%

Interpretation of the peripheral blood smear:

• Screen the slide and note any of the abnormalities present in the smear as regards RBCs.
• Also, it can evaluate the number or any abnormality of white cells.
• Also, the number of platelets can be evaluated.
• So the peripheral smear gives the following information.
  • Any abnormality of RBCs.
  • Any abnormality in white cells.
  • can assess the number of platelets.
• One can see the following picture in various types of anemia :
  1. In hemolysis, or hemorrhage or in increased erythropoiesis. There are basophilic or polychromatophilic macrocytes
  2. Megaloblastic anemia shows oval macrocytes with an increased number of lobules in the neutrophils.
  3. Hemoglobinopathies anemia there are target cells e.g. in thalassemia and Hb C.
  1. Target cells are also seen in iron- deficiency anemia and liver diseases.
  2. Thalassemia and lead poisoning show microcytes with stippling.
     

     Red blood cells morphology and their etiology:

     Type of RBCs abnormality	Etiology for the abnormality
     Microcytic	Iron-deficiency anemia Thalassemia Sideroblastic anemia Lead poisoning
     Macrocytic	Megaloblastic anemia Liver diseases Myelodysplastic syndrome Increased reticulocyte count
     Spherocytes	Hereditary spherocytosis Hemolytic anemia Post transfusion
     Target cells	Thalassemia Liver diseases Sideroblastic anemia Hemoglobinopathies
     Teardrop cells	Severe anemia Pernicious anemia Myeloproliferative anemia
     Elliptocytes	Hereditary elliptocytosis Thalassemia Iron-deficiency anemia
     Sickle cells	Sickle cell anemia Sickle-thalassemia
     Stomatocytes	Malignant tumors Acute alcoholism
     Burr cells	Renal diseases Liver diseases Bleeding gastric ulcer Severe burns
     Acanthocytes	Alcohol intoxication Postsplenectomy Vitamin E deficiency Congenital abetalipoproteinemia
     Hemet cells	G-6-PD deficiency Pulmonary emboli
     Schistocytes	Hemolytic uremic syndrome Thrombotic idiopathic thrombocytopenia (ITP) Disseminated intravascular coagulopathy (DIC)

• Note please see more information on CBC and peripheral blood smear.

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