What is Peripheral Blood Film Study?
In This WriteUp
Diagnosis of the peripheral blood film should be measured, along with evaluation of the outcomes of measurable blood cell counts, including the manifestation of red blood cells, a vital element of the preliminary assessment of all patients having hematologic problems.
The test of blood films usually stains with a dye, which is called as Wright’s stain. This staining process usually conducted for obtaining important clinical evidences in the diagnosis of anemia and a variety of disorders related to white blood cells and platelets. (1)
Definition of Poikilocytosis
When the red blood cells diverge greatly in shape is clinically termed as poikilocytosis. Poikilocytosis may take a shape of pencils, teardrops or sickles. (1,2)
Anatomical features of Red Blood Cells
Healthy individual has biconcave disc like shaped red blood cells, which has a 7.5 μm diameter. The size of the red blood cells is smaller than the white blood cells. The hemoglobin is the essential pigmenting component of red blood cells, which is located at the marginal border of the cells and almost 30 to 45% central area of the diameter is denoted as central pallor. The normal size red blood cells with standard hemoglobin content is termed as normocytic and normochromic. (1)
Abnormal structural findings in Red Blood Cells
Abnormal inconsistency in size is clinically expressed as anisocytosis and as we discussed earlier that abnormal difference in shape is termed as poikilocytosis. Any considerable variation along with red blood cells in the diameter of central pallor is called as asanisochromia, whereas Polychromatophilia refers as the red blood cells have a blue-gray tinge in their cytoplasm.
- The increased size means the diameter of the red blood cells is greater than 9 μm in contrast with the normal red blood cell size is termed as macrocytes;
- The smaller size, that means the diameter of the red blood cells is less than 6 μm in contrast with the normal red blood cell size is termed as microcytes; and
- The central empty or pallor diameter covers greater than 50% is termed as (1,2,4)
Clinical significance of Peripheral Blood Film
Typically true poikilocytosis involves comparatively smaller numbers of cells throughout the peripheral blood film. The usual findings of the assessment of peripheral blood films of healthy individuals are very small quantity of poikilocytes, i.e. less than 2%. In the estimation of the consequence of poikilocytosis, an individual must recognize the main anomalous morphologic shape and keep out artifactual alterations of the red blood cells.
Fragmented blood cells or schistocytes are a significant clinical outcome; they signify the involuntary destruction of the cells. The variety of situations can responsible for this phenomena, some more prominent causes include: destruction due to the RBC itinerant through filaments of fibrin or through anomalous microvascularity, may vascular neoplasm contain them.
Certain diseases like valvular disease, abnormalities in renal glomerulus or other disease conditions can result in fragmentation also.
The findings of schistocytes is very rare in comparison with other morphological alterations in red blood cells, average only one fragment is distinguishable in each 5-10 100x objective fields of observation site.
Considerable poikilocytosis for supplementary morphological alterations is when several morphological deformities are observed in each 100x objective field of observation site.
The authentic method of preparing the blood film should not to rule out the finding of fragmentation; however, it is significant to identify other types of poikilocytosis including acanthocytosis, oxidant damage alterations, etc., where the RBC is easily broken, noticeable fragmented cells may or may not be observed. (3,4,5)
- Edward C. Lynch.; Chapter 155Peripheral Blood Smear; Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition, (1990); Retrieve from: http://www.ncbi.nlm.nih.gov/books/NBK263/
- Kathy W. Jones; Evaluation of Cell Morphology and Introduction to Platelets and White Blood cells Morphology; Chapter 5 ; Retrieve from: http://cytothesis.us/3.0/Oil_Cell-Morphology_Blood-Cell.pdf
- Dan L. Longo (2012); Atlas of Hematology and Analysis of Peripheral Blood Smears; CHAPTER e17; Retrieve from: https://www.mhprofessional.com/mediacenter/hpim18/assets/pdf/Harr18_e17.pdf
- EVALUATING BLOOD FILMS Take 3 minutes to bring abnormalities to light (2004); Clinical Solutions for Companion-Animal Practitioners; Retrieve from: http://www.idexx.de/pdf/de_de/smallanimal/education/3minute-blood-film-evaluations.pdf
- Dennis DeNicola (2008); Evaluate a Blood Film in less than 3 minutes; Retrieve from: http://www.idexx.com.au/pdf/en_au/corporate/newsletter/blood-film-review-faqs.pdf