Hematology and Coagulation

A Comprehensive Review for Board Preparation, Certification and Clinical Practice

Amer Wahed, Andres Quesada, Amitava Dasgupta

• Publisher: Academic Press
• Year: 2019
• Print ISBN: 9780128149645
• eBook ISBN: 9780128149652
• Edition: 2
• Topic: Biological Sciences
• Subtopic: Biology
• Index: Biological Sciences

Hematology and Coagulation: A Comprehensive Review for Board Preparation, Certification and Clinical Practice, Second Edition, takes a practical and easy-to-read approach to understanding hematology and coagulation at an appropriate level for both board preparation and refresher courses. The book bridges the gap between large textbooks and medical technology books written for laboratory technicians, providing the sufficient background in genetics, toxicology and immunology that residents and medical students need to know in order to become successful physicians. Readers will use this quick reference to understand how tests are performed and how to interpret results.This clear and easy-to-read presentation of core topics and detailed case studies illustrates the application of hematopathology on patient care.- Provides a newly updated source that's in accordance with World Health Organization guidelines on the diagnosis of hematological malignancies- Succinctly covers all important clinical information found in larger textbooks in an easy-to-understand manner- Highlights essential concepts in hematopathology in such a way that pathology fellows and clinicians can understand methods without being specialists in the field

Chapter 1

Complete blood count and peripheral smear examination

Abstract

A complete blood count (CBC) is one of the most common laboratory tests ordered by clinicians even during routine health check. For CBC analysis, the specimen must be collected in an EDTA (ethylenediamine tetraacetic acid) tube (lavender or purple top). CBC consists of certain numbers that are printed out from the hematology analyzer. In addition, the printout contains certain graphs and “flags.” Flags are essentially messages provided by the analyzer to the interpreting person that certain abnormalities may be present. To make a meaningful interpretation of the peripheral smear, the CBC printout should be reviewed along with patient's electronic medical records. CBC parameters that are printed from an automated hematology analyzer are red blood cell–related numbers, white blood cell–related numbers, and platelet-related numbers. Review of peripheral blood smear is also very important, and sometimes correlating abnormal findings of bone marrow biopsy with abnormalities observed during review of peripheral blood smear may be very helpful for obtaining a proper diagnosis.

Keywords

Complete blood count; EDTA tube; Hematocrit; Platelets; Red blood cells; White blood cells

Introduction

A complete blood count (CBC) is one of the most common laboratory tests ordered by clinicians. Even for a routine health checkup of a healthy person, CBC is ordered to ensure there is no underlying disease when the individual may be asymptomatic. Tefferi et al. commented that in Mayo Clinic, Rochester, MN, approximately 10%–20% of CBC results are reported as abnormal. Common abnormalities associated with an abnormal CBC include anemia, thrombocytopenia, leukemia, polycythemia, thrombocytosis, and leukocytosis [1]. For CBC analysis, the specimen must be collected in an EDTA (ethylenediamine tetraacetic acid) tube (lavender or purple top).

CBC consists of certain numbers that are printed out from the hematology analyzer. In addition, the printout contains certain graphs and “flags.” Flags are essentially messages provided by the analyzer to the interpreting person that certain abnormalities may be present. For example, an analyzer may flag that blasts are present. Therefore, reviewing blood smear slide is required to ensure presence of blasts. To make a meaningful interpretation of the peripheral smear, the CBC printout should be reviewed along with patient's electronic medical records. CBC parameters that are printed from an automated hematology analyzer are red blood cell (RBC)–related numbers, white blood cell (WBC)–related numbers, and platelet–related numbers (Table 1.1).

Analysis of various parameters by hematology analyzers

A modern hematology analyzer is capable of counting and determining size of various circulating blood cells in blood, including RBC, WBC, and platelets [2].

Different hematology analyzers may use different methods for counting. Examples of different methods include (one analyzer may employ multiple methods) the following:

1. • Impedance: The traditional method for counting cells is electrical impedance, which was first used by Wallace Coulter in 1956. This is also known as the Coulter principle. It is used in almost all hematology analyzer. Whole blood passes between two electrodes through an aperture. This aperture allows only one cell to pass through at a time. The impedance changes as each cell passes through. The change in impedance is proportional to the volume of the cell. The cell is counted, and the volume of the cell is measured. This method is unable to distinguish between the three granulocytes accurately.
3. Table 1.1

   Various parameters printed by a hematology analyzer following complete blood count analysis.

   Parameter	Individual number
   RBC (red blood cell)-related numbers	• RBC count • Hemoglobin level • Hematocrit • Red cell differential width • Mean corpuscular volume • Mean corpuscular hemoglobin • Mean corpuscular hemoglobin concentration • Reticulocyte count
   WBC (white blood cell)-related numbers	• Total WBC count corrected • Total WBC count uncorrected • WBC differential • Absolute count of each type of WBC
   Platelet-related numbers	• Platelet count • Mean platelet volume • Platelet differential width

   
4. • Conductivity measurements with high frequency electromagnetic current (depends on the internal structure including nuclear cytoplasmic ratio, nuclear density to granularity ratio).
5. • Light scatter: Cells are made to pass in a single file in front of a light source. Light is scattered by the cells passing through the light beam. The amount of light scatter is detected, and electrical impulses are generated for counts.
6. • Flow cytometry is an excellent method to determine the five-part WBC differential.
7. • Fluorescence flow cytometry: It is useful for analysis of platelets, nucleated RBCs, and reticulocytes.
8. • Peroxidase-based cell counter.
9. • Immunological-based cell counters.

Modern hematology analyzers are capable of multimodal assessment of cell size and cell count, thus providing additional information regarding various categories of WBCs such as neutrophils, lymphocytes, monocyte...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Dedication
• Preface
• Chapter 1. Complete blood count and peripheral smear examination
• Chapter 2. Bone marrow examination and interpretation
• Chapter 3. Red blood cell disorders
• Chapter 4. Hemoglobinopathies and thalassemias
• Chapter 5. Benign white blood cell and platelet disorders
• Chapter 6. Myeloid neoplasms
• Chapter 7. Monoclonal gammopathies and their detection
• Chapter 8. Application of flow cytometry in diagnosis of hematological disorders
• Chapter 9. Cytogenetic and genetic abnormalities in hematologic neoplasms
• Chapter 10. Benign lymph node
• Chapter 11. Precursor lymphoid neoplasms, blastic plasmacytoid dendritic cell neoplasm, and acute leukemias of ambiguous lineage
• Chapter 12. B-cell lymphomas
• Chapter 13. T- and natural killer–cell lymphomas
• Chapter 14. Hodgkin lymphoma
• Chapter 15. Lymphoproliferative disorders associated with immune deficiencies, histiocytic and dendritic cell neoplasms, and blastic plasmacytoid dendritic cell neoplasm
• Chapter 16. Essentials of coagulation
• Chapter 17. Thrombophilia and their detection
• Chapter 18. Sources of errors in hematology and coagulation
• Index