Complete Blood Count PDF

Complete Blood Count Clinical Biochemistry Blood Blood has been defined as a highly specialized modified connective tissue, which along with the circulatory system is adapted to meet the needs of the body tissues and organ systems. Such as exchange of gases, provisi...

Complete Blood Count Clinical Biochemistry Blood Blood has been defined as a highly specialized modified connective tissue, which along with the circulatory system is adapted to meet the needs of the body tissues and organ systems. Such as exchange of gases, provision of nutrients and removal of waste products Plasma: the fluid portion of the blood Blood cells: the solid portion of the blood Composition of blood Specialized cells (Erythrocytes and Leukocytes) Cell fragments (Platelets or Thrombocytes)  Blood Cells All the blood cells are derived from a single population of stem cells located in red bone marrow called (pluripotent stem cells) during the Hemopoiesis which is the process of blood cells production. Myeloid progenitor cells which are derived from the pluripotent stem cells, are differentiated into 1. Proerythroblasts, from which erythrocytes develop during Erythropoiesis 2. Myeloblasts, from which Leukocytes develop during Leukopoiesis 3. Megakaryoblasts, from which thrombocytes develop during Thrombopoiesis Another pathway for pluripotential stem cells to develop, is to become a Lymphoid progenitor cells, which will be further differentiated into lymphocytes during Leukopoiesis  Proerythroblasts Erythrocytes Myeloid Myeloblasts Leukocytes progenitor cells Pluripotent Stem Megakaryoblasts Thrombocytes Cells Lymphoid Lymphocytes progenitor cells Erythropoiesis  Red blood cells (RBCs) Erythrocytes are about 95% of the volume of the blood cells. They have no nuclei, that is why they are called red blood corpuscles. The rate of erythropoiesis is regulated by a hormone called erythropoietin. Erythropoietin is produced mainly in the kidneys, and it stimulate stem cells to differentiate into proerythroblasts. The main factor that causes the release of erythropoietin is hypoxia (low blood oxygen level). Vitamin B12 and Folic acid are essential for the synthesis of DNA and for final maturation of the RBC. The main component of erythrocytes is the pigmented protein hemoglobin which causes their red colour  Erythrocytes Morphology According to size: Microcytic Normocytic Macrocytic According to colour (Hemoglobin) Hypochromic Normochromic Hyperchromic  White blood cells (WBCs) Leukocytes are spherical cells with a nucleus, white in color because it lacks hemoglobin. They are classified according to the presence or absence of granules in cytoplasm into: 1. Granulocytes: cytoplasm contains granules Neutrophils Eosinophils Basophils 2. Agranulocytes: cytoplasm contains NO granules Lymphocytes Monocytes  Platelets (Thrombocytes) Platelets are referred to as thrombocytes because of their sealing function as they form a thrombus, or a plug when there is a break in the circulatory system Complete Blood Count Hemocytometer (Counting Chamber) A hemocytometer is a tool used for manual cell counting It was originally invented for quantifying blood cells.  Cell Counter (CBC Machine) It is a machine that automatically counts cells. The sample is loaded and forced through a small tube while the machine uses optical or electrical sensors to count the cells that go through the tube. It is used in medical and research labs for complete blood count to determine the number and types of cells in the samples.  Blood Smear (Film) A blood smear is a sample of blood that is spread on a glass slide which is treated with a special stain. In the past, all blood smears were examined under a microscope. Now automated digital systems may be used to help examine blood smears.  CBC Report Components Hemoglobin (Hb) Red Blood Cells count (RBCs) Hematocrit (Hct) Red Blood Cell Indices o Mean Corpuscular Volume (MCV) o Mean Corpuscular Hemoglobin (MCH) o Mean Corpuscular Hemoglobin Concentration (MCHC) o Red cell distribution width (RDW) Platelets Total White Blood Cells Counts (WBCs) Differential White Blood Cells counts  Hemoglobin Concentration (Hb) Hemoglobin concentration (Hb) is used clinically to determine the presence of anemia, which is functionally defined as insufficient red blood cell (RBC) mass to adequately deliver oxygen to peripheral tissues. Reference ranges in adults: Men: 14-17.5 g/dL Women: 12.3-15.3 g/dL Erythrocyte Count (RBC) Red blood cell count (RBC) is the number of red blood cells per unit volume of blood. RBC increases either due to relatively decreased plasma volume such as dehydration or due to absolute increase in red blood cell production such as in renal cell carcinoma (due to erythropoietin production) or polycythemia vera Reference range: Male (4.5-5.9 x 1012/L) Female (4.1-5.1 x 1012/L) 𝐑𝐁𝐂𝐬 𝐧𝐮𝐦𝐛𝐞𝐫 RBC (1012/L) = 𝐮𝐧𝐢𝐭 𝐛𝐥𝐨𝐨𝐝 𝐯𝐨𝐥𝐮𝐦𝐞  Hematocrit (Hct) Packed Cell Volume (PCV) is the ratio of the volume of RBCs to the total volume of blood as determined by separation of red blood cells from the plasma using centrifuge  Hematocrit (Hct) Hematocrit rises with an increase of number of RBCs or decrease in the plasma volume. It decreases when plasma volume increases or in case erythropoiesis decreases or increased red cell destruction or loss Reference ranges: Males: (40-54%) Females (36-46%) 𝐑𝐁𝐂𝐬 𝐯𝐨𝐥𝐮𝐦𝐞 PCV or Hct (%)= x 100 𝐁𝐥𝐨𝐨𝐝 𝐯𝐨𝐥𝐮𝐦𝐞 Red Blood Cell Indices Mean Cell Volume (MCV) MCV refers to the average size of one red blood cell constituting the sample in femtoliters (fL) Reference range for adults is typically 80-100 fL MCV gives an indication of Red Blood Cells’ size Microcytic Normocytic Macrocytic  Mean cell hemoglobin (MCH) Mean cell hemoglobin (MCH) refers to the average weight of hemoglobin in one red blood cell (RBC) in the sample in picograms (pg) Reference range for adults is typically 26-32 pg 𝐇𝐛 𝐠/𝐝𝐋 𝐱 𝟏𝟎 MCH= = 𝐩𝐠 𝐑𝐁𝐂 𝐜𝐨𝐮𝐧𝐭  Mean cell hemoglobin concentration (MCHC) Mean cell hemoglobin concentration (MCHC) refers to the average concentration of hemoglobin in the RBCs contained within the sample (g/dL) Reference range for adults is 32-36 g/dL Both MCH and MCHC indicate the colour of RBCs Hypochromic Normochromic 𝐇𝐛 𝐠/𝐝𝐋 𝐱 𝟏𝟎𝟎 MCHC = = 𝐠/𝐝𝐋 𝐇𝐜𝐭%  Red cell distribution width (RDW) The red cell distribution width (RDW) is a measurement derived from the RBC distribution curves generated on automated hematology analyzers in percentage and is an indicator of variation in RBC size within a blood sample. The RDW measures the deviation of the RBC width, NOT the actual width size of individual cells. It is used to differentiate between iron deficiency anemia and thalassemia. Anisocytosis is a condition in which the red blood cells are of different sizes. The cells may be larger or smaller than the usual Anisocytosis can be caused by Iron-deficiency anemia Megaloblastic anemia Sickle cell anemia Anemia Testing Reticulocytes Reticulocytes are RBCs that are still developing They are also known as immature RBCs They are synthesized in the bone marrow then sent to the blood stream Reticulocyte Count Reticulocyte count or percentage is used to estimate the degree of effective erythropoiesis as well as bone marrow. The reticulocyte count as a marker of RBC production, provide an initial evaluation as to whether anemia is due to loss of RBCs or inadequate production. Inappropriate responses to peripheral RBC loss (bleeding or hemolysis) increased RBC production from the bone marrow is expected and increased reticulocytes should be noticed On the other hand, the failure of the adequate bone marrow response to anemia usually correlated with a low reticulocyte count and is associated with bone marrow-related disorders Corrected Reticulocyte Index If the patient is anemic, the reticulocyte count percentage is falsely increased, in which case the value needs to be adjusted based on the patient’s hematocrit to the corrected reticulocyte count. The corrected reticulocyte index is a factor that is adjusted for both the degree of anemia and the maturation time of reticulocyte. Reference range in adults is 0.5%-1.5% % 𝐑𝐞𝐭𝐢𝐜𝐮𝐥𝐨𝐜𝐲𝐭𝐞𝐬 𝐗 𝐏𝐚𝐭𝐢𝐞𝐧𝐭’𝐬 𝐇𝐜𝐭 𝐂𝐨𝐫𝐫𝐞𝐜𝐭𝐞𝐝 𝐫𝐞𝐭𝐢𝐜𝐮𝐥𝐨𝐜𝐲𝐭𝐞𝐬 𝐜𝐨𝐮𝐧𝐭 = 𝐍𝐨𝐫𝐦𝐚𝐥 𝐇𝐜𝐭 Blood Differential Diagnosis Scheme White Blood Cells and Platelets  Leukocyte Count WBCs, also called leukocytes, are an important part of the immune system. They originate in the bone marrow but move throughout the blood stream. These cells help fight infection by attacking bacteria, viruses and germs that invade the body. Reference range in adults: 4.5-11 x 109 /L Differential count of WBCs can be expressed in 2 ways Absolute count: The exact number of each type of WBCs Percentage count Percentage of each type compared to the total leukocytes count  Neutrophils Neutrophils are the most common type of white blood cell in the body, which makes them a first line of defense to heal injuries and fight infections. Neutrophils help prevent infections by blocking, disabling and digesting invading particles and microorganisms. They’re constantly searching for signs of infection, and quickly respond to trap and kill pathogens. Their cytoplasm is slightly acidophilic and c ontains many very fine granules that stain wi th neutral dyes; the granules stain a faint pur ple color Neutrophils Neutrophils increased in: Acute infections Inflammations Neutrophils decreased in: Infections Chemotherapy Folic acid or B12 deficiency  Eosinophils Eosinophils are another type of granulocyte with cytoplasm that contains large granules that generally stain bright red with a red dye eosin, and can also stain with other acid dyes, hence also known as acidophils. Eosinophils are a type of white blood cell that protect the body from parasites, allergens, foreign bacteria and outside organisms. Eosinophils Eosinophils increased in Allergy Parasitic infections Eosinophils decreased in Cushing’s syndrome Stress  Basophils Basophils are the least common type of granulocytes. They are the largest type of granulocyte. They are responsible for inflammatory reactions during immune response, as well as in the formation of acute and chronic allergic diseases, including anaphylaxis, asthma, Basophils get their name from their prominent (0.2–1 µm) cytoplasmic granules that have an affinity for basic dyes. These granules are numerous and unevenly distributed, with colors varying from deep purplish-blue to dark purple-red. Basophils Basophils increased in Chronic myelocytic leukemia Ulcerative colitis Basophils decreased in Stress Pregnancy  Lymphocytes Lymphocytes play an important role in the immune system, which helps the body fight disease and infection. There are two main types of lymphocytes: T lymphocytes (T cells): T cells control the body’s immune system response and directly attack and kill infected cells and tumor cells. B lymphocytes (B cells): B cells make antibodies. Antibodies are proteins that target viruses, bacteria and other foreign invaders. Lymphocytes Lymphocytes increased in Lymphocytic leukemia Viral infections Autoimmune diseases Lymphocytes decreased in Immune deficiency / suppression Monocytes They are the largest type of leukocyte in blood and can differentiate into macrophages and monocyte-derived dendritic cells. Monocytes are part of the innate immune response and functions to regulate cellular homeostasis, especially in infection and inflammation Monocytes Monocytes increased in Monocytic leukemia Infections Carcinoma/ lymphoma Autoimmune diseases Platelets Count Reference range in adults: 150-400 x 109 /L Platelets are assessed by blood smear or by hematology analyzer Thrombocytopenia, a low platelet count increase the risk of hemorrhage or severe bleeding. It is caused by: Alcoholism Autoimmune disease Chemotherapy Bone marrow diseases Thrombocytosis, increased platelets count can lead to thrombosis, heart attack or strokes. Thank you