Hematology Lecture Overview

Hematology Lecture Notes

• The lecture is about hematology.
• The instructor is Hanzely, DMSc, PA-C, RD.
• The course is offered at South College, focusing on career paths.

Instructional Objectives

• Inventory the components of a complete blood count (CBC), including RBC indices (MCV, MCH, MCHC).
• Compare common causes of anemia and polycythemia.
• Debate the importance of the reticulocyte count.
• Contrast ferritin, iron, total iron binding capacity, and transferrin, and their indications.
• Inspect the relationship between vitamin B12, folate, and megaloblastic anemia.
• Inventory the function of segmented neutrophils, lymphocytes, monocytes, eosinophils, basophils, and thrombocytes, and causes for increased or decreased levels.
• Inspect white blood cell inclusions and associated indications.
• Contrast Hodgkin's and non-Hodgkin's lymphoma.
• Compare chronic lymphocytic leukemia (CLL), acute lymphoblastic leukemia (ALL), chronic myeloid leukemia (CML), and acute myeloid leukemia (AML), and their corresponding laboratory findings.
• Recognize the importance of understanding Dr. Hanzely's memes.

Blood Components

• Blood is composed of plasma, white blood cells and platelets, and red blood cells.

Fishbone Diagrams

• Diagrams present a visual representation of various blood components and tests.

Complete Blood Count (CBC)

• A series of blood tests evaluating RBCs, platelets, and WBCs; easy, fast, inexpensive.
• Includes RBCs, hemoglobin, hematocrit, platelets, and RBC indices (MCV, MCH, MCHC, RDW).
• WBC count and differential are also included, assessing five distinct white blood cell types: neutrophils, lymphocytes, monocytes, eosinophils, and basophils.

Erythrocyte Count (RBCs)

• Reference range (males): 4.7 – 6.1 x10¹²/L; (females): 4.2 – 5.4 x10¹²/L.
• Measures RBCs in a cubic millimeter of peripheral blood.
• Female values are lower than male values, and RBC counts decrease with age.
• Decreased RBCs indicate anemia, caused by bone marrow production issues or increased loss.
• Conditions that increase loss include: hemorrhage, hemolysis, or dilution from body fluids (i.e., pregnancy).

CBC Example - Lab Results

• Provides sample CBC results and their flags (e.g., normal, abnormal).

Increased Erythrocyte Count (RBCs)

• Elevated RBCs indicate polycythemia.
• This is often caused by physiological induction due to increased oxygen requirements (e.g., high altitudes).
• Other causes include chronic hypoxia (e.g., smokers) or dehydration.

Anemias

• Macrocytic anemias (large RBCs) are associated with DNA synthesis impairment during RBC production, resulting in larger RBCs with fewer numbers.
• Microcytic anemias (small RBCs) are caused by iron deficiencies.
• Pancytopenia is the deficiency of all blood cell types, often caused by aplastic anemia (toxic exposure, hereditary factors, autoimmune diseases, or idiopathic).

Reticulocytes

• Aka "retic count," these are immature RBCs.
• Reference range in adults: 0.5%-2.0%.
• Increased reticulocytes suggest the bone marrow is producing more RBCs, often as a response to blood loss or hemolysis.
• Decreased reticulocytes mean the bone marrow is not responding adequately to anemia.

Hemoglobin (Hgb)

• The reference range (male): 14-18 g/dL; (female): 12-16 g/dL.
• Critical values for hemoglobin are less than 5 or greater than 20 g/dL.
• Hemoglobin (Hgb) is the RBC protein responsible for oxygen transport.
• Low hemoglobin is associated with anemia.

Hematocrit (Hct)

• Reference range (male): 42-52%; (female): 37-47%.
• Critical values are below 15% or above 60%.
• Reflects the percentage of total blood volume consisting of RBCs.
• Closely related to hemoglobin (Hgb) values.

Platelet Count (Plt)

• Reference range: 150,000-400,000/mm³.
• Critical values are below 50,000 or above 1 million/mm³.
• Essential for blood clotting.
• Decreased platelet count indicates thrombocytopenia, which has various potential causes, including problems with bone marrow production, hypersplenism, increased destruction, or consumption.
• Increased platelet count indicates thrombocytosis which sometimes accompany iron deficiency anemia and cancer.

Mean Platelet Volume (MPV)

• Measures the average size of platelets.
• Increased MPV usually indicates the bone marrow is releasing more immature platelets; this can happen in response to severe blood loss.
• Decreased MPV indicates the bone marrow isn't producing enough platelets.

Red Blood Cell Indices

• Provide information regarding RBC size, hemoglobin content, and concentration.
• Types of indices include MCV, MCH, MCHC, and RDW.

White Blood Cell Count

• Two components: WBC count and WBC differential.
• Reference range: 5,000-10,000/mm³.
• Critical values are below 2,500 or above 30,000/mm³.
• Routinely used to diagnose and track infections. Increased WBCs can result from infections, inflammation, stress, trauma, and cancers.
• Decreased WBCs indicate leukopenia, associated with bone marrow failure, overwhelming infection, and cancer treatment.

White Blood Cell Differential

• Percentage of each leukocyte type (neutrophils, lymphocytes, monocytes, eosinophils, basophils).
• Increased neutrophils indicate bacterial infections.
• Decreased or increased values of other types may reflect various medical conditions.

WBC Inclusions

• Hypersegmented neutrophils: abnormally high number of segments in neutrophils; usually seen in megaloblastic anemias.
• Dohle bodies: oval inclusions in neutrophils; often indicate severe stress or improper maturation.
• Auer rods: rod-shaped inclusions in white blood cells; indicative of acute myeloid leukemia.

Leukemia

• Cancer arising from WBCs; acute and chronic types.
• Chronic leukemia is often asymptomatic and characterized by the presence of many abnormal WBCs.
• May be identified via WBC differential showing high levels of certain cells like monocytes or lymphocytes.

Lymphomas

• Cancers arising in lymphocytes; two main types (Hodgkin's and non-Hodgkin's).
• Hodgkin's lymphoma is associated with Reed-Sternberg cells; associated with better prognosis
• Non-Hodgkin's lymphoma makes up a larger percentage of these cancers.

Iron Panel

• Includes serum iron, total iron-binding capacity (TIBC)/transferrin, transferrin saturation, ferritin.
• Serum iron levels reflect the amount of iron in the blood.
• TIBC reflects proteins available for iron binding.
• Transferrin saturation measures the extent to which TIBC is occupied by iron.
• Ferritin reflects iron stores in the body, its levels reflect iron stores in the body.

Erythrocyte Sedimentation Rate (ESR)

• Measures the rate at which RBCs settle.
• Increased ESR may indicate various inflammatory conditions (infection, cancer, necrosis).
• A non-specific test.

C-reactive Protein (CRP)

• An acute-phase reactant protein produced by the liver in the presence of inflammation or infection.
• More sensitive than ESR, and responds faster to inflammation; better as a marker of inflammation.
• Frequently used to monitor inflammatory conditions.

Coagulation Panel

• A group of tests assessing blood clotting mechanisms.
• Includes bleeding time, prothrombin time (PT), partial thromboplastin time (PTT), and fibrinogen.
• Bleeding time is useful in estimating platelet function.
• PT measures the extrinsic pathway of blood clotting.
• PTT is used to evaluate the intrinsic pathway of clotting.
• Fibrinogen is a protein necessary for blood clotting.

D-dimer

• Produced when fibrin degrades; increased levels indicate clot formation/degradation, suspicion of blood clots (DVT, PE).
• Important in diagnosing and monitoring conditions related to blood clots.

Other Information

• PA students' quotes on PA school.