Hematology Flashcards
Factors influencing the CBC?
- Activity
- Stress
- Altitude
- Time of day
- Medications
Information in a routine CBC?
- Total White blood cell count
- Total red cell count
- Hemaglobin
- Hematocrit: % of red blood cells in X volume of blood
- Mean cell volume (MCV): average size of RBCs
- Mean cell haemoglobin (MCH)
- Mean corpuscular hemoglobin concentration (MCHC)
- Red Cell Distribution width
- Platelet count
- Mean platelet volume
- Relative (can be wrong)
- Neutrophil
- Lymphocyte
- Monocyte
- Eosinophil
- Basophil
- Absolutes
- Manual Differentials (microscope)
- Automated (machine)
- Reticulocytes/nucleated red blood cells
What test is not included in a CBC that is very important in the diagnosis of RBCs disorders??
Reticulocyte count: should be the starting point for any assessment of anemia (low blood hemoglobin)
- Too few reticulocytes – impaired production
- Increased reticulocytes – accelerated destructions
What are white blood cells counts?
- All circulating nucleated hematopoietic cells with the exception of nucleated red blood cells (NRBCs).
- WBC used to diagnose and manage patients with hematologic and infectious diseases, or problems with the immune system.
- Used to monitor patients receiving cytotoxic drugs, radiation therapy, and some antimicrobial drugs
- The absolute neutrophil count, (ANC) is helpful in monitoring chemotherapy patients, and the absolute neutrophil count is a superior indicator of infection and inflammation
What is the role of Neutrophils?
Neutrophils are granulocytes and account for 50%–62% of WBC
Neutrophils are subclassified according to their age or maturity, which is indicated by changes in the nucleus
- Metamyelocyte: youngest neutrophil, large nucleus, round or bean-shaped
- Neutrophil band or stab (3%–6%): the nucleus is elongated and curved (horseshoe or S-shape)
- Segmented neutrophil: mature neutrophil, the nucleus is separated into 2-5 segments or lobes
Don’t normally circulate, they stick to blood vessels and go where they need to go when there is a signal (demargination)
What is the role of Lymphocytes?
Lymphocytes are agranulocytes. They are the brain of the immune system, response to specific organisms, types:
- T cell: matures in thymus, recognize antigen and stimulates immune response
- B cell: stimulated by T cells, matures in the bone marrow, several subtypes divided into regulator or effector cell, synthesis antibodies
- Natural killer cells: respond to a changes in normal cell states, directly attacks tumour and virally infected host cells
What is the role of Monocytes?
- Monocytes are agranulocytes
- Monocytes: the largest WBC circulating in peripheral blood
- Monocyte –> macrophage in the tissue
- Macrophages in tissue have different names related to the particular tissue in which they are found
* Are the predominant leukocyte within 48 hours after injury - Monocytes and macrophages are described as one system: mononuclear phagocyte system
- Macrophages: first cell to engulf and process the antigen and present it to the lymphocytes stimulating a specific immune response to that antigen. They destroy the organism while keeping its cell surface markers to give to the lymphocytes so that they can identify that organism and mount a defense
In what conditions basophils and eosinophils increase?
- Bacterial infections
- Acute inflammatory diseases
- Cancer (particularly with marrow metastasis)
- Tissue necrosis
- Acute transplant rejection
- Surgical and orthopedic trauma
- Myeloproliferative diseases
- Steroid use
- Pregnancy (mainly during the third trimester)
What is the role of eosinophils ?
To kill larger organisms
What is the role of basophils?
hypersensitivity reactions (allergies)
What are the granulocytes WBC?
- Eosinophils
- Basophils
- Neutrophils
What are the agranulocytes WBCs?
- Lymphocytes
- Monocytes
What WBCs are hard to count?
- Monocytes
- Basophils
What is Neutrophilia?
+++ neutrophils
- Caused by acute bacterial infection Þ rise 4 to 6 hours after an invasion by microorganisms
* *“Shift to the left”:** infection present, new neutrophils, immune system is active - Associated with obesity and smoking, the stress of surgery, medications
* *“Shift to the right”** = an increased neutrophil count without the immature cells
What is Neutropenia?
- neutrophils due to severe prolonged infection
What is Monocytosis?
+++ monocytes
- Absolute monocytosis: marker of a myeloproliferative disorder (e.g., chronic myelomonocytic leukemia) until proved otherwise Þ bone marrow examination and cytogenetic studies + hematology consultation
- Relative monocytosis: seen during recovery from drug-induced neutropenia
What is Lymphocytosis?
+++ lymphocytes due to viral or B-cell leukemia
What is Eosinophilia?
+++ eosinophils in response to parasitic infections (e.g. toxoplasmosis, GI parasites)
What is Basophilia?
An hypersensitive response, look for allergies
Gross component of blood?
55% plasma (acellular), serum = plasma without clotting factors
45% cellular elements
What are the causes of anemia?
- Deficiency of RBC “building blocks”
- Congenital anomaly of the contents of RBC
- Anomaly in the production of the RBC
- Accelerated RBC loss via bleeding
- Accelerated destruction of RBC (i.e. decreased lifespan) – hemolysis
- Chronic illness with suppressed erythropoiesis
What is the approach to anemia?
B12 deficiency can be due to what?
- Pernicious anemia (autoimmune destruction of parietal cells of the stomach Þ no intrinsic factor)
- Nutrition
- Malabsorption due to associated gastrointestinal abnormalities
Folate deficiency can be caused by what?
- drugs
- increased loss (dialysis)
- increased utilization (pregnancy, psoriasis)
- malabsorption
- nutrition
Most common cause of anemia worldwide?
Iron deficiency
What is Thalassemia anemia?
An haemoglobin structure problem, common in Mediterranean, Middle Eastern, African, South and Southeast Asian descent
What is Hemolytic anemia?
An increased breakdown of red blood cells –> high LDH, biliburin, reticulocyte
CAUSES:
- Extra-corpuscular (outside)
- Red blood cell membrane (inside) Þ sickle cell anemia
- Enzyme defects (inside)
- Hemoglobin (inside)
Myeloproliferative Disease?
- Increased cell number but intact differentiation
- May affect one ore more cell lines
- CML – protoype disease driven by bcr-abl kinase
lMyelodysplastic Disease?
- Low and high risk disease – may transform to AML
- Impaired Differentiation: Increased bone marrow cells with decreased circulating cells
Acute Myeloid Leukemia?
- Most common in adults
- Variable prognosis depending on cytogenetics
- Treatment is targeted treatment and chemotherapy
lAcute Promyelocytic Leukemia (M3)?
- Type of AML
- PML-RARa gene from translocation of chromosomes 15 and 17
- Good prognosis with All-trans-Retinoic Acid
Acute Lymphoblastic Leukemia?
- Most common in children
- Excellent response to multiagent chemotherapy if in childhood, prognosis worse in adults
- Types:
- B lineage (80%)
- T lineage (20%)
Types of Chronic leukemia?
- Chronic lymphocytic leukemia (CLL)
- A subtype of B cell lymphoma
- Atypical CD5 expression (CD5 is a T cell marker)
- Chronic myeloid leukemia (CML)
Types of Myeloproliferative neoplasms?
- Chronic Myeloid Leukemia
Mainly white blood cells affected that results in accumulation of uncontrolled granulocytes
Starts with chronic phase (4-7 years) Þ accelerated Þ blast phase
Treatment is targeted therapy - Essential Thrombocytosis – mainly platelets affected
- Polycythemia vera – mainly rbc cells affected
- Myelofibrosis – mainly accumulation of bone marrow fibroblasts
Clinical manifestations of acute leukemia?
- Pancytopenia from marrow failure: neutropenia, anemia, thrombocytopenia
- Constitutional Symptoms: fevers, fatigue, bone pain, malaise
- Direct Tissue Infiltration by blast cells
- Leukostasis syndromes: accumulation of blasts in microcirculation with impaired perfusion
- Tumour Lysis Syndrome
- Coagulation Disturbances
- Usually short duration of symptoms (weeks to months)
