Week 7 Flashcards
Composition of whole blood by volume
Plasma: ~55%
RBC’s: ~45%
WBC’s/platelets:
List the different WBC’s and their prevalence in normal blood:
Neutrophils: 60% Lymphocytes: 25% Monocytes: 5% Eosinophils: 3% Basophils:
Structure and function of leukopoetic tissue: what two main events do they carry out?
The basic function of blood leukocytes is as a defense system against infectious foreign invaders and non-infectious challenges. This is divided into two separate, but interconnected events:
–Phagocytosis
•Involves granulocytes and monocytes
–Development of a specific immune response
•Involves monocytes (macrophages) and lymphocytes
•The vascular system is only a temporary residence for leukocytes. The main function of the vasculature with respect to WBCs is to transport the leukocytes to body tissues.
Function of the Bone marrow
Bone Marrow is the production site for all hematopoiesis (cells that comprise blood)
•Located primarily in hollow portions of long flat bones like the sternum and hips
•Two types of marrow; red and yellow. Majority of RBCs, WBCs and platelets are formed in red marrow.
•Healthy marrow produces as many cells as the body needs
Pluripotent Stem Cells
Pluripotent: pluri = more + potential = power
Refers to the ability of a cell to become many different types of cells
•2 types of stem cells in bone marrow:
Mesenchymal: connective tissue, blood vessels and lymphatic tissue
Hematopoietic: blood cells: RBCs, WBCs, platelets
How are Leukocytes differentiated from each other?
Leukocytes are differentiated from each other by nuclear and cytoplasmic characteristics: Basically Granulocytes and Agranulocytes
–Granulocytes (contain granules)
•The granules in eosinophils have affinity for the acid part of the Wright’s stain and they stain orange-pink
•The granules of basophils have affinity for the basic part of the stain and they stain bluish-black.
•The granules of neutrophils have an affinity for both acid and basic parts of the stain and they stain pinkish-blue.
Agranulocytes (lack granules):
•Monocytes are usually large with a horseshoe shaped nucleus
•Lymphocytes may be small (non-reactive) with a large nuclear to cytoplasmic ratio or large (reactive) with a smaller nuclear to cytoplasmic ratio. The nucleus is usually round (small lymphs) or may be slightly indented (large lymphs).
•Leukocytes differentiate into mature cells from the pluripotential stem cell in the bone marrow.
General maturation process of WBC’s and RBC’s
General Maturation Scheme in direction of
LESS mature to MORE mature
First 4 characteristics apply to WBC (and RBC) Development:
•Cytoplasm: More basophilia Þ less basophilia
•Large nucleus Þ smaller nucleus
•Large nucleoli Þ Small nucleoli Þ then absent
•Large cell size Þ smaller cell size
5th Characteristic: For WBC granulocytes only:
nucleus large & round Þ smaller & segmented
Maturation of Granulocytes
Granulocytes
Six general stages of maturation following commitment of stem cell in bone marrow:
1. Myeloblast Non-granular cytoplasm & red nucleus
2. Promyelocyte distinct granules
3. Myelocyte [cell division possible through this stage] granules differentiate enough to be identified n/e/b
4. Metamyelocyte slightly indented nucleus
5. BandIndentation > ½ Width hypothetical round nucleus
6. Segmented cell
Assessment of circulating WBC’s
-How are they counted?
The total white blood cell count (WBC) and differential are measured in an automated counter
•WBC reflects the circulating pool of myeloid and lymphoid cells
•WBC in each microliter (ml;mm3) is reported
Normal values for WBC counts
Total WBC count
Adult/child > 2 yrs: 4,500-10,000 per mm3
Child
What levels of WBC’s qualify as Leukocytosis?
-Under what conditions would leukocytosis occur?
WBC > 11,000/mm3
Leukocytosis
- Infections
- Leukemic neoplasia
- Other malignancy
- Trauma, stress, hemorrhage
- Tissue necrosis
- Inflammation
- Dehydration
- Thyroid storm
- Steroid drugs
- Post Splenectomy
What levels of WBC’s qualify Leukopenia?
-in what conditions might you see leukopenia?
WBC
When are WBC’s released into the blood in relation to their maturation process? At birth leukocyte count is…
Normally only mature cells are released into the peripheral blood.
•Mature cells may also remain as storage in the bone marrow.
•At birth the leukocyte count is high: 9-30 x 109/L ; in adults the normal is 4-10.5 x 109/L
•An increase or decrease in WBC count may be caused by an alteration of all WBC cell lines, but more commonly results from an alteration of only one type of WBC.
Therefore, a differential is important. From the differential and the -WBC count, the absolute values for each type of WBC can be calculated (relative differential (%) x total WBC count).
•Most variations in the leukocyte count are due to increases or decreases in the number of neutrophils since by percentage they are the most numerous
How to do a differential WBC count
Place one drop of blood onto glass slide, spread the drop & air dry.
•Wright’s Stain: A mixture of Methylene Blue basic dye and Eosin red-orange acidic dye.
•Phosphate buffer applied directly on top of stain, rinse, dry & examine.
•Oil immersion [100x] lens: count 100 WBCs
•This gives the RELATIVE # of each type of WBC, expressed as a percentage of the 100 cells counted.
WBC: Wright Stain
Cell structures with acidic groups bind the basic dye & appear blue.
Cell structures with basic groups bind the acidic dye & appear various shades of pink or red-orange.
How to identify each of the WBC’s by appearance/color
Agranulocytes:
- Lymphocytes = scant cytoplasm
- Monocytes =ground glass cytoplasm
Granulocytes:
- Neutrophils = Lavender
- Eosinophils = Orange/red
- Basophils = Blue/Black
60, 30, 6, 3, O, Never Let Monkeys Eat Blow
Neutrophils 60% Lymphocytes 30% Monocytes 6% Eosinophils 3% Basophils ~0.1%
WBC count normal ranges graph on SLides!
Look at it
When is the “absolute” number of cell type helpful?
Absolute” (ABS) Number of cell type:
Important for determining if patient has a sufficient # cells of a specific type.
ABS # = (total WBC) X Relative #
of each cell type on the Diff. WBC count.
NOTE: Convert relative percentage to a decimal prior to performing calculation.
Absolute vs. relative WBC counts
Ex:
Example:
Adult with total WBC = 15,000 (rr:4,500-10,000)
WBC Diff.: 30% neutrophils (RR:55-70)
70% lymphocytes
Is this patient REALLY neutropenic?
Abs # neutrophils = 15,000 X 0.30 = 4500
(rr:2500-8000)
Patient has a normal absolute neutrophil count and only has a relative neutropenia, NOT absolute neutropenia.
Talk about Neutrophils
All PMNs capable of phagocytosis
•Neutrophils are the most common PMN (polymorphonuclear leukocytes) & are primary defense against microbial invasion
•Stored in bone marrow for 5-7 days (mature neutrophil reserve). Circulate in blood for about 7 hours. And live in tissue for 2 more before they apoptose
•Acute bacterial infection, inflammation, & trauma stimulate neutrophil production leading to increased total WBC count
•Granules contain leukocyte alkaline phosphatase (LAP)
Cytoplasm may show vacuoles during active phagocytosis
•Toxic granulation:
Dark purple granules in cytoplasm
due to severe infections, burn pts.
•Shift to the left:
Band neutrophils in peripheral circulation – response to bacterial infection
•Nucleus becomes hypersegmented with vitamin B12 or folic acid deficiency
Toxic granulation of Neutrophils
Toxic granulation is found in severe inflammatory states. The toxic granules are azurophilic, and is thought to be due to impaired cytoplasmic maturation in the effort to rapidly generate large numbers of granulocytes.
Hypersegmentation of Neutrophils
More that 3 cells (per 100) with 5 lobes or one with 6 lobes is evidence of hypersegmentation
Nucleus becomes hypersegmented with vitamin B12 or folic acid deficiency
Neutrophilia
-What conditions can cause it?
Neutrophilia = increase •Acute infection •Trauma •Physical/emotional stress •Inflammatory disorders •Metabolic disorders •Myelocytic leukemia •Cushing’s syndrome
Neutropenia
-What can cause it?
Neutropenia = decrease •Overwhelming bacterial infection •Viral infections •Aplastic anemia •Radiation therapy •Addison’s disease •Chemotherapy •Dietary deficiency
Eosinophils
Cytoplasm stains what color?
Contain 4 proteins to help eliminate parasites:
How might stress affect eosinophil count?
Increased eosinophils can aid in the diagnosis of ______________.
Cytoplasm contains red-orange granules
•contain 4 proteins help eliminate parasites:
peroxidase
major basic protein
eosinophil cationic protein
eosinophil-derived neurotoxin
•Increased cortisol levels suppress eosinophils
•Increased eosinophils in nasal smear aid in diagnosis of allergic rhinitis
Eosinophilia
what is it? what causes it?
Eosinophilia (>5%) = increase •Parasitic infections •Allergic reactions •Asthma, hay fever •Hodgkin’s Disease •Eosinophil Myalgia Syndrome •Eczema •Leukemia •Autoimmune disease •Ovarian Cancer
Eosinopenia
what is it? What causes it?
Eosinopenia = decrease
•Cushing Syndrome
•Endogenous or exogenous cortisol excess
•Stress (shock, severe burns, severe infections)
Talk about Basophils
Granules contain?
Similar to mast cells
•Capable of phagocytosis of immune complexes
•Granules contain:
heparin, histamine and serotonin
•Basophils and mast cells degranulate during allergic reactions, releasing histamine, etc.
Good chart comparing Basophils and Mast Cells!
Check it out
Basophilia
what causes it?
Basophilia >50/mm3 increase •Myleoproliferative diseases: Polycythemia •Granulocytic leukemia •Chronic Myelocytic Leukemia (CML) •Hodgkin’s Lymphoma
Basopenia
Basopenia(
List the agranulocytes
Lymphocytes – three types
•T cells: Mature in thymus. Involved in cellular mediated immunity:
T-suppressor cells (CD8)
T-Helper cells (CD4)
2 B cells (CD19, CD20): Mature in bone marrow. Participate in humoral immunity, as plasma cells they produce antibodies.
3 NK -Natural killer cells (CD56, CD57)
•Monocytes
Lymphocytes arise from….
Where do they mature?
Arise from the fixed tissue reticulum cell in the bone marrow
•B lymph. mature in BM
•T lymph. mature in the thymus
•Plasma cells B lymphocytes that are committed to active production of antibodies
•Atypical lymphocytes: are seen in some viral infections, e.g. infectious mononucleosis
Lymphocytosis
Lymphocytosis >4000/mm3 •*Viral infections*: CMV, HIV •Some bacterial infections (pertussis,TB) •Lymphocytic leukemia •Multiple myeloma (plasma cell proliferation) •Infectious mononucleosis/EBV •Infectious hepatitis •Hypoadrenalism (Addison’s Disease)
Lymphopenia
Lymphopenia
Lymphocyte immunophenotyping:
Normal findings
T cells
60-95
800-2500
T helper CD4
60-75
600-1500
T suppressor CD8
25-30
300-1000
Normal CD4:CD8 ratio = 2:1 (in HIV+ patients once it drops below >1:1, that’s when it technically becomes AIDS)
B cells
4-25
100-450
Natural killer
4-30
75-100
CD4/CD8
> 1.0
Monocytes
(monocytes are just macrophages in circulation. Once they leave circulation, that’s when they are technically macrophages.)
Arise in bone marrow
from a common progenitor
cell with the granulocytes
•Can be produced rapidly as
needed, spend longer time
in circulation
•Function as phagocytes, much the same as neutrophils do, engulf bacteria
•Remove necrotic debris from blood
•3 classic characteristics
Monocytosis
Monocytosis (>500/mm3) increase •Some viral infections, •infectious mono=EBV •Chronic bacterial inf. •Tuberculosis •Subacute Bacterial Endocarditis SBE •Syphilis •Chronic ulcerative colitis •Parasites, e.g. malaria •Monocytic leukemia
Monocytopenia
Monocytopenia (
WBC summary chart
checck it out
WBC, response to infection
WBCs released from bone marrow pool
•Increase production from myelocyte stage in bone marrow via cell division
•Immature forms are released from bone marrow
•Band cells are most common = left shift
•Severe infections may see occasional metamyelocyte
Granulocyte pools
Bone Marrow Pool: BMP
•Circulating Granulocyte Pool: CGP
•Marginal Granulocyte Pool: MGP (attached to the endothelium)
WBC, early infection
Circulating granulocyte pool (CGP) “marginates” along endothelial lining of blood vessels near infected tissues
•Extravasation of CGP “diapedesis”
towards site of infection
•Rapid migration to tissues, in excess of marrow release rate, can result in decreased WBC count in early stages of infection
b/c they are all attached to the endothelium about to undergoe diapedesis
Early infection to later infection to recovery from infx
BM pool holds a 4-10 day supply of immature cells:
released as needed as they mature. Immature forms seen in circulation indicate dysregulation of release mechanism, OR increased DEMAND
•Bone marrow responds to demand for increased WBCs
•With increasing bone marrow output, the total body granulocyte pool (TBGP) increases, but due to continued margination, WBC count may still appear normal or decreased, aka “masked neutrophilia”
Later infx
CGP and MGP finally equilibrate due to
increased marrow output
•WBC count increases & left shift appears
•Indication that body is responding effectively
Recovery from infx
Marrow output drops
•WBC count decreases & left shift disappears
•WBC count returns to normal
Leukemoid reaction
Leukemoid reaction:
A nonleukemic WBC count greater than 50,000/mm3, on a differential count with NO more than 5% metamyelocytes or earlier cells.
Associated with:
Severe bacterial infections, severe toxic states (burns, necrotic tissue), marrow replacement by tumor, severe hemolytic anemia, severe acute blood loss, juvenile rheumatoid arthritis
Leukemoid reaction vs. Leukemia
Neutrophil granules contain leukocyte alkaline phosphatase (LAP), an enzyme marker used to differentiate
CML (chronic Myeloid Leukemia) => LAP low
Leukemoid reactions => LAP high
•Requires special stain: Leukocyte Alkaline Phosphatase stain= “LAP” stain
Leukoerythroblastic reaction
Leukoerythroblastic reaction:
Defined by the presence of both immature WBCs and nucleated RBCs in the peripheral blood
Causes: Metastatic tumor in marrow – 25-30% Leukemia – 20% Myeloid metaplasia or polycythemia – 10% Severe infection, megaloblastic anemia, severe acute hemorrhage – about 5% each
WBC counts based on dz state graph
check it ou
Platelets primary and secondary roles
have a primary role in blood clotting, vasoconstriction and vascular integrity
secondary role as hormone serotonin carrier.
Platelet count
Formed by what cell, where?
Life span?
How are they removed from circulation?
Formed in the bone marrow
•Parent cell is the megakaryocyte, platelets are cytoplasmic fragments
•Small, round anucleated “cells”
•Platelets form aggregates when injury occurs to vascular endothelium to help maintain vascular integrity
•Most platelets are found in the circulating blood where they survive for 7-10 days
•25% -30% found in the spleen & liver (reservoir)
Platelet counts
Normal values:
Critical values:
Normal findings:
Adult/elderly/child: 140,000-400,000/mm3
Infant: 200,000-475,000
Newborn: 150,000-300,000
Critical values:
1,000,000/mm3
Platelet deficiency is called?
High Platelet count is called?
Crazy high platelet count is called?
What levels are associated with each?
Platelet terminology:
•Thrombocytopenia = count 400,000
•Thrombocythemia = count > 1,000,000
Thrombocytosis
-conditions it’s associated with?
Increased levels - Thrombocytosis
•Malignant disorders, esp CML (malignancy is found in 50% of those with unexpected increased platelet counts)
•Polycythemia vera PCV
•Acute infections, sepsis
•Post-splenectomy syndrome = no reservoir
•Rheumatoid arthritis and other inflammatory dz
•Iron deficiency anemia
•Primary (Essential) thrombocytosis
Thrombocytopenia
-Causes:
-Hypersplenism
-Hemorrhage
•Immune thrombocytopenia
•Leukemia (except CML increases)
•Myelofibrosis
•TTP-Thrombotic thrombocytopenia purpura
•ITP-Idiopathic
•Aplastic anemia
- Graves’ disease
- Pre-eclampsia
- Inherited disorders
- DIC
- SLE
- Pernicious anemia
- Hemolytic anemia
- Cancer chemotherapy
- Severe infection
- Drug reactions
Dangers of thrombocytopenia
Thrombocytopenia:
•danger of spontaneous hemorrhage.
•Counts above 40,000 rarely exhibit spontaneous hemorrhage, but prolonged bleeding with surgery is common.
At counts of
Dangers with thrombocytosis? Thrombocythemia?
Thrombocytosis count > 400,000:
• As the platelet count increases, the probability of ABN platelet function also increases, danger from thrombosis rises
- Thrombocythemia count > 1,000,000:
- Not uncommon for patient to experience spontaneous bleeding & thrombosis. Aggregation usually abnormal
What can alter platelet counts?
High altitude increases count
•Strenuous exercise may increase levels
•Decreased levels may occur prior to menses
•Estrogens increase levels
•Many drugs
EDTA can cause platelets to form “satellites” around WBCs Falsely decreases platelet count.
•Difficult blood draw microclots in EDTA tube Falsely decreases Platelet Count.
•Investigation of Plt count should ALWAYS start with the above – ask lab to review a peripheral blood smear to check for these phenomena.
Mean Platelet volume
Normal finding:
WHat is it?
Normal findings: 7.4-10.4 mm3 (or fl)
•The MPV is the average volume of a population of platelets determined by an automated cell counter
•MPV relationship to platelets is the same as MCV relationship to red cells
•MPV varies with total platelet production
In thrombocytopenia with a normally reactive bone marrow: large immature platelets are released in attempt to maintain normal function (e.g., hypersplenism)
In thrombocytopenia with a suppressed bone marrow: the platelets that are released are small (e.g., cancer chemotherapy)
Interferring factors with MPV
Interfering factors EDTA anticoagulant (the standard for cell count blood samples) can create variation of up to 25% increase in size of platelets
Increased MPV causes
Increased volume •*Valvular heart disease* •ITP •Sepsis •Immune thrombocytopenia •Severe hemorrhage •*B12/Folate deficiency* •Myelocytic leukemia
Decreased MPV
Decreased volume
•Aplastic anemia
•Cancer chemotherapy
•Wiskott-Aldrich syndrome
CBC include what info?
RBC info: # RBCs, Size (MCV & RDW), Hgb, Average Hgb content of RBCs (MCH, MCHC), hematocrit (% of blood comprised of RBCs).
WBC info: number of WBCs, WBC differential (WBC populations)
PLT info: number of platelets, platelet volume (MPV)
