Overview Part 2 Flashcards
A______ is performed on automated blood cell analyzers and includes the RBC, WBC, and platelet measurements
complete blood count (CBC)
No matter who collects, the ______ is responsible for the integrity of the specimen and ensures that it is submitted in the appropriate anticoagulant and tube and is free of clots and hemolysis
medical laboratory professional
red-tinted plasma indicating RBC damage
Hemolysis
The specimen must be of sufficient____, because “short draws” result in incorrect anticoagulant-to-blood ratios.
volume
The specimen must be tested or prepared for storage within the appropriate time frame to ensure accurate analysis and must be accurately registered in the work list, a process known as…
specimen accession
may be automated, relying on bar code or radio-frequency identification technology, thus reducing instances of identification error.
Accession
Although all laboratory scientists and technicians are equipped to perform visual RBC, WBC, and platelet counts using dilution pipettes, hemacytometers, and microscopes, most laboratories employ______ to generate the CBC.
automated blood cell analyzers
Many blood cell analyzers also provide comments on RBC, WBC, and platelet______.
When one of the results from the blood cell analyzer is abnormal, the instrument provides an indication of this, sometimes called a_____.
morphology
flag
In case of a flag, a________ is performed
“reflex” blood film examination
The_______ is a specialized, demanding, and fundamental CBC activity.
Nevertheless, if all blood cell analyzer results are within reference intervals, the it is usually omitted from the CBC.
How-ever, physicians may request it on the basis of clinical suspicion even when the analyzer results fall within their respective reference intervals.
blood film examination
To accomplish a blood film examination, the microscopist prepares a “______” blood film on a glass microscope slide, allows it to dry, and fixes and stains it using Wright or Wright-Giemsa stain
wedge-prep
Blood film examination
The microscopist visually performs an estimate of the WBC count (objective and examination???) and platelet count (objective and examination???) for comparison with their respective analyzer counts, and investigates discrepancies.
with the 40X or 50x objective at 400X or 500X magnification
with the 100× oil immersion objective at 1000% mag-nification
Blood film examination
Next, the microscopist svstematicallv reviews, identifies, and tabulates 100 (or more) WBCs to determine their percent distribution. This process is referred to as determining the…
WBC differential (“diff”)
True or False
The WBC differential relies on the microscopist’s skill, visual acuity, and integrity, and it provides extensive diagnostic in-formation.
True
Blood film examination
Finally the microscopist examines the morphology of WBCs, RBCs, and platelets by light microscopy for abnormalities of shape, diameter, color, or inclusions using ______magnification.
1000×
Visual recognition systems such as the_______ automate the WBC, RBC and platelet morphology assessment and WBC differential processes, but the medical laboratory professional or the hematopathologist is the final arbiter for all cell identification.
Cellavision DM96
Results of the CBC, including all automated blood cell analysis and blood film examination parameters and interpretive comments, are provided in paper or digital formats for physician review with______ results highlighted.
abnormal
Because they are structural and do not flow in the bloodstream,________, the endodermal cells that form the inner surface of the blood vessel, are seldom studied in the hematology laboratory
endothelial cells
are important in maintaining normal blood flow, in tethering (decelerating) platelets during times of injury, and in enabling WBCs to escape from the vessel to the surrounding tissue when needed
endothelial cells
______are a key component of hemostasis, as previously described;
_______is the second component
Platelets
plasma coagulation
The _______employs a complex sequence of plasma proteins, some enzymes, and some enzyme cofactors to produce clot formation after blood vessel injury.
Another six to eight enzymes exert control over the coagulation mechanism, and a third system of enzymes and cofactors digests clots to restore vessel patency, a process called______.
coagulation system
fibrinolysis
The medical laboratory professional focuses especially on blood specimen integrity for the______, because minor blood specimen defects, including clots, hemolysis, lipe-mia, plasma bilirubin, and short draws, render the specimen useless
coagulation laboratory
High-volume coagulation tests suited to the acute care facility include the:
platelet count and MPV
prothrombin time and partial thromboplastin time (or activated partial thromboplastin time)
thrombin time (or thrombin clotting time)
fibrinogen assay
D-dimer assay
_______ and ______ are particularly high-volume assays used in screening pro-files.
These tests assess each portion of the coagulation pathway for deficiencies and are used to monitor anticoagulant therapy
The prothrombin time and partial thromboplastin time
Another 30 to 40 moderate-volume assays, mostly clot-based, are available in________ facilities.
The _______ coagulation laboratory with its interpretive complexities attracts advanced medical laboratory scientists with specialized knowledge and communication skills.
specialized or tertiary care facilities
Advanced hematology procedures
Besides performing the CBC, the hematology laboratory provides: (4)
Performing these tests may require advanced preparation or particular dedication by medical laboratory scientists with a desire to specialize.
bone marrow examinations
flow cytometry immunopheno-typing
cytogenetic analysis
molecular diagnosis assays
______ and ______ specimens are collected and stained to analyze nucleated cells that are the immature precursors to blood cells
Bone marrow aspirates and biopsy
Cells of the_______ are precursors to RBCs
erythroid series
mature to form bands and neutrophils, eosinophils, and basophils
myeloid series cells
myeloid series cells mature to form…
bands and neutrophils, eosinophils, and basophils
produce platelets
megakaryocytes
Medical laboratory scientists, clinical pathologists, and hematologists review Wright-stained aspirate smears for morphologic abnormalities, high or low bone marrow cell concentration, and inappropriate cell line distributions.
For instance, an increase in the______ may indicate bone marrow compensation for excessive RBC destruction or blood loss
erythroid cell line
The biopsy specimen, enhanced by ________staining, may reveal abnormalities in bone marrow architecture indicating leukemia, bone marrow failure, or one of a host of additional hematologic disorders.
hematoxylin and eosin (H&E)
Results of examination of bone marrow aspirates and biopsy specimens are compared with____ results generated from the peripheral blood to correlate findings and develop pattern-based diagnoses.
CBC
In the bone marrow laboratory,_____ stains may occasionally be employed to differentiate abnormal myeloid, erythroid, and lymphoid cells.
cytochemical stains
Cytochemical stains include
myeloperoxidase
Sudan black B
nonspecific and specific esterase
periodic acid-Schiff
tartrate-resistant acid phosphatase
alkaline phosphatase
Since 1980, however,________ methods have enabled identification of cell lines by detecting lineage-specific antigens on the surface or in the cytoplasm of leukemia and lymphoma cells.
immunostaining
An example of______ is a visible dye that is bound to antibodies to CD42b, a membrane protein that is present in the megakaryocytic lineage and may be diagnostic for megakaryo-blastic leukemia
immunostaining
________may be:
quantitative, such as _______that have grown from the original Coulter principle, or
qualitative, including_____ that have migrated from research applications to the clinical laboratory
Flow cytometers
clinical flow cytometers
laser-based instruments
_______ are automated clinical blood cell analyzers that generate the quantitative parameters of the CBC through application of electrical impedance and laser or light beam interruption.
Qualitative _______ are mechanically simpler but technically more demanding.
Clinical flow cytometer
laser-based flow cytometers
True or False
Both qualitative and quantitative flow cytometers are employed to analyze cell populations by measuring the effects of individual cells on laser light, such as forward-angle fluorescent light scatter and right-angle fluorescent light scatter, and by immunophenotyping for cell membrane epitopes using monoclonal antibodies labeled with fluorescent dyes.
True
The ______ is indispensable to leukemia and lymphoma diagnosis.
qualitative flow cytometry laboratory
a time-honored form of chromosome analysis, is employed in bone marrow aspirate examination to find gross genetic errors
Cytogenetics
_______, a reciprocal translocation between chromosomes 9 and 22 that is diagnostic in chronic myeloid leukemia
_______, a translocation between chromosomes 15 and 17 diagnostic in acute promyelocytic leukemia.
Philadelphia chromosome
t(15;17)
True or False
Cytogenetic analysis remains essential to the diagnosis and treatment of leukemia.
True
the fastest-growing area of laboratory medicine, enhance and even replace some of the advanced hematologic methods.
Molecular diagnostic techniques
Real-time polymerase chain reaction, microarray analysis, fluorescence in situ hybridization, and DNA sequencing systems are sensitive and specific methods that enable medical laboratory scientists to detect various chromosome translocations and gene mutations that confirm specific types of leukemia and lymphoma, establish their therapeutic profile and prognosis, and monitor the effectiveness of treatment.
Molecular diagnostic techniques
The___________ phenotypically detects an inherited RBC enzyme deficiency causing episodic hemolytic anemia
glucose-6-phosphate dehydrogenase assay
The _________and its follow-up tests,______ and ______ are used to detect and diagnose sickle cell anemia and other inherited qualitative hemoglobin abnormalities and thalassemias
sickle cell solubility screening assay
hemoglobin electrophoresis and high-performance liquid chromatography,
One of the oldest hematology tests, the_______, detects inflammation and roughly estimates its intensity
erythrocyte sedimentation rate
the medical laboratory professional reviews the cellular counts, distribution, and morphology in body fluids other than blood
These include: (5) in which RBCs and WBCs may be present in disease and in which malignant cells may be present that require specialized detection skills.
cerebrospinal fluid
synovial (joint) fluid
pericardial fluid
pleural fluid
peritoneal fluid
Analysis of_______ is always performed with a rapid turnaround, because cells in these environments rapidly lose their integrity.
The conditions leading to a need for body fluid analysis are invariably acute.
nonblood body fluids
Medical laboratory professionals employ particularly complex quality control systems in the hematology laboratory.
Because of the unavailability of weighed standards, the measurement of cells and biological systems defies chemical standardization and requires elaborate calibration, validation, matrix effect examination, linearity, and reference interval determinations.
An internal standard methodology known as the_______ also supports hematology laboratory applications.’
moving average
Medical laboratory professionals in all disciplines compare methods through______ that produce clinical sensitivity, specificity, and positive and negative predictive values for each assay.
clinical efficacy calculations
They must monitor specimen integrity and test ordering patterns and ensure the integrity and delivery of reports, including numerical and narrative statements and reference interval comparisons.
Medical laboratory professionals
RBC Parameters
- RBC: Red Blood Cell count
- HGB: Hemoglobin
- HCT: Hematocrit
- MCV: Mean Corpuscular Volume
- MCH: Mean Corpuscular Hemoglobin
- MCHC: Mean Corpuscular Hemoglobin Concentration
- RDW: Red Cell Distribution Width
- RETIC: Reticulocyte Count
WBC parameters
- WBC: White Blood Cell count
- NEUT: Neutrophil count (percentage and absolute)
- LYMPH: Lymphocyte count (percentage and absolute)
- MONO: Monocyte count (percentage and absolute)
- EO: Eosinophil count (percentage and absolute)
- BASO: Basophil count (percentage and absolute)
Platelet parameters
- PLT: Platelet count
- MPV: Mean Platelet Volume
