Transcript Chapter One - cvadultcma

CHAPTER 19
BLOOD CHEMISTRY AND SEROLOGY
PRETEST
True or False
1.
Most of the cholesterol found in the blood comes
from the intake of dietary cholesterol.
2.
The primary use of the cholesterol test is to screen
for the presence of coronary heart disease.
3.
LDL picks up cholesterol from ingested fats and the
liver and carries it to the cells.
4.
The function of glucose in the body is to build and
repair tissue.
5.
Insulin is required for normal utilization of glucose in
the body.
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PRETEST, CONT.
True or False
6.
An abnormally low level of glucose in the body is
known as hypoglycemia.
7.
The hemoglobin A1C test measures the average
amount of blood glucose over a 3-month period.
8.
An antibody is a substance that is capable of
combining with an antigen.
9.
Mononucleosis is transmitted through coughing and
sneezing.
10. Blood antigens (A, B, Rh) are located on the surface
of red blood cells.
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Content Outline
Introduction to Blood Chemistry and Serology
1. Automated blood analyzers: designed for
use in medical office
a. Perform blood chemistry tests in a short
period of time
b. Operating manual includes:
•
Operation
•
Test parameters
•
Care and maintenance
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Blood Chemistry
1. Chemicals are dissolved in liquid part of
blood
2. Quantitative measurement of chemical
substances in blood
a. Quantitative test: indicates the exact
amount of a substance that is present
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Blood Chemistry, cont.
3. Serum specimen
usually required
for blood
chemistry tests
4. Type of test
ordered:
depends on
clinical diagnosis
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Automated Blood Chemistry
Analyzers
1. Reflectance photometer: measures light
intensity to determine amount of substance
present
a. Provides a quantitative measurement of
chemical substances or analytes present
2. Examples of blood chemistry analyzers
a. ATAC laboratory system
b. Reflotron Analyzer
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Automated Blood Chemistry
Analyzers, cont.
3. Operating manual explains how to:
a. Collect and handle specimen
b. Perform quality control procedures
c. Test specimen
(Personnel available for on-site training)
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Quality Control
1. Quality control: consists of methods and
means to ensure that test results are reliable
and valid
a. Calibration of the analyzer
b. Running controls
2. Calibration: the use of a standard to check
precision of the blood chemistry analyzer
a. If analyzer not properly calibrated: unable
to produce accurate results
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Quality Control, cont.
3. Control: consists of a sample with a
known value
a. Processed in same way as patient
specimen
b. Results should fall within a specified range:
•
Indicated on reference sheet that comes with
control
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Quality Control, cont.
c. Types of controls:
• Normal control: results fall within normal
range
• Abnormal control: results fall outside of
normal range
– Low abnormal: below normal range
– High abnormal: above normal range
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Quality Control, cont.
d. If control does not fall within specified
range may be caused by:
•
Problems or errors with analyzer
•
Problem with technique used to perform test
•
Problem with chemical reagents
– Consult operating manual
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Quality Control, cont.
4. CLIA requirement: for moderate
complexity tests
a. Calibration: at least every 6 months
b. Two levels of controls: daily
•
Example: Running a normal and high control
c. When problems or errors are identified:
•
Must document action to correct them
d. Medical office running CLIA-waived tests
•
Required to follow manufacturer’s instructions
- Include quality control procedures that must be
performed
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Cholesterol
1. White, waxy, fatlike substance (lipid)
2. Essential for normal functioning of body
a. Important component of cell membranes
b. Used in production of:
•
Hormones
•
Bile
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Cholesterol, cont.
3. Cholesterol in the blood:
a. Most manufactured by liver
b. Portion comes from individual's diet: dietary
cholesterol
•
Found only in animal products (organ meats,
egg yolks, dairy products)
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Cholesterol, cont.
4. Cholesterol level determined by:
a. Genetic makeup
b. Amount of dietary cholesterol and
saturated fat consumed
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Cholesterol, cont.
5. High cholesterol: excessive amount of
cholesterol in blood
a. May cause atherosclerosis
• Atherosclerosis: buildup of fatty deposits
(plaque) on the walls of the arteries
•
As progresses: arteries become more occluded
– Can lead to heart attack or stroke
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Cholesterol, cont.
b. High blood cholesterol: risk factor for
coronary heart disease (CHD)
•
Efforts should be made to lower cholesterol
level
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HDL and LDL Cholesterol
1. Cholesterol transported in blood as a
complex molecule known as a
lipoprotein
a. Lipoprotein: A complex molecule consisting
of protein and a lipid fraction such as
cholesterol
•
Lipoproteins function in transporting lipids in
the blood
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HDL and LDL Cholesterol, cont.
2. Two types of lipoproteins:
a. LDL: low-density lipoprotein
b. HDL: high-density lipoprotein
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HDL and LDL Cholesterol, cont.
3. LDL
a. Picks up cholesterol from ingested fats and
the liver
•
Delivers it to blood vessels and muscles where it
is deposited in cells
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HDL and LDL Cholesterol, cont.
b. Often referred to as "bad cholesterol"
•
Excess causes plaque to build up on the arterial
walls (atherosclerosis)
– Risk factor for CHD
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HDL and LDL Cholesterol, cont.
4. HDL
a. Removes excess cholesterol from cells
•
Carries it to liver to be excreted
b. Protective and beneficial to the body
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HDL and LDL Cholesterol, cont.
c. Often called "good cholesterol"
d. High HDL cholesterol level: reduces risk of
CHD
e. Below 40 mg/dL: risk factor for CHD
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Cholesterol Testing
1. Adults over age 20:
a. Should have a cholesterol test every 5 years
2. Initial testing includes:
a. Total cholesterol determination
•
Combined measurement of LDL and HDL
cholesterol
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Cholesterol Testing, cont.
3. Most physicians also order HDL
determination
a. Measures only HDL cholesterol in the blood
4. Elevated results: usually require
confirmation through further testing
a. Before diagnosis of high blood cholesterol
can be made
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Interpretation of Results
1. Total cholesterol
a. Desirable: Below 200 mg/dL
b. Borderline high: 200 to 239 mg/dL
c. High: 240 mg/dL or higher
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Interpretation of Results, cont.
2. High category: increased risk for CHD
3. Borderline high category: at increased risk
if other risk factors present
a. Example: overweight, smoker
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Interpretation of Results, cont.
4. HDL Cholesterol
a. Optimal: 60 mg/dL or above
b. Desirable: 45 to 59 mg/dL
c. Borderline low: 40 to 45 mg/dL
d. Increased risk for CHD: Below 40 mg/dL
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Patient Preparation
1. Total cholesterol and HDL cholesterol:
a. Fasting not usually required
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Patient Preparation, cont
2. If total cholesterol level is 200 mg/dL or
higher: lipid profile usually ordered
a. Lipid profile includes:
•
Total cholesterol
•
HDL cholesterol
•
LDL cholesterol
•
Triglycerides
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Patient Preparation, cont.
b. Triglycerides affected by food consumption
•
Patient must fast
– For at least 12 hours before test
• Fasting: Abstaining from food or fluids (except
water) for a specified amount of time before the
collection of a specimen
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Patient Preparation, cont.
3. Interpretation of Test Results
a. Triglycerides
•
Normal: Below 150 mg/dL
•
Borderline high: 150 to 199 mg/dL
•
High: 200 to 499 mg/dL
•
Very high: 500 mg/dL or higher
•
Increased risk for CHD: Over 150 mg/dL
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Patient Preparation, cont.
b. LDL Cholesterol
•
Optimal: Below 100 mg/dL
•
Near optimal: 100 to 129 mg/dL
•
Borderline high: 130 to 159 mg/dL
•
High: 160 to 189 mg/dL
•
Very high: 190 mg/dL or higher
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What Would You Do?
What Would You Not Do?
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What Would You Do?
What Would You Not Do?
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Blood Urea Nitrogen
1. Blood urea nitrogen (BUN): kidney
function test
2. Urea: end product of protein metabolism
a. Normally present in blood
3. Kidney disease: may cause abnormal
increase in BUN
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Blood Glucose
1. Glucose: end product of carbohydrate
metabolism
2. Function of glucose: chief source of
energy for body
a. Energy needed to:
•
Carry out normal body functioning
•
Maintain body temperature
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Blood Glucose, cont.
3. Glucose can be stored as glycogen for
later use in:
a. Muscle tissue
b. Liver tissue glycogen in muscle and liver
tissue for later use
4. When no more tissue space available to
store glycogen:
a. Glucose is converted to fat and stored as
adipose tissue
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Blood Glucose, cont.
5. Insulin
a. Hormone secreted by beta cells of
pancreas
b. Required for normal utilization of glucose
c. Enables glucose to enter cells and be
converted to energy
d. Also needed for proper storage of glycogen
in liver and muscle cells
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Blood Glucose, cont.
6. Blood Glucose Testing
a. Glucose measurement used to detect:
•
Diabetes mellitus
•
Hypoglycemia
•
Liver and
adrenocortical
dysfunction
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Blood Glucose, cont.
7. Testing methods
a. Fasting blood sugar (FBS)
b. 2-hour postprandial glucose test (PPBS)
c. Glucose tolerance test (GTT)
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Fasting Blood Sugar
1. FBS: patient must be
fasting
a. No food or fluid (except
water) for 12 hours
before test
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Fasting Blood Sugar, cont.
2. Medications that may affect test:
a. Oral contraceptives
b. Salicylates
c. Diuretics
d. Steroids
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Fasting Blood Sugar, cont.
3. Physician may restrict medications
before testing
4. Test should be scheduled in the morning
a. Minimizes patient inconvenience due to
fasting
5. FBS normal range: 70 to 110 mg/dL
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Fasting Blood Sugar, cont.
6. Purpose of FBS
a. Evaluate progress of diabetic patients
b. Regulate treatment of diabetic patients
c. Routine
screening
procedure to
detect
diabetes
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Fasting Blood Sugar, cont.
7. FBS above 120 mg/dL: dividing point
between normal and hyperglycemic values
a. Indicative of diabetes mellitus
8. Elevated FBS: further testing required
(e.g., GTT)
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Two-Hour Postprandial Blood Sugar
1. Purpose
a. Screen for presence of diabetes
b. Monitor effects of insulin dosage in
diagnosed diabetes
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Two-Hour Postprandial Blood
Sugar, cont.
2. Fasting required: beginning at midnight
until breakfast
a. Breakfast: Patient consumes a prescribed
meal containing 100 grams of
carbohydrates
•
Alternative: drink 100 grams of glucose solution
3. Blood specimen collected 2 hours after
consumption
4. Nondiabetic patient: glucose returns to
normal within 1½ to 2 hours
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Two-Hour Postprandial Blood
Sugar, cont.
5. Diabetic patient: does not return to
fasting level
6. 140 g/dL or higher: suggestive of
diabetes
a. Warrants further testing
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Glucose Tolerance Test (GTT)
1. Provides more detailed information on
glucose utilization
a. Assesses insulin response to glucose load
2. Used to diagnose:
a. Diabetes mellitus
b. Hypoglycemia
c. Liver and adrenocortical dysfunction
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Glucose Tolerance Test (GTT), cont.
3. Testing Requirements
a. High carbohydrate diet
for 3 days before test
(150 grams)
b. Fasting
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Glucose Tolerance Test (GTT), cont.
4. Testing procedure
a. FBS performed and urine is tested for
glucose
•
If FBS indicates hyperglycemia: notify physician
– Hyperglycemia contraindicates
administering the glucose solution
b. After FBS: patient drinks measured amount
of glucose (100 grams)
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Glucose Tolerance Test (GTT), cont.
c. Blood and urine specimens collected at
intervals: 30, 60, 120, and 180 minutes
d. Label blood and urine specimens with exact
time of collection
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Glucose Tolerance Test (GTT), cont.
e. Restrictions during test
•
No eating or drinking except water: affects
glucose level
– Encourage water: easier to produce urine
specimen
•
No smoking: stimulant that increases blood
glucose level
•
Remain at test site: so patient is present for
specimen collection
•
Minimize activity: activity uses glucose
– Affects test results
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Glucose Tolerance Test (GTT), cont.
5. Side Effects
a. Patient may exhibit normal side effects
during the test
•
Weakness
•
Feeling of faintness
•
Perspiration
– Reassure patient that it is only temporary
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Glucose Tolerance Test (GTT), cont.
b. Serious symptoms: immediately report to
physician
•
Indicate severe hypoglycemia
– Headache
– Pale
– Cold and clammy skin
– Irrational speech or behavior
– Profuse perspiration
– Fainting
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Glucose Tolerance Test (GTT), cont.
6. Interpretation of Results
a. Nondiabetic patient after ingestion of
glucose solution
•
Glucose absorbed into bloodstream
•
Rises to a peak level: between 160 and 180
mg/dL
– Approximately 30 to 60 minutes after
consumption of glucose solution
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Glucose Tolerance Test (GTT), cont.
•
Pancreas secretes insulin to compensate for
rise
•
Blood glucose returns to fasting level within 2 to
3 hours
•
Urine is negative for glucose
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Glucose Tolerance Test (GTT), cont.
b. Diabetic patient after ingestion of glucose
solution
•
Blood glucose level peaks at a much higher level
•
Glucose present in urine
•
Blood glucose levels above normal throughout
test
– Due to lack of insulin
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Glucose Tolerance Test (GTT), cont.
7. Hypoglycemia
a. Blood glucose is
abnormally low
b. During GTT
patients exhibits
low level
•
Beginning at 2hour interval
•
Continues up to
4 to 5 hours
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Glucose Tolerance Test (GTT), cont.
c. Hypoglycemia results from:
•
Glucose removed from blood at an excessive
rate
•
Decreased secretion of glucose into blood
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Glucose Tolerance Test (GTT), cont.
d. Hypogylcemia can be caused by:
•
Overdose of insulin
•
Addison's disease
•
Bacterial sepsis
•
Pancreatic cancer
•
Hepatic necrosis
•
Hypothyroidism
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Glucose Tolerance Test (GTT), cont.
e. GTT not required if:
•
FBS is above 140 mg/dL
•
2-hour PPBS is above 180 mg/dL
– Results greater than these amounts: qualify
for diabetes diagnosis
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What Would You Do?
What Would You Not Do?
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What Would You Do?
What Would You Not Do?
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Tests for Management of Diabetes
1. Important for diabetic patients to
manage their condition
a. Best accomplished: keeping blood glucose
levels close to normal
•
Patient experiences fewer symptoms
•
Delays or prevents long-term complications
– Leads to a longer life
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Tests for Management of Diabetes,
cont.
2. Types of tests
a. Self-monitoring of blood
glucose
•
Performed by patient at
home
•
Measures day-day
fluctuations in blood
glucose level
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Tests for Management of Diabetes,
cont.
b. Hemoglobin A1C test
•
Ordered by physician
•
Provides overall picture of blood glucose level
over a period of time
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Self-Monitoring of Blood Glucose
(SMBG)
1. Diabetic patients: usually cannot tell by
the way they feel
a. Whether blood glucose is within normal
range
b. Only way to know for sure: SMBG
•
Provides patient with feedback for maintaining
normal blood glucose level
•
Assists in anticipating and treating fluctuations
in blood glucose caused by:
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Self-Monitoring of Blood Glucose
(SMBG), cont.
•
Assists in anticipating and treating fluctuations
in blood glucose caused by:
– Food
– Exercise
– Stress
– Infection
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Self-Monitoring of Blood Glucose
(SMBG), cont.
2. Insulin-dependent diabetic patients:
a. Must monitor glucose at home for effective
management
•
Based on results: decisions can be made
regarding insulin and dietary adjustments
– To maintain normal blood glucose levels
•
Avoids extremes of hypoglycemia and
hyperglycemia
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Self-Monitoring of Blood Glucose
(SMBG), cont.
•
Reduces symptoms of the disease
•
Helps delay or prevent long-term complications
– Examples: Retinopathy, peripheral vascular
disease
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Self-Monitoring of Blood Glucose
(SMBG), cont.
3. Frequency of Testing
a. Depends on:
•
Severity of the diabetes
•
Diet
•
Presence of special conditions (e.g., pregnancy)
•
Activity level
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Self-Monitoring of Blood Glucose
(SMBG), cont.
b. Insulin-dependent diabetic patient:
•
Ideally should monitor four times a day
– In the morning: after an 8-hour fast (best
overall indicator of control)
– Before lunch
– Before dinner
– Bedtime
•
Before lunch, dinner, and at bedtime: provide
guidance for adjusting insulin dosage, diet, and
exercise
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Self-Monitoring of Blood Glucose
(SMBG), cont.
4. Test Results
a. Blood glucose levels
•
Measured using a glucose
meter
– Results displayed in
mg/dL (milligrams per
deciliter)
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Self-Monitoring of Blood Glucose
(SMBG), cont.
b. Diabetic patients: should keep a record of
daily glucose test results
•
For periodic review by the physician
– Assists physician in making decisions
regarding diabetic management plan
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Self-Monitoring of Blood Glucose
(SMBG), cont.
5. Advantages of SMBG:
a. Most effective way to maintain normal blood
glucose level
•
High blood glucose for a long period of time
(above 180 mg/dL)
– Causes progressive damage to body organs
leading to:
1) Blindness
2) Kidney disease
3) Nerve damage
4) Circulation problems
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Self-Monitoring of Blood Glucose
(SMBG), cont.
b. Convenience of testing
•
No physician order required
•
Can test any time of day
•
Can test when side effect
occurs (e.g., hypoglycemia)
– Treatment can be
instituted immediately
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Self-Monitoring of Blood Glucose
(SMBG), cont.
c. More involvement in self-management
decisions
•
Insulin dosage, meal planning, physical activity
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Self-Monitoring of Blood Glucose
(SMBG), cont.
d. Reliable decisions can be made regarding
insulin dosage
•
During situations that affect blood glucose level:
– Illness
– Emotional stress
– Increased physical activity
– Suspected hypoglycemia
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Self-Monitoring of Blood Glucose
(SMBG), cont.
e. Prevent or delay in long-term complications
•
Increases chance of staying healthy
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What Would You Do?
What Would You Not Do?
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What Would You Do?
What Would You Not Do?
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Hemoglobin A1C Test (Hb A1C)
1. Assessment of average amount of
glucose in the blood: over a 3-month
period
2. Food consumed containing glucose
a. Glucose absorbed into circulation
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Hemoglobin A1C Test (Hb A1C), cont.
b. Glucose has sticky quality
•
Sticks to protein making up hemoglobin
(glycosylation)
•
Hemoglobin: found in red blood cells (RBCs)
– Function: transports oxygen to tissues of
body
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Hemoglobin A1C Test (Hb A1C), cont.
c. Glycosylation: the process of glucose
attaching to hgb
•
Occurs in all individuals
– Both diabetic and normal
•
Forms a compound: hemoglobin A1C
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Hemoglobin A1C Test (Hb A1C), cont.
d. Amount of glucose that attaches to hgb:
•
Proportional to amount of glucose in an
individual's blood
e. Undiagnosed or poorly controlled diabetic
patients
•
Have a higher than normal blood glucose level
•
More Hb A1C forms in these patients
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Hemoglobin A1C Test (Hb A1C), cont.
1. Hb A1C test: measures the percentage of
Hb A1C
a. Attachment of glucose to hemoglobin:
permanent for life of RBC (90 to 120 days)
b. Provides overall picture of blood glucose for
the past 3 months
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Hemoglobin A1C Test (Hb A1C), cont.
2. Interpretation of Results
a. Normal individuals: 4% to 6%
b. Diabetic individuals:
•
Recommendation: Less than 7%
– Better chance of delaying or preventing
diabetic complications
•
If higher than 8%: change in diabetic
management plan required
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Hemoglobin A1C Test (Hb A1C), cont.
3. Testing recommendations
a. When patient is first diagnosed with
diabetes
b. Several times after management plan has
been prescribed for a newly diagnosed
patient
•
To verify blood glucose control is being
achieved
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Hemoglobin A1C Test (Hb A1C), cont.
c. For diagnosed diabetic patients: to evaluate
effectiveness of mgt plan
•
Stable diabetic patients under good control: At
least 2 times a year (every 6 months)
•
Patients who have difficulty maintaining control:
Test ordered more frequently
d. After physician makes an adjustment to
diabetic management plan
•
To assess effectiveness of change in treatment
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Glucose Meters
1. Quantitatively measures blood glucose
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Glucose Meters, cont.
2. On-site testing
a. Provides immediate results
•
Physician can make decisions regarding:
– Diagnosis
– Treatment
– Follow-up care
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Glucose Meters, cont.
3. Reagent Test Strips
a. Plastic strip with a
reaction pad
•
Pad contains
chemicals: react
with glucose in blood
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Glucose Meters, cont.
b. Results displayed as a
digital readout in mg/dL
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Glucose Meters, cont.
c. Storage: cool, dry area at room
temperature with cap tightly closed:
•
Chemicals on strip: sensitive to heat, light, and
moisture
•
Causes deterioration of chemicals
– Leads to inaccurate test results
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Glucose Meters, cont.
d. Strips that are discolored or have
darkened: discard
•
To prevent inaccurate test results
e. Container includes desiccant
•
Absorbs moisture to promote dryness
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Glucose Meters, cont.
3. Care and Maintenance of Glucose Meter
a. Handle carefully
•
Physical jar could result in malfunction
b. Do not place in high humidity area (e.g.,
bathroom)
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Glucose Meters, cont.
c. Do not expose to severe variations in
environmental temperature
•
Example: Leaving in a vehicle on a hot/cold day
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Glucose Meters, cont.
d. Clean meter properly
•
Exterior of meter:
– Use a soft, clean cloth dampened with mild
cleaning agent
– Dry thoroughly
•
Do not let water run into glucose meter
– Could damage internal components
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Glucose Meters, cont.
e. Replace battery
•
Screen displays alert of low battery
– Directions for installation: specified in
operator's manual
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Glucose Meters, cont.
4. Calibration Procedures
a. Purpose of calibration:
•
Ensures the glucose meter is functioning
properly
•
Ensures accurate and reliable test results
– Programs the electronics of the glucose
meter to match reactivity of strips in current
use (compensates for variables in the
manufacturing process of the reagent strip)
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Calibrating the Meter
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Glucose Meters, cont.
5. Control Procedure
a. Ensures:
•
Test results are reliable and valid
•
Errors are eliminated
b. Commercially available glucose control
solutions
•
Use two of the following levels of controls
– High
– Low
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Glucose Meters, cont.
c. Control solution
•
Effective for 3 months from date opened
•
After opening: write date on label
•
Can be used for (whichever comes first):
– 3 months from date opened
– Expiration date stamped on label
•
Store control in cool, dry area at room temperature
-Solution is sensitive to heat, light, moisture
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Glucose Meters, cont.
d. If control results not within acceptable range:
•
Check expiration date of test strips and control
solution
•
Make sure test strips were stored at room
temperature
•
Make sure code on meter matches code on test
strips
•
Review technique used to run control procedure
– Correct any errors and run control again
– If still not in acceptable range: contact
manufacturer
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Glucose Meters, cont.
e. Should be performed
•
Daily, before using meter for first time
•
When new container of reagent strips is opened
•
If cap left off vial of strips for a length of time
– If meter is dropped
– If test has been repeated and result is lower
or higher than expected
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Serology
1. Study of the serum of the blood
a. Specifically deals with the study of antigen
and antibody reactions
2. Antigen: a substance capable of
stimulating the formation of antibodies
a. Examples: Bacteria, viruses, bacterial
toxins, allergens, blood antigens
3. Antibody: a substance capable of
combining with an antigen
a. Results in an antigen-antibody reaction
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Serology, cont.
4. Use of serology tests
a. Assess the presence of a substance
•
Example: ABO blood typing
b. Diagnosis of disease
•
Example: Mononucleosis testing
•
Follow the course of a disease
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Serologic Tests
1. Hepatitis Test: detection of viral
hepatitis
a. Five types of viral hepatitis: A, B, C, D, E
b. Determines specific type of hepatitis
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Serologic Tests, cont.
2. Syphilis Test
a. Sexually transmitted disease caused by
Treponema pallidum
b. Screening tests most commonly used
•
VDRL (Venereal Disease Research Laboratory)
•
RPR (Rapid Plasma Reagin)
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Serologic Tests, cont.
c. Syphilis results reported as:
•
Nonreactive: negative
•
Weakly reactive: positive
•
Reactive: positive
d. Positive result warrants more specific
testing
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Serologic Tests, cont.
3. Mononucleosis (mono) Test
a. Detects presence of infectious
mononucleosis
4. Rheumatoid Factor (RF)
a. Rheumatoid arthritis (RA): chronic
inflammatory disease that affects joints
b. Blood of individual with RA: contains
rheumatoid factor (RF)
c. Test detects presence of RF antibodies
•
Assists in diagnosis of rheumatoid arthritis
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Serologic Tests, cont.
5. Antistreptolysin O test
a. Detects ASO antibodies
b. Used to detect conditions resulting from
strep infections and secondary strep
infections:
•
Rheumatic fever
•
Glomerulonephritis
•
Bacterial endocarditis
•
Scarlet fever
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Serologic Tests, cont.
6. C-Reactive Protein (CRP)
a. CRP appears in blood: during inflammation
and tissue destruction
b. Used to diagnose and determine progress
of:
•
Rheumatoid arthritis
•
Acute rheumatic fever
•
Widespread malignancy
•
Bacterial infections
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Serologic Tests, cont.
7. Cold Agglutinins
a. Detect presence of cold agglutinin
antibodies
b. Cold agglutinins found in patients with:
•
Infectious mononucleosis
•
Mycoplasmal pneumonia
•
Chronic parasitic infections
•
Lymphoma
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Serologic Tests, cont.
8. ABO and Rh Blood Typing
a. Determines ABO and Rh blood type
b. Purpose
•
Prevent blood transfusion or transplant
reactions
•
Identify problems (e.g., hemolytic disease of
newborn)
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Serologic Tests, cont.
9. Rh Antibody Titer
a. Determines amount of Rh antibodies in the
blood
b. Can occur in a pregnant woman
•
Rh-negative woman carrying Rh-positive fetus
•
Most frequent use of test:
– Detect Rh incompatibility problem with a
mother and an unborn child
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Rapid Mononucleosis Testing
1. Infectious mononucleosis: acute infectious
disease caused by Epstein-Barr virus (EBV)
a. Most frequently affects children and young
adults
b. Transmitted: saliva by direct oral contact
•
Often called "kissing disease"
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Rapid Mononucleosis Testing, cont.
c. Symptoms
•
Mental and physical fatigue
•
Fever
•
Sore throat
•
Severe weakness
•
Headache
•
Swollen lymph nodes
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Rapid Mononucleosis Testing, cont.
2. Rapid mononucleosis test: often
performed in medical office
a. Assists in diagnose of infectious
mononucleosis
3. Individuals with mononucleosis: produce
heterophile antibody
a. Usually by sixth to tenth day of the illness
b. Test detects this antibody
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Rapid Mononucleosis Testing, cont.
4. A positive mononucleosis test and
patient symptoms
a. Basis for diagnosis of infectious
mononucleosis
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Blood Typing
Blood Antigens
1. Each individual has a blood type
a. Depends on antigens on the surface of
RBCs
• Blood antigen: A protein present on the
surface of RBCs that determines a person's
blood type
– Inherited through genes
– Programs the body to produce a particular
antigen
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Blood Antigens, cont.
2. Blood antigens: Grouped into
categories known as blood group
systems
3. ABO and Rh blood group systems:
a. Most likely to cause problems in:
•
Blood transfusions
•
Rh disease of newborn
b. Most commonly tested for in medical
laboratory
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Blood Antigens, cont.
4. ABO blood group system:
a. Type A blood: A antigen present
b. Type B blood: B antigen present
c. Type AB blood: A and B antigens present
d. Type O blood: Neither A or B antigen is
present
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ABO Blood Antigens
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Blood Antibodies
1. Blood antibody: A protein present in the
plasma that is capable of combining with
its corresponding blood antigen
a. To produce an antigen-antibody reaction
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Blood Antibodies, cont.
2. Body never produces an antibody to
combine with its own blood antigen
a. Example: If blood type is A: Plasma does
not contain the A antibody
•
B antibody naturally occurs in this patient's
plasma
•
B antibody cannot combine with A antigen
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Blood Antibodies, cont.
3. If a blood antigen and its corresponding
antigen combine:
a. A serious antigen-antibody reaction takes
place
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Blood Antibodies, cont.
4. Antibodies present
a. Type A blood: B antibody
b. Type B blood: A antibody
c. Type AB blood: Neither A or B antibody
d. Type O blood: Both A and B antibodies
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The Rh Blood Group System
1. Discovered by Landsteiner and Weiner
a. While working with rhesus monkeys (1940)
2. Rh-positive: Have Rh antigen present on the
surface of RBCs
a. Most of population is Rh-positive
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The Rh Blood Group System, cont.
3. Rh-negative
a. 15% of white population do not have Rh
antigen
b. 7% of black population do not have Rh
antigen
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Blood Antigen and Antibody
Reactions
1. When blood antigen and its corresponding
antibody unite
a. Results in clumping of RBCs: known as
agglutination
b. Can be serious or fatal if occurs in the living
body (in vivo)
c. Clumped RBCs cannot pass through small
tubules of kidneys
•
Results in kidney failure
d. Eventually leads to hemolysis
2. Can occur if wrong blood type
administered during transfusion
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Agglutination and Blood Typing
1. Agglutination of RBCs: basis for ABO
and Rh blood typing
a. Antigen-antibody reaction occurs in vitro
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Agglutination and Blood Typing,
cont.
2. To perform blood typing:
a. Commercially prepared antiserum used
•
Antiserum: a serum containing antibodies
b. Added to an unknown blood specimen
c. Example: Antiserum with A antibody added
to unknown blood specimen
•
If A antigen present: combines with A antibody
– Results in agglutination: indicates type A
blood
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Antigen Antibody Reaction
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POSTTEST
True or False
1.
2.
3.
4.
5.
Serum is required for most blood chemistry tests.
The buildup of plaque (due to high cholesterol) on
the walls of arteries is known as thrombophlebitis.
An HDL cholesterol level greater than 50 mg/dL is a
risk factor for coronary heart disease.
The triglyceride test requires that the patient not eat
or drink for 12 hours before the test.
The normal range for a fasting blood sugar is 120 to
160 mg/dL.
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POSTTEST, CONT.
True or False
6.
The glucose tolerance test is used to assist in the
diagnosis of diabetes mellitus.
7. Before meals, it is recommended that the blood
glucose level for a diabetic patient fall between 60 to
80 mg/dL.
8. The recommended A1C level for an individual with
diabetes is 4 % to 6%.
9. The RPR test is a screening test for syphilis.
10. The varicella virus causes infectious mononucleosis
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