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Chapter 19 - Blood Chemistry and Immunology

Clinical Procedures for the Medical Assistant
What is Agglutination?
Clumping of the blood cells
What is an Analyte?
A substance that is being identified or measured in a lab test.
What is an Antibody?
A substance that is capable of combining with an antigen, resulting in an antigen-antibody reaction.
What is an Antigen?
A substance capable of stimulating the formation of antibodies.
What is Antiserum or Antisera?
A serum that contains antibodies.
What is Blood Antibody?
A protein present in the blood plasma that is capable of combining with its corresponding blood antigen to produce an antigen-antibody reaction.
What is a Blood Antigen?
A protein present on the surface of RBCs that determines a person's blood type.
What is a Donor?
One who furnishes something, such as blood, tissue or organs to be used in another individual.
What is a Gene?
A unit of heredity.
What is Glycogen?
The form in which CARBOHYDRATES are stored in the body.
What is Glycosylation?
The process of glucose attaching to hemoglobin.
What is HDL Cholesterol?
A lipoprotein, consisting of protein and cholesterol, that removes excess cholesterol from the cells. GOOD!
What is Hemoglobin A1C?
Compound formed when glucose attaches or glycosylates to the protein in hemoglobin.
What is Hyperglycemia?
An abnormally high level of glucose in the blood.
What is Hypoglycemia?
Abnormally low level of glucose in the blood.
What does 'In Vitro" mean?
Occurring in GLASS. Refers to tests performed under artificial conditions as in a lab.
What does 'In Vivo" mean?
Occurring in the living body or organism.
What is LDL Cholesterol?
A lipoprotein, consisting of protein and cholesterol, that picks up cholesterol and delivers it to the cells.
What is a Lipoprotein?
Lipo - Fat
A complex molecule consisting of protein and a lipid fraction such as cholesterol.

Lipoproteins function in transporting lipids in the blood.
What is a Recipient?
One who receives something, such as a blood transfusion, from a donor.
What does Blood Chemistry testing involve?
The quantitative measurement of chemical substances in the blood.

These chemicals are dissolved in the liquid portion of the blood.
What do most blood chemistry tests require?
A serum specimen for analysis
In the medical office, what is most often used to perform blood chemistry testing?
CLIA waived automated blood chemistry analyzers.
What is Quality Control?
This consists of methods and means to ensure that test results are reliable and valid.
What is Calibration?
Involves the use of a standard to check the precision of the blood chemistry analyzer.
What is an analyzer is not properly calibrated?
It cannot produce accurate test results and should not be used.
What does a control consist of?
A sample of a known value.

Normal controls will illicit a normal number in the normal reference range, whereas abnormal controls fall outside the normal range.
What is glucose an end-product of?
Carbohydrate metabolism.
What is glucose's function?
It serves as the chief source of energy for the body.
What happens to glucose that is not needed by the body for energy?
it can be stored in the form of glycogen in muscle and liver tissue for later use.
What is Insulin?
It is a hormone secreted by the pancreas and is required for normal use of glucose in the body.
Measuring this substance in a blood specimen is one of the most common blood chemistry tests. What is the substance?
Why is glucose measured?
Used to detect abnormalities in carb metabolism, such as occur in prediabetes, diabetes, gestational diabetes, hypoglycemia and liver and adrenocortical dysfunction.
When is blood glucose usually measured?
When the patient is in a fasting state.
What does FBG stand for?
Fasting Blood Glucose
What is the patient prep for an FBG?
Patient needs to have had nothing by mouth for at least 12 hours (excluding water).
What is the normal range for FBG?
70 to 99 mg/dl
When will a doctor order an FBG?
Often performed on patients with diabetes to:
Evaluate progress
Regulate treatment

Also as a routine screening procedure in patients to detect pre-diabetes and diabetes.
What is the 2-hour PPBS?
2 hour Postprandial blood sugar test

Used to screen for diabetes and to monitor the effects of insulin dosage in diagnosed diabetic patients.
What is the OGTT?
The oral glucose tolerance test.

Provides more detailed information about the ability of the body to metabolize glucose by assessing the insulin response to a glucose load.
What is the OGTT used to diagnose?
Pre-diabetes, Diabetes and Gestational Diabetes
Hypoglycemia and liver and adrenocortical dysfunction.
What is the HbA1c or Hemoglobin A1c?
A test that provides valuable information for determining that a diabetic patient's blood glucose level is under control.
What is the period of time that the A1c gives an average over?
A 3 month period.

Assessment of the average amount of glucose in the blood over 3 months.
What is the normal A1c for an individual without diabetes?
4% to 6%.
What percentage does the American Diabetes Association strongly recommend diabetics maintain as a hemoglobin A1c?
Less than 7%
What is cholesterol?
A white, waxy, fat like substance that is essential for normal functioning of the body.
Where is the majority of the cholesterol circulating in the body manufactured?
The liver, although a portion of it comes from dietary intake.
Where is Dietary Cholesterol found?
Only in animal products.
What does high blood cholesterol cause?
Fatty deposits, or plaque, to build up on the walls of the arteries; This is known as atherosclerosis.
Which cholesterol is considered bad, and which is considered good?
LDL is "bad" = an excess amount of it in the blood can cause atherosclerosis.
HDL is "good" = removes excess cholesterol from the walls of the blood vessels.
How are Total Cholesterol Levels interpreted?
Less than 200 mg/dL is desirable.
Levels between 200 and 239 mg/dL are borderline high
Levels of 240 mg/dL and greater are high.
How are HDL Cholesterol Levels interpreted?
Greater than 60 mg/dL is optimal
Level less than 40 mg/dL is a risk factor for CAD
What is Immunology?
The scientific study of the serum of the blood.
What are some of the Immunologic tests?
Heptatitis, HIV, Syphilis, Mono, Rheumatoid Factor, Anti-Streptolysin O test, C-Reactive Protein, Cold Agglutinins, ABO and Rh blood typing and Rh antibody titer.
What is infectious mononucleosis?
An acute infectious disease caused by the Epstein-Barr Virus (EBV).
What are the symptoms for Mono?
Mental/Physical fatigue, fever, sore throat, severe weakness, headache and swollen lymph nodes
What do blood antigens consist of ?
They consist of protein and are inherited through genes.
What are the four main blood types in the ABO blood group system?
A, B, AB and O
Are blood antibodies naturally present in the plasma of the blood?
Yes, they are proteins that are naturally present in the plasma.
What does an antibody combine with?
Capable of combining with an antigen.
What happens with a blood antigen and its corresponding antibody unite?
The result is the clumping (agglutination) of RBCs.

This can be serious and fatal if it occurs in the living body.
What is the Rh Factor?
It's a type of protein on the surface of RBCs.

Most people HAVE the Rh Factor.

Those who do NOT are considered Rh (-)
What is the reference range for Magnesium?
"C" or 1.7-2.1 mg/dl
If the antibody A is present what is the blood type?
B....because blood type B has a Antigen B with Antibody Anti-A.
What antigens does O type blood have?
Neither antigen BUT BOTH antibody Anti-A and Anti-B
What is the Reference Range (RR) for Alkaline phosphatase?
25-140 U/L
Increased with: Liver and bone disease
Decreased with: Malnutrition, hypothyroidism
What is the RR with Blood Urea Nitrogen (BUN)?
7-25 mg/dL
Increased with: Kidney disease and dehydration
Decreased with: Liver failure, Malnutrition
What is the RR for Calcium (Ca)?
8.5-10.8 mg/dL
Increased with: Hyperthyroidism and Bone metastes
Decreased with: Hypoparathyroidism and Acute pancreatitis
What is the RR for Chloride? (Cl)
96-109 mmol/L
Increased with Dehydration and Cushings
Decreased with Severe vomiting and Severe Diarrhea
What is the RR for Cholesterol (Chol)?
Desirable: <200 mg/dl
Borderline: 200-239 mg/dl
High: >240 mg/dl or greater
Increased with Atherosclerosis and Cardiovascular disease
Decreased with Liver disease and Hyperthyroidism
What is the LDL cholesterol RR?
Optimal: Less than 100 mg/dl
Near Optimal: 100-129 mg/dl
Borderline high: 130-159 mg/dl
High: 160-189 mg/dl
Very High: 190 mg/dl or greater
Wht is the HDL Cholesterol RR?
Optimal: 60 mg/dl or GREATER
Desireable: Males 40-50 mg/dl, Females 50-60 mg/dL
Increased risk for CAD: Men = less than 40mg/dl and
Women = Less than 50 mg/dl
What is the RR for FBG?
Normal: 70-99 mg/dl
Pre-diabetes: 100-125 mg/dl
Diabetes: 126 mg/dl or above
What is the RR for 2 hour PostPrandial Blood Sugar (PPBS)?
2 Hr : Less than 140 mg/dl
What is the RR for Oral Glucose Tolerance Test (OGTT)?
2 hour
Normal: 139 mg/dl and BELOW
Pre-diabetes: 140-199 mg/dl
Diabetes: 200 mg/dl or ABOVE
What is the RR for Phosphorus (P) or Phosphates?
2.5-4.5 mg/dl
Increased with: Hypoparathyroidism, hypocalcemia
Decreased with: Hyperparathyroidism, Diabetic coma
What is the RR for Potassium (K)?
3.5 - 5.3 mmol/L
Increased with Renal Failure or Internal Bleeding
Decreased with Diarrhea or Starvation
What is the RR for Sodium (Na)?
135-147 mmol/L
Increased with Dehydration and Cushings
Decreased with Severe burns and Severe diarrhea
What is the RR for Triglycerides (Trig)?
Desirable: < 150 mg/dl
Borderline high: 150-199 mg/dl
High: 200-499 mg/dl
Very high: 500 mg/dl or GREATER
If Plasma is the antibody then....
Your plasma cannot have the antibody of the SAME as your antigen.
What is the Rh factor?
Rhesus Factor: is an inherited trait that refers to a specific protein found on the surface of red blood cells. If your blood has the protein, you're Rh positive — the most common Rh factor. If your blood lacks the protein, you're Rh negative.
When is the Rh Factor an issue?
During pregnancy: If you're Rh negative and your baby is Rh positive, however, your body might produce Rh antibodies after exposure to the baby's red blood cells. If you are Rh issue exists.
What is the percentage of people who are Rh (+) and (-)?
15% of white people are NEGATIVE
7% of African American are NEGATIVE

The rest are positive.
What is the percentage that the doctors prefer an A1c remain under and why?

Reduce complications of diabetes
Where do we get our blood antigens?
What specimen do serological chem tests require for testing?
What are 'Controls'?
A quality control method. A solution that is used to monitor a blood chemistry analyzer to ensure the reliability and accuracy of the test results.
Why are Controls used?
To determine if the testing reagents are performing properly and to detect any errors in technique by the performer of the test.
Come in: High and low control; performed similarly to test itself
What is Calibration?
Mechanism used to check the precision and accuracy of a blood chemistry analyzer and to determine if the system is providing accurate results.
What does a calibration check detect?
Errors caused by lab equipment not working properly.
When is Calibration typically performed?
Using a calibration device called a standard, they are done at a minimum when a new lot number of testing reagents is put into use; or according to manufacturer's instructions.
What are the characteristics of cholesterol?
it is a white, waxy, fatlike substance (lipid) that is essential for normal function of the body.
What is a CMP and what purpose does it serve?
Comprehensive Metabolic Profile: Contains numerous blood chemistry tests and is used primarily in routine health screenings.
When is a CMP appropriate to order?
When the doctor needs more information because the symptoms are vague.

As a routine health screening.
What type of measurement will a blood chemistry analyzer produce?
Quantitative measurement
What may cause a failure of a control to produce expected results?
1. Expired testing components
2. Improper storage
3. Improper environmental testing conditions
4. Errors in technique
How often should Controls be performed?
As often as manufacturer's instructions indicate OR at a minimum on each new lot number of testing reagents and thereafter on a regular basis such as MONTHLY.
The condition caused by fatty deposits in the blood vessels is known as?
What is glucose?
The end product of carb. metabolism; is the chief source of energy for the body.
What is glycogen?
It is the ingested glucose that is NOT needed for energy can can be stored in muscle or liver for later use./ if not tissue storage is available, it will be converted to TRIG and stored as fat tissue.
What is Insulin?
1. A hormone from the pancreas.
2. Required for normal use of glucose.
3. Enables glucose to enter cells and be converted to energy.
4. Needed for proper storage of glycogen in liver and muscle cells.
What are the three glucose testings?
2 hour PPBG
Describe the FBG?
Pt fasts for 12 hours
Certain meds may be discontinued for 3 days
Morning testing to minimize inconvenience
Done to screen/detect pre diabetes and diabetes
Evaluate and regulate treatment
Describe the 2 hour PPBG?
Used to screen for DM and monitor effects of insulin dosage
Fast for 12; Then breakfast with 100g of carbs (OJ, Cereal with sugar, toast and milk) OR 100g load of glucose solution
Blood specimen collected exactly 2 hours after consumption.
Fail this and you are usually given the OGTT
Describe the OGTT?
More detailed information is obtained by assessing insulin response to a glucose load.
DX of prediabetes, DM, Gestational Diabetes, hypoglycemia and liver and adrenocortical dysfunction.
Consule high carb diet, 150g of carbs X3 days. then FAST when test begins. IF hyperglycemic at this point, do not proceed with test. Otherwise 75g of glucose load and blood specimens taken after that.
What occurs during the OGTT load phase?
A nondiabetic individual will peak at 160 to 180 mg/dl approx. 30 to 60 minutes.
BG returns to normal within 2 hours.
How is hypoglcemia diagnosed via the OGTT?
The glucose in the blood is abnormally low (FBG <70 mg/dl)
What are the advantages of SMBG?
1. Self monitoring blood glucose allows patients with feedback for maintaining normal blood glucose levels
2. Assists them in anticipating and treating day to day or even hour to hour issues
3. Avoids extremes
4. Relieves symptoms helps delay or prevent LT complications.
What is the antigen-antibody reaction?
Immune reaction- involves binding antigens to antibodies.
How often should the blood glucose level for an insulin dependent patient be measured?
4 X a day
Morning (after 8 hour fast)
Before lunch, dinner and at bedtime.
Which measurement is the most accurate indicator of control on a blood glucose meter check?
The FBG in the morning
What type of complications can occur from long term maintenance of an elevated BSG > 180 ?mg/dl
Blindness, kidney disease, nerve damage, circulation problems.
What are some of the other advantages for SMBG?
Convenience of testing at home.
Greater involvement in self management decisions
Reliable decision making regarding insulin dosage
Delay in or prevention of LT complications.
The A1c test supplies the physician with an assessment of ?
The average amount of glucose in the blood over a 3 month period.
What is the normal A1c for an individual without diabetes?
4% to 6%
Brief explanation of the table comparison of Hemoglobin A1c percentage and the average daily blood glucose level it represents.
Starts at 65 for 4%
Climbs 35 points each % thereafter
When is the A1c test ordered? How often is it ordered?
It is ordered periodically for patients already dx with DM to evaluate effectiveness of their diabetes management plan.

If stable, the test is typically ordered at least 2 times a year.
How should the Glucometer and Reagent Strips be stored and handled?
Strips are sensitive to heat, light and moisture and must be stored in a cool, dry area at RT. Cap tightly closed. Keep the dessicant in it to absorb moisture.
How long is the control solution good for?
3 mos. Store at 36 to 86 degrees F
When should a control test be scheduled?
1. Meter is new
2. Daily before first use
3. If cap is left off vial of strips
4. New container of strips
5. Meter is dropped
6. Test results do not agree with the way pt. feels
7. If test has been repeated and BG is still lower or higher than expected.
Where does cholesterol in the blood come from?
Most of it is manufactured by the LIVER
A portion (dietary cholesterol) is found from animal products such as organ meats, egg yolks and dairy products.
What does it mean when it's said that someone's cholesterol is high?
An excessive amount of cholesterol is present in the blood.
Can an individual who eats well still have high cholesterol?
Yes, an individual's cholesterol level is determined by his or her genetic makeup, by the amounts of dietary cholesterol, saturated fat and trans fat consumed.
Describe LDL and HDL.
LDL is considered 'bad' because an excess amount of it can cause plaque to build on arterial walls.

HDL is considered 'good' because it removes cholesterol from the wall of blood vessels.
Should a patient having a total cholesterol and HDL determination be in a fasting state?
No, not unless the physician would prefer it.
Total cholesterol and HDL are NOT affected significantly by food consumption.
How is a patient instructed for preparation for a Lipid Profile?
The should fast for at least 12 hours because TRIGs are affected by food consumption.
What is the primary use of cholesterol testing?
To screen for the presence of high blood cholesterol related to CAD, but also as a study of thyroid and liver function.
What are triglycerides?
They are the chemical form in which most fat exists in food, as well as in the body.
Where are triglycerides derived from?
Two sources: Synthesis by the body as ingested glucose that is NOT needed for energy (glucogen) in muscle and liver tissue as adipose tissue. AND Secondly by eating foods containing fat.
What type of test is BUN?
Blood urea nitrogen
Kidney function test
What does immunology testing consist of?
Studying antigen-antibody reactions
Assist with dx of disease

Immunologic tests are used for the early dx of disease and are used to follow the course of the disease.
How many types of Hepatitis is there?
Five - A, B, C, D, and E
What does Hepatitis testing detect?
Not only the presence of viral hepatitis but also determines the type of hepatitis present.
What causes Syphilis?
The MO Treponema Pallidum.
What is the name of the most common test used to detect the presence of syphilis?
VDRL = Venereal Disease research Laboratories and the rapid plasma reagin or RPR test.
How is a weakly reactive result interpreted?
As a positive and must have more testing.
Is a negative HIV test conclusive for the absence of HIV infection?
No, it means the antibodies many not have had time to develop as yet.

Generally takes 2 to 12 weeks to appear in the blood.
What causes Mono?
EBV or Epstein Barr Virus
What are the symptoms of Mono?
Affects children and young adults
Kissing disease = transmitted by saliva
SX are: Mental and physical fatigue, fever, sore throat, severe weakness, headache and swollen lymph nodes.
What test is used to test in the medical office for mono?
The CLIA waived rapid mono test.
What test is performed when a woman is pregnant?
Rh antibody titer- detects Rh incompatibility with a mother and her unborn child.

Mother is negaive, child is positive.
Guidelines for blood donor criteria.
Age: at least 17 sometimes 16
Last Donation: 56 (8 weeks) days between
Weight: at least 110 or 105, no upper wt limit
Temperature: can not exceed 99.5
Pulse: 50-110
BP: 180/100
Hgb: 12.5 g/dl men or women
What is the blood donating process?
Takes approx. 1 hour
Health HX, mini physical, vitals and hgb level
I pint taken using sterile needle and sterile plastic bag
No pain during it
Takes approx 8-10 minutes
NOT possible to contract AIDS donating blood
Each blood donation is tested for?
AIDS, Hepatitis and Syphilis
Blood is TYPED with its ABO and Rh blood type
What antigen and antibody does an AB type blood have?
AB has BOTH A and B antigens but NEITHER antibody A or B