MLS 2213 Unit 9 Lipids

What is optimal total cholesterol?

Less than 200

What is borderline total cholesterol?

200-239

What is high risk cholesterol?

>240

What is optimal LDL?

Less than 100

What is above optimal LDL

100-129

What is borderline risk LDL

130-159

What is high risk LDL

160-189

What is optimal HDL

60 or higher

What is borderline HDL

40-59

What is high risk HDL

Less than 40

What are optimal triglycerides?

Less than 150 mg/dL

What are borderline triglycerides?

150-199 mg/dL

What are high triglycerides?

Greater than 200 mg/dL

What is average risk total cholesterol/HDL ratio for men and women

• Men = 5.0

• Women 4.5

What is half average risk total cholesterol/HDL ratio for men and women

• Men = 3.4

• Women = 3.3

What is double risk total cholesterol/HDL ratio for men and women

• Men = 9.5

• Women = 7.0

What is average risk LDL/HDL ratio for men and women

• Men = 3.5

• Women = 3.2

What is half risk LDL/HDL ratio for men and women

• Men = 1.0

• Women = 1.5

What is double risk LDL/HDL ratio for men and women

• Men = 6.3

• Women = 5.0

How long should a patient be fasting before a lipid panel?

12 hours

What type of specimen is suitable for lipid testing and how should it be stored if not able to be tested immediately?

• Plasma is typically preferred but serum is acceptable

• Serum or plasma should be separated from the cells and kept cold but not frozen

How does atherosclerosis happen?

• Theres injury to the blood vessels which causes LDL and calcium to increase

• LDL and platelets penetrate the artery which can calcify and slowly enlarge

How does high lipid levels lead to higher risk of atherosclerosis

Elevated lipid levels, particularly LDL cholesterol, contribute to the development of atherosclerosis by promoting plaque formation in the arteries, leading to narrowed blood vessels and increased risk of cardiovascular events.

What are some risk factors for atherosclerosis?

• Age

• Gender

  • Men more than women until menopause

• Heredity

• Diabetes

• Dietary fat intake

• Smoking

• Obesity

• Hypertension

• Impaired glucose tolerance

What lipids are in apolipoprotein class A?

• HDL

• Chylomicrons

What apolipoprotein class are HDL and chylomicrons?

Apolipoprotein class A

What apolipoproteins are in class B?

• LDL

• VLDL

• IDL

What apolipoproteins class are LDL, VLDL and IDL

Class B

What apolipoproteins class are chylomicrons

Class C

What are apolipoproteins class C

Chylomicrons

Why test for apolipoproteins A, B and a

They have a high correlation to cardiovascular disease and atherosclerosis risk

What are the two ways the HDL decreases atherosclerosis risk?

• By blocking the LDL receptors of cell membranes

• HDL activated LCAT and as HDL removed cholesterol from the cell membrane LCAT esterified the cholesterol which is then stored in the cell of HDL

What is the LDL calculation using the Friedewald method

Total Chol  -  [HDL-C  +  (TG/5) ]

Why does Friedewald not work for people with low triglycerides?

If someone has low triglycerides then with the Friedewald method, it calculates a higher LDL

Why does Friedewald not work for people with high triglycerides?

The Higher your Triglycerides are, the Lower your LDL-Cholesterol becomes

Why does Friedewald not work for people with chylomicron remnants?

Chylomicrons are mostly triglycerides so they’ll mess with the calculations

What is the reference method for total cholesterol

Liebermann-Buchard method

What reagents are used in the Leibermann-Buchard method

• Acetic anhydride

• Glacial acetic acid

• Sulfuric acid

• sodium sulfate

What is the preferred method for total cholesterol

Trinder cholesterol oxidase

What are the reagents used in the Trinder cholesterol oxidase method?

• Cholesterol oxidase

• hydrogen peroxide

• Cholesterol ester hydrolase

How is the Trinder cholesterol oxidase method work?

• Unesterified cholesterol is turned into hydrogen peroxide by cholesterol oxidase

• The hydrogen peroxide then oxidizes a compound which becomes red

What reagents are used in testing HDL using the precipitate method

• Heparin and Manganese Chloride

• Dextran Sulfate and Calcium or Magnesium salts

• Magnesium Chloride and Phosphotungstic Acid

What method is used for testing HDL using the precipitiation method

Reagents are added to the sample that cause the precipitation of VLDL and LDL which only leaves HDL so it can be tested

What reagents are used in testing HDL using a direct method

• IgG antibodies

• Cholesterol oxidase

• Cholesterol ester hydrolase

What method is used to test HDL using the direct method

IgG antibodies against LDL, VLDL, and chylomicrons are added to the specimen. Then cholesterol oxides then cannot react with anything bound by antibodies

What is the method used to calculate LDL called?

Friedwald

What level of triglycerides does friedewald calculation become invalid

400

What are the reagents used in testing for LDL

IgG antibodies to VLDL, HDL and chylomicrons

What is the method used to test for LDL

IgG antibodies added to the sample to bind to VLDL, HDL, and chylomicrons. The sample is then added to a tube with a mesh that filters out anything that is bound by an antibody. This allows LDL to pass through the mesh

What is the method used to test for triglycerides using the glycerol kinase method?

Lipase is used to hydrolyze the fatty acid off of the triglyceride.

The Glycerol is the substrate for Glycerol Kinase, which converts Glycerol to Glycerol-3-Phospate and ADP. From here the various methods link to other enzyme systems to get either a colored product or NADH.

What are the reagents used to test for triglycerides using the glycerol kinase method?

• Lipase

• Glycerol kinase

What lipoprotein is in the albumin band

Free fatty acids

What lipoprotein is in Alpha 1 band

• High-density lipoprotein (HDL)

• Alpha

• Phospholipids

What lipoprotein is in the Alpha 2 band

• VLDL

• pre-beta

• Triglycerides

What lipoproteins are in the Alpha 2/Beta bridge

• Intermediate-density lipoprotein (IDL)

• Floating beta

• Cholesterol

• Triglycerides

What lipoproteins are in the Beta band

• Low-density lipoprotein (LDL)

• Beta

• Cholesterol

What lipoproteins are in the gamma band

• Chylomicrons

What does the serum look like in hyperlipoproteinemia type 1, what fraction is elevated and what lipoprotein is elevated?

• Layer of chylomicrons on clear serum

• A slight decrease in alpha band and huge elevation in chylomicron band

• TG values can reach as high as 10,000 mg/dL

  VLDL usually normal, HDL and LDL are slightly decreased.

What does the serum look like in hyperlipoproteinemia type IIa, what fraction is elevated and what lipoprotein is elevated?

• Usually clear serum

• Increase in Beta band

• Large increase in LDL. Normal TG

What does the serum look like in hyperlipoproteinemia type IIb, what fraction is elevated and what lipoprotein is elevated?

• Clear or faintly turbid, no chylomicrons

• Beta and Pre beta

• This has a large increase in the LDL, and a slight increase in VLDL

  

What does the serum look like in hyperlipoproteinemia type III, what fraction is elevated and what lipoprotein is elevated?

• Turbid, creamy layer on top

• Can cause broad Beta, high chylomicrons

• High chylomicrons and VLDL

What does the serum look like in hyperlipoproteinemia type IV, what fraction is elevated and what lipoprotein is elevated?

• Turbid with no chylomicrons

• Pre beta band is elevated

• High elevation in VLDL. There can be a slight increase in LDL, but TG are the big ones.

What does the serum look like in hyperlipoproteinemia type V, what fraction is elevated and what lipoprotein is elevated?

• Creamy layer over turbid layer

• Pre beta and chylomicrons

• Increase in VLDL and persistence of chylomicrons.

  

What is this?

Type V

What is this?

Type I - missing lipoprotein lipase

What is this?

Type IIa

What is this?

Type IIb

What is this?

Type III

What is this?

Type IV

What is the most abundant lipoprotein class in lipoprotein electrophoresis?

LDL

What is lipoprotein X?

• An abnormal LDL that migrates between the Chylomicron and Beta band

• Appears in hepatobiliary obstructs

• Since patients will have other symptoms way before the band will apear has no clinical significance

What phospholipid is found in amniotic fluid that can measure lung development?

Lecithin

What are the two tests used to test for fetal lung maturity

FPOL

Lecithin/Sphingomyelin ratio

Why is a lecithin/sphingomyelin ratio done instead of another test?

This method can be done regardless of the hydration status of the mother.

What L/S ratio indicates mature lungs?

>2.0

What L/S ratio indicated immature lungs?

<1.6

What L/S ratio indicates an indeterminate result?

1.6-2

What must be considered when doing an L/S ratio on a diabetic mother? How is this circumvented?

Diabetic mothers have much higher L/S ratio. If P-glycerol is also detectable with a L/S ratio >2 that indicates mature lungs

In a diabetic pregnant mother, what does a L/S of >2.0 and an undetectable PG mean?

Immature fetal lungs

This lipid contains a chain of 12 or more carbons bound to a hydroxy group

fatty acid

The four types of lipids found in blood are

fatty acid, glyceride, phospholipids, cholesterol

Fatty acids have a ____ lipid portion and a ____ hydroxy group.

nonpolar, polar

Fatty acids bind to this protein

albumin

Three carbons bound to hydroxy groups is known as

glycerol

A glycerol molecule with one hydroxy group replaced with a fatty acid is termed

monoglyceride

A glycerol molecule with two hydroxy groups replaced with fatty acids is termed

diglyceride

A glycerol molecule with all three hydroxy groups replaced with fatty acids is termed

triglyceride

Of the different glycerol derivatives, only triglycerides have a(n)

disease correlation

This lipid has no clinical significance in serum or plasma

phospholipid

This lipid is a major risk marker for myocardial infarction and stroke

cholesterol

In the bloodstream, lipids are bound to

lipoproteins

A lipoprotein with no lipid bound to it is also known as a(n)

apolipoprotein

A lipoprotein of dietary origin is

exogenous

A lipoprotein manufactured by the liver is

endogenous

Class A lipoproteins are

HDL, chylomicrons

Class B lipoproteins are

LDL, VLDL, IDL

Chylomicrons are usually irrelevant because they are

exogenous

Frederickson based his lipid classification system on

electrophoresis migration

Svedberg based his lipid classification system on

ultracentrifugation

Fatty acids migrate to the _____ band of a normal protein electrophoresis.

albumin