ClinLab 2: Lect 4 & 5 Flashcards
What are the classes of plasma proteins?
Albumin
Globulin: A-1, A-2, B-globulin, G-globulin
Miscellaneous
The total protein concentration of serum from healthy ambulatory adult is between ?
How does plasma protein level differ?
6.3 and 8.3
Plasma- 0.3g higher
What is the albumin/globulin ratio?
What can cause the ratio to change?
0.8-2.0
Dec in response to low albumin/high globulin
Primary function of albumin class proteins?
Highest concentration (60% of total) contributes nearly 80% of colloid osmotic pressure of intravascular fluid to maintain appropriate fluid balance in tissue
What is the secondary function of albumin class proteins?
Carrier protein for bilirubin, hormones and FAs
In what conditions would a decreased albumin level be seen?
Low intake, synthesis= malnutrition or liver dz
Inc loss= nephrotic syndromee, burns
GI- protein losing enteropathy
Albumin levels are increased in what type of condition?
Dehydration
What is the function of pre-albumin?
Low concentrations that are carriers for T3/4.
When complexed with retinol binding protein, transports Vit A
What is the clinical significance of pre-albumin levels?
Sensitive marker for inadequate dietary protein intake
Dec- hepatic dz, inflammation, poor nutrition
Inc- steroid therapy, Chronic RF, alcoholism
What are the Alpha-1 globulins?
1 Antitrypsin- AAT (majority)
1 Lipoprotein- HDL
1 Fetoprotein- AFP
What are the Alpha-2 globulins?
Haptoglobin
Ceruloplasmin
Alpha 2 macroglobulin
Which Alpha-1 globulin is an acute phase reactant?
AAT
What is the function of AAT?
Protease inhibitor that neutralizes trypsin like enzymes (elastase) that can damage structural proteins
When/where are elastase and trypsin-like enzymes released from/during?
WBCs
Phagocytosis
What is the clinical significance of AAT?
Deficiency associated with severe destruction of alveolar walls/pulmonary deficiency
Increased during inflammatory disorders
What is the function of AFP?
When is maternal screening performed for this globulin?
Fetus protection
15-20wks
What is the clinical significance of AFP?
Inc during pregnancy= open neural tube defect
Dec during pregnancy= Downs
Liver/gonad cancer
What is the function of haptoglobin?
Acute phase reactant that binds free Hgb to prevent loss of Hgb and iron from kidneys
What is the clinical significance of haptoglobin?
Inc during trauma/burns to help prevent loss of Hgb from damaged RBCs
Dec in liver dz and nephrotic syndrome
Function of Ceruloplasmin
Cu containing protein w/ enzymatic activity and is an acute phase reactant
What is the clinical significance of Ceruloplasmin?
Low level in Wilson’s, liver dz, malnutrition/absorbtion
Inc in pregnancy, inflammatory disorder and oral estrogen
Where is Alpha-2 Macroglobulin found and what is it’s function?
Intravascular spaces to inhibit portease enzymes (trypsin, pepsin, plasmin)
What is the clinical significance of Alpha-2 Macroglobulin?
Elevated in renal dz, contraceptive use, pregnancy and estrogen therapy
Dec in acute inflammatory disorders and acute pancreatitis
What are the Beta-Globulins?
Transferrin Hemopexin Complement proteins Fibrinogen CRP LDL
Which Alpha globulins are not acute phase reactants?
AFP
A2 Macroglobulin
Characteristics and function of Transferrin?
Synth in liver and major component of B-globulin fraction
Transports Fe and prevents loss through kidneys (2Fe to each transferrin with 1/3 occupied at a time)
Clinical significance of Beta Globulins?
Dec in liver dz
Inc in Fe deficiency anemia
Pregnancy
Fucntion of Hemopexin?
Removes circulating heme and porphyrins (part of heme)
What is the clinical significance of hemopexin?
Inc in malignant melanoma
Complement protein family is involved in?
Immune and inflammatory response
Functions of complement proteins?
Lysis of celll to which Ag-Ab complexes attach to
Opsonization
What is the clinical significance of Complement proteins?
Inc level in inflammation
Dec in Systemic Lupus
What is the function of fibrinogen?
Formation of fibrin clot when activated by thrombin
What is the clincial significance of fribrinogen?
Dec in DIC and afibrinogenemia
How does CRP move and what is it’s function?
Moves with gamma globulins to facilitate opsonization
What is the clinical significance of CRP?
Inc in inflammatory dz
Assayed for risk assessment of CVD
Inc levels indicate chronic inflammatory process in vascular system
What is the most abundant gamma-globulin?
Where are they synthesized?
IgE
By plasma cells (B cells)
Synth stim’d by immune response
Clinical significance of gamma globulins?
Inc A- liver dz, autoimmune, infection
Inc D- liver dz, infection, CT disorders, multiple myeloma
Inc IgE- asthma, allergic, parasitic infections
Inc IgG- liver dz, infection, collagen dz
IgM- first to appear in immune response
Decreased immunoglobulins are caused by?
Faulty plasma cell function/inherited immunodeficiency
Clinical significance of immunoglobulins?
Inc in monoclonal gammopathies- group of disorders that proliferate singel clone of plasma cells that produce homogenous monoclonal protein
Multiple myeloma will have increased immunoglobulins except which one?
IgM
Inc in Waldenstroms Macroglobulinemia
What are the acute phase reactants?
CRP Alpha-1 Antitrypsin Fibrinogen Haptoglobin Complement proteins Ceruloplasmin
What organ synthesizes most of the plasma proteins?
Liver
What Dz is characterized by decrease in serum albumin, alpha 1, beta and gamma but increased levels of Alpha 2 proteins detected by electrophoresis?
Nephrotic syndrome
An insufficiency in what plasma protein leads to pulmonary insufficiency?
Alpha-1 Antitrypsin
Define Lipid
Hydrophobic compounds soluble in organic solvents and insoluble in water
What are the five subdivisions of lipids?
Sterol- choleserol, steroids, Vit D
FA- short/long chain, prostaglandins
Glycerol esters- tri/phsphoglycerides
Sphingosine derivatives- sphingomyelin, glychosphingolipids
Terpenes- isoprene polymers, Vit A E and K
How are lipids transported?
In plasma in macromolecular lipoproteins
What are the categories of lipoproteins?
Chylomicron VLDL iDL VLDL HDL Lipoprotein
____ are the protein components of a lipoprotein
Apolipoprotein
What is the function of apolipoprotein?
Activate enzymes in lipoprotein metabolic paths
Maintain integrity of lipoprotein complex
Facilitate uptake of lipoprotein into cells through receptors
Clinical significance of lipids is associated with ?
Coronary heart disease and other vascular disorders
When are adults tested for lipids?
Every 5yrs
If total cholesterol is above 200 or HDL is <40, fasting lipoprotein is required
Lipoprotein A result greater than 30mg is indicator of increased risk of?
CHD
Apolipoprotein E is found where?
Chylomicron
iDL
Apolipoprotein A-I is the major lipoprotein of ____
HDL
Less than 120- risk of CHD
+160= protective
Apolipoprotein B-100 is the major lipoprotein of ____
LDL
100-120mg correspond to borderline high LDL point
Define dyslipoporteinemia
Based on relationship between lipoprotein concentrations and risk for CHD
Define 1* and 2* Hyperlipoproteinemia Dx
Dx of primary after 2* causes are ruled out
What are causes of 2* hyperlipidemia and dyslipoproteinemia?
Drugs/ETOH DM/hypothyroid Glycogen storage dz Tay-Sachs Dz Nephrotic Synd. Chronic RF Hepatitis Burns
Which lipoprotein is more important for therapeutic decision making?
LDL
Which apoprotein is inversely related to risk of CHD and a surrogate marker for HDL?
Apo A-1
What is the secretory unit of the thyroid gland?
Thyroid follicle
Where is thyroglobin made by follicular cells stored?
Outer layer of epithelial cells enclosed in colloid
What do parafollicular cells secrete?
Hormone called calcitonin
Abbreviations for
Free Thyroxine
Free Triodothyroinin
DIT + DIT= FT4
DIT + MIT= FT3
Abbreviation for
Total Thyroxine
Total Triodothyronine
DIT + DIT= T4
DIT + MIT= T3
Abbreviation for
Reverse Triodothyronine
Monoiodotyrosine
Diodotyrosine
rT3
MIT
DIT
What protein is the most important carrier of T4?
Thyroxine binding protein TGB
T4 and T3 circulate bound to one of what three proteins?
TBG
Transthretin TBPA
Albumin
Alterations in concentration or affinity for thyroid binding protein will cause what change?
Amount of bioavailable T3/4
Majority of T3 is produced by?
Extrathyrodial deiodination of T4 in liver and kidneys
___ has more biological activity than the other thyroid hormone
T3 10x more
Thyroid hormone synthesis and secretion are controlled by negative feed back loops to what organs?
Hypothalamus
Pituitary
Thyroid follicle cells
Funtion of TRH
Thyrotoponin releasing hormone- from hypothalamus, enter portal system to release TSH thyrotropin from anterior thyroid thyrotrophs
TSH stimulates the release of ? from ?
T4 and 3 from thyroid gland
T4/3 negatively feed back onto what?
Hypothalamus and pituitary
What are the functions of thyroid hormones?
Basal metabolic rate Mitochndrial metabolism Neural development/growth Sexual maturation Inc HR Protein synthesis Inc Ca and PO4 metabolism
What is tested in a Thyroid Function Test?
TSH
T4
T3
Free T4
What is the best way to measure thyroid function?
TSH level
High= failing thyroid from primary hypothyroidism
Low- overactive thyroid producing too much thyroid hormone (hyperthyroidism)
T4 and T3 circulates in the blood in what two forms?
Protein bound
Free fraction- most important for determining thyroid function
What are the names of the Free Fraction tests?
FT4I or FTI
PTs with hyperthyroidism will have an elevated __ or ___
PTs with hypothyroidism will have low __ or __
FT4 or FTI
FT4 or FTI
T3 tests are usually used to diagnose ? or to determine?
Hyerthyroidsism
Severity of hyperthyroidism
What part of the thyroid function test is the least helpful for hypothyroid PTs?
T3- last to become abnormal
In hypo/hyperthyroid PTs what process happens that is counter effective for their health?
Lymphocytes make Abs (Anti TPO or Anti-Tg) against the thyroid to stim/destroy it