6.2 PLASMA PROTEINS POE Flashcards
What is the most abundant protein in plasma?
Albumin
What protein is the most abundant in the human body?
Collagen
What is responsible for nearly 80% of the colloid osmotic pressure (COP) of intravascular fluid?
Albumin
Osmotic pressure exerted by large molecules, primarily albumin.
colloid osmotic pressure (COP).
What role does albumin play in maintaining fluid in the vasculature?
It helps fluid stay within the vasculature instead of leaking into tissues.
What type of acute-phase reactant protein is albumin classified as?
Negative acute-phase reactant protein.
What happens to albumin levels during inflammation?
Albumin levels decrease
Name three substances albumin binds to during transport.
Unconjugated bilirubin (B1)
Aspirin
Fatty acids
Name two conditions that decrease albumin due to inadequate amino acid supply.
Malnutrition
Malabsorption
Name two diseases that lead to decreased albumin levels due to loss or excretion.
Protein-losing enteropathy (gastrointestinal loss)
Renal disease
The absence of albumin.
analbuminemia
The presence of albumin with unusual molecular characteristics.
bisalbuminemia
What causes an increase in albumin levels?
Dehydration (due to hemoconcentration)
Excessive albumin infusion
It inhibits the protease neutrophil elastase to prevent tissue damage
α1-antitrypsin
What gene is responsible for α1-antitrypsin synthesis
SERPINA1 gene
What conditions increase α1-antitrypsin levels
Inflammatory reactions, pregnancy, and contraceptive use
What is the function of α1-fetoprotein (AFP) in the fetus?
Binds estradiol.
Protects the fetus from immunologic attack by the mother
Name one condition associated with increased maternal AFP
Neural tube defects (e.g., spina bifida, anencephaly)
Name one condition associated with decreased maternal AFP levels.
Down syndrome (trisomy 21).
What is the primary carrier protein for vitamin D in the circulation?
Gc-Globulin (Vitamin D–Binding Protein)
What protein binds free hemoglobin to prevent iron loss?
Haptoglobin
What is a key diagnostic feature of Wilson’s disease involving the eyes?
Kayser-Fleischer rings.
What is the function of fibrinogen
form a fibrin clot when activated by thrombin.
Name the five classes of immunoglobulins.
IgG, IgA, IgM, IgD, IgE
What is the most abundant protein in plasma?
Albumin
What is the most abundant protein in the human body?
Collagen
What percentage of colloid osmotic pressure (COP) of intravascular fluid is albumin responsible for?
Nearly 80%
A protein that increases during inflammation.
acute-phase reactant protein
A protein that decreases during inflammation.
negative acute-phase reactant protein
What happens to albumin levels during inflammation
Albumin levels decrease
Why does albumin bind unconjugated bilirubin (B1)?
Unconjugated bilirubin cannot be excreted without being conjugated in the liver, so it complexes with albumin to proceed to the liver
Name at least five substances that albumin can bind and transport.
Unconjugated bilirubin (B1)
Aspirin
Fatty acids
Calcium
Magnesium ions
Why does malnutrition and malabsorption decrease albumin levels?
Due to an inadequate supply of amino acids needed to synthesize albumin
How does liver disease lead to decreased albumin levels?
decreases synthesis of albumin by hepatocytes.
A condition where intestinal fluids containing proteins leak, causing decreased albumin levels.
protein-losing enteropathy
How does renal disease lead to decreased albumin levels?
Increased excretion of proteins by the kidneys results in decreased albumin levels
How do burns or exfoliative dermatitis lead to decreased albumin levels?
They cause extracellular fluid loss, leading to decreased albumin levels.
Name three other conditions that decrease albumin levels
Hypothyroidism
Polydipsia or excess IV administration
Mutation
How does hypothyroidism affect albumin metabolism?
Decreased thyroid hormones impair albumin metabolism, leading to decreased albumin levels.
How does polydipsia or excess IV fluids decrease albumin levels?
It causes a dilutional effect in the intravascular compartment.
What is one condition that increases albumin levels?
Dehydration (due to hemoconcentration from decreased plasma volume).
An increase in the concentration of substances in the blood, such as albumin, due to decreased plasma volume.
hemoconcentration
What are the two main causes of increased albumin levels?
Dehydration
Excessive albumin infusion
A serine protease inhibitor that inhibits neutrophil elastase to prevent tissue damage.
α1-antitrypsin
What happens if α1-antitrypsin does not inhibit neutrophil elastase?
Uncontrolled neutrophil elastase activity can destroy the alveoli, causing emphysema
What gene provides instructions for α1-antitrypsin synthesis?
SERPINA1 gene
What conditions increase α1-antitrypsin levels?
Inflammatory reactions, pregnancy, and contraceptive use.
is a protein synthesized in the developing embryo and fetus, and later by liver parenchymal cells.
α1-fetoprotein (AFP
Binds the hormone estradiol in normal fetuses.
Protects the fetus from immunologic attack by the mother.
α1-fetoprotein (AFP)
Name conditions that increase maternal AFP levels
Neural tube defects (e.g., spina bifida, anencephaly).
Abdominal wall defects.
Fetal distress.
What condition is indicated by decreased maternal AFP levels?
Chromosomal disorders such as Down syndrome (trisomy 21) and trisomy 18 (Edwards syndrome)
A chromosomal disorder caused by an extra or partial copy of chromosome
Down syndrome
A chromosomal disorder where a baby has three copies of chromosome 18, leading to abnormal organ development.
trisomy 18
What is α1-Acid Glycoprotein (orosomucoid), and what type of protein is it?
It is an acute-phase reactant protein
Name conditions that increase α1-Acid Glycoprotein levels
Stress
Inflammation
Tissue damage
Acute myocardial infarction (AMI)
Trauma
Pregnancy
Cancer
Pneumonia
Rheumatoid arthritis
Surgery
It is a serine proteinase inhibitor and an acute-phase reactant
α1-Antichymotrypsin
What enzymes does α1-Antichymotrypsin inhibit
Cathepsin G
Pancreatic elastase
Mast cell chymase
Chymotrypsin
Name conditions that increase α1-Antichymotrypsin levels.
Inflammatory conditions
Name conditions that decrease α1-Antichymotrypsin levels.
Liver disease, Parkinson’s disease, COPD, Alzheimer’s disease
What is the role of α1-Antichymotrypsin in Alzheimer’s disease
integral component of amyloid deposits
They are a family of serine proteinase inhibitors that play a role in inflammation and carcinogenesis/oncogenesis.
Inter-α-Trypsin Inhibitors
What causes increases in Inter-α-Trypsin Inhibitors?
Inflammatory disorders
It is the major carrier protein of vitamin D and its metabolites in the circulation.
Gc-Globulin (Vitamin D–Binding Protein)
Name conditions that increase Gc-Globulin levels.
Third trimester of pregnancy
Patients taking oral contraceptives
Name conditions that decrease Gc-Globulin levels.
Severe liver disease
Protein-losing syndromes
is an α2-glycoprotein and an acute-phase reactant.
It binds free hemoglobin to prevent the loss of hemoglobin and its iron constituent.
haptoglobin
Name conditions that increase haptoglobin levels.
Inflammatory diseases
Burns
Nephrotic syndrome
Name a condition that decreases haptoglobin levels.
Hemolytic anemia
A reaction caused by incompatibility between the patient and donor blood products.
Hemolytic Transfusion Reaction
A blood problem in newborns, often occurring when an Rh-negative mother has a baby with an Rh-positive father, leading to an immune response against the baby’s red blood cells.
Hemolytic Disease of the Newborn
is a copper-containing α2-glycoprotein and an acute-phase reactant.
ceruloplasmin
What percentage of copper in the body is bound to ceruloplasmin?
90%
Name conditions that increase ceruloplasmin levels.
Inflammation, some cancers, and pregnancy
Name conditions that decrease ceruloplasmin levels
Wilson’s disease
Malnutrition
Malabsorption
Severe liver disease
Nephrotic syndrome
Menkes syndrome (kinky hair disease)
An autosomal recessive disorder associated with decreased ceruloplasmin levels and copper accumulation in the liver, brain, and other organs.
Wilson’s disease
What is a diagnostic feature of Wilson’s disease in the eyes?
Kayser-Fleischer rings (copper deposition in the cornea).
A major component of the α2 band that inhibits proteases like trypsin, thrombin, kallikrein, and plasmin
α2-Macroglobulin
Name a condition that increases α2-Macroglobulin levels.
Nephrotic syndrome (10× increase due to its large size preventing filtration
What is transferrin (siderophilin), and what type of protein is it?
Transferrin is a negative acute-phase reactant.
To transport iron and prevent its loss through the kidneys.
transferrin
Name conditions that decrease transferrin levels
Liver disease, malnutrition, and nephrotic syndrome
Name conditions that increase transferrin levels.
Iron deficiency anemia (IDA)
Hemochromatosis (bronze diabetes)
is an acute-phase reactant that binds free heme released during hemoglobin degradation to protect against oxidative damage.
Hemopexin
What is the hemopexin-to-heme ratio?
1:1
Name a condition that decreases hemopexin levels.
Hemolytic anemia
transports cholesterol, triglycerides, and phospholipids in the blood.
lipoproteins
What are the types of lipoproteins
Chylomicrons (CMs)
Very low-density lipoproteins (VLDL)
Low-density lipoproteins (LDL)
High-density lipoproteins (HDL)
It is the light chain component of the major histocompatibility complex (MHC).
Found on the surface of most nucleated cells and in high concentrations on lymphocytes.
β2-Microglobulin
Name conditions that increase β2-Microglobulin levels.
Rheumatoid arthritis, systemic lupus erythematosus, and HIV.
is an acute-phase reactant and one of the first to increase during inflammation
C-Reactive Protein (CRP)
Name conditions that increase CRP levels
Acute rheumatic fever
Bacterial infections
Myocardial infarction
Rheumatoid arthritis
Carcinomatosis
Gout
Viral infections
are glycoproteins produced by B cells that confer humoral immunity.
Immunoglobulins
