Lecture 8 "Iron and other proteins" Flashcards
What medications can alter iron levels?
antibiotics, birth control, estrogen, hypertension medicine, cholesterol medications, deferoxamine (removes excess iron from the body), gout medication, testosterone
What can increase iron level?
beta-thalassemia, alcoholic cirrhosis, high iron intake, hereditary hemochromatosis
What is the mechanism behind hereditary hemochromatosis increasing iron level?
HFE gene, impaired iron detection and regulation
How does alcoholic cirrhosis increase iron levels?
damage to liver leads to increased ferritin levels (iron storage)
What can decrease iron levels?
iron deficiency anemia, anemia of chronic disease, chronic renal failure, inadequate absorption, increased loss (from GI tract, nose bleeds, menstruation, cancer, trauma, phlebotomy), increased demand in pregnancy
What is the function of ferritin in the body?
it serves as the storage unit for iron
What allows the release of iron through the channels of ferritin when demands occur?
Iron is stored as Fe(III) and then it is oxidized to Fe(II) which allows the release
How much of the body’s iron is stored within ferritin?
15-20%
Where is ferritin stored?
liver, spleen, skeletal muscles, and bone marrow
What is an acute phase reactant?
when ferritin can increase in response to liver disease, cancer, inflammation, and infection
What is the gold standard in diagnosing iron deficiency anemia?
serum ferritin
What can cause increased ferritin?
hereditary hemochromatosis, excess iron intake/poisoning, chronic hepatitis, other chronic disease states (cancer, alcoholism)
What can cause decreased ferritin?
iron deficiency anemia
What are transferrin’s?
they are glycoproteins that are responsible for the transport of iron
How many iron molecules can transferrin bind?
2 iron molecules
How many transferrin binding sites are typically filled?
33%
Where is transferrin synthesized?
transferrin is synthesized in the liver and synthesis increase in a state of iron deficiency
What is total iron binding capacity?
The maximum amount of iron that serum proteins, mainly transferrin, can bind to. TIBC represents the potential from iron binding if ALL of the binding sites on a protein were filled.
What factors increase total iron binding capacity?
iron deficiency anemia, pregnancy, oral contraceptives, viral hepatitis
What factors decrease total iron binding capacity?
anemia of chronic disease, hemochromatosis, sideroblastic anemia
What is transferrin saturation a measurement of?
a percentage of the transferrin binding sites that are actually bound by iron
What causes increased transferrin saturation?
megaloblastic anemia, sideroblastic anemia, iron overload status, hemochromatosis
What causes decreased transferrin saturation?
iron deficiency anemia, chronic infection, malignancy, pregnancy, anemia of chronic disease
What are the components of plasma?
a large majority is water, the blood proteins (globulin, fibrinogen, albumin), nutrients (amino acids, lipids, sugars), and hormones and electrolytes
What are the different types of globulins?
alpha and beta globulins- produced by the liver and are involved in transportation or act as substrates
gamma globulins- produced by lymphoid tissue involved in immune system
What are some purposes Albumin serves?
Functions as the most important regulator of oncotic pressure within the vasculature system. Can also serve as a transporter for hormones, lipids, drugs and other substances.
What causes increased albumin levels?
dehydration
What causes decreased albumin levels?
liver disease, malabsorption, malnutrition, dilution by IV fluids, genetic variations and congenital causes, abnormal loss from renal disease, GI loss, Skin loss, severe burns
What is the function of alpha-1-antitrypsin?
It inhibits the action of many key enzymes that are released during inflammatory reactions in the lungs.
What is an example of an Alpha-1 globulin?
Alpha-1-antitrypsin
What are some deficient alpha-1-ntitrypsis manifestations?
chronic obstructive lung disease in adults, prolonged jaundice or hepatitis in infants, live dysfunction in children, portal hypertension, chronic hepatitis, cirrhosis, hepatocellular carcinoma
Where is ceruloplasmin made and what is its function?
it is made in the liver and is involved in copper transport within the body
What is an example of an alpha-2 globulin?
ceruloplasmin –> contains 6 or seven copper atoms
What causes increased ceruloplasmin?
oral contraceptives, first trimester of pregnancy, infections
What is the function of haptoglobin?
it is produced in the liver and its function is to bind to free hemoglobin when RBCs are destroyed.
What happens once haptoglobin is bound to hemoglobin?
It transports hemoglobin back to the liver where the heme is converted to bilirubin.
What happens to haptoglobin when there is an increase in RBC destruction?
The haptoglobin becomes depleted and its levels decrease.
What can cause hemolytic anemia?
hereditary abnormalities that cause increased RBC destruction, pathogens, infection, inflammation, and toxins
What can cause increased haptoglobin levels?
infection, inflammation, neoplastic disease, pregnancy, trauma, acute MI
What can cause decreased haptoglobin levels?
hemolytic anemia, transfusion reaction, artificial heart valves
What is the function of complement proteins?
they supplement the action of antibodies to destroy and eliminate pathogens from the body
Which complement proteins are considered acute phase reactants?
C3 and C4
When does the complement pathway begin?
The cascade begins when the first protein, C1, recognizes an antibody-antigen complex or when certain components of the surface of a bacteria or virus are recognized.
In the complement pathway what causes inflammation and opsonization?
When C3 is eventually cleaved.
What is the ultimate goal of the complement pathway?
to produce a membrane attack complex (MAC) and insert itself into the membrane of the pathogen, causing lysis and destruction
What is opsonization?
it is the coating of bacterial surfaces which enhances phagocytosis
When may complement levels be reduced?
in any disease that has an increased level of circulating immune complexes or autoimmune antibodies
When may measurement of complement proteins be useful?
in autoimmune diseases such a lupus or recurrent infections.
What is the CH50 test used for?
to measure immune processes or to detect complement deficiency
What is needed in order to have a normal CH50 test result?
all nine proteins C1-C9 must be present
When are C3 and C4 tests primarily used?
used to investigate the undetectable CH50 level
When can C3 and C4 tests be used?
used to monitor some disease such as SLE(lupus). also tested in the presence of certain fungal infections, gram negative septicemia, and shock
When can complement testing (C3,C4) levels be decreased?
systemic lupus erythematosus, bacterial infections, cirrhosis, hepatitis, malnutrition
When can complement testing (C3,C4) levels be increased?
cancer, ulcerative colitis