Plasma Proteins Practice Questions Flashcards
A 26-year-old man reported to the pulmonary clinic complaining of shortness of breath. His history shows that he has been a chronic smoker for the past 10 years. His lung function tests show that he has emphysema. Which of the following are likely to be decreased in this patient?
- Haptoglobin
- alpha 2-Macroglobulin
- beta 2-Microglobulin
- alpha 1-antitrypsin
- Ceruloplasmin
alpha 1-antitrypsin
Emphysema is rare in young adults, even with a history of smoking. In this case, homozygous deficiency of alpha1-antitrypsin is a real possibility. This inherited deficiency has a frequency of about 1 in 7000 in the white population and is one of the most common serious single-gene disorders.
The serum of a 47-year-old woman was subjected to electrophoresis and the following was found:
What does this patient most likely have?
- Acute injury, or surgery
- Multiple myeloma
- Monoclonal gammopathy of unknown significance (MGUS)
- Nephrotic syndrome
- Chronic inflammation
Chronic inflammation
This is most compatible with chronic inflammation. Some abnormalities are explained by the acute phase reactants, which change both in acute and chronic stress: decreased albumin, increased α2-macroglobulin. However, γ-globulins rise only after several days in response to infections and many other diseases (autoimmune, liver cirrhosis, cancer…). Monoclonal gammopathies, including multiple myeloma (the malignant form of monoclonal gammopathy), would show an abnormal sharp peak consisting of a single overproduced immunoglobulin (M protein, or paraprotein). Here, however, we are dealing with a “polyclonal gammopathy”, with increase in the entire broad γ-globulin peak. Nephrotic syndrome (protein loss through the kidneys) would also show low albumin and high α2 peak, but γ-globulins would also be reduced.
A 51-year-old man is rushed to the ED in a rural area while on safari. His wife reports that he has been having severe chest pain for the past 12 hours. The clinical laboratory at the hospital has limited facilities and can only determine his lactate dehydrogenase levels to determine whether he has had a myocardial infarct. The determination of which of the following will provide this information?
- LDH 2 and 5
- LDH 1 and 5
- LDH 4 alone
- LDH 1 and 2
- LDH 2 and 4
LDH 1 and 2
LDH has 5 isoenzymes that are formed by two slightly different but equivalent subunits forming the active tetramer. There are M subunits in skeletal muscle and H subunits in the heart, and a mix of both in most other organs. The H4 tetramer is LDH-1, and the M4 tetramer is LDH-5, numbered according to electrophoretic mobility. Therefore, acute MI will raise isoenzymes 1 and 2. Elevations of isoenzymes 4 and 5 would suggest damage to skeletal muscle.
A 7-year-old boy with a history of seizures was found to have a cerebellar tumor. Which of the following is likely to elevated in his cerebrospinal fluid?
- Creatine kinase MM
- Amylase
- Alanine transaminase
- Alkaline phosphatase
- Creatine kinase BB
Creatine kinase BB
Creatine kinase BB is the brain isoenzyme. It is rarely elevated in the blood, unless there is serious disruption of the blood-brain barrier, but is elevated in cerebrospinal fluid in destructive brain diseases. The other answer choices are proteins that are associated with other tissues such as muscle (creatine kinase MM), bones and biliary system (alkaline phosphatase), pancreas (amylase) or liver (alanine transaminase).
A 43 old man presents to the veterans affairs clinic for alcohol and substance abuse. The patient had previously been on antiviral treatment for hepatitis Which had been acquired while on active duty in Asia. During the routine evaluation the patient appeared gaunt and had lost 10 pounds, lowering his BMI to 17.5kg/m2. The electrophoresis of his sera indicates peaks of albumin and alpha2 globin. The alpha1 globulin, beta globulin and gamma globulins were about ¼ the albumin level. What does the electrophoresis indicate about the patient.
- The antiviral medication use has caused a decrease in liver function.
- The patient has internal bleeding.
- The patient’s has had a chronic infection, probably the Hep C, for a long time.
- The patient’s kidney’s are failing.
- The patient has a cancer, most likely a cancer inthe bone marrow.
The patient’s kidney’s are failing.
The patient has advance nephrotic disease, likely ESRD. Chronic infections lead to elevated gamma globulin but unless the kidneys are failing the alpha2 and albumin peaks are generally very different with albumin about 10 times more than all other peaks..
Why would α2-globulins increase during acute phase of Inflammation?
- Ceruloplasmin, α2-macroglobulin and α2-antiplasmin regulate inflammation, fibrinolysis and clotting
- α2-antiplasmin, α2-macroglobulin and Protein C regulate inflammation, fibrinolysis and clotting
- Albumin decreases during acute phase making the α2-globulins appear to increase
- Haptoglobin and α2-macroglobulin regulate fibrinolysis and clotting
- α2-antiplasmin and Protein C regulate fibrinolysis
α2-antiplasmin, α2-macroglobulin and Protein C regulate inflammation, fibrinolysis and clotting
Why would the concentrations of α2-globulins, beta-globulins and gamma-globulins increase during cirrhosis of the liver?
- They don’t, it’s the level of albumin that drops and alters the fraction of other proteins
- The protease inhibitors are increased due to cirrhosis
- Albumin is decreased so it carries fewer globulins
- Transferrin, α2-macroglobulin and ceruloplasmin are needed for increased iron transport
They don’t, it’s the level of albumin that drops and alters the fraction of other proteins
Wrong answers secretion in the liver fall during cirrhosis making answer B incorrect. Albumin carries fatty acids and negatively charged molecules but not generally large globular proteins. α2-macroglobulin has no role in Iron transport.
Why does the albumin levels decrease in nephrotic syndrome?
- Glomerular loss decrease the need for albumin
- Increases in the protease inhibitors of α2-macroglobulin, α2-antiplasmin, and protein C change the fraction of Albumin
- Kidney inflammation up regulates fibrinolysis an clotting
- Basement membrane of glomeruli looses repulsion of albumin and now allows its excretion
Basement membrane of glomeruli looses repulsion of albumin and now allows its excretion
Glomerular loss is the cause of nephrotic syndrome is some cases but it does not effect the needs or uses of albumin. Although inflammation is another cause of nephrotic syndrome, it does not effect the needs or uses of albumin. All proteins are lost at a higher than normal rate and the fractional changes show loss of the smaller molecules faster than larger proteins. Also, the proteins listed in are not greatly increased in production.
A 23 year old man presents to the Emergency room with yellow sclera and swollen legs and feet. The swelling has worsened in the last week of travel. Palpation of the abdomen indicates an enlargement which is tender in the upper right quadrant. The electrophoresis of his blood was remarkable for the near complete loss of the alpha 1- globulin peak. What protein is most likely deficient in this patient?
- Protein C
- alpha 1 antitrypsin
- Plasminogen
- Transferrin
- IgG
alpha 1 antitrypsin
Only alpha 1 antitrypsin is found in the alpha 1 globulin band.
An unconscious male is brought to the emergency room after being found unresponsive under a highway overpass. Initial physical evaluation indicates that the patient is dirty and has a strong odor of urine but has no signs of injury other than the needle tracks on his arms and legs. A complete blood workup is conducted and the electrophoresis of the sera is found to have a very large broad peak for gamma globulins. Which of the following is the most likely cause of these findings?
- Hemophilia
- Homelessness
- Internal bleeding
- Alcoholism
- Chronic viral Hepatitis
Chronic viral Hepatitis
The increased and broad peak of gamma globulins indicates the patient has had a infection of more than a day or two. Although other of the answers may also apply to this patient, they do not account for the increased gamma globulins
