100 Questions
What is the consequence of abnormal oxidase activity in phagocytes?
Impaired bacterial killing
Which of the following microorganisms is associated with recurrent suppurative infections in individuals with impaired phagocytic activity?
Burkholderia cepacian
What is the result of increased respiratory burst activity in individuals with myeloperoxidase deficiency?
Compensated bacterial killing
What is the function of myeloperoxidase in phagocytes?
Bacterial killing
What is the result of a negative Nitroblue Tetrazolium (NBT) screening test?
Impaired respiratory burst
Which of the following is a characteristic of myeloperoxidase deficiency?
Absence of myeloperoxidase enzyme from neutrophils and monocytes
What is the consequence of impaired NADPH oxidase activity in phagocytes?
Impaired bacterial killing
What is the primary defect in Chronic Granulomatous Disease (CGD) that leads to impaired phagocytic activity?
Decreased ability of phagocytes to produce superoxide and reactive oxygen species
Which of the following is a direct consequence of a mutation in the NADPH oxidase system in CGD?
Inability to form hydrogen peroxide
What is the purpose of the NADPH oxidase enzyme in normal phagocytic cells?
To form hydrogen peroxide and reactive oxygen species
Which of the following is a characteristic of Lazy Leukocyte Syndrome?
Defective release of cells from the bone marrow
What is the result of a genetic defect in the NADPH oxidase system in CGD?
Inability of neutrophils to generate an oxidative burst
What is the primary function of the NADPH oxidase enzyme in normal phagocytic cells?
To form hydrogen peroxide and reactive oxygen species
Which test is used to diagnose Chronic Granulomatous Disease (CGD)?
Nitroblue Tetrazolium Reduction Test
What is the primary defect in the neutrophils of individuals with Schwachman Syndrome?
Abnormal actin filament structure
What is the primary function of NADPH oxidase in phagocytic cells?
To generate an oxidative burst to kill engulfed microorganisms
What is the consequence of mutations in the genes responsible for NADPH oxidase proteins?
Inability of phagocytes to produce superoxide and reactive oxygen species
What is the significance of the Nitroblue Tetrazolium (NBT) test in diagnosing phagocytic disorders?
It determines the ability of neutrophils to reduce NBT to formazan
What is the primary consequence of defective chemotaxis in neutrophils?
Impaired mobility and directed migration
Which of the following is a characteristic feature of catalase-positive microorganisms?
They are resistant to killing by reactive oxygen species
What is the primary mechanism by which NADPH oxidase produces reactive oxygen species?
By producing hydrogen peroxide from molecular oxygen
What is the primary problem in individuals with MPO deficiency?
Absence of oxidative destruction of microbes
What is the effect of MPO deficiency on bacterial killing?
Bacterial killing is slowed but complete
In which of the following conditions is MPO deficiency commonly seen?
Acute and Chronic Leukemia
What is the genetic basis of CHS disease?
Mutation in the CHS1 LYST gene on chr 1q42.1-2
What is the effect of CHS disease on lysosomes?
Abnormal lysosomes cannot fuse with phagosomes
What is a common symptom of CHS disease?
Partial albinism (oculocutaneous)
What is the relationship between NADPH oxidase and reactive oxygen species production?
NADPH oxidase produces reactive oxygen species
What is the effect of NADPH oxidase mutations on phagocytic activity?
Phagocytic activity is impaired
What is the effect of microfilament structure on chemotaxis?
Microfilament structure enhances chemotaxis
What is the typical time frame for hemoglobin levels to return to normal after initiating adequate treatment?
2 months
What can a failure to respond to iron treatment indicate?
Occult bleeding or inadequate absorption
Why is it essential to continue iron therapy for another 3-4 months?
To prevent a relapse
What is reflected in the peripheral blood film and indices for several months?
Biphasic population including microcytic cells
What should be investigated if the patient has been adherent to the therapeutic regimen but fails to respond to iron treatment?
Hereditary causes of iron deficiency
When does the anticipated rise in hemoglobin typically appear?
2-3 weeks
What is the eventual outcome of the normocytic population?
It eventually predominates
What is the goal of maintaining mild anemia in patients with hereditary hemochromatosis?
To prevent iron overload
Why can't individuals who rely on transfusions to maintain Hgb levels be treated with phlebotomy?
Because transfusions are required to maintain Hgb levels
What is the purpose of using iron-chelating drugs like deferoxamine?
To remove excess iron from the body
How often should maintenance phlebotomy be performed in patients with hereditary hemochromatosis?
For life
What is the typical volume of blood removed during each phlebotomy treatment session?
500 mL
What is the duration of deferoxamine infusion pump treatment?
8-12 hours
Why are oral iron chelators being developed?
All of the above
What is the primary reason for taking iron supplements on an empty stomach?
To maximize absorption of the supplement
In which cases is intravenous administration of iron dextrans typically used?
When intestinal absorption of iron is impaired
What is the typical duration of iron replacement therapy?
6 months or longer
When can a response to iron treatment be expected?
Within 2 days of treatment
What is the significance of reticulocyte counts in assessing treatment response?
They increase within 5-10 days of treatment
In which situations are RBC transfusions rarely warranted?
When patients have uncomplicated iron deficiency
What is the advantage of using oral bovine lactoferrin for iron supplementation?
It has reduced intestinal side effects compared to ferrous sulfate
What is the primary goal of treating any underlying contributing cause of iron deficiency?
To replenish the body's iron stores
What is the effect of iron deficiency on red blood cell production?
Slowed production
What is a characteristic of polychromatic normoblasts in iron-deficient bone marrow?
Nuclear-cytoplasmic asynchrony
What is the standard prescription for iron supplementation?
Ferrous sulfate
What is a characteristic of iron-deficient bone marrow initially?
Hyperplastic
What is the reason for performing a bone marrow examination for iron deficiency?
When a bone marrow specimen is collected for other reasons
What is the effect of iron supplementation on the body's iron stores?
Replenishment
What is the significance of soluble transferrin receptor (sTfR) levels in iron deficiency?
They increase progressively with iron deficiency
What is the effect of iron deficiency on the appearance of cell membranes?
They become irregular and shaggy
What is the primary function of the Dense Tubular System in platelets?
To sequester calcium ions
Which of the following events occurs during platelet activation?
Uptake of extracellular substances
What is the purpose of platelet aggregation?
To form a temporary plug at the site of injury
Which of the following coagulation factors interacts on the platelet surface to produce fibrin?
Factor X
What is the role of the Open Canalicular System (SCCS) in platelets?
To uptake extracellular substances
Which of the following is a consequence of impaired platelet adhesion?
Prolonged bleeding time
What is the purpose of fibrin stabilization in the coagulation cascade?
To strengthen the fibrin clot
Which of the following blood vessels plays a crucial role in repair after injury?
All of the above
What is the primary function of platelets in the circulation?
To surveil blood vessel continuity
What is the result of platelet activation and shape change?
Secretion of platelet granules
What is the role of platelets in the coagulation cascade?
To provide a surface for coagulation factors
What is the primary function of platelet aggregation?
To reinforce the primary hemostatic plug
What is the ultimate outcome of the coagulation cascade?
Stable fibrin-platelet plug formation
What is the primary mechanism by which blood clots are dissolved?
Fibrinolysis
What is the role of platelets in blood vessel repair?
To aid in the healing of injured tissues
What is the response to collagen exposure and tissue factor exposure in the coagulation cascade?
Extrinsic pathway activation
What is the purpose of platelet-fibrin clot formation?
To prevent blood loss
What is the primary component of hemostasis?
Platelets
What is the result of primary hemostasis?
Formation of a primary hemostatic plug
What is the function of smooth muscle cells in blood vessels?
To control blood vessel diameter
What is the layer of the blood vessel wall that comes into contact with blood cells?
Tunica intima
What is the term for the process by which platelets become activated and aggregate?
Platelet aggregation
What is the purpose of TPA (Tissue Plasminogen Activator) in fibrinolysis?
To dissolve blood clots
What is the layer of the blood vessel wall that contains smooth muscle cells and connective tissue?
Tunica media
Which of the following platelet granules is involved in platelet aggregation and activation of the coagulation system?
α-granules
What is the primary mechanism by which thrombin stimulates platelet aggregation?
Stimulation of phospholipases to form TxA2
Which of the following platelet disorders is characterized by the absence or mutation of the GP IIb-IIIa receptor?
Glanzmann thrombasthenia
What is the primary function of von Willebrand factor in platelet adhesion?
Linking platelets to the subendothelial matrix
Which of the following platelet agonists is dependent on the presence of the GP IIb-IIIa receptor?
ADP
What is the primary function of prostacyclin (PGI2) in the vascular endothelium?
Inhibiting platelet aggregation and inducing vasodilation
Which of the following is a characteristic feature of Gray platelet syndrome?
Deficiency of α-granules
What is the primary mechanism by which thromboxane A2 (TxA2) stimulates platelet aggregation?
Inducing platelet shape change
Which platelet granule is responsible for releasing thrombospondin, a substance that promotes vascular repair?
a-granules
What is the primary role of platelet-derived growth factor in the process of hemostasis?
Promoting smooth muscle growth for vessel repair
Which platelet granule is involved in the release of serotonin, a substance that promotes vasoconstriction?
Dense bodies
What is the primary mechanism by which platelets promote coagulation?
Providing a phospholipid surface for coagulation to occur
Which of the following is NOT a function of platelets in the process of hemostasis?
Inducing apoptosis
What is the primary role of thromboxane A2 in platelet function?
Promoting platelet aggregation
Which platelet granule is involved in the release of fibrinogen, a cofactor in fibrin clot formation?
a-granules
What is the primary function of HMWK in the coagulation cascade?
Enhancing coagulation cascade
This quiz covers the causes, symptoms, and diagnosis of Chronic Granulomatous Disease (CGD), a rare genetic disorder affecting the immune system. Learn about the bacteria and fungi associated with CGD, as well as its clinical features and diagnostic tests.
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