Hematology

. A healthcare professional in an urban clinic is seeing a patient who has iron deficiency anemia (IDA). What question by the professional is most appropriate to assess for the cause of IDA?

"Have you ever noticed any blood in your stool?" The most common causes of IDA in well-developed countries are pregnancy and chronic blood loss. The healthcare professional would assess for any sources of blood loss. A dietary deficiency of iron may be the cause, but is not common in developed countries. A mechanical heart valve can lead to hemolytic anemia. Recent infections are not associated with iron deficiency anemia.

A patient has been hospitalized for a large deep vein thrombosis and states he is the third person in his family to have this condition in the last 2 years. What response by the healthcare professional is most appropriate?

"We can test your blood for factor V Leiden." Factor V Leiden results from a single nucleotide mutation of guanine to adenine at nucleotide 1691 (G1691A) and is the most common hereditary thrombophilia. It is autosomal dominant so would not be confined to one sex. Most people with this disorder do not have clinically significant events

What is the life span of platelets (in days)?

10 A platelet circulates for approximately 8 to 11 days and ages. Macrophages of the mononuclear phagocyte system, mostly in the spleen, remove platelets.

What is the life span of an erythrocyte (in days)?

100 to 120 Because it cannot undergo mitotic division, the erythrocyte has a limited life span of up to approximately 120 days.

What does the student learn about the role of collagen in the clotting process?

Activates platelets Collagen and thrombin are particularly strong stimuli for platelet aggregation. Collagen does not initiate the clotting cascade, stimulate fibrin, or deactivate fibrinogen.

What is the most abundant class of plasma protein?

Albumin Albumin (approximately 60% of total plasma protein at a concentration of about 4 g/dL) is the most abundant plasma protein.

Shortened erythrocyte life span, ineffective bone marrow response to erythropoietin, and altered iron metabolism describe the pathophysiologic characteristics of which type of anemia?

Anemia of chronic disease Anemia of chronic disease specifically results from a combination of (1) decreased erythrocyte life span, (2) suppressed production of erythropoietin, (3) ineffective bone marrow erythroid progenitor response to erythropoietin, and (4) altered iron metabolism and iron sequestration in macrophages.

What term is used to describe the capacity of some erythrocytes to vary in size, especially in relationship to some anemias?

Anisocytosis Anisocytosis means assuming various sizes and is a term used to describe erythrocytes in some anemias. Poikilocytosis is used to describe erythrocytes that can assume various shapes. Isocytosis and microcytosis are not terms that are associated with this condition

What are the primary anticoagulant mechanisms? (Select all that apply.)

Antithrombin III Tissue factor pathway inhibitor Phagocytosis The major regulatory factors that control hemostasis reside where the greatest probability of clotting would occur—on the endothelial cell surface. The primary anticoagulant mechanisms include thrombin inhibitors (e.g., antithrombin III), tissue factor inhibitors (e.g., tissue factor pathway inhibitor), and mechanisms for degrading activated clotting factors (e.g., protein C). Hematopoiesis and phagocytosis are processes that are not related to anticoagulation.

An allogenic bone marrow transplantation remains the preferred method for treating which anemia?

Aplastic Bone marrow and, most recently, peripheral blood stem cell transplantation from a histocompatible sibling are the preferred treatments for the underlying bone marrow failure observed in aplastic anemias. This is not a treatment for polycythemia vera, sideroblastic anemia, or anemia of chronic disease.

A healthcare professional works with recent refugees. A mother brings in her children who have been diagnosed with iron deficiency anemia. What action by the professional is most appropriate?

Arrange to test for parasitic infections Children in developing countries often are affected by chronic parasite infestations that result in intestinal blood and iron loss that outpaces dietary intake. The professional should arrange testing for parasites in the newly arrived children. An iron-rich diet and iron supplements may be appropriate, but unless the cause is addressed, the problem will not be solved by those two actions. Weekly iron infusions are not needed.

A student asks the professor what the most common pathophysiologic process is that triggers aplastic anemia (AA). What response by the professor is most accurate?

Autoimmune disease against hematopoiesis by activated cytotoxic T (Tc) cells Most cases of AA result from an autoimmune disease directed against hematopoietic stem cells. Tc cells appear to be the main culprits in this process. AA does not include proliferation of erythrocytes. The autoimmune process seems to be mediated by alterations in CD4+, CD8+, and Th-17 T-cell responses and reduced numbers of regulatory T cells. Only a small percentage of patients have an inherited or familial form.

A professor explains to a class that the reason lymph nodes enlarge and become tender during infection is because of what reason?

B lymphocytes proliferate. The B lymphocyte proliferation in response to significant antigen (e.g., during infection) may result in lymph node enlargement and tenderness (reactive lymph node). The nodes are not specifically inflamed or filled with purulent exudate.

What are granulocytes that contain granules of vasoactive amines, such as histamine, called?

Basophils Basophils contain cytoplasmic granules that hold an abundant mixture of biochemical mediators, including histamine, chemotactic factors, proteolytic enzymes, and an anticoagulant (heparin). These substances are not found in neutrophils, monocytes, or eosinophils

Which nutrients are necessary for the synthesis of DNA and the maturation of erythrocytes? (Select all that apply.)

Cobalamin (vitamin B12) Folate Cobalamin and folate are necessary for the synthesis of DNA and for the maturation of erythrocytes. The remaining options are not necessary for these processes to occur.

Which of these is the role of nitric oxide (NO) in hemostasis?

Controls platelet activation through in concert with prostacyclin. Endothelial cell NO synthase produces NO, which controls platelet activation in concert with prostacyclin. The other options do not present an accurate description of the role of NO in hemostasis.

The students learn that deficiencies in folate and vitamin B12 alter the synthesis of which of these?

DNA Deficiencies in folate and vitamin B12 result in defective erythrocyte precursor DNA synthesis. These deficiencies are not associated with alterations of RNA, cell membranes, or mitochondria.

What is plasmin's role in the clotting process?

Degrades the fibrin within blood clots. Plasmin (also called fibrinase or fibrinolysin) is a serine protease that degrades fibrin polymers in clots. It is not capable of stimulating platelet aggregation, inhibiting platelet adhesion, or preventing conversion of prothrombin.

A healthcare professional is evaluating laboratory results for a patient who has disseminated intravascular coagulation (DIC). What results would the professional consider consistent with this condition? (Select all that apply.)

Elevated d-dimer Elevated creatinine Decreased protein Lab results consistent with DIC include elevated d-dimer and creatinine (showing kidney damage), and decreased protein C. The lactate dehydrogenase would be elevated and the pH would be decreased.

What does the student learn about warm autoimmune hemolytic anemia?

Erythrocytes are bound to macrophages and sequestered in the spleen. The immunoglobulin G-coated red blood cells bind to the Fc receptors on monocytes and splenic macrophages and are removed by phagocytosis. This disease occurs mainly in people older than 40 years of age. It is one of the hemolytic anemias and destruction of red blood cells occurs by extravascular processes. The erythrocytes are bound to macrophages, not monocytes

What does the student learn about erythrocytes?

Erythrocytes have the ability to change shape to squeeze through microcirculation. Reversible deformity enables the erythrocyte to assume a more compact torpedo-like shape, squeeze through the microcirculation, and return to normal. The mature erythrocyte lacks a nucleus and cytoplasmic organelles so it cannot synthesize protein or carry out oxidative reactions. Men have more erythrocytes than women (48% to 42% respectively).

A patient has chronic anemia associated with chronic renal failure. What substance does the healthcare professional tell the patient is needed to treat this anemia?

Erythropoietin One of the most significant advances in the study of hematopoietic growth factors has been the development of erythropoietin for individuals with chronic renal failure. The other options are not associated with the treatment of chronic anemia.

Which form of iron (Fe) can be used in the formation of normal hemoglobin?

Fe2+ It is crucial that the iron be correctly charged; only reduced ferrous iron (Fe2+) can bind oxygen in the lungs and release it in the tissues. Fe+ is simple iron. Fe3+ is bound with oxygen. Fe4+ is ferryl iron.

A healthcare professional is reviewing a patient's laboratory results and sees that the patient has a low reticulocyte count and a high iron level. Which type of anemia does the professional associate these findings with?

Folate deficiency anemia These results are characteristic of folate deficiency. Iron deficiency would manifest with normal reticulocyte count and high iron. Hemolytic anemia would show high reticulocyte count and normal or high iron levels. Anemia of chronic disease would have a normal reticulocyte count but low iron levels.

A healthcare professional has educated a student on folic acid. Which statement by the student indicates that more teaching is needed?

Folic acid absorption is dependent on the enzyme folacin Folic acid absorption is not dependent on the enzyme folacin. The professional would need to provide more teaching if the student made this statement. The other options are true statements regarding folic acid.

Which condition resulting from untreated pernicious anemia (PA) is fatal

Heart failure Untreated PA is fatal, usually because of heart failure.

A healthcare professional is caring for five patients. Which one would the professional assess for disseminated intravascular coagulation (DIC) as the priority? (Select all that apply.)

Heat stroke Severe pancreatitis HELLP syndrome Snake bite Common causes of DIC include heat stroke, severe pancreatitis, HELLP syndrome (and other OB complications), and snake bite. A normal term delivery would not put a patient at high risk for developing DIC.

A student asks the professor to explain the jaundice that accompanies hemolytic anemia. Which statement is by the professor is most accurate?

Heme destruction exceeds the liver's ability to conjugate and excrete bilirubin. Jaundice (icterus) is present when heme destruction exceeds the liver's ability to conjugate and excrete bilirubin. Jaundice is not as directly related to the destruction of the erythrocytes. It is also not related to liver enzyme elevation or being coated with an immunoglobulin.

A patient has hepatomegaly, bronze-colored skin, and cardiac dysrhythmias. What condition does the healthcare professional prepare to teach the patient about?

Hereditary hemochromatosis Hereditary hemochromatosis presents with hepatomegaly, bronze-colored skin, and cardiac dysrhythmias. Aplastic anemia specifically presents with total bone marrow failure. Pernicious anemia can be characterized with neurocognitive dysfunction in addition to the classic signs of all anemias. ITP presents with minor signs of bleeding such as petechiae but soon show major bleeding.

What is the fundamental physiologic manifestation of anemia?

Hypoxia The fundamental physiologic manifestation of anemia is a reduced oxygen-carrying capacity of the blood, resulting in tissue hypoxia. Hypotension may result when the initial compensatory mechanism, vasoconstriction, fails to provide adequate perfusion to tissues. Ischemia may result if the oxygen deficit in tissues and organs is severe or prolonged. Hyperesthesia is not a finding.

A patient has polycythemia vera and presents to the Emergency Department with plethora and neurological changes. The student asks the healthcare professional to explain the primary cause of these symptoms. What response by the professional is best?

Increased blood viscosity As polycythemia vera progresses, many of the symptoms are related to the increased blood cellularity and viscosity. These include plethora, engorgement of the retinal and cerebral veins. Individuals also may experience headache, drowsiness, delirium, mania, psychotic depression, chorea, and visual disturbances. The symptoms of polycythemia vera are not related to decreased erythrocyte counts, destruction of erythrocytes, or tissue destruction by macrophages.

Which of these describes how the body compensates for anemia?

Increasing rate and depth of breathing Tissue hypoxia from anemia creates additional demands and compensatory actions on the pulmonary and hematologic systems. The rate and depth of breathing increase in an attempt to increase the availability of oxygen. The body does not compensate by decreasing vasoconstriction, tightening the hemoglobin bonds with oxygen, or releasing more erythropoietin.

The drug heparin acts in hemostasis by which processes?

Inhibiting thrombin and antithrombin III (AT-III) Clinically administered heparin binds to AT-III and induces a conformational change that greatly enhances its activity. Under normal conditions, the presence of endothelial cell heparin sulfate and available AT-III in the circulation cooperate to protect the vessels from the effects of spontaneously activated thrombin. Heparin does not prevent the conversion of prothrombin to thrombin, shorten fibrin strands, or degrade the fibrin in blood clots.

Which nutrients are necessary for hemoglobin synthesis? (Select all that apply.)

Iron B6 (pyridoxine) Iron and B6 (pyridoxine) are necessary for hemoglobin synthesis. The remaining options are not necessary for hemoglobin synthesis.

Which anemia produces small, pale erythrocytes?

Iron deficiency The microcytic-hypochromic anemias, which include iron deficiency anemia (IDA), are characterized by erythrocytes that are abnormally small (microcytic) and contain abnormally reduced amounts of hemoglobin (hypochromic). Folic acid and pernicious anemias are megaloblastic. Hemolytic anemia consists of normal red blood cells that are destroyed more frequently than normal.

Which statements characterize albumin? (Select all that apply.)

It provides colloid osmotic pressure. It is synthesized in the liver. It is a carrier for drugs that have low water solubility. Albumin is a plasma protein produced by the liver. It serves as a carrier molecule for the normal components of blood, as well as for drugs that have low solubility in water (e.g., free fatty acids, lipid-soluble hormones, thyroid hormones, bile salts). Albumin molecules are large and do not diffuse freely through the vascular endothelium; thus they maintain the critical colloidal osmotic pressure (or oncotic pressure) that regulates the passage of water and solutes into the surrounding tissues.

Where are Kupffer cells located?

Liver The liver macrophages are the only location for Kupffer cells

What change to the hematologic system is related to age?

Lymphocyte function decreases. Blood composition changes little with age. A delay in erythrocyte replenishment may occur after bleeding, presumably because of iron deficiency. Lymphocyte function appears to decrease with age. Particularly affected is a decrease in cellular immunity. Platelet adhesiveness probably increases with age.

Which hemoglobin is made from oxidized ferric iron (Fe3+) and lacks the ability to bind oxygen?

Methemoglobin Without reactivation by methemoglobin reductase, the Fe3+-containing hemoglobin (methemoglobin) cannot bind oxygen. Deoxyhemoglobin is hemoglobin available for oxygen binding. Oxyhemoglobin is bound with oxygen. Glycosylated hemoglobin is hemoglobin with which glucose is bound.

What are blood cells that differentiate into macrophages known as?

Monocytes Monocytes migrate into a variety of tissues and fully mature into tissue macrophages and myeloid dendritic cells. Neutrophils, eosinophils, and basophils do not undergo this transformation.

The paresthesia that occurs in vitamin B12 deficiency anemia is a result of which of these?

Myelin degeneration in the spinal cord Effects on the nervous system can occur if a vitamin B12 deficiency causes anemia. Myelin degeneration may occur with the resultant loss of fibers in the spinal cord, producing paresthesia (numbness), gait disturbances, extreme weakness, spasticity, and reflex abnormalities. The paresthesia is not caused by reduction in acetylcholine receptors, destruction of myelin in peripheral nerves, or altered neuronal function in the parietal lobe.

Without prior exposure to an antigen, which cells are able to destroy some types of tumor cells and some virus-infected cells?

Natural killer (NK) cells NK cells, which resemble large granular lymphocytes, kill some types of tumor cells (in vitro) and some virus-infected cells without being induced by previous exposure to these antigens. This capability is not true of lymphocytes, plasma cells, or megakaryocytes.

patient in the healthcare clinic reports fatigue, weakness, and dyspnea, as well as pale conjunctiva of the eyes and brittle, concave nails. What assessment by the healthcare professional is most appropriate for the suspected anemia?

Oral mucus membranes and tongue Early symptoms of iron deficiency anemia (IDA) include fatigue, weakness, and shortness of breath. Pale earlobes, palms, and conjunctivae are also common signs. Progressive IDA causes more severe alterations, with structural and functional changes apparent in epithelial tissue. The nails become brittle, thin, coarsely ridged, and spoon-shaped or concave (koilonychia) as a result of impaired capillary circulation. The tongue becomes red, sore, and painful. The healthcare professional should assess the patient's mouth and tongue. Blood pressure and pulse readings would not be specific for any one type of anemia. Dysphagia (difficulty swallowing) could indicate pernicious anemia. Jaundice (most often seen in the sclera and on the skin) would be a characteristic of hemolytic anemia, although it is not always noticed.

What is the effect of low plasma albumin?

Osmotic pressure decreases; thus water moves from the capillaries to the interstitium. In the case of decreased production (e.g., cirrhosis, other diffuse liver diseases, protein malnutrition) or excessive loss of albumin (e.g., certain kidney diseases, extensive burns), the reduced oncotic pressure leads to excessive movement of fluid and solutes into the tissues and decreased blood volume. Low plasma albumin does not affect clotting factors, immunoglobulins, or iron.

A patient is 8 hours postoperative after a long orthopedic procedure. The student asks why this patient is at particular risk of developing a thromboembolism. What response by the healthcare professional is best?

Patients tend to have venous stasis from orthopedic operations. Thromboembolic events are caused by some component of Virchow triad: endothelial injury, abnormal blood flow, and hypercoagulability of the blood. Long operative procedures such as orthopedic cases promote venous stasis. Anesthetic agents are not implicated. Endothelial repair is not appreciably hindered by postoperative pain. Atherosclerotic buildup can lead to endothelial injury but that is not specific to this patient.

After a person has a subtotal gastrectomy for chronic gastritis, which type of anemia will result?

Pernicious A gastrectomy will lead to deficient intrinsic factor which is related to pernicious anemia. The gastrectomy would not lead to iron deficiency, aplastic, or folic acid anemia.

Which of these classified as a megaloblastic anemia?

Pernicious Megaloblastic anemia is characterized by a low red blood cell count and larger-than-normal red blood cells. Pernicious anemia is the most common type of megaloblastic anemia. Iron deficiency is a hypochromic, microcytic anemia meaning the red blood cells are pale and small. The red blood cells in sideroblastic anemia are not abnormally large; they have an abnormal ring of iron around the nucleus of the RBC. Hemolytic anemia is normochromic, normocytic anemia caused by blood loss.

Which of these are formed elements of the blood that are not cells but are disk-shaped cytoplasmic fragments essential for blood clotting?

Platelets Platelets (thrombocytes) are not true cells but are disk-shaped cytoplasmic fragments that are essential for blood coagulation and control of bleeding. Monocytes, macrophages, and erythrocytes are cells.

Which statements about plasma proteins are correct? (Select all that apply.)

Provide clotting factors. Transport triglycerides. Synthesize complement proteins. Transport cholesterol. Plasma proteins do not create hydrostatic pressure. The other options are all accurate statements regarding plasma proteins.

How is the effectiveness of vitamin B12 therapy measured?

Reticulocyte count The effectiveness of cobalamin replacement therapy is determined by a rising reticulocyte count. The other options are not used as indicators of the effectiveness of vitamin B12 therapy

Which characteristics allow erythrocytes to function as gas carriers? (Select all that apply.)

Reversible deformability Biconcavity A red blood cell (RBC) is a small disk with two unique properties: (1) a biconcave shape and (2) the capacity to be reversibly deformed. Compactness is not a feature that promotes gas exchange. Erythrocytes do not contain mitochondria.

The student learns that Langerhans cells are only found in which organ?

Skin. The skin is the only location for Langerhans cells.

By which structure are mature erythrocytes removed from the bloodstream?

Spleen At the end of their life spans, old erythrocytes are removed by tissue macrophages, primarily in the spleen.

Fetal hematopoiesis occurs primarily in which structure?

Spleen The spleen is the largest of the secondary lymphoid organs and the primary site of fetal hematopoiesis. The bone marrow and thymus are other primary lymphoid organs. Peyer patches in the small intestine are considered secondary lymphoid organs.

What is the role of thromboxane A (TXA2) in the secretion stage of hemostasis?

Stimulates platelet aggregation. Platelet aggregation is primarily stimulated by TXA2 and adenosine diphosphate (ADP), which induce functional fibrinogen receptors on the platelet. Thromboxane A is not involved with serotonin synthesis, vasodilation, or production of cyclooxygenase.

. In aplastic anemia (AA), pancytopenia develops as a result of what?

Suppression of the bone marrow to produce adequate amounts of erythrocytes, leukocytes, and thrombocytes AA is a critical condition characterized by pancytopenia, which is a reduction or absence of all three blood cell types, resulting from the failure or suppression of bone marrow to produce adequate amounts of blood cells. It is not related to lack of DNA.

A patient in the hospital has been receiving heparin injections. The platelet count on admission was 222,000/mm3 and four days later is 113,000/mm3. What action by the healthcare professional is best?

Switch the heparin to lepirudin After initiating heparin in the hospital this patient's platelet count dropped by 51%. A drop in more than 50% of the platelet count is seen in more than 95% of patients with heparin-induced thrombocytopenia. The treatment is to withdraw the heparin and use alternatives such as lepirudin. If the platelet count were severely low, transfusion would be indicated. There is no need to stop all the patient's medications.

An adult patient has been hospitalized with thrombocytopenia with a platelet count of 8000/mm3. What action by the healthcare professional is most appropriate?

Tell the patient not to get out of bed without assistance. Thrombocytopenia is a platelet count of less than 150,000/mm3. A platelet count of 8,000/mm3 is low enough to produce spontaneous bleeding, which would be devastating if it occurred in the brain. The healthcare professional should advise the patient not to get out of bed without assistance to help prevent falls. Whole blood is not needed since only platelets are deficient. The patient would not receive heparin as this would increase the chance of bleeding. A normal platelet count in an adult is 150,000 to 350,000/mm3.

Soon after birth, a newborn has cord blood drawn which shows hemoglobin of 28.2 mg/dL. What does the healthcare professional understand about this finding?

The baby suffered from hypoxia in utero. normal cord blood hemoglobin mean is 16.8 mg/dL, so this is a high value. A hypoxic intrauterine environment stimulates erythropoietin production in the fetus and accelerates fetal erythropoiesis, producing polycythemia. This value does not indicate a need for transfusion nor does it demonstrate immature bone marrow.

What is the consequence of a splenectomy?

The number of defective cells in circulation increases. Splenic absence from any cause (e.g., atrophy, traumatic injury, removal because of disease) has several secondary effects on the body, among them an increase in morphologically defective blood cells in the circulation, confirming the spleen's role in removing old or damaged cells. Loss of the spleen does not increase iron blood levels, increase antibody production, or increase the number of clotting factors.

What does the student learn regarding the role of the endothelium in clot formation? (Select all that apply.)

The surface of the endothelium produces plasma protease inhibitors. Plasma protease inhibitors assist in preventing clot formation. Thrombomodulin is a protein that is converted on the surface of endothelial The surface of the endothelium produces plasma protease inhibitors to resist clot formation. Thrombomodulin is a membrane thrombin-binding protein matter and is converted to activated protein C on the surface of endothelial cells. Protein C in the circulation binds to thrombomodulin. Activated protein C inhibits the adhesion of neutrophils to the endothelium.

What does treatment for polycythemia vera involve?

Therapeutic phlebotomy and radioactive phosphorus In low-risk individuals, the recommended therapy is phlebotomy and low-dose aspirin, whereas radioactive phosphorus has been used to suppress erythropoiesis. Plasma expanders, cyanocobalamin, and blood transfusions are not treatments for this disease.

What is the function of erythrocytes?

Tissue oxygenation Erythrocytes are solely responsible for tissue oxygenation. Hemostasis occurs due to the actions of multiple substances such as fibrin, collagen, and clotting factors. Infection control and allergic responses are mediated by white blood cells.

A patient has defective secretion of the intrinsic factor leading to anemia. What treatment option does the healthcare professional discuss with the patient?

Vitamin B12 injections initially given once a week Intrinsic factor (IF) is responsible for B12 uptake from the gut. A lack of IF leads to pernicious anemia, which is treated with vitamin B12 injections for the rest of the person's life. The injections are weekly at first the monthly. Increasing dietary iron would help with irondeficiency anemia. A bone marrow transplant might be used to treat aplastic anemia. Better control of an underlying medical condition would be important in anemia of chronic disease.

A patient has pernicious anemia and asks the healthcare professional to explain the disease. Which statement by the professional is most accurate?

Your body cannot absorb vitamin B12. Dietary vitamin B12 is a large molecule that requires a protein secreted by parietal cells in the stomach (intrinsic factor [IF]) to transport across the ileum. Defects in IF production lead to decreased B12 absorption and pernicious anemia. A lack of certain foods (i.e., meat) might lead to iron-deficiency anemia. Vitamin C lack would not lead to anemia, but in a severe state could lead to scurvy. If the bone marrow had totally failed, that would be termed aplastic anemia.