HEMATOLOGY Flashcards
(128 cards)
In a patient who presents with pallor, which of the following disorders would you consider if work-up reveals a reticulocyte index of > 2.5?
a. Aplastic Anemia
b. Hemoglobinopathy
c. Iron deficiency anemia
d. Vitamin B12 Deficiency
In the first branch point of the classification of anemia, a reticulocyte production index >2.5 indicates that hemolysis is most likely. A reticu¬locyte production index <2.5 indicates either a hypoproliferative anemia or maturation disorder.
The correct answer is: Hemoglobinopathy
A 47-year-old female with no known comorbidities came into your clinic because of elevated hemoglobin (165 mg/dL) and hematocrit (58%) levels found on routine blood exam. You measured her RBC mass and found out that it was elevated, but her serum EPO levels were below normal. What mutation does this patient most likely have?
a. BCR-ABL mutation
b. JAK2 mutation
c. NPM1 mutation
d. PML-RARA mutation
In approaching patients with polycythemia, the first step is to document the presence of an increased red cell mass using the principle of isotope dilution by administering 51Cr-labeled autologous red blood cells to the patient and sampling blood radioactivity over a 2-h period. If the red cell mass is normal (<36 mL/kg in men, <32 mL/kg in women), the patient has spurious or relative polycythemia. If the red cell mass is increased (>36 mL/kg in men, >32 mL/kg in women), serum EPO levels should be measured.
If EPO levels are low or unmeasurable, the patient most likely has polycythemia vera. A mutation in JAK2 (Val617Phe), a key member of the cytokine intracellular signaling pathway, can be found in 90–95% of patients with polycythemia vera.
The correct answer is: JAK2 mutation
How much iron is needed to replace red cells lost through senescence daily?
a. 1 mg
b. 5 mg
c. 10 mg
d. 20 mg
Because each milliliter of red cells contains 1 mg of elemental iron, the amount of iron needed to replace those red cells lost through senescence amounts to 20 mg/d (assuming an adult with a red cell mass of 2 L). Any additional iron required for daily red cell production comes from the diet.
Normally, an adult male will need to absorb at least 1 mg of elemental iron daily to meet needs, while females in the childbearing years will need to absorb an average of 1.4 mg/d. The amount of iron required from the diet to replace losses averages ∼10% of body iron content a year in men and 15% in women of childbearing age.
The correct answer is: 20 mg
At which stage of iron deficiency does microcytic cells first appear on peripheral blood smear?
a. Negative iron balance
b. Iron – deficient erythropoiesis
c. Iron – deficiency anemia
d. At serum ferritin of 100
By definition, marrow iron stores are absent when the serum ferritin level is <15 μg/L. As long as the serum iron remains within the normal range, hemoglobin synthesis is unaffected despite the dwindling iron stores. Once the transferrin saturation falls to 15–20%, hemoglobin synthesis becomes impaired. This is a period of iron-deficient erythropoiesis. Careful evaluation of the peripheral blood smear reveals the first appearance of microcytic cells, and if the laboratory technology is available, one finds hypochromic reticulocytes in circulation. Gradually, the hemoglobin begins to fall, reflecting iron-deficiency anemia. The transferrin saturation at this point is <10–15%.
The correct answer is: Iron – deficient erythropoiesis
A 28yo female patient who appeared pale and cachectic due to a fad diet came into your clinic. Work-up shows absence of marrow iron stores, serum ferritin of 17 ug/L, and total iron binding capacity of 370. RBC morphology is normal. At which stage of iron deficiency does the patient belong?
a. Normal
b. Negative iron balance
c. Iron – deficient erythropoiesis
d. Iron – deficiency anemia
The correct answer is: Negative iron balance
A 61yo female consulted at your clinic due to pallor and her CBC result shows a hemoglobin of 9.2 g/dL with note of microcytic and hypochromic RBCs. She complains of intermittent joint pains and has no other comorbidities. Which of the following should be first ruled out in this patient?
a. Anemia of chronic disease
b. Bone marrow aplasia
c. Peptic ulcer disease
d. Renal disease
A cardinal rule is that the appearance of iron deficiency in an adult male or post-menopausal female means gastrointestinal blood loss until proven otherwise. The fact that the patient complains of intermittent joint pains is also a clue that she may be taking NSAIDs that could also contribute to her peptic ulcer disease.
The correct answer is: Peptic ulcer disease
Which is the most convenient laboratory test to estimate iron stores?
a. Serum apoferritin levels
b. Serum ferritin levels
c. Serum hepcidin levels
d. Serum transferrin levels
Under steady-state conditions, the serum ferritin level correlates with total body iron stores; thus, the serum ferritin level is the most convenient laboratory test to estimate iron stores. The normal value for ferritin varies according to the age and gender of the individual. Adult males have serum ferritin values averaging 100 μg/L, while adult females have levels averaging 30 μg/L.
The correct answer is: Serum ferritin levels
In a patient with iron-deficiency anemia, which of the following is expected to be elevated?
a. Marrow sideroblasts
b. RBC protoporphyrin
c. Serum ferritin
d. Transferrin saturation
Protoporphyrin is an intermediate in the pathway to heme synthesis. Under conditions in which heme synthesis is impaired, protoporphyrin accumulates within the red cell. This reflects an inadequate iron supply to erythroid precursors to support hemoglobin synthesis. Normal values are <30 μg/dL of red cells. In iron deficiency, values >100 μg/dL are seen. The most common causes of increased red cell protoporphyrin levels are absolute or relative iron deficiency and lead poisoning.
The correct answer is: RBC protoporphyrin
In the differential diagnosis of a hypochromic, microcytic anemia, which of the following would have low serum iron, normal or increased ferritin, and a low transferrin saturation or total iron binding capacity?
a. Inflammation
b. Iron deficiency
c. Sideroblastic anemia
d. Thalassemia
The distinction between true iron deficiency anemia and anemia of inflammation (AI) is among the most common diagnostic problems encountered by clinicians. Usually, AI is normocytic and normochromic but is sometimes microcytic. The iron values usually make the differential diagnosis clear, as the ferritin level is normal or increased and the percent transferrin saturation and TIBC are typically below normal.
The correct answer is: Inflammation
A 35-year-old female with no known comorbidities consulted your clinic due to abdominal discomfort, mild nausea, and occasional vomiting. She notes that these symptoms started when she started taking her “vitamins.” Which of the following would be the most likely cause?
a. Ascorbic Acid
b. Calcium + Vitamin D
c. Ferrous sulfate
d. Vitamin B complex
Of the complications of oral iron therapy, gastrointestinal distress is the most prominent and is seen in at least 15–20% of patients. Abdominal pain, nausea, vomiting, or constipation may lead to noncompliance. Although small doses of iron or iron preparations with delayed release may help somewhat, the gastrointestinal side effects are a major impediment to the effective treatment of a number of patients.
The correct answer is: Ferrous sulfate
A 38-year-old male with chronic glomerulonephritis who is on maintenance hemodialysis had an anaphylactic reaction to parenteral iron infusion and was adequately managed. What should be done with regards to his iron supplementation?
a. Erythropoietin should be increased to compensate for the lack of iron
b. He should be shifted to oral iron therapy
c. Iron therapy is contraindicated for this patient
d. Other parenteral iron preparations maybe safely given
In administering any intravenous iron preparation, anaphylaxis is a concern. Anaphylaxis is much rarer with the newer preparations. The factors that have correlated with an anaphylactic-like reaction include a history of multiple allergies or a prior allergic reaction to an iron preparation.
Generalized symptoms appearing several days after the infusion of a large dose of iron can include arthralgias, skin rash, and low-grade fever. These may be dose-related, but they do not preclude the further use of parenteral iron in the patient. To date, patients with sensitivity to one iron preparation have been safely treated with other parenteral iron preparations.
The correct answer is: Other parenteral iron preparations maybe safely given
Which of the following characterizes anemia of chronic inflammation?
a. Hepcidin decreases iron absorption and release from storage sites
b. IL-1 and TNF increases the response of the erythroid marrow to EPO
c. Serum ferritin is decreased threefold over basal levels
d. The bone marrow is hyperproliferative
Typically, serum ferritin values increase threefold over basal levels in the face of inflammation. IL-1, acting through accessory cell release of interferon γ (IFN-γ), suppresses the response of the erythroid marrow to EPO—an effect that can be overcome by EPO administration in vitro and in vivo. In addition, tumor necrosis factor (TNF), acting through the release of IFN-β by marrow stromal cells, also suppresses the response to EPO.
Hepcidin, made by the liver, is increased in inflammation via an IL-6 mediated pathway, and acts to suppress iron absorption and iron release from storage sites. The overall result is a chronic hypoproliferative anemia with classic changes in iron metabolism.
The correct answer is: Hepcidin decreases iron absorption and release from storage sites
A 35-year-old patient went to your clinic for consult. He has poorly controlled type 2 diabetes mellitus for 8 years, and upon reviewing his laboratory results you saw that his creatinine and BUN have been constantly elevated for the past 4 years. You also noted that his latest Hemoglobin is 89 mg/dL. The patient recently had an EGD – Colonoscopy done which were normal. No masses or bleeding was noted. Which of the following is the most likely primary cause of this patient’s anemia?
a. Decreased iron absorption from the diet
b. Decreased response to EPO stimulation
c. Failure of EPO production
d. Failure to utilize iron stores
The anemia is primarily due to a failure of EPO production by the diseased kidney and a reduction in red cell survival. Assessment of iron status provides information to distinguish the anemia of CKD from the other forms of hypoproliferative anemia (Table 93-6) and to guide management. Patients with the anemia of CKD usually present with normal serum iron, TIBC, and ferritin levels.
The correct answer is: Failure of EPO production
A 57-year-old male was admitted due to chest pain and was managed as a case of acute coronary syndrome – ST elevation myocardial infarction. On the third hospital day, he had upper GI bleeding and his hemoglobin went down to 92 mg/dL. An esophagogastroduodenoscopy was done and bleeding was effectively controlled. What would be the best management for his anemia?
a. Repeat CBC the following day
b. Add oral iron supplement
c. Start EPO injections
d. Blood transfusion
In general, patients without serious underlying cardiovascular or pulmonary disease can tolerate hemoglobin levels above 7–8 g/dL and do not require intervention until the hemoglobin falls below that level. Patients with more physiologic compromise may need to have their hemoglobin levels kept above 11 g/dL. Usually, a unit of packed red cells increases the hemoglobin level by 1 g/dL.
Rational Use of Blood Products CPG page 28
The correct answer is: Blood transfusion
A new staff nurse on duty asks you how long one unit of PRBC should be transfused. You know that blood transfusion should be completed after how many hours since commencement?
a. 4 hours
b. 5 hours
c. 6 hours
d. 8 hours
Complete transfusion within 4 hours of commencement.
The correct answer is: 4 hours
A 55-year-old male with chronic kidney disease (CKD) secondary to diabetic nephropathy who is on maintenance hemodialysis for the past 3 years consulted your clinic. You found out that his hemoglobin level is 9.2 g/dL and is asymptomatic. You plan to start erythropoietin (EPO) together with iron therapy. What is the usual dose of EPO in patients with CKD?
a. 50-150 U/kg once a week intravenously
b. 50-150 U/kg once a week subcutaneously
c. 50-150 U/kg three times a week intravenously
d. 50-150 U/kg three times a week subcutaneously
In patients with CKD, the usual dose of EPO is 50–150 U/kg three times a week intravenously. Hemoglobin levels of 10–12 g/dL are usually reached within 4–6 weeks if iron levels are adequate; 90% of these patients respond.
The correct answer is: 50-150 U/kg three times a week intravenously
A 23-year-old female was admitted due to acute onset of severe pain and tenderness of the different muscles of both upper and lower extremities which last for a few hours, sometimes longer. This started when she was treated for a urinary tract infection last week. On further probing, you found out that this episode has already happened for the 5th time this year. A review of her CBC shows that her hemoglobin is 8.5 g/dL, and her RBC morphology is shown on the figure below.
What is considered the mainstay of therapy for this patient?
a. Aggressive analgesia
b. Oxygen support
c. Start hydroxyurea
d. Vigorous but careful hydration
Figure: The elongated and crescent-shaped red blood cells seen on this smear represent circulating irreversibly sickled cells. Target cells and a nucleated red blood cell are also seen.
The management of an acute painful crisis includes vigorous but careful hydration, thorough evaluation for underlying causes (such as infection), and aggressive analgesia administered by a standing order and/or patient-controlled analgesia (PCA) pump. The most significant advance in the therapy of sickle cell anemia has been the introduction of hydroxyurea as a mainstay of therapy for patients with severe symptoms.
Hydroxyurea (10–30 mg/kg per day) increases fetal hemoglobin and may also exert beneficial effects on RBC hydration, vascular wall adherence, and suppression of the granulocyte and reticulocyte counts; dosage is titrated to maintain a white cell count between 5000 and 8000/μL. White cells and reticulocytes may play a major role in the pathogenesis of sickle cell crisis, and their suppression may be an important side benefit of hydroxyurea therapy.
The correct answer is: Start hydroxyurea
A 48-year-old male who works in a chemical factory came in due to severe headache and dizziness. You noticed that he has a characteristic bluish-brown muddy color, but his PaO2 is 95%. What is an effective emergency therapy?
a. Ascorbic acid IM
b. Intubate patient immediately
c. Mannitol intravenously
d. Methylene blue intravenously
Methemoglobin is generated by oxidation of the heme iron moieties to the ferric state, causing a characteristic bluish brown muddy color resembling cyanosis. The characteristic muddy appearance of freshly drawn blood can be a critical clue. The best diagnostic test is methemoglobin assay, which is usually available on an emergency basis.
Methemoglobinemia often causes symptoms of cerebral ischemia at levels >15%; levels >60% are usually lethal. Intravenous injection of 1 mg/kg of methylene blue is effective emergency therapy. Milder cases and follow-up of severe cases can be treated orally with methylene blue (60 mg three to four times each day) or ascorbic acid (300–600 mg/d).
The correct answer is: Methylene blue intravenously
A 25-year-old female patient with B-thalassemia major was admitted to the ER due to severe anemia. You ordered blood transfusion and upon reviewing her records, you realized that she would be receiving her 7th unit of PRBC this year. Which of the following parenteral medications is also indicated?
a. Ascorbic acid
b. Deferasirox
c. Deferoxamine
d. Sodium bicarbonate
A unit of packed RBCs contains 250–300 mg iron (1 mg/mL). The iron assimilated by a single transfusion of 2 units of packed RBCs is thus equal to a 1- to 2-year oral intake of iron. Iron accumulates in chronically transfused patients because no mechanisms exist for increasing iron excretion: an expanded erythron causes especially rapid development of iron overload because accelerated erythropoiesis promotes excessive absorption of dietary iron. Vitamin C should not be supplemented because it generates free radicals in iron excess states. The decision to start long-term transfusion support should also prompt one to institute therapy with iron-chelating agents.
Deferoxamine (Desferal) is for parenteral use. Its iron-binding kinetics require chronic slow infusion via a metering pump. Deferasirox is an oral iron-chelating agent. Single daily doses of 20–30 mg/kg deferasirox produced reductions in liver iron concentration comparable to deferoxamine in long-term transfused adult and pediatric patients.
The correct answer is: Deferoxamine
A 72-year-old female patient who has Type 1 Diabetes Mellitus (controlled by insulin) came into your clinic for consult due to pallor. She has also been having anorexia and some paresthesia. To rule out upper GI bleeding as the cause of anemia, an esophagogastroduodenoscopy was done which showed no masses, ulcers, nor bleeding. Gastric biopsy showed atrophy of all layers of the body and fundus, with loss of glandular elements and replacement of mucous cells with a mixed inflammatory cell infiltrate.
Her hemoglobin was 8.7 g/dL with an elevated mean corpuscular volume (MCV). Which of the following should be given to the patient?
a. Cobalamin
b. Ferrous sulfate
c. Folic acid
d. Thiamine
PA may be defined as a severe lack of IF due to gastric atrophy. The ratio of incidence in men and women among whites is ~1:1.6, and the median age of onset is 70–80 years, with only 10% of patients being <40 years of age. The disease occurs more commonly than by chance in close relatives and in persons with other organ-specific autoimmune diseases, for example, thyroid diseases, vitiligo, hypoparathyroidism, Type 1 diabetes, and Addison’s disease. A single endoscopic examination is recommended if PA is diagnosed.
Gastric biopsy usually shows atrophy of all layers of the body and fundus, with loss of glandular elements, an absence of parietal and chief cells and replacement by mucous cells, a mixed inflammatory cell infiltrate, and perhaps intestinal metaplasia.
Replenishment of body stores should be complete with six 1000-μg IM injections of hydroxocobalamin given at 3- to 7-day intervals. More frequent doses are usually used in patients with cobalamin neuropathy, but there is no evidence that they produce a better response. Allergic reactions are rare and may require desensitization or antihistamine or glucocorticoid cover. For maintenance therapy, 1000 μg hydroxocobalamin IM once every 3 months is satisfactory.
Because a small fraction of cobalamin can be absorbed passively through mucous membranes even when there is complete failure of physiologic IF-dependent absorption, large daily oral doses (1000–2000 μg) of cyanocobalamin are used in PA for replacement (especially in Canada and Sweden) and maintenance of normal cobalamin status in, for example, food malabsorption of cobalamin.
The correct answer is: Cobalamin
Your 32-year-old female patient who is a known hypertensive recently got pregnant with her first baby. Her BP is controlled with her current medications. You advised her to also schedule an appointment with her obstetrician however the next available slot for check-up is after 4 weeks. At this point, which of the following would you give her to prevent megaloblastic anemia?
a. Folic acid 200ug OD
b. Folic acid 300ug OD
c. Folic acid 400ug OD
d. Folic acid 500ug OD
Folic acid, 400 μg daily, should be given as a supplement before and throughout pregnancy to prevent megaloblastic anemia and reduce the incidence of NTDs, even in countries with fortification of the diet. In women who have had a previous fetus with an NTD, 5 mg daily is recommended when pregnancy is contemplated and throughout the subsequent pregnancy.
The correct answer is: Folic acid 400ug OD
Among the causes of hemolytic anemia, which of the following is acquired and is associated with intracorpuscular defects?
a. Hemoglobinopathies
b. Hemolytic uremic syndrome
c. Microangiopathic destruction
d. Paroxysmal nocturnal hemoglobinuria
Hereditary causes correlate with intracorpuscular defects because these defects are due to inherited mutations; the one exception is PNH because the defect is due to an acquired somatic mutation. Similarly, acquired causes correlate with extracorpuscular factors because mostly these factors are exogenous; the one exception is familial hemolytic-uremic syndrome (HUS; often referred to as atypical HUS) because here an inherited abnormality allows complement activation to be excessive, with bouts of production of membrane attack complex capable of destroying normal red cells.
The correct answer is: Paroxysmal nocturnal hemoglobinuria
A 23 year-old-female presented with a chief complaint of left upper quadrant abdominal pain that has slowly progressed over the last two weeks. Upon examination, you noted that she has pale palpebral conjunctivae, and splenomegaly. Her laboratory results also showed elevated unconjugated bilirubin. Upon review of her laboratories, which of the following would mainly indicate that there is an erythropoietic response by the bone marrow?
a. Elevated ferritin
b. Elevated LDH
c. Elevated MCV
d. Elevated reticulocyte
The main sign of the erythropoietic response by the bone marrow is an increase in reticulocytes (a test all too often neglected in the initial workup of a patient with anemia). Usually the increase will be reflected in both the percentage of reticulocytes (the more commonly quoted figure) and in the absolute reticulocyte count (the more definitive parameter).
The correct answer is: Elevated reticulocyte
A 26-year-old female was admitted due to jaundice which was first noted 3 weeks prior. Physical examination shows an enlarged spleen, and ultrasound reveals the presence of gallstones. The patient was also noted to have normocytic anemia, with an elevated mean corpuscular hemoglobin concentration. Her peripheral blood smear is shown below. What is the main diagnostic test that needs to be done?
a. Electrophoresis
b. Osmotic fragility
c. Prothrombin time
d. Western blot
Image: Hereditary spherocytosis
In vitro studies revealed that the red cells were abnormally susceptible to lysis in hypotonic media; indeed, the presence of osmotic fragility became the main diagnostic test for Hereditary spherocytosis. The main clinical findings are jaundice, an enlarged spleen, and often gallstones; indeed, it may be the finding of gallstones in a young person that triggers diagnostic investigations. decompensation.
The anemia is usually normocytic, with the characteristic morphology that gives the disease its name. An increased mean corpuscular hemoglobin concentration (MCHC >34) on an ordinary blood count report should raise the suspicion of HS, because HS is almost the only condition in which this abnormality occurs.
The correct answer is: Osmotic fragility