Hematology MCQ’s ( Hemolytic Anemias and Anemia Due to Acute Blood Loss ) MCQs With Answers
472 The main cytoskeletal protein is ?
A. Band 3
B. Band 4.1
C. Glycophorin
D. Spectrin
Explanation:- RBC cell membrane (7 nm thick) is a lipid bilayer. Most abundant of the membrane proteins are glycophorins & band 3 (anion transporter). Main cytoskeletal protein is spectrin. Membrane is physically linked to cytoskeleton by proteins (ankyrin & band 4.1 / band 4.2). Spectrin, actin with Bands 4.1 & 4.2 together form a fibrillar, weblike network on inner surface of RBC membrane.
473 Which is the largest component of RBC cell membrane ?
A. Protein
B. Lipid
C. Carbohydrate
D. Others
Explanation:- RBC cell membrane contain ~52% protein, 40% lipid & 8% carbohydrate by weight.
474 Enzyme required for the production & utilization of ATP in RBC cell membrane is ?
A. Aldolase
B. Glyceraldehyde-3 phosphate dehydrogenase (G-3PD)
C. Phosphoglycerate kinase
D. All of the above
Explanation:- A three-enzyme sequence concerned with ATP production is membrane bound – aldolase, glyceraldehyde-3 phosphate dehydrogenase (G-3PD) & phosphoglycerate kinase. Together, they convert fructose diphosphate to 3-phosphoglycerate with production of ATP.
475 Phospholipid of RBC membrane is ?
A. Phosphatidylcholine (lecithin)
B. Phosphatidylethanolamine
C. Sphingomyelin
D. All of the above
Explanation:- Most of phospholipid of RBC membrane is phosphatidylcholine (lecithin), phosphatidylethanolamine, sphingomyelin & phosphatidylserine. Lecithin & sphingomyelin can substitute each other.
476 Which of the following gene mutation accounts for majority of autosomal dominant hereditary spherocytosis (HS) ?
A. ANK1
B. SPTA1
C. SLC4A1
D. EPB41
Explanation:- Mutations in ANK1 gene on chromosome 8p11.2 producing ankyrin protein accounts for majority of autosomal dominant hereditary spherocytosis (HS).
477 Mutation in which of the following gene is not a cause of hereditary spherocytosis ?
A. ANK1
B. SPTA1
C. SLC4A1
D. EPB42
Explanation:- Mutations of SPTA1 gene account for ~65% of Hereditary elliptocytosis (HE).
478 Which of the following is false about hereditary spherocytosis ?
A. Increased ratio of RBC surface area to volume
B. Splenomegaly is very common
C. Mean corpuscular volume usually normal
D. Mean corpuscular hemoglobin concentration increased
Explanation:- Anemia in HS is normocytic. Increase in MCHC is a characteristic feature. HS is the only condition in which high MCHC is seen.
479 Which of the following is false about hereditary spherocytosis ?
A. Due to defect in ankyrin / protein 3 / spectrin / palladin
B. Pigmented gallstones are common
C. RBC survival after splenectomy is normal
D. None of the above
Explanation:- Main clinical findings of HS are jaundice, an enlarged spleen, and gallstones. Splenectomy is regarded as an obligatory therapeutic measure in HS.
480 Spherocytes are seen in ?
A. Cirrhosis liver
B. Clostridial infections
C. Snake envenomations
D. All of the above
481 Pink test is a modified version of which of the following ?
A. RBC absolute values
B. Red cell survival study
C. Osmotic fragility test
D. Schilling test
Explanation:- A modified version of osmotic fragility test is called the “pink test”.
482 Which of the following is false about pyruvate kinase deficiency ?
A. High reticulocytosis
B. Oxygen delivery to tissues is increased
C. Oral folic acid should be given constantly
D. None of the above
Explanation:- Metabolic block at the last step in glycolysis increase bisphosphoglycerate (or DPG), a major effector of hemoglobin-oxygen dissociation curve. Thus, oxygen delivery to tissues is increased.
483 Which of the following protects RBC’s against oxidant stress ?
A. Glutathione
B. Glucose-6-phosphate dehydrogenase (G6PD)
C. Pyruvate
D. Erythropoietin (EPO)
Explanation:- G6PD protects RBC’s proteins from oxidative damage by generating NADPH, which maintains high levels of reduced glutathione. Glutathione protects RBC’s against oxidant stress.
484 Glucose-6-phosphate dehydrogenase (G6PD) is related to which of the following pathways ?
A. Embden-Meyerhof pathway
B. Hexose monophosphate shunt
C. Purine salvage pathway
D. All of the above
Explanation:- G6PD is a HMP shunt enzyme.
485 Which of the following reactions is releted to G6PD ?
A. ATP to ADP
B. ADP to ATP
C. NADP to NADPH
D. NADPH to NADP
Explanation:- G6PD reduces NADP to NADPH while oxidizing glucose-6-phosphate (G6P) to 6-phosphogluconate (6PG). NADPH then provides the reducing power that converts oxidized glutathione (GSSG) to reduced glutathione (GSH). Reduced glutathione protects against oxidant injury by catalyzing breakdown of oxidant compounds like H2O2.
486 Which of the following protects the patient from malaria ?
A. G6PD Deficiency
B. Hemoglobin S
C. Hereditary ovalocytosis
D. All of the above
487 The G6PD gene is located on ?
A. X chromosome
B. Y chromosome
C. Autosome
D. Any of the above
Explanation:- Gene for G6PD is located on X chromosome. Mode of transmission of G6PD deficiency is Xlinked recessive. It is the most common enzymatic disorder of RBC’s in humans. Defect is expressed in all erythrocytes of the affected male. In heterozygous female, two populations of red cells, some deficient, others normal, are present owing to random inactivation of the X chromosomes. It follows that males are more vulnerable to oxidant injury than females are.
488 The normal G6PD is designated as ?
A. Type A (+)
B. Type A (-)
C. Type B
D. Any of the above
Explanation:- Most common normal “wild type” G6PD enzyme is designated as G6PD-B. Two variants, designated G6PD A- ((10 – 60% of activity) and G6PD Mediterranean (<10% of normal activity), lead to clinically significant hemolysis. A- type is present in ~10% of American blacks, G6PD Mediterranean is found in Middle East, G6PD Vianchan & G6PD Mahidol in Southeast Asia, G6PD Canton in China, and G6PD Union worldwide.
489 Which of the following ‘vitamins’ can cause hemolysis in G6PD deficient subjects ?
A. Vitamin A
B. Vitamin D
C. Vitamin E
D. Vitamin K
Explanation:- Vitamins that G6PD deficient persons should avoid include vitamin C & K. Vitamin E is protective.
490 Which of the following ‘antimalarials’ can cause hemolysis in G6PD deficient subjects ?
A. Chloroquine
B. Quinine
C. Primaquine
D. Mefloquine
Explanation:- Deficiency of G6PD protects against malaria due to Plasmodium falciparum.
491 Which of the following can precipitate an episode of hemolysis in G6PD deficient subjects ?
A. Viral & bacterial infections
B. Naphthalene
C. Metabolic acidosis
D. All of the above
492 Which population of RBC is rapidly destroyed during hemolysis in G6PD deficient subjects ?
A. Immature
B. Mature
C. Older
D. All of the above
Explanation:- G6PD enzyme activity is normal in reticulocytes, but older RBC’s are markedly deficient. Exposure to oxidants induces hemolysis of older red cells but not of younger ones.
493 Which of the following is a peripheral blood finding of hemolysis in G6PD deficiency ?
A. Heinz bodies
B. Bite cells or blister cells
C. Spherocytes
D. All of the above
Explanation:- Hemolysis in G6PD deficiency is both intravascular & extravascular. Exposure to oxidants causes oxidation of sulfhydryl groups of globin chains leading to denaturation of hemoglobin & formation of precipitates (Heinz bodies) which damage RBC membrane to cause intravascular hemolysis. Heinz bodies decrease RBC deformability, macrophages pluck out or bite Heinz bodies, giving rise to “bite cells”. Membrane damage induces formation of spherocytes. Bizarre poikilocytes with RBC’s having unevenly distributed hemoglobin are called hemighosts.
494 The enzymatically active form of G6PD is a ?
A. Monomer
B. Dimer
C. Trimer
D. All of the above
Explanation:- Enzymatically active form of G6PD is either a dimer or a tetramer of a single protein subunit of 514 amino acids.
495 Which of the following is false about acute hemolytic anemia due to G6PD deficiency ?
A. Hemoglobinemia
B. Hemoglobinuria
C. Raised plasma haptoglobin
D. Raised LDH
Explanation:- Acute hemolytic anemia due to G6PD deficiency leads to anisocytosis, poikilocytosis, polychromasia, spherocytes, reticulocytosis, unconjugated hyperbilirubinemia, hemoglobinemia, hemoglobinuria, low or absent plasma haptoglobin, raised LDH, gallstones, splenomegaly.
496 Which of the following is false about CNSHA ?
A. Patient is always a male
B. History of neonatal jaundice (NNJ)
C. Chronic hemolysis
D. None of the above
Explanation:- Chronic nonspherocytic hemolytic anemia (CNSHA) is a severe clinical phenotype of G6PD deficiency, always in a male, with history of NNJ.
497 Which of the following element is essential for the activity of glutathione peroxidase (GSHPx) ?
A. Cobalt
B. Zinc
C. Mercury
D. Selenium
Explanation:- Infantile poikilocytosis is due to deficiency of glutathione peroxidase (GSHPx) due to nutritional deficiency of selenium which is an essential element for the activity of GSHPx.
498 Basophilic stippling is a highly distinctive feature of ?
A. Autoimmune Hemolytic Anemia (AIHA)
B. Familial Hemolytic Uremic Syndrome (HUS)
C. Pyrimidine 5′-Nucleotidase (P5N) Deficiency
D. All of the above
Explanation:- P5N is a key enzyme in catabolism of nucleotides arising from degradation of nucleic acids that takes place in final stages of RBC maturation. Basophilic stippling is highly distinctive feature of P5N deficiency. HA caused by lead poisoning is also characterized by basophilic stippling.
499 Drug that can cause hemolysis by depletion of ATP is ?
A. Dapsone
B. Ribavirin
C. Cisplatin
D. Methyldopa
Explanation:- Ribavirin causes hemolysis by depletion of ATP. Hyperbaric oxygen, nitrates, chlorates, methylene blue, dapsone, cisplatin cause hemolysis by their oxidative potential. Penicillin acts as a hapten & induces antibody production leading to hemolysis. Methyldopa, through mimicry, produces of an antibody (Rhesus antibody anti-e) against RBC antigen causing hemolysis.
500 Which of the following about HUS due to Shiga toxin producing Escherichia coli O157:H7 is false ?
A. Nonimmune [Coombs test (–)] hemolytic anemia
B. Microangiopathic hemolytic anemia
C. Thrombocytopenia
D. Leucopenia
Explanation:- Shiga toxin producing Escherichia coli O157:H7 is an etiologic agent of HUS, more common in children, developing several days after diarrhea. HUS is a nonimmune [Coombs test (–)] hemolytic anemia with classical triad – microangiopathic hemolytic anemia, thrombocytopenia & acute renalm failure due to thrombosis of glomerular capillaries. Leucocytosis can cause in HUS.
501 Direct Coombs test is also called ?
A. Direct antiglobulin test
B. Direct agglutination test
C. Direct antigen test
D. Direct antibody test
Explanation:- Direct Coombs test is also called Direct antiglobulin test (DAT).
502 Which of the following is false about direct antiglobulin test (DAT) ?
A. Reflects in-vivo antibody sensitization of RBC’s
B. Reflects in-vitro antibody sensitization of RBC’s
C. Erythrocytes are washed before the test
D. Anti-IgG antihuman globulin (AHG) reagent is used
Explanation:- DAT reflects in-vivo antibody sensitization of RBC’s. RBC’s are washed to remove unbound Ab’s & anti-IgG AHG reagent is then added. IgG antibodies cannot cause direct RBC agglutination, but if RBC’s are coated with IgG antibodies, AHG reagent will cause them to agglutinate.
503 Which of the following is false about indirect antiglobulin test (IAT) ?
A. Used to detect IgG antibodies in serum
B. Reflects in-vitro antibody sensitization of RBC’s
C. Reagent RBC’s are incubated in with serum
D. Anti-IgG antihuman globulin reagent is not used
Explanation:- Indirect antiglobulin test (IAT) is used to detect the presence of IgG antibodies in serum (in-vitro sensitization). Reagent RBC’s are incubated with serum that potentially contains antibodies. If Ab’s are present, they bind to their target antigens on reagent RBC’s. After an incubation period, RBC’s are washed to remove unbound antibodies. Anti-IgG AHG reagent is then added and will cause IgG-coated RBC’s to agglutinate.
504 Cold Autoimmune Hemolytic Anemia (AIHA) is caused by ?
A. IgA antibody
B. IgG antibody
C. IgM antibody
D. ANy of the above
Explanation:- AIHA is usually classified on the basis of thermal amplitude of the autoantibody. Warm AIHA is caused by IgG antibody, whereas cold AIHA is caused by an IgM antibody that fixes complement to the surface of the RBC.
505 Conditions associated with hemolysis and a negative DAT result include all except ?
A. Hemoglobinopathies
B. Systemic lupus erythematosus (SLE)
C. Thrombotic thrombocytopenic purpura (TTP)
D. Disseminated intravascular coagulation (DIC)
Explanation:- Antierythrocyte membrane autoantibodies in SLE have positive direct Coombs’ test (60% prevalence). Some may develop overt hemolysis. Conditions associated with hemolysis and a negative DAT result are Microangiopathic hemolytic anemias (TTP, DIC), Hypersplenism, Liver disease, Hemoglobinopathies (sickle cell disease, thalassemia), Erythrocyte membranopathies (spherocytosis), Erythrocyte enzymopathies (G-6-PD deficiency, pyruvate kinase deficiency), Infectious diseases (Clostridium difficile infection), Erythrocyte trauma (mechanical heart valves).
506 RBC’s of which blood group are used in indirect antiglobulin test (IAT) ?
A. A
B. B
C. AB
D. O
507 Which of the following should be considered in differential diagnosis of chronic Coombs-negative HA ?
A. Drug-induced hemolytic anemias
B. Enzymopathies
C. Paroxysmal Cold Hemoglobinuria (PCH)
D. Acute hemolytic transfusion reaction
Explanation:- Enzymopathies (G-6-PD deficiency, pyruvate kinase deficiency) should be considered in the differential diagnosis of any chronic Coombs-negative HA.
508 Most common form of acquired hemolytic anemia in areas where malaria is not endemic is ?
A. Paroxysmal Nocturnal Hemoglobinuria (PNH)
B. Paroxysmal Cold Hemoglobinuria (PCH)
C. Autoimmune Hemolytic Anemia (AIHA)
D. Hemolytic Uremic Syndrome (HUS)
Explanation:- Autoimmune Hemolytic Anemia (AIHA) is the most common form of acquired hemolytic anemia in areas where malaria is not endemic.
509 Paroxysmal cold hemoglobinuria (PCH) was more frequent when which of the following disease was prevalent ?
A. Tuberculosis
B. Tertiary syphilis
C. Gonorrhoea
D. Protein calorie malnutrition
510 Antibody in Paroxysmal cold hemoglobinuria (PCH) is ?
A. Anti-Jo-1 antibody
B. Anti-Smith antibody
C. Ki-67 monoclonal antibody
D. Donath-Landsteiner antibody
Explanation:- Antibody in PCH is Donath-Landsteiner antibody which has anti-P specificity and binds to RBC’s only at a low temperature (~4°C), and in the presence of complement when temperature becomes 37°C, lysis of RBC’s, intravascular hemolysis & hemoglobinuria occurs.
511 Cold Agglutinin Disease (CAD) is related to which of the following ?
A. Familial cold autoinflammatory syndrome (FCAS)
B. Cold urticaria
C. Waldenström macroglobulinemia (WM)
D. Systemic Mastocytosis
Explanation:- CAD is a form of chronic AIHA & affects elderly. Autoantibody (IgM with anti-I specificity) reacts with RBC’s strongly at lower temperatures (cold exposure), not at all at 37°C. Antibody is produced by expanded clone of B lymphocytes and may show as a spike in plasma protein electrophoresis resembling monoclonal gammopathy and may be related to Waldenström macroglobulinemia (WM).
512 Which of the following is the most important protective RBC membrane protein ?
A. CD29
B. CD39
C. CD49
D. CD59
Explanation:- CD59 (membrane inhibitor of reactive lysis) is a protective RBC membrane protein.
513 Which of the following is diagnostic of PNH ?
A. CD59–, CD55–
B. CD59+, CD55–
C. CD59–, CD55+
D. CD59+, CD55+
Explanation:- Discrete population of cells that is CD59–, CD55– is diagnostic of PNH.
514 Which of the following is the action of CD59 ?
A. Inhibits insertion of C9 into cell membrane
B. Binds C3b
C. Inhibiting C3 convertases
D. All of the above
Explanation:- Erythrocytes defend themselves from membrane attack complexes with two membrane-bound proteins, CD55 (decay-accelerating factor), which binds C3b, and CD59, which inhibits the insertion of C9 into the membrane.
515 Which of the following is false about Paroxysmal Nocturnal Hemoglobinuria (PNH) ?
A. Intracorpuscular defect acquired at stem cell level
B. Hemolytic anemia
C. Arterial thrombosis
D. Bone marrow failure
Explanation:- PNH has three attributes – complement-dependent acquired chronic intravascular hemolytic anemia, venous thrombosis & bone marrow failure. Hemolysis often occurs during sleep, when decline in blood pH triggers activation of complement components. Urine is black when patient awakens. Hemoglobin-drenched renal tubules lock iron of Hb into hemosiderin and continuous sloughing of these cells into urine culminates in iron deficiency.
516 Which of the following is false about Paroxysmal Nocturnal Hemoglobinuria (PNH) ?
A. Hemolysis due to activation of complement
B. Hemosiderinuria is usually absent
C. Granulocytopenia & thrombocytopenia
D. May present as Budd-Chiari syndrome
Explanation:- In PNH, RBC’s have an increased susceptibility to complement (C) due to the deficiency on their surface of CD59 & CD55 proteins that normally protect RBC’s from activated C. When thrombosis affects hepatic veins, Budd-Chiari syndrome occurs. The hemoglobin-drenched renal tubules lock iron of hemoglobin into hemosiderin, and the continuous sloughing of these cells into the urine culminates in iron deficiency.
517 In Paroxysmal Nocturnal Hemoglobinuria, name of the defective gene is ?
A. HNF4
B. PIG-A
C. BRCA1
D. CFTR
Explanation:- PNH results from clonal expansion of hematopoietic stem cells that have somatic mutations in the X-linked gene called PIG-A (phosphatidylinositol glycan class A). PIG-A mutations cause an early block in the synthesis of glycosylphosphatidyl-inositol (GPI) anchors, which tether many proteins to the cell surface. Consequently, the blood cells in PNH have a partial deficiency (type II) or a complete deficiency (type III) of GPI-linked proteins. Intravascular hemolysis is the consequence of absence of GPI-linked complement regulatory protein CD59. CD59 blocks the formation of terminal complement complex (membrane-attack complex) on the cell surface, thereby preventing erythrocyte lysis and in vitro platelet activation.
518 Which of the following tests is useful in diagnosing Paroxysmal Nocturnal Hemoglobinuria ?
A. Acidified serum lysis test (Ham’s test)
B. Sucrose lysis test
C. Analysis of GPI-linked proteins (CD59, DAF)
D. All of the above
Explanation:- Thomas Hale Ham (1938) developed Ham’s test at Thorndike Laboratory of Boston City Hospital and reported that RBC’s in PNH are highly susceptible to lysis in an acidic environment. CD55 is called decay-accelerating factor (DAF).
519 Pathway of activation of the complement system is called ?
A. Classical pathway
B. Mannose-binding lectin pathway
C. Alternative pathway
D. All of the above
Explanation:- There are three pathways of activation of the complement system – the classical, mannosebinding lectin and alternative pathways. Terminal pathway is common to these three pathways leads to membrane attack complex that lyses cells.
520 Pathways of activation of the complement system converge at the point of cleavage of ?
A. C3
B. C4
C. C5
D. C6
Explanation:- 3 activation pathways of complement converge to generate C3 convertase that cleaves C3.
521 Eculizumab binds specifically to ?
A. C1
B. C3
C. C4
D. C5
Explanation:- Eculizumab is a recombinant humanized monoclonal antibody that binds specifically to terminal complement protein C5, inhibiting its cleavage into C5a and C5b, thereby preventing release of inflammatory mediator C5a & formation of the cytolyticpore C5b–C9. Blockade of complement cascade at C5 preserves early components of complement that are essential for opsonization of microorganisms & clearance of immune complexes.
522 RBC membrane is unstable at temperatures above ?
A. 38 ºC
B. 42 ºC
C. 46 ºC
D. 49 ºC
Explanation:- RBC membrane is unstable at temperatures > 49°C due to denaturation of cytoskeletal protein spectrin.
523 In hemolysis, level of unconjugated bilirubin never exceeds ?
A. 1 to 2 mg / dL
B. 2 to 3 mg / dL
C. 3 to 4 mg / dL
D. 4 to 5 mg / dL
Explanation:- In patients with hemolysis, the level of unconjugated bilirubin never exceeds 4 to 5 mg/dL unless liver function is impaired.
524 Which fraction of lactate dehydrogenase (LDH) is elevated by accelerated RBC destruction ?
A. 1
B. 2
C. 3
D. 4
Explanation:- LDH, particularly LDH-2, is elevated by accelerated RBC destruction. Serum AST (SGOT) may be elevated but ALT (SGPT) is not.
525 Which of the following is false about ‘Haptoglobin’ ?
A. globulin
B. Binds to heme in hemoglobin
C. Decreased in hepatocellular disease
D. Increased in inflammatory states
Explanation:- Haptoglobin binds specifically to the globin in hemoglobin.
526 Which of the following is false about ‘Haptoglobin’ ?
A. Serum concentration is ~1.0 g/L
B. Low or absent is significant hemolysis
C. Hemoglobin-haptoglobin complex is cleared rapidly by mononuclear phagocyte system
D. None of the above
527 Urine is positive with benzidine reaction in ?
A. Hemoglobinuria
B. Hematuria
C. Myoglobinuria
D. All of the above
Explanation:- Urine is positive with benzidine reaction in hemoglobinuria, hematuria and myoglobinuria.
528 Which of the following stains is used to detect hemosiderin in urinary sediment ?
A. Prussian blue
B. Giemsa’s stain
C. Methylene blue
D. Crystal violet
Explanation:- Prussian blue is used to detect presence of hemosiderin in urine. Positive result indicates that a significant amount of circulating free hemoglobin has been filtered by the kidneys.
529 Drug that cause immunohemolytic anemia is ?
A. -methyldopa
B. Penicillin
C. Quinidine
D. All of the above
Explanation:- Drugs causing warm antibody immunohemolytic anemia are -methyldopa, penicillin & quinidine.
530 Which of the following can directly parasitize RBC’s & cause severe hemolysis ?
A. Bartonellosis
B. Malaria
C. Babesiosis
D. All of the above
Explanation:- Bartonellosis, malaria & babesiosis directly parasitize RBC & cause severe hemolysis.
531 Spur cell anemia is due to ?
A. Clostridium welchii infection
B. HELLP syndrome
C. Severe hepatocellular disease
D. Hemolytic-uremic syndrome
Explanation:- Spur cells are irregularly spiculated acanthocytes. Spur cell anemia is a hemolytic anemia with bizarre-shaped RBC occuring in severe hepatocellular disease (Laennec’s cirrhosis).
532 Surface membrane of a spur cell (acanthocytes) contain excess of ?
A. Phospholipid
B. Cholesterol
C. Triglyceride
D. Glycoprotein
Explanation:- Surface membrane of a spur cell contains 50 to 70% excess cholesterol, but its total phospholipid content is normal. This decreases membrane fluidity & cell deformability forbiding their passage through filtering system of spleen.
533 ‘Burr cells’ are found in ?
A. Severe hepatocellular disease
B. Uremia
C. DIC
D. HELLP syndrome
Explanation:- Burr cells or echinocytes are seen in uremia. In such RBC’s numerous, regularly spaced, small spiny projections are seen. Echinocytes are a frequent artifact in PBF.
