Haematology EMQs Flashcards
A Iron deficiency anaemia B β-Thalassaemia C Anaemia of chronic disease D Blood loss E Alcohol F Vitamin B12 deficiency G Renal failure H Aplastic anaemia I Lead poisoning
A 35-year-old man presents to his GP with a 1-month history of increased
tiredness. The patient also admits to diarrhoea and minor abdominal pain during
this period. His blood tests reveal the following:
Hb 9.5 (13–18 g/dL)
MCV 64 (76–96 fL)
Fe 12.2 (14–31 μmol/L)
TIBC 74 (45–66 μmol/L)
Ferritin 9.2 (12–200 μg/L)
A Iron deficiency anaemia
Iron deficiency anaemia (IDA; A) causes a hypochromic (pallor of the
red blood cells on blood film due to reduced Hb synthesis), microcytic
(small size) anaemia (low haemoglobin). A reduction in serum iron can
be caused by a number of factors, including inadequate intake, malabsorption
(coeliac disease; most likely cause in this case given diarrhoea
and abdominal pain), increased demand (pregnancy) and increased
losses (bleeding and parasitic infections). Further studies are required to
distinguish IDA from other causes of microcytic anaemia: serum ferritin
will be low, while total iron binding capacity (TIBC) and transferrin will
be high.
A Iron deficiency anaemia B β-Thalassaemia C Anaemia of chronic disease D Blood loss E Alcohol F Vitamin B12 deficiency G Renal failure H Aplastic anaemia I Lead poisoning
A 56-year-old vagrant man presents to the accident and emergency department
with weakness in his legs. The patient has a history of poorly controlled
Crohn’s disease. His blood tests demonstrate Hb 9.4 (13–18 g/dL) and MCV 121
(
76–96 fL). A blood film reveals the presence of hypersegmented neutrophils.
F Vitamin B12 deficiency
The majority of cases of vitamin B12 deficiency (F) occur secondary to
malabsorption: reduced intrinsic factor production due to pernicious
anaemia or post-gastrectomy, as well as disease of the terminal ileum.
Clinical features will be similar to those of anaemia in mild cases,
progressing to neuropsychiatric symptoms and subacute degeneration
of the spinal cord (SDSC) in severe cases. Vitamin B12 deficiency
results in a macrocytic megaloblastic anaemia as a result of inhibited
DNA synthesis (B12 is responsible for the production of thymidine).
Hypersegmented neutrophils are pathognomonic of megaloblastic
anaemia.
A Iron deficiency anaemia B β-Thalassaemia C Anaemia of chronic disease D Blood loss E Alcohol F Vitamin B12 deficiency G Renal failure H Aplastic anaemia I Lead poisoning
A 65-year-old man is referred to the haematology department by his GP after
initially presenting with tiredness, palpitations, petechiae and recent pneumonia.
His blood tests reveal Hb 9.8 (13–18 g/dL), MCV 128 (76–96 fL), reticulocyte
count 18 (25–100 × 109/L), 1.2 (2–7.5 × 109/L) and platelet count 125
(150–400 × 109/L).
H Aplastic anaemia
Aplastic anaemia (H) is caused by failure of the bone marrow resulting
in a pancytopenia and hypocellular bone marrow. Eighty per cent
of cases are idiopathic, although 10 per cent are primary (dyskeratosis
congenita and Fanconi anaemia) and 10 per cent are secondary (viruses,
SLE, drugs and radiation). The pathological process involves CD8+/
HLA-DR+ T cell destruction of bone marrow resulting in fatty changes.
Investigations will reveal reduced Hb, reticulocytes, neutrophils, platelets
and bone marrow cellularity as well as a raised MCV. Macrocytosis
results from the release of fetal haemoglobin in an attempt to compensate
for reduced red cell production.
A Iron deficiency anaemia B β-Thalassaemia C Anaemia of chronic disease D Blood loss E Alcohol F Vitamin B12 deficiency G Renal failure H Aplastic anaemia I Lead poisoning
A 56-year-old woman presents to her GP with increased tiredness in the past few weeks. A past medical history of rheumatoid arthritis is noted. Her blood tests demonstrate the following: Hb 8.6 (11.5–16 g/dL) MCV 62 (76–96 fL) Fe 10.2 (11–30 μmol/L) TIBC 38 (45–66 μmol/L) Ferritin 220 (12–200 μg/L)
C Anaemia of chronic disease
Anaemia of chronic disease (ACD; C) occurs in states of chronic infection
and inflammation, for example in tuberculosis (TB), rheumatoid
arthritis, inflammatory bowel disease and malignant disease. ACD is
mediated by IL-6 produced by macrophages which induces hepcidin
production by the liver. Hepcidin has the effect of retaining iron in
macrophages (reduced delivery to red blood cells for erythropoiesis) and
reduces export from enterocytes (reduced plasma iron levels). Laboratory features of ACD include a microcytic hypochromic anaemia, rouleaux
formation (increased plasma proteins), raised ferritin (acute phase protein)
as well as reduced serum iron and TIBC.
A Iron deficiency anaemia B β-Thalassaemia C Anaemia of chronic disease D Blood loss E Alcohol F Vitamin B12 deficiency G Renal failure H Aplastic anaemia I Lead poisoning
A 12-year-old Mediterranean boy presents to his GP with increased tiredness
over the past few weeks which is affecting his ability to concentrate at school.
Examination is normal. Blood tests demonstrate the following:
Hb 9.5 (13–18 g/dL)
MCV 69 (76–96 fL)
Fe 18.2 (14–31 μmol/L)
TIBC 54 (45–66 μmol/L)
Ferritin 124 (12–200 μg/L)
B β-Thalassaemia
β-Thalassaemia (B) is a genetic disorder characterized by the reduced or
absent production of β-chains of haemoglobin. Mutations affecting the
β-globin genes on chromosome 11 lead to a spectrum of clinical features
depending on the combinations of chains affected. β-Thalassaemia
minor affects one β-globin chain and is usually asymptomatic, but may
present with mild features of anaemia. Haematological tests reveal a
microcytic anaemia but iron studies will be normal, differentiating from
iron deficiency anaemia. β-Thalassaemia major occurs due to defects
of both β-globin chains and results in severe anaemia requiring regular
blood transfusions, as well as skull bossing and hepatosplenomegaly.
A Hereditary sherocytosis B Sickle cell anaemia C β-Thalassaemia D Glucose-6-phosphate dehydrogenase deficiency E Pyruvate kinase deficiency F Autoimmune haemolytic anaemia G Haemolytic disease of the newborn H Paroxysmal nocturnal haemoglobinuria I Microangiopathic haemolytic anaemia
A 48-year-old woman diagnosed with chronic lymphocytic leukaemia develops
jaundice and on examination is found to have conjunctival pallor. Direct
antiglobulin
test is found to be positive at 37°C.
F Autoimmune haemolytic anaemia
Autoimmune haemolytic anaemia (AIHA; F) is caused by autoantibodies
that bind to red blood cells (RBCs) leading to splenic destruction. AIHA
can be classified as either ‘warm’ or ‘cold’ depending on the temperature
at which antibodies bind to RBCs. Warm AIHA is IgG mediated,
which binds to RBCs at 37°C; causes include lymphoproliferative disorders,
drugs (penicillin) and autoimmune diseases (SLE). Cold AIHA is
IgM mediated which binds to RBCs at temperatures less than 4°C; this
phenomenon usually occurs after an infection by mycoplasma or EBV.
Direct antiglobulin test (DAT) is positive in AIHA and spherocytes are
seen on blood film.
A Hereditary sherocytosis B Sickle cell anaemia C β-Thalassaemia D Glucose-6-phosphate dehydrogenase deficiency E Pyruvate kinase deficiency F Autoimmune haemolytic anaemia G Haemolytic disease of the newborn H Paroxysmal nocturnal haemoglobinuria I Microangiopathic haemolytic anaemia
An 18-year-old man presents to accident and emergency after eating a
meal containing Fava beans. He is evidently jaundiced and has signs suggestive
of anaemia. The patient’s blood film reveals the presence of Heinz
bodies.
D Glucose-6-phosphate
Glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency; D) is
caused by an X-linked recessive enzyme defect. G6PD is an essential
enzyme in the red blood cell pentose phosphate pathway; the pathway maintains NADPH levels which in turn supply glutathione to neutralize
free radicals that may otherwise cause oxidative damage. Therefore,
G6PD deficient patients are at risk of oxidative crises which may be
precipitated by certain drugs (primaquine, sulphonamides and aspirin),
fava beans and henna. Attacks result in rapid anaemia, jaundice and a
blood film will demonstrate the presence of bite cells and Heinz bodies.
A Hereditary sherocytosis B Sickle cell anaemia C β-Thalassaemia D Glucose-6-phosphate dehydrogenase deficiency E Pyruvate kinase deficiency F Autoimmune haemolytic anaemia G Haemolytic disease of the newborn H Paroxysmal nocturnal haemoglobinuria I Microangiopathic haemolytic anaemia
A 10-year-old girl presents to accident and emergency with jaundice. Blood
tests reveal uraemia and thrombocytopenia. A peripheral blood film demonstrates
the presence of schistocytes.
I Microangiopathic haemolytic
anaemia
Microangiopathic haemolytic anaemia (I) is caused by the mechanical destruction of RBCs in circulation. Causes include thrombotic thrombocytopenic pupura (TTP), haemolytic uraemic syndrome (HUS; E. coli O157:57), disseminated intravascular coagulation (DIC) and systemic lupus erythematosus (SLE). In all underlying causes, the potentiation of coagulation pathways creates a mesh which leads to the intravascular destruction of RBCs and produces schistocytes (helmet cells). Schistocytes are broken down in the spleen, raising bilirubin levels and initiating jaundice.
A Hereditary sherocytosis B Sickle cell anaemia C β-Thalassaemia D Glucose-6-phosphate dehydrogenase deficiency E Pyruvate kinase deficiency F Autoimmune haemolytic anaemia G Haemolytic disease of the newborn H Paroxysmal nocturnal haemoglobinuria I Microangiopathic haemolytic anaemia
A 9-year-old boy from sub-Saharan Africa presents to accident and emergency
with abdominal pain. On examination the child is found to have dactylitis.
Blood haemoglobin is found to be 6.2 g/dL and electrophoresis reveals the
diagnosis.
B Sickle cell anaemia
Sickle cell anaemia (B) is an autosomal recessive genetic haematological
condition due to a point mutation in the β-globin chain of haemoglobin
(chromosome 11); this mutation causes glumatic acid at position six to
be substituted by valine. Homozygotes for the mutation (HbSS) have
sickle cell anaemia while heterozygotes (HbAS) have sickle cell trait.
The mutation results in reduced RBC elasticity; RBCs therefore assume a
sickle shape which leads to the numerous complications associated with
a crisis. Blood tests will reveal an anaemia, reticulocytosis and raised
bilirubin. Haemoglobin electrophoresis will distinguish between HbSS
and HbAS.
A Hereditary sherocytosis B Sickle cell anaemia C β-Thalassaemia D Glucose-6-phosphate dehydrogenase deficiency E Pyruvate kinase deficiency F Autoimmune haemolytic anaemia G Haemolytic disease of the newborn H Paroxysmal nocturnal haemoglobinuria I Microangiopathic haemolytic anaemia
A 1-day old baby has developed severe jaundice on the neonatal ward.
The mother is rhesus negative and has had one previous pregnancy. Due
to having her first baby abroad, she was not administered prophylactic
anti-
D.
G Haemolytic disease of the
newborn
Haemolytic disease of the newborn (G) occurs when the mother’s blood is
rhesus negative and the fetus’ blood is rhesus positive. A first pregnancy
or a sensitizing event such as an abortion, miscarriage or antepartum
haemorrhage leads to fetal red blood cells entering the maternal circulation
resulting in the formation of anti-D IgG. In a second pregnancy,
maternal anti-D IgG will cross the placenta and coat fetal red blood cells
which are subsequently haemolyzed in the spleen and liver. Therefore,
anti-D prophylaxis is given to at-risk mothers; anti-D will coat any fetal
red blood cells in the maternal circulation causing them to be removed
by the spleen prior to potentially harmful IgG production.
A Anisocytosis B Howell–Jolly bodies C Heinz bodies D Rouleaux formation E Spherocytes F Target cells G Cabot rings H Pappenheimer bodies I Tear-drop cells
A 34-year-old man, who has a past medical history of splenectomy following
splenic trauma, presents to his GP with malaise 2 weeks after returning from
abroad. Routine blood results are found to be normal but a blood film demonstrates
inclusions within erythrocytes.
B Howell–Jolly bodies
Howell–Jolly bodies (B) are nuclear DNA remnants found in circulating
erythrocytes. On haematoxylin and eosin stained blood film they appear
as purple spheres within erythrocytes. In healthy individuals erythrocytes
expel nuclear DNA during the maturation process within the
bone marrow; the few erythrocytes containing Howell–Jolly bodies are
removed by the spleen. Common causes of Howell–Jolly bodies include
splenectomy secondary to trauma and autosplenectomy resulting from
sickle cell disease.
A Anisocytosis B Howell–Jolly bodies C Heinz bodies D Rouleaux formation E Spherocytes F Target cells G Cabot rings H Pappenheimer bodies I Tear-drop cells
A 66-year-old man has a gastroscopy and colonoscopy following a blood test
which demonstrated a microcytic anaemia. The patient had complained of tiredness
and significant weight loss over a 1-month period.
A Anisocytosis
Anisocytosis (A) is defined as the variation in the size of circulating
erythrocytes. The most common cause is iron deficiency anaemia (IDA),
but thalassaemia, megaloblastic anaemia and sideroblastic anaemia are
all causative. As well as blood film analysis, anisocytosis may be detected
as a raised red cell distribution width (RDW), a measure of variation
in size of red blood cells. In the case of IDA, anisocytosis results due to
deficient iron supply to produce haemoglobin.
A Anisocytosis B Howell–Jolly bodies C Heinz bodies D Rouleaux formation E Spherocytes F Target cells G Cabot rings H Pappenheimer bodies I Tear-drop cells
A 36-year-old woman presents to her GP after a 1-month history of tiredness
and recurrent chest infections. Blood tests reveal a pancytopenia and a subsequent
bone marrow aspirate reveals a dry tap.
I Tear-drop cells
Tear-drop cells (I), also known as dacrocytes, are caused by myelofibrosis.
The pathogenesis of myelofibrosis is defined by the bone marrow
undergoing fibrosis, usually following a myeloproliferative disorder
such as polycythaemia rubra vera or essential thrombocytosis. Bone
marrow production of blood cells decreases resulting in a pancytopenia.
The body compensates with extra-medullary haemopoiesis causing
hepatosplenomegaly. Blood film will demonstrate leuko-erythroblasts,
tear-drop cells and circulating megakaryocytes. Bone marrow aspirate is
described as a ‘dry and bloody’ tap.
A Anisocytosis B Howell–Jolly bodies C Heinz bodies D Rouleaux formation E Spherocytes F Target cells G Cabot rings H Pappenheimer bodies I Tear-drop cells
A 3-week-old neonate is found to have prolonged jaundice with serious risk of
kernicterus. Blood film demonstrates the presence of ‘bite cells’ as well as inclusions
within erythrocytes.
C Heinz bodies
Heinz bodies (C) are inclusion bodies found within erythrocytes that
represent denatured haemoglobin as a result of reactive oxygen species.
Heinz bodies are most commonly caused by erythrocyte enzyme deficiencies
such as glucose-6-phosphate dehydrogenase (G6PD) deficiency,
which may present in neonates with prolonged jaundice and NADPH
deficiency (leading to accumulation of hydrogen peroxide), as well
as chronic liver disease and α-thalassaemia. Damaged erythrocytes are
removed in the spleen by macrophages leading to the formation of ‘bite
cells’.
A Anisocytosis B Howell–Jolly bodies C Heinz bodies D Rouleaux formation E Spherocytes F Target cells G Cabot rings H Pappenheimer bodies I Tear-drop cells
A 45-year-old woman with known Graves’ diseases presents to her GP with
increased tiredness. She is found to have a megaloblastic anaemia.
G Cabot rings
Cabot rings (G) are looped structures found within erythrocytes which
may be caused by megaloblastic anaemia, i.e. inhibition of erythrocyte
production occurring as a result of reduced DNA synthesis secondary to vitamin B12 deficiency. Vitamin B12 deficiency is most commonly caused
by intrinsic factor (a protein required for vitamin B12 absorption) deficiency
as a result of pernicious anaemia. Pernicious anaemia is caused
by antibody destruction of gastric parietal cells which produce intrinsic
factor and may be associated with other autoimmune diseases.
A Immune thrombocytopenic purpura B Idiopathic thrombotic thrombocytopenic purpura C Disseminated intravascular coagulation D Glanzmann’s thrombasthenia E Von Willebrand disease F Haemophilia A G Haemophilia B H Hereditary haemorrhagic telangiectasia I Bernard–Soulier syndrome
A 4-year-old girl is seen by her GP due to recent onset petechiae on her feet
and bleeding of her gums when she brushes her teeth. The child’s platelet count
is found to be 12 500 per μL. The GP prescribes prednisolone and reassures the
child’s mother that the bleeding will resolve.
A Immune thrombocytopenic
purpura
Immune thrombocytopenic purpura (ITP; A) may follow either an acute or
chronic disease process. Acute ITP most commonly occurs in children, usually
occurring 2 weeks after a viral illness. It is a type 2 hypersensitivity
reaction, with IgG binding to virus-coated platelets. The fall in platelets is
very low (less than 20 × 109/L) but is a self-limiting condition (few weeks).
Chronic ITP is gradual in onset with no history of previous viral infection.
It is also a type 2 hypersensitivity reaction with IgG targeting GLP-2b/3a.
A Immune thrombocytopenic purpura B Idiopathic thrombotic thrombocytopenic purpura C Disseminated intravascular coagulation D Glanzmann’s thrombasthenia E Von Willebrand disease F Haemophilia A G Haemophilia B H Hereditary haemorrhagic telangiectasia I Bernard–Soulier syndrome
A 28-year-old man attends the haematology outpatient clinic regarding a longstanding
condition he has suffered from. His disorder is related to a deficiency
in factor 8 and therefore requires regular transfusions to replace this clotting
factor.
F Haemophilia A
Haemophilia A (F) is an X-linked genetic disorder and hence only
affects men. Haemophilia A is characterized by a deficiency in factor 8.
Haemophilia A is diagnosed by a reduced APTT as well as reduced
factor
8. Symptoms depend on severity of disease: mild disease features
bleeding after surgery/trauma; moderate disease results in bleeding
after minor trauma; severe disease causes frequent spontaneous bleeds.
Clinical features include haemarthrosis (causing fixed joints) and muscle
haematoma (causing atrophy and short tendons).
A Immune thrombocytopenic purpura B Idiopathic thrombotic thrombocytopenic purpura C Disseminated intravascular coagulation D Glanzmann’s thrombasthenia E Von Willebrand disease F Haemophilia A G Haemophilia B H Hereditary haemorrhagic telangiectasia I Bernard–Soulier syndrome
A 34-year-old man is taken to the local accident and emergency after suffering
an episode of jaundice, fever and worsening headache. Blood tests reveal a low
platelet count and blood film is suggestive of a microangiopathic haemolytic
anaemia picture.
B Idiopathic thrombotic
thrombocytopenic purpura
Idiopathic thrombotic thrombocytopenic purpura (B) occurs due to
platelet microthrombi. Presenting features include microangiopathic
haemolytic anaemia (red blood cells coming into contact with microscopic
clots are damaged by shear stress), renal failure, thrombocytopenia,
fever and neurological signs (hallucinations/stroke/headache). A
mutation in the ADAM-ST13 gene, coding for a protease that cleaves
von Willebrand factor (vWF) allows for the formation of vWF multimers
enabling platelet thrombi to form causing organ damage.
A Immune thrombocytopenic purpura B Idiopathic thrombotic thrombocytopenic purpura C Disseminated intravascular coagulation D Glanzmann’s thrombasthenia E Von Willebrand disease F Haemophilia A G Haemophilia B H Hereditary haemorrhagic telangiectasia I Bernard–Soulier syndrome
A 68-year-old man on the Care of the Elderly ward is confirmed to have Gramnegative
sepsis. The patient is bleeding from his mouth and is in shock. Initial
blood tests reveal a reduced platelet count, anaemia and renal failure.
C Disseminated intravascular
coagulation
Disseminated intravascular coagulation (DIC; C) may be caused by
Gram-negative sepsis, malignancy, trauma, placental abruption or
amniotic fluid embolus. Tissue factor is released which triggers the
activation of the clotting cascade, leading to platelet activation
(thrombosis in microcirculation) and fibrin deposition (haemolysis).
The consumption of platelets and clotting factors predisposes to
bleeding. Plasmin is also generated in DIC which causes fibrinolysis,
perpetuating the bleeding risk. The clinical manifestations of
DIC are therefore linked to microthombus production (renal failure
and neurological signs) and reduced platelets, clotting factors
and increased fibrinolysis (bruising, gastrointestinal bleeding and
shock).
A Immune thrombocytopenic purpura B Idiopathic thrombotic thrombocytopenic purpura C Disseminated intravascular coagulation D Glanzmann’s thrombasthenia E Von Willebrand disease F Haemophilia A G Haemophilia B H Hereditary haemorrhagic telangiectasia I Bernard–Soulier syndrome
A 2-year-old boy is taken to see the GP due to his mother noticing bruising
on his arms and legs after playing in the park. The parent mentions that she
has also noticed several recent nose bleeds in her son but thought he would
‘grow out of it’. Investigations reveal a low APTT, low factor 8 levels and low
Ristocetein cofactor activity.
E Von Willebrand disease
von Willebrand disease (vWD; E) is an autosomal dominant condition
caused by a mutation on chromosome 12. Physiologically, von
Willebrand factor (vWF) has two roles: platelet adhesion and factor 8
production. Therefore, in vWD, where there is a deficiency in vWF,
there is a defect in platelet plug formation as well as low levels of factor
8. Clinically, patients will present with gum bleeding, epistaxis or
prolonged bleeding after surgery. Investigations will reveal a high/
normal APTT, low factor 8 levels, low ristocetin cofactor activity, poor
ristocetin aggregation and normal PTT,
