Haematology Flashcards
1
Q
What is the definition of iron deficiency anaemia?
A
A reduction in haemoglobin concentrations due to inadequate iron supply
2
Q
What is the aetiology of iron deficiency anaemia?
A
Blood loss (haemorrhage, GI bleeding or heavy menstruation), poor diet or poverty in children, and malabsorption in coeliac disease
3
Q
What is the clinical presentation of iron deficiency anaemia?
A
Fatigue, dyspnoea on exertion, pica (craving for non-food substances), restless leg syndrome, nail changes (thinning, flattening, and then spooning of the nails (koilonychia)), glossitis and angular stomatitis
4
Q
What are the investigations of iron deficiency anaemia?
A
o Haemoglobin: low o MCV: low o Peripheral blood smear: microcytic, hypochromic anaemia, with anisocytosis and poikilocytosis (variation in size and shape) o Iron studies: oDecreased ferritin oDecreased serum iron oIncreased TIBC (serum transferrin)
5
Q
What is the treatment of iron deficiency anaemia?
A
Oral iron replacement (ferrous sulfate), ascorbic acid (vitamin C) to help with the absorption of non-haem iron, IV iron
6
Q
What is the definition of anaemia of chronic disease?
A
Inflammation-mediated reduction in red blood cell production and survival
7
Q
What is the pathophysiology of anaemia of chronic disease?
A
The release of proinflammatory cytokines trigger systemic changes in iron metabolism by decreasing red cell production and reducing red blood cell survival
8
Q
What is the clinical presentation of anaemia of chronic disease?
A
Systemic symptoms of underlying condition
9
Q
What are the investigations of anaemia of chronic disease?
A
o Haemoglobin: low
o MCV: initially normocytic, then microcytic as iron is depleted
o Iron studies:
oDecreased serum iron
oElevated serum ferritin (stored iron cannot be utilised)
oDecreased TIBC
10
Q
What is the treatment of anaemia of chronic disease?
A
Treatment of underlying condition, erythropoietin, red blood cell transfusion, supplemental iron
11
Q
What is the definition of sideroblastic anaemia?
A
The bone marrow produces ringed sideroblasts rather than healthy red blood cells
12
Q
What is the aetiology of sideroblastic anaemia?
A
Congenital, myeloproliferative diseases, chemotherapy, anti-TB drugs, irradiation, alcohol, lead excess
13
Q
What is the pathophysiology of sideroblastic anaemia?
A
The body has sufficient iron, but it cannot be incorporated into haemoglobin. There is an accumulation of iron in the mitochondria of erythroblasts which results in a ring sideroblast around the mitochondrial nucleus
14
Q
What is the clinical presentation of sideroblastic anaemia?
A
Fatigue, dyspnoea on exertion, weakness, palpitations, headaches, irritability, chest pain
15
Q
What are the investigations of sideroblastic anaemia?
A
o Haemoglobin: low
o MCV: low
o Iron studies:
oElevated ferritin
oDecreased TIBC
o Peripheral blood smear: microcytic, hypochromic anaemia with basophilic stippling
o Bone marrow aspirate: ringed sideroblasts
16
Q
What is the treatment of sideroblastic anaemia?
A
Cessation of the offending agent, pyridoxine (vitamin B6)
17
Q
What is the definition of beta thalassemia?
A
Inherited microcytic anaemia caused by a mutation of the beta-globin gene leading to decreased or absent synthesis of beta-globin, resulting in ineffective erythropoiesis
18
Q
What is the aetiology of beta thalassemia?
A
Mutation in the beta globin gene on chromosome 11
19
Q
What is the pathophysiology of beta thalassemia?
A
The imbalance between alpha and beta chains leads to precipitation of the excess alpha chains in erythroid precursors and maturing red cells, resulting in membrane damage and cell destruction
20
Q
What is the clinical presentation of beta thalassemia?
A
Asymptomatic, failure to feed, listlessness, crying, pallor
21
Q
What are the investigations of beta thalassemia?
A
o Haemoglobin: severely low, 30-70 g/L
o MCV: severe microcytic anaemia
o Haemoglobin analysis (low HbA, elevated HbF and HbA2)
o Peripheral blood smear: microcytic red cells, dacrocytes (tear drops), microspherocytes, target cells
o PCR: beta-thalassaemia mutation
22
Q
What is the treatment of beta thalassemia?
A
Blood transfusions
23
Q
What is the definition of sickle cell anaemia?
A
Autosomal recessive single gene defect in the beta chain of haemoglobin, which results in production of sickle cell haemoglobin, HbS
24
Q
What is the pathophysiology of sickle cell anaemia?
A
Valine replaces glutamic acid and can fit into the hydrophobic pocket of another haemoglobin molecule, causing the haemoglobin to polymerise
25
What is the clinical presentation of sickle cell anaemia?
Persistent pain in skeleton, chest and/or abdomen, dactylitis
26
What are the investigations of sickle cell anaemia?
o Positive neonatal screening
o Peripheral blood smear: nucleated red blood cells, sickle-shaped cells, Howell-Jolly bodies
o DNA-based assay: replacement of both beta haemoglobin subunits with HbS
o Reticulocyte count: elevated
27
What is the treatment of sickle cell anaemia?
o Crisis: analgesia, IV fluids, oxygen, and antibiotics
| o Long-term: Hydroxycarbamide, folic acid, bone marrow transplantation
28
What is the definition of glucose-6-phospahte dehydrogenase deficiency?
X-linked recessive disorder which leads to a deficiency in the glucose-6-phosphate dehydrogenase enzyme
29
What is the pathophysiology of glucose-6-phospahte dehydrogenase deficiency?
Glucose-6-phosphate dehydrogenase is required by all cells to protect them from damage by oxidation. Failure to withstand oxidative stress damages the red cell membrane and causes haemolysis
30
What are the triggers of glucose-6-phospahte dehydrogenase deficiency?
Oxidants (fava beans), infections, drugs (primaquine, sulphonamides, nitrofurantoin, quinolones), and mothballs which contain naphthalene
31
What is the clinical presentation of glucose-6-phospahte dehydrogenase deficiency?
Asymptomatic, haemolysis, jaundice, anaemia, pallor, back pain, dark urine, nausea
32
What are the investigations of glucose-6-phospahte dehydrogenase deficiency?
o Haemoglobin: low
o Reticulocyte count: elevated
o Peripheral blood smear (during a crisis): Bite cells, blister cells, Heinz bodies
o Enzyme assay: reduced glucose-6-phosphate dehydrogenase activity
33
What is the treatment of glucose-6-phospahte dehydrogenase deficiency?
Avoidance of oxidant factors, transfusions, folic acid
34
What is the definition of hereditary spherocytosis?
Inherited abnormality of the red blood cell, caused by defects in structural membrane proteins
35
What is the pathophysiology of hereditary spherocytosis?
Defects in membrane structural proteins result in a weakening of vertical linkages between membrane surface proteins and the phospholipid bilayer. This alters the red-cell shape, becoming spherical, and reduces its flexibility. The spherocytes are fragile and are selectively removed by, and destroyed in, the spleen
36
What is the clinical presentation of hereditary spherocytosis?
Pallor, jaundice, splenomegaly
37
What are the investigations of hereditary spherocytosis?
o Haemoglobin: normal or reduced
o Reticulocyte count: elevated
o Peripheral blood smear: spherocytes, pincer cells
o Osmotic fragility test: fragility in hypotonic solutions
38
What is the treatment of hereditary spherocytosis?
Splenectomy (after childhood to minimise the risk of infection), folic acid
39
What is the definition of hot autoimmune haemolytic anaemia?
Increased red cell destruction due to red cell autoantibodies
40
What is the aetiology of hot autoimmune haemolytic anaemia?
Idiopathic or occur secondary to lymphoma, leukaemia and other malignancies, drugs, and autoimmune diseases
41
What is the pathophysiology of hot autoimmune haemolytic anaemia?
IgG autoantibodies bind optimally to red blood cells at warm temperatures (37 ºC). This results in extravascular haemolysis in the spleen
42
What is the clinical presentation of hot autoimmune haemolytic anaemia?
Fatigue, dyspnoea, headache, palpitations, pallor
43
What are the investigations of hot autoimmune haemolytic anaemia?
o Haemoglobin: low
o Reticulocyte count: elevated
o Direct Coombs Test: positive for IgG on red blood cells
44
What is the treatment of hot autoimmune haemolytic anaemia?
Corticosteroids, splenectomy, rituximab, folic acid, transfusions
45
What is the definition of cold autoimmune haemolytic anaemia?
Increased red cell destruction due to red cell autoantibodies
46
What is the aetiology of cold autoimmune haemolytic anaemia?
Idiopathic, secondary to infection
47
What is the pathophysiology of cold autoimmune haemolytic anaemia?
IgM autoantibodies bind optimally to red blood cells at cold temperatures (0-5 ºC), activating the complement cascade and causing lysis of red blood cells in the circulation
48
What is the clinical presentation of cold autoimmune haemolytic anaemia?
Fatigue, dyspnoea, headache, palpitations, pallor
49
What are the investigations of cold autoimmune haemolytic anaemia?
o Haemoglobin: low
o Reticulocyte count: elevated
o Direct Coombs Test: positive for complement alone
50
What is the treatment of cold autoimmune haemolytic anaemia?
Avoid exposure to cold, rituximab
51
What is the definition of aplastic anaemia?
Bone marrow failure causes a reduction in the number of pluripotent stem cells and consequently a lack of haemopoiesis
52
What is the pathophysiology of aplastic anaemia?
Activated cytotoxic T cells in the blood and bone marrow are responsible for the bone marrow failure
53
What is the clinical presentation of aplastic anaemia?
Fatigue, dyspnoea, faintness, palpitations, headache, epistaxis, tachycardia, pallor
54
What are the investigations of aplastic anaemia?
o FBC: pancytopenia
o Reticulocyte count: low
o Bone marrow biopsy: hypocellular marrow with increased fat spaces and no abnormal cell populations
55
What is the treatment of aplastic anaemia?
Broad spectrum parenteral antibodies, transfusions, bone marrow transplant, immunosuppression (ciclosporin and antithymocyte)
56
What is the aetiology of vitamin B12 deficiency anaemia?
Decreased dietary intake, diminished gastric breakdown of vitamin 12 from food, and malabsorption from the GI tract, pernicious anaemia (autoimmune destruction of the parietal cells?
57
What is the pathophysiology of vitamin B12 deficiency anaemia?
Vitamin B12 is required for the synthesis of thymine and hence DNA
58
What is the clinical presentation of vitamin B12 deficiency anaemia?
Lemon tinge (due to pallor and mild jaundice), peripheral neuropathy, fatigue, lethargy, headaches, palpitations, dyspnoea
59
What are the investigations of vitamin B12 deficiency anaemia?
o Haemoglobin: low
o MCV: elevated
o Peripheral blood smear: macrocytic cells with hypersegmented neutrophils
o Serum vitamin B12: decreased
o Intrinsic factor and anti-parietal cell antibodies: positive in pernicious anaemia
o Schilling test (B12 absorption test): low in pernicious anaemia
60
What is the treatment of vitamin B12 deficiency anaemia?
Oral B12, intramuscular hydroxocobalamin
61
What is the aetiology of folate deficiency anaemia?
Malabsorption, drugs and toxins, increased demand (during pregnancy, haemolysis, malignancy, inflammatory disease, and renal dialysis), dietary deficiency (green vegetables), or alcohol use
62
What is the clinical presentation of folate deficiency anaemia?
Asymptomatic, headache, no neuropathy
63
What are the investigations of folate deficiency anaemia?
```
o Haemoglobin: low
o MCV: elevated
o Peripheral blood smear: oval macrocytic cells with hypersegmented neutrophils
o Serum or red cell folate: low
o Serum B12 (to assess level)
```
64
What is the treatment of folate deficiency anaemia?
Folic acid (5 mg of folic daily for 4 months), if B12 deficiency, B12 should be corrected first
65
What is the definition of deep vein thrombosis?
Development of a blood clot in a major deep vein in the leg, thigh, pelvis, or abdomen
66
What is the clinical presentation of deep vein thrombosis?
Asymptomatic, unilateral calf swelling, localised pain along the deep venous system
67
What are the investigations of deep vein thrombosis?
o D-dimer: elevated (but not specific)
| o Proximal leg vein ultrasound: unable to compress lumen
68
What is the treatment of deep vein thrombosis?
Anti-coagulation (apixaban, rivaroxaban, LMWH, fondaparinux)
69
What is the definition of acute myeloid leukaemia?
Malignant clonal expansion of myeloid progenitors in the bone marrow, peripheral blood, or extramedullary tissues
70
What is the aetiology of acute myeloid leukaemia?
Pre-existing haematologic malignancies
71
What is the clinical presentation of acute myeloid leukaemia?
Anaemia (fatigue, breathlessness, angina, pallor), neutropenia (recurrent infections), thrombocytopenia (petechiae, nose bleeds, bruising)
72
What are the investigations of acute myeloid leukaemia?
o FBC: leucocytosis with neutropenia, thrombocytopenia, anaemia
o Peripheral blood smear: blast cells, with the presence of Auer rods (crystalised granules)
o Bone marrow aspirate and biopsy: myeloid blast count of ≥ 20%
73
What is the treatment of acute myeloid leukaemia?
Supportive treatment (blood and platelet transfusions, IV fluids, allopurinol (to prevent tumour lysis syndrome)), chemotherapy, bone marrow transplant
74
What is the definition of acute lymphoblastic leukaemia?
Malignant clonal expansion of lymphoid progenitors in the bone marrow
75
What is the epidemiology of acute lymphoblastic leukaemia?
Under the age of 5
76
What is the clinical presentation of acute lymphoblastic leukaemia?
Anaemia (fatigue, breathlessness, angina, pallor), neutropenia (recurrent infections), thrombocytopenia (petechiae, nose bleeds, bruising)
77
What are the investigations of acute lymphoblastic leukaemia?
o FBC: leucocytosis with neutropenia, thrombocytopenia, anaemia
o Peripheral blood smear: blast cells
o Bone marrow aspirate and biopsy: lymphoblast count of ≥ 20%
78
What is the treatment of acute lymphoblastic leukaemia?
Supportive treatment (blood and platelet transfusions, IV fluids, allopurinol (to prevent tumour lysis syndrome)), chemotherapy, intrathecal chemotherapy (for CNS involvement), bone marrow transplant
79
What is the definition of chronic myeloid leukaemia?
Clonal myeloproliferative neoplasm characterised by abnormal clonal expansion of cells of the myeloid lineage (neutrophils, basophils, eosinophils, and monocytes)
80
What is the aetiology of chronic myeloid leukaemia?
Philadelphia chromosome (t9;22)
81
What is the pathophysiology of chronic myeloid leukaemia?
Excessive activity of the enzyme tyrosine kinase which leads to unregulated cell division
82
What is the clinical presentation of chronic myeloid leukaemia?
Asymptomatic, anaemia (breathlessness, pallor, fatigue), hepatosplenomegaly, night sweats, fever, gout (due to purine breakdown)
83
What are the investigations of chronic myeloid leukaemia?
o FBC: marked leukocytosis (increased neutrophils, monocytes, basophils, and eosinophils), anaemia
o Peripheral blood smear: mature or maturing myeloid cells, elevated neutrophils, basophils and eosinophils
o Bone marrow aspirate and biopsy: hypercellular, granulocytic hyperplasia
o Cytogenetics: Philadelphia chromosome positive
84
What is the treatment of chronic myeloid leukaemia?
Oral imatinib (tyrosine kinase inhibitor), bone marrow transplantation
85
What is the definition of chronic lymphocytic leukaemia?
Malignant clonal expansion of B lymphocytes in the bone marrow
86
What is the clinical presentation of chronic lymphocytic leukaemia?
Asymptomatic
87
What are the investigations of chronic lymphocytic leukaemia?
o FBC: marked lymphocytosis, hypogammaglobulinemia, anaemia, thrombocytopenia
o Peripheral blood smear: smudge cells
o Flow cytometry: clonal lymphocytes
88
What is the treatment of chronic lymphocytic leukaemia?
Observation, supportive treatment (transfusions, steroids for haemolytic anaemia, and human IV immunoglobulins), chemotherapy, bone marrow transplant
89
What is the definition of Hodgkin’s lymphoma?
Malignant proliferation of lymphocytes in the lymph nodes characterised by the presence of Reed-Sternberg cells
90
What is the aetiology of Hodgkin’s lymphoma?
EBV, immunosuppression
91
What is the pathophysiology of Hodgkin’s lymphoma?
Malignant proliferation of lymphocytes, usually B lymphocytes, but also T lymphocytes and natural killer cells, leads to the accumulation of cells in the lymph nodes causing lymphadenopathy
92
What is the clinical presentation of Hodgkin’s lymphoma?
Lymphadenopathy (painless, symmetric, multiple sites, spreads discontinuously), B symptoms (fever, weight loss night sweats), pruritus, lethargy, pain in the neck when drinking alcohol
93
What are the investigations of Hodgkin’s lymphoma?
Lymph node and bone marrow biopsy: Reed-Sternberg cells (mirror image nuclei), in classical Hodgkin’s lymphoma, and popcorn cells in nodular lymphocyte-predominant Hodgkin’s
94
What is the treatment of Hodgkin’s lymphoma?
o Stages IA-IIA: radiotherapy + short courses of chemotherapy
o Stages IIA-IVB (with >3 areas involved): longer courses of chemotherapy
o Relapsed disease: high-dose chemotherapy followed by autologous stem cell transplant
95
What is the definition of Non-Hodgkin’s lymphoma?
Malignant proliferation of lymphocytes, 80% are of B lymphocyte origin, while 20% is of T lymphocyte origin
96
What is the aetiology of Non-Hodgkin’s lymphoma?
Viruses and bacteria, autoimmune disorders, immunodeficiency, and environmental factors, such as pesticides
97
What is the pathophysiology of Non-Hodgkin’s lymphoma?
Malignant proliferation of lymphocytes leads to the accumulation of cells in the lymph nodes causing lymphadenopathy
98
What is the clinical presentation of Non-Hodgkin’s lymphoma?
Lymphadenopathy (enlarged, non-tender, rubbery superficial lymph nodes)
99
What are the investigations of Non-Hodgkin’s lymphoma?
o FBC: pancytopenia
| o Lymph node and bone marrow biopsy: absence of Reed-Sternberg cells
100
What is the treatment of Non-Hodgkin’s lymphoma?
o Low-grade (incurable): radiotherapy (curative in localised disease), chemotherapy, remission maintained by rituximab
o High-grade: R-CHOP chemotherapy, radiotherapy
101
What is the definition of multiple myeloma?
Plasma cell dyscrasia characterised by terminally differentiated plasma cells, infiltration of the bone marrow by plasma cells, and the presence of a monoclonal immunoglobulin or immunoglobulin fragment in the serum and/or urine
102
What is the pathophysiology of multiple myeloma?
Accumulation of malignant plasma cells in the bone marrow which leads to progressive bone marrow failure. The malignant clone of plasma cells can secrete excess amounts of a monoclonal antibody, known as monoclonal paraprotein, and is usually IgG or IgA
103
What is the clinical presentation of multiple myeloma?
o Hypercalcaemia (confusion, bone pain, constipation, nausea, thirst, abdominal pain)
o Renal failure (thirst, nausea, itching, confusion, fatigue)
o Anaemia (shortness of breath, pallor, fatigue), neutropenia (infection), and thrombocytopenia (bleeding)
o Osteolytic bone lesions (backache, bone pain, pathological fractures, vertebral collapse)
104
What are the investigations of multiple myeloma?
o FBC: pancytopenia
o U&E: elevated calcium and alkaline phosphatase
o Peripheral blood smear: Rouleaux formation
o Serum electrophoresis: elevated paraprotein and hypogammaglobulinemia
o Urine electrophoresis: elevated Bence-Jones protein
o Bone marrow aspirate and biopsy: monoclonal plasma cell infiltration in the bone marrow ≥ 10%
105
What is the treatment of multiple myeloma?
Chemotherapy, analgesia, bisphosphonates, bone marrow transplant
106
What is the definition of malaria?
Parasitic infection caused by protozoa of the genus Plasmodium
107
What is the aetiology of malaria?
Bite of a female Anopheles mosquito
108
What is the clinical presentation of malaria?
Fever, anaemia, jaundice, hepatosplenomegaly, black urine, headache, myalgia, fatigue, malaise, diarrhoea, vomiting, abdominal pain
109
What are the investigations of malaria?
o Giemsa-stained thick and thin blood smears: detection of asexual or sexual forms of the parasites inside erythrocytes (thick film tells indicates malaria is present, while thin films identify the species)
o Rapid diagnostic test: detection of parasite antigen or enzymes
110
What is the treatment of malaria?
Artemisinin combination therapies, chloroquine (patients with G6PDD require specialised assessment)
111
What is the definition of polycythaemia vera?
Myeloproliferative, clonal hematopoietic disorder characterised clinically by erythrocytosis, thrombocytosis, leukocytosis, and splenomegaly
112
What is the aetiology of polycythaemia vera?
JAK2 mutation
113
What is the pathophysiology of polycythaemia vera?
The erythroid progenitor offspring are unusual in not needing erythropoietin to avoid apoptosis. This results in the excess proliferation of red blood cells, white blood cells and platelets which causes a raised haematocrit
114
What is the clinical presentation of polycythaemia vera?
Asymptomatic, headache, dizziness, tinnitus, visual disturbances, pruritus after a hot bath, erythromelalgia (burning sensation in fingers and toes), gout, hypertension, angina, intermittent claudication, plethoric complexion (congested or swollen with blood in facial skin), hepatosplenomegaly
115
What are the investigations of polycythaemia vera?
o FBC: erythrocytosis, thrombocytosis, leukocytosis
o Haematocrit: elevated
o JAK2 gene mutation screen: positive
o Serum erythropoietin: low
o Bone marrow biopsy: hypercellularity with prominent erythroid, granulocytic, and megakaryocytic proliferation
116
What is the treatment of polycythaemia vera?
Venesection, hydroxycarbamide, aspirin
117
What is the definition of von Willebrand disease?
Quantitative or qualitative abnormality of von Willebrand factor
118
What is the aetiology of von Willebrand disease?
Mutation in the von Willebrand factor gene
119
What is the pathophysiology of von Willebrand disease?
von Willebrand factor links platelets and exposed vascular subendothelium at sites of vascular injury, and binds and stabilises coagulation factor VIII
120
What is the clinical presentation of von Willebrand disease?
Bleeding from minor wounds, postoperative bleeding, easy and excessive bruising, menorrhagia, mucosal bleeding, epistaxis
121
What are the investigations of von Willebrand disease?
o FBC: normal platelets
o Prothrombin time: prolonged
o Plasma von Willebrand factor: low
122
What is the treatment of von Willebrand disease?
Care when using NSAIDs and anti-platelets, desmopressin (induces von Willebrand factor release), tranexamic acid (controls bleeding)
123
What is the definition of immune thrombocytopenic purpura?
Isolated thrombocytopenia due to autoimmune antibody destruction of peripheral platelets
124
What is the clinical presentation of immune thrombocytopenic purpura?
Easy bruising, epistaxis, menorrhagia, purpura, gum bleeding
125
What are the investigations of immune thrombocytopenic purpura?
o FBC: thrombocytopenia
| o Platelet autoantibodies: positive
126
What is the treatment of immune thrombocytopenic purpura?
o Childhood: usually requires no treatment as it is self-limiting
o Adult: oral corticosteroids, splenectomy, rituximab
127
What is the aetiology of thrombotic thrombocytopenic purpura?
Production of unusually large von Willebrand factor multimers due to a lack of von Willebrand factor cleaving enzyme (ADAMTS-13) or the presence of autoantibodies against the enzyme. Secondary causes of TTP include pregnancy, oral contraceptives, systemic lupus erythematosus, infection, and drug treatment.
128
What is the pathophysiology of thrombotic thrombocytopenic purpura?
Platelets adhere to the von Willebrand factor and microthrombi form. The microthrombi cause end-organ ischaemia, especially in the brain and kidneys, and fragmentation of red blood cells
129
What is the clinical presentation of thrombotic thrombocytopenic purpura?
o Flu-like symptoms (fever, fatigue, arthralgia)
o Microangiopathic haemolytic anaemia (fatigue, dyspnoea, pallor, jaundice)
o Thrombocytopenia (petechiae, purpura)
o Acute kidney injury
o Neurological symptoms (headache, palsies, seizure, confusion, coma)
130
What are the investigations of thrombotic thrombocytopenic purpura?
o FBC: anaemia, thrombocytopenia
o Lactate dehydrogenase: elevated due to haemolytic anaemia
o Peripheral blood smear: microangiopathic blood film with schistocytes
o ADAMTS-13 activity assay: low
131
What is the treatment of thrombotic thrombocytopenic purpura?
Plasma exchange to remove antibodies against ADAMTS-13 and provide a source of the enzyme, corticosteroids to suppression the immune system
132
How is Haemolytic uraemia syndrome different to thrombotic thrombocytopenic purpura?
There are no neurological symptoms or fever and it usually affects children under the age of five following a diarrhoeal disease
133
What is the definition of Haemophilia?
X-linked recessive disorder, which results from the deficiency of clotting factor VIII in Haemophilia A and clotting factor IX in Haemophilia B
134
What is the clinical presentation of Haemophilia?
Bleeding into muscles, mucocutaneous bleeding, hemarthrosis, excessive bruising, fatigue
135
What are the investigations of Haemophilia?
o APTT: prolonged
o Plasma factor VIII assay: low in haemophilia A
o Plasma factor IX assay: low in haemophilia B
136
What is the treatment of Haemophilia?
Avoid NSAIDs and IM injections, desmopressin (in haemophilia A), factor concentrations should be given prophylactically
137
What is the definition of disseminated intravascular coagulation?
Acquired syndrome characterised by activation of coagulation pathways, resulting in formation of intravascular thrombi and depletion of platelets and coagulation factors
138
What is the aetiology of disseminated intravascular coagulation?
Major trauma, organ destruction, sepsis or severe infection, severe obstetric disorders, some malignancies, major vascular disorders, and severe toxic or immunologic reactions
139
What is the clinical presentation of disseminated intravascular coagulation?
Oliguria, hypotension, tachycardia, purpura fulminans, gangrene, acral cyanosis, delirium or coma, petechiae, ecchymosis, haematuria, bruising, renal failure
140
What are the investigations of disseminated intravascular coagulation?
```
o FBC: thrombocytopenia
o PTT: prolonged
o APTT: prolonged
o Fibrinogen: decreased
o D-dimer and fibrin degradation products: elevated
```
141
What is the treatment of disseminated intravascular coagulation?
Treat the underlying cause, platelets, cryoprecipitate, heparin (in severe, non-bleeding patients)
142
What is the aetiology of vitamin K deficiency?
Decreased intake, malabsorption (decreased bile), oral anti-coagulants
143
What is the pathophysiology of vitamin K deficiency?
Vitamin K is an important factor in the synthesis of coagulation factors II, VII, IX and X, and proteins C and S
144
What is the clinical presentation of vitamin K deficiency?
Petechiae, purpura, easy bruising, gingival bleeding, melena, haematuria
145
What are the investigations of vitamin K deficiency?
o PTT: prolonged
| o Serum vitamin K: low
146
What is the treatment of vitamin K deficiency?
Increased vitamin K intake
