Haematological Disorders Flashcards
(30 cards)
Describe hyposplenism
-Causes
-Blood film
-Risk
-Treatment
Causes:
-Splenectomy
-Sickle cell disease
-GI diseases e.g. Coeliac, Crohn’s, Ulcerative Colitis
-Autoimmune disease: Rheumatoid arthritis
Blood film:
-Reveals Howell-Jolly bodies
Risk:
-Risk of sepsis from encapsulated bacteria e.g streptococcus pneumoniae, Haemophilus influenzae
Treatment:
-Patients must be immunised and given life long antibiotic prophylaxis
Describe neutrophilia
-What is it?
-Causes
-An increase in the absolute number of circulating neutrophils
Causes:
-Infection
-Smoking
-Acute inflammation
-Drugs
Describe neutropenia
-Neutrophil count
-Causes (reduced production, increased removal or use)
-Consequences
-Neutropenic sepsis and its treatment
-Neutrophil count <1.5x10^9/L (severe if <0.5x10^9/L)
Causes:
-Reduced production: B12/folate deficiency, aplastic anaemia, radiation, drugs
-Increased removal or use: Immune destruction, sepsis, splenic pooling
Consequences:
-Severe life threatening bacterial/fungal infection
-Mucosal ulceration e.g. painful mouth ulcers
Neutropenic sepsis is a medical emergency, intravenous antibiotics must be given immediately
Describe anaemia
-Definition
-Signs and symptoms
-Anaemia is when the haemoglobin concentration is lower than the normal range.
Signs and symptoms:
-Symptoms: Shortness of breath, palpitations, headaches, claudication, confusion, lethargy, angina
-Signs: Pallor, tachycardia, hypotension
Why might anaemia develop?
-Bone marrow
-Peirpheral RBCs
-Removal
Bone marrow:
-Reduced or dysfunctional erythropoiesis
-Abnormal haem synthesis
-Abnormal globin chain synthesis
Peripheral RBCs:
-Abnormal structure
-Mechanical damage
-Abnormal metabolism
Removal:
-Increased removal by reticuloendothelial system
Describe folate deficiency
-Causes
-Symptoms
-When do you require more folate?
Causes:
-Dietary deficiency
-Disease of duodenum and jejunum (coeliac, Crohn’s)
-Alcoholism
-Drugs which inhibit dihydrofolate
Symptoms:
-Diarrhoea
-Reduced sense of taste
-Numbness and tingling in hands and feet
-Muscle weakness
When do you require more folate?
-Pregnancy
-Increased erythropoiesis
-Severe skin disease
Vitamin B12 deficiency
-Causes
-Symptoms
Causes:
-Dietary deficiency
-Lack of intrinsic factor
-Crohn’s disease
Symptoms:
-Glossitis and mouth ulcers
-Diarrhoea
-Parasthesia
Treatment of vitamin B12 and folate deficiency
-Folate
-Pernicious anaemia
-Other B12 deficiency
Folate:
-Oral folic acid
Pernicious anaemia:
-Hydroxycobalamine intramuscular for life
Other causes of B12 deficiency:
-Oral cyanocobalamine
Appearance of megaloblastic anaemia on blood film
-Anisopoikilocytosis (variance in shape and size)
-Tear drop red cells
-Ovalocytes
-Hypersegmented neutrophils
-Macrocytic red cells
Investigation of megaloblastic anaemia:
-What levels are low?
-What levels are raised?
Low:
-Haemoglobin
-Erythrocyte count
-Reticulocyte count
Raised:
-MCV
-Serum ferritin
-LDH
-Bilirubin
Microcytic Anaemia:
-TAILS
-Thalassaemia
-Anaemia of chronic disease
-Iron deficiency anaemia
-Lead poisoning
-Sideroblastic anaemia
Anaemia of chronic disease
-What is it?
-What is released by immune cells
-Erythropoietin production
-Hepcidin production and its effects
-Overall inhibition
-Anaemia of chronic disease is an inflammatory condition, e.g. rheumatoid arthritis, chronic infection.
-Immune cells release cytokines, e.g. IL6
-Inhibition of erythropoietin production by kidneys
-Increased production of hepcidin by liver -> inhibition of ferroportin -> plasma iron reduced
-This all leads to inhibition of erythropoiesis in bone marrow, therefore -> anaemia
Iron deficiency
-Causes
-At risk groups
-Signs and symptoms
-Treatment
Causes:
-Insufficient iron in diet
-Malabsorption of iron
-Bleeding
-Increased requirement e.g. pregnancy
At risk groups:
-Infants
-Children
-Women of child bearing age
-Geriatric age group
Signs and symptoms:
-Physiological effects: Tiredness, pallor, increased respiratory rate, angina, reduced exercise tolerance
-Epithelial changes: Angular cheilitis, glossitis, koilonychia (spoon nails)
Treatment:
-Dietary advice
-Oral iron supplements
-IV iron
-Blood transfusion
FBC results in iron deficiency anaemia
-Low MCV
-Elevated platelet count
-Normal or elevated WBC count
-Low serum ferritin
-Low reticulocyte haemoglobin cotent (CHr)
Peripheral blood film results in iron deficiency anaemia
-RBCs are microcytic and hypochromic
-Anisopoikilocytosis
-Sometimes pencil cells and target cells
Hereditrary Haemochromatosis
-Mode of inheritance and what it is
-What happens?
-Treatment
-Autosomal recessive disease caused by mutation in HFE gene
-Too much iron enters cells and accumulates in end organs causing damage
-Treat with venesection
Thalassaemia
-Blood smear
-Consequences
-Treatment
Blood smear:
-Hypochromic and microcytic red cells
-Anisopoikilocytosis with frequent target cells and circulating nucleated red blood cells and Heinz bodies
Consequences:
-Extramedullary haemopoiesis
-Reduced O2 delivery causing stimulation of EPO
-Iron overload (major cause of premature death)
-Reduced life expectancy
Treatment of thalassaemia:
-Red cell transfusion from childhood
-Folic acid
-Iron chelation
Sickle cell disease
-Mode of inheritance and mutation
-Region most common
-Amino acid change
-3 crises
-Symptoms
Mode of inheritance and mutation:
-Autosomal recessive disease resulting form a mutation of B-globin gene
Region:
-Black Africans
-Arab
-Mediterranean
-South Asia
Amino acid change:
-GAG codon changed to GTG, causing glutamic acid to be replaced by valine
Crises:
-Haemolytic
-Vaso-occlusive
-Aplastic anaemia
Symptoms:
-Jaundice
-Splenic atrophy
Haemolytic anaemia
-Key laboratory findings
-Signs and symptoms
-Severe consequences
Key lab findings:
-Raised reticulocytes
-Raised bilirubin
-Raised LDH
Signs and symptoms:
-Jaundice and associated risk of complications such as pigment gallstones
-Splenomegaly
Severe consequences:
-Massive sudden haemolysis can cause cardiac arrest and hyperkalaemia
Hereditary spherocytosis
-Shape
-Defects and what they disrupt
-How are cells affected?
Shape:
-Many cells take on spherical shape
Defects:
-Ankyrin, spectrin, protein 4.2 or Band 3 defects disrupt membrane-cytoskeletal interactions
How are cells affected:
-Cells less flexible and more easily damaged
Hereditary eliptocytosis
-Shape
-Defects
-Hereditary Pyropoikilocytosis
Shape:
-Many cells elliptical rather than biconcave disc shape
Defects:
-Spectrin most common defect
-Also defects in band 4.1, Band 3 and glycophorin C proteins
Hereditary Pyropoikilocytosis:
-Severe form of hereditary eliptocytosis
Polycythaemia Vera
-Clinical features
-Management
Clinical features:
-Significant cause of arterial thrombosis
-Venous thrombosis
-Gout
-Haemorrhage into skin or GI tract
-Pruritis (itchy skin)
Management:
-Venesection
-Aspirin
-Manage CVS risk factors
-Sometimes consider drugs to reduce overproduction of cells
Essential Thrombocythaemia
-Clinical features
-What should you screen for?
-Management
Clinical features:
-Excess platelets in blood
-Large and excess megakaryocytes in bone marrow
-Thrombotic events
Screening:
-Screen for Jak2 and CALR mutations
Management:
-Aspirin
-Hydroxycarbomide for >60yrs, platelet count >1500, or disease related to thrombosis/haemorrhage.
Myelofibrosis
-Symptoms
-Treatment
Symptoms:
-Hepatosplenomegaly
-Bruising
-Fatigue
-Weight loss
-Fever
-Portal hypertension
Treatment:
-Supportive
-Some benefits using hydroxycarbamide, folic acid
-Advance disease: Blood transfusions, splenectomy
