Haematology Flashcards
What do both the extrinsic and intrinsic pathways activate
Activate factor X
What does the activation of factor X lead to?
The conversion of prothrombin into thrombin
What does thrombin do
Converts fibrinogen to fibrin which triggers activation of factor XIII to stabilise clot
What is a stable clot formed by?
Activated platelets, fibrin and factor XIIIa
What factors does haemophillia type A and type B affect?
Type A- factor VIII
Type B- factor IX
How would haemophillia effect a coagulation screen?
Cause an isolated increase in APTT
What mutation is on the most common thrombophillia?
Factor V mutation which causes resistance to inactivation by protein C.
What factor does Von Willebrand factor transport
Transports factor 8
Treatment for febrile non-haemolytic transfusion reactions
Slow the transfusion and give 1mg paracetamol
When does the intrinsic pathway become activated?
When blood is exposed to collagen (due to vascular damage), the intrinsic pathway is initiated and factor XII is converted to ‘activated Factor XII’ (factor XIIa)
When does the extrinsic pathway become activated?
When tissue factor comes into contact with blood, activating factor VII
What can cause ferritin to rise?
Acute infection/illness
Describe hepcidin and its function?
A major regulator of iron uptake, produced in the liver in response to iron load and inflammation.
Binds to ferroportin and causes degradation
Iron therefore trapped in duodenal cells and macrophages
Hepcidin levels decrease when iron deficient
What is the treatment for autoimmune haemolytic anaemia
Corticosteroids
Treatment for Von Willebrand’s disease?
Desmopressin- causes the release of VwF
How long is treatment for an unprovoked DVT?
6 months
How long is treatment for a provoked DVT?
3 months
How long is treatment for DVT in patients with active cancer?
3-6 months
What do Howell-Jolly bodies suggest?
Represent DNA material of red cells usually removed by the spleen so show hyposplenism
When are target cells seen?
Obstructive liver disease, haemoglobinopathies, and post splenectomy
What does G6PD deficiency cause?
Haemolytic anaemia
What inheritance pattern is G6PD deficiency?
X-linked recessive
How do you reverse the effects of warfarin?
IV vit K and prothrombin complex
What is the inheritance pattern of Haemophilia A?
X linked recessive
What are heinz bodies seen in?
G6PD deficiency (heinz beans -> fava beans -> G6PD)
When is there likely a polyclonal increase in plasma cells?
Infection
When is there likely a monoclonal increase in plasma cells?
Malignancy eg multiple myeloma
What are smudge cells seen in?
Chronic Lymphocytic Leukaemia
How can you tell the difference between chronic and acute myeloid leukaemia
Acute= thrombocytopenia
Chronic= normal or raised platelets
Characteristics of chronic myeloid leukaemia?
Massive splenomegaly
Raised RBC, WBC and platelets
Which vitamin can vegans be deficient in?
B12
What kind of drug is methotraxate
Folate antagonist so should always be prescribed with folic acid supplements
What are teardrops seen in?
Myelofibrosis
Where does extravascular haemolysis occur?
In the spleen
1st line treatment for VwF disease?
Desmopressin
Why could you get you frontal bossing and hepatosplenomegaly in Beta Thal major in children?
As the beta chains are defective, fetal haemoglobin in made to compensate and this is made in abnormal locations such as the skull or spleen
What does G6PD deficiency present as?
Acute haemolytic anaemia
What are target cells seen in?
Beta Thal
Sickle Cell
Hyposplenism
Liver disease
What is seen in biopsy of Hodgkin’s lymphoma?
Reed-sternberg cells
What are spherocytes seen in?
Hereditary spherocytosis
Autoimmune haemolytic anaemia
What are howell-jolly bodies seen in
Hyposplenism
What are Heinz bodies seen in?
G6PD deficiency
Alpha thal
What are schistocytes seen in?
Intravascular haemolysis
Mechanical Heart valve
DIC
How does sideroblastic anaemia happen?
A red cell fails to completely form haem leading to iron deposits in the mitochondria
Sufficient iron but ineffective erythropoiesis causes deposition of iron in multiple organs.
What is a common cause of sideroblastic anaemia
alcohol
What is the investigation for autoimmune haemolytic anaemia?
Coombs test
What triggers G6PD deficiency crises?
Jaundice and anaemia after medication, infection or eating fava beans
Which ethnicities is G6PD most common?
Middle Eastern, Mediterranean and african
What is the Ann Arbor staging system used to classify?
Hodgkin’s Lymphoma
What are Auer rods seen in?
Acute Myeloid Leukaemia
What are smudge cells seen in?
Chronic lymphocytic leukaemia. In CLL lymphocytes are fragile so damage easily on prep
What blood cancer can present asymptomatically with a high WCC?
chronic lymphocytic leukaemia
What is the first factor to be activated in the intrinsic pathway?
Factor 12
What is the first factor to be activated in the extrinsic pathway?
Factor 7. Has the shortest half life of all the factors of the coag cascade
What can cause anaemia of chronic disease?
Inflammatory conditions such as rheumatoid arthritis, diabetes
What is microscopic haemolytic anaemia? (MAHA)
Haemolytic anaemia caused by factors in small blood vessels eg HUS, DIC, TTP
What does Waldenström macroglobulinaemia present with?
Signs of hyperviscosity: headaches, blurred vision, papilloedema, ischaemic stroke, venous thromboembolism
Signs of anaemia
Signs of thrombocytopenia
B symptoms
What are macroovalocytes and hypersegmented neutrophils seen in?
Vitamin B12 or folic acid deficiency
How can TACO lead to pulmonary oedema?
When patients with chronic oedema and high cardiac output are given a large volume overload = pulmonary oedema
How does TRALI occur?
Anti- leucocyte antibodies present in donation bind to the patients white cells and degranulation of the affected neutrophils in the lungs causing lung injury. Pulmonary infiltrates are seen on CXR.
What are red cells that have lost their central pallor?
Spherocytes
How does a aplastic crisis arise?
Patients with sickle cell <16 as result of parvovirus B19 reducing erythropoiesis
What typically cause HUS?
Shiga toxin
What is polycythaemia rubra vera characterised by ?
Erythrocytosis so increased Hb
Management of Waldenstrom’s
Plasmapharesis to filter IgM
Which blood type is the universal donor
O negative because no antigens (A,B or D)
Which blood type is the universal recipient?
AB+ because no antibodies
Diagnostic test for multiple myeloma?
Bone marrow aspirate and trephine biopsy
How could total biliary obstruction lead to bleeding/prolonged INR?
Deficiency in fat soluble vitamins eg K,D,E,A and fat malabsorption so greater INR
Best diagnostic test for polycythaemia rubra vera?
Jak 2 mutation status
Which antibodies in cold autoimmune haemolytic anaemia?
IgM
An acute haemolytic transfusion reaction is mediated by which antibody?
IgM -> activate the complement system
Treatment for warm autoimmune intravascular haemolysis?
Prednisolone
Which antibodies in warm autoimmune haemolytic anaemia?
IgG
Where is most iron absorbed and in what state?
In the duodenum in the Fe2+ state (ferrous form)
What is aplastic anaemia?
Normochromic, normocytic anaemia with pancytopenia and hypoplastic bone marrow
In both B12 and folate deficiencies which one must be treated first?
Vit B 12 to avoid subacute degeneration of the spinal cord
Management of B12 deficiency?
1mg IM hydroxocobalamin 3 times each week for 2 weeks then once every 3 months
What is a sequestration crisis?
Blood pool in organs due to sickling eg splenomegaly, causes worsening anaemia due to loss of blood in vasculature and increase in reticulocytes as body compensates for loss
What would bloods show in an aplastic crisis?
Sudden drop in Hb with pancytopenia
What does haptoglobin do?
Bind to free haemoglobin so low haptoglobin level in haemolysis
Hypersegmented neutrophils are seen in what disease?
Megaloblastic anaemia
What is imatinib and what is it used for?
A tyrosine kinase inhibitor- first line treatment of CML
What can be used for patients with repeated painful sickle cell crises?
Hydroxyurea
ADAMTS-13 is associated with what?
Thrombotic thrombocytopenic purpura
TACO symptoms?
SOB and hypertension
Target action of ritixumab?
Monoclonal antibody that targets CD20. Important in the maturation of B cells into plasma cells
Why are blood products irridiated?
To avoid transfusion associated graft vs host disease
Most common organism implicated in neutropenic sepsis?
Staph epidermidis- gram positive coag negative
Primary AL amyloidosis is due to what?
Protein deposition due to excess production of monoclonal immunoglobulin light chains
Secondary AA amyloidosis is due to what?
Associated with inflammatory conditions involving chronic inflammation/infection.
Protein deposition due to excess production of serum amyloid A an acute phase protein
Pentad of symptoms in thrombotic thrombocytopenic purpura?
Fever, haemolytic anaemia, thrombocytopenia, acute renal failure and neurological symptoms
What does prothrombin complex replace?
Vit K clotting factor used in bleeding on warfarin
Lymph node presentation of hodgkin’s lymphoma?
Painless, rubbery cervical nodes
When does LDH increase?
In haemolytic anaemia due to increased response by bone marrow to increase red cell production
What is serum iron
Measures the serum iron levels in the blood- represents iron almost completely bound to transferrin
What is TIBC
Measures the blood’s ability to attach itself to iron and transport it around the body
What is serum ferritin
The bodies ability to store iron
How does LMWH work?
Activates anti-thrombin-> activates factor Xa -> stops conversion of prothrombin to thrombin-> which stops fibrinogen to fibrin to reduce blood clotting
What are pappenheimer bodies seen in?
Sideroblastic anaemia
