Flashcards in general haem Deck (66):
What is term for primary polycythaemia?
polycythaemia rubra vera
how can we differentiate primary and secondary polycythaemia on blood test?
high EPO= secondary polycythaemia whereas normal EPO for primary polycythaemia
what is the type of disease is polycythaemia rubra vera?
what are 2 causes of a high haematocrit?
reduced plasma volume (dehydration) and polycythaemia
what are some causes of secondary polycythaemia
• Living at high altitudes
• Tumours like posterior cranial fossa, renal cell carcinoma
• Cyanotic congestive heart disease- R to L shunts (tetratology of fallot)
• (bad lung disease)
• High affinity variance (changes O2 affinity to Hb)
• Hereditary persistence of HbF
is there any increased risk of thrombosis in secondary polycythaemia?
what drugs/foods can cause oxidative haemolysis?
what can cause eosinophillia on FBE?
1. Parasitic infections
3. small cell vasculitis- chugg strauss
what is paroxysmal nocturnal haemoglobinuria?
acquired clonal defect of red cells that results in production of erythrocytes with an increase susceptibility to lysis by complement.
-Patients intermittently pass bloody urine, more frequently at night
- associated with increase thrombotic risk
what are the three conditions that constitute myeloproliferative disorders?
what is a mutation commonly associated with them?
what do they predispose?
1. polycythaemia rubovera
2. Essential thrombocythaemia
predispose acute myeloid leukaemia
what is the difference between myelodysplastic disorders and myeloproliferative disorders?
Myelodysplastic syndrome is ineffective maturation whereas myeloproliferative neoplasm is an overproduction of mature cells.
oxygen saturation equation?
CO x [Hb] x %saturation x 1.34
what are some general features/symptoms of myeloproliferative disorders?
digital ischaemia and gangrene
pruritis after exposure to water
what are the 4 groups of causes of pancytopenia
1. Ineffective erythropoesis (megaloblastic anaemia, AIDS)
2. Increased peripheral destruction (SLE)
3. Bone marrow infiltration (leukaemia)
4. Bone marrow failure (drugs)
what happens when you have RhD+ve autoantibodies passing to the unborn child (from rhesus d neg mother to rhesus d positive baby)
haemolytic disease of the newborn
what is the difference between Group and Hold and crossmatched blood?
take patient's blood and order Group and Hold.
what is the difference between bone marrow aspirate and trephine?
how might anti thrombin 3 be pathologically/iatrogenically reduced?
nephrotic syndrome, plasma exchange and asparaginase chemotherapy drugs
what causes hyperviscosity?
1.very high red cell count (polycythaemia)
2.high white cell counts (e.g. leukaemias)
3.high paraprotein content like myeloma
4.drugs- OCP, EPO, chemo, diuretics, IVIg
what do we mean by venesection? when might we do this?
removal of blood for treatment
for conditions like haemachromatosis and high blood viscosity syndrome
general cause of hypersplenism?
sequestering abnormal blood cells in the spleen
what do you think when you see small white nodules affecting the entire parenchyma of the spleen (pathology)
what constitutes an Fe study?
does haemolytic anaemia cause dark urine?
would you be worried about a slightly elevated platelet count in the setting of inflammation/infection?
no bc platelets are an acute phase reactant
what consists of haemoglobinopathy?
Sickle cell anaemia
what is the mutation in sickle cell anaemia?
glutamate to valine in position 6 of the beta chain
where are B thalassaemias most prevalent?
where are A thalassemias most prevalent?
what is HbH
tetramer of beta chains
what are normoblasts?
what is the difference between haemosiderin and ferritin?
haemosiderin= insoluble iron protein complex
ferritin= soluble iron protein complex
what is aplastic anaemia?
pancytopenia with hypocellularity in the bone marrow
what is haemophilia A also known as?
factor 8 deficiency
what is haemophilia B also known as?
factor 9 deficiency
what is the inheritance pattern of haemophilia A
x linked recessive
how many types of VWF disease is there?
Type 1: not enough VWF
Type 2: malformed VWF
Type 4: no VWF
what is the mutation involved in factor 5 leiden disease?
Factor V Leiden differs from normal factor V by a single
nucleotide substitution (Arg506Gln). This variation makes
factor V less likely to be cleaved by activated protein C.
--> increases likelihood of thrombosis
is anti-thrombin deficiency an inherited or an acquired condition?
it is BOTH
inherited and acquired
how many porphyria conditions are there? which is the most common?
8 porphyria conditions
Porphyria cutanea tarda is the most common
what is porphyria?
condition that affects haem synthesis, due to deficient enzymes. You get a build of porphyrins which is toxic to the body
what is the pathophysiology of porphyria cutanea tarda, PCT?
UROD deficiency (uroporphyrinogen decarboxylase).
symptoms and signs of porphyria cutanea tarda?
• Blistering skin lesions in sun exposed areas
• Skin hyperpigmentation
• Red urine
- excess iron deposition
What is the inheritance pattern like for porphyria cutanea tarda?
autosomal dominant or SPORADIC (most are sporadic)
how to manage porphyria cutanea tarda?
- avoid alcohol, oestrogen and UV sunlight
- phlebotomy to remove iron excess
triggers for ITP?
1. Medications- Quinine (Gin and Tonic)
2. Viral infection- EBV, CMV, HIV
3. Lymphoproliferative disorders (B cell CLL/NHL)
4. Connective tissue disorders
what is ITP
autoimmune destruction to platelets
management of ITP
• Remove the trigger
• Intravenous immunoglobulin (IVIg) (often combined with steroids INTRAGAM)
• Anti CD20 Rituximab
• Thrombopoietin receptor agonist
Ix for ITP
• FBE and blood film
• Viral screening
• Screen for lymphoma if relevant
Anti platelet antibody tests NOT usually relevant
pentad for TTP
2. Microangiopatic haemolytic anaemia
3. Neurologic abnormalities
4. Renal failure
what are the two key findings on blood film for TTP?
1. evidence of microangiopathy with red cell fragmentation
triad for TTP?
3. Elevated LDH
what can trigger TTP?
It can be triggered by viral infection, shigellosis, pregnancy and malignancy
but mostly IDIOPATHIC
What deficiency is associated with TTP
ADAMTS13 deficiency --> leading to inability to cleave VWF precursor leading to micro thrombi formation
what is the key difference between DIC and TTP?
DIC is due to activation of the clotting cascade --> micro thrombi whereas TTP does not activate the clotting cascade
DIC- low fibrinogen prolonged APTT time
TTP- normal fibrinogen levels, normal APTT/PT time
DIC = abnormal clotting (micro thrombi) and haemorrhage
TTP= just micro thrombi
what is the mainstay treatment of TTP?
plasmapheresis + FFP
what part of the coagulation pathway does APTT look at?
intrinsic (TT is played indoors)
what part of the coagulation pathway does PT/INR look at?
extrinsic (tennis is played outdoors)
what coagulation study change can indicate VWF disease?
raised APTT levels and decreased levels of VWF antigen
what are some symptoms that make you suspicious of VWF disease?
epistaxis, bleeding gums, mucocutaneous bleeding
treatment of type 1 VWF disease?
why do we get haemorrhage in DIC?
consumption of clotting factors
do you treat B12 deficiency anaemia with blood transfusion?
NO. use IM hydroxycobalamin
what are the inherited thrombophillia disorders?
1. Factor 5 leidin mutation
2. Protein C and S mutation
3. Prothrombin mutation
4. Anti-thrombin 3 deficiency
what are the acquired thrombophilia disorders?
1. Anti phospholipid disorder