Haematology Flashcards
Sites of extramedullary haematopoiesis
Liver + spleen
also in utero
Types of bone marrow
Red + yellow (can convert into red)
Causes of splenomegaly
Infections: bacterial, viral, parasitic
Haem: haemoglobinopathes, haemolytic anaemias
Haem malignancies
Congestive: liver cirrhosis, RVF, thrombosis of portal/ hepatic/ splenic veins
Trauma: intracapsular haematoma
Infiltrative
Effects of hypersplenism
-poenias and release of immature blood cells
Which microbes are asplenic patients vulnerable to? Why?
Encapsulated bacteria (Neisseria meningitides, Strep pneumoniae, Haemophilus influenzae)
Spleen main site of IgM site for opsonisation of encapsulated organisms
Interventions for asplenic patients
Pneumococcal (boosters every 5-10 years) Haemophilus influenzae course Meningococcal vaccines Influenza (annually) Lifelong prophylactic abx, eg Pen V or erythromycin
Causes of microcytic anaemia
Iron deficiency (hypochromic)
Anaemia of chronic disease (sometimes normocytic)
Thalassaemia
How long should iron supplements be taken for?
3 months+ to replenish stores
Causes of megaloblastic anaemia
Folate and B12 deficiencies - must be co-administered
Which has smaller supplies: B12 or folate?
Folate
What is usually damaged in pernicious anaemia?
Gastric parietal cells (causing failure of IF secretion)
Common causes of B12 deficiency in elderly
Malabsorption as pH of stomach too high (eg PPI, H.pylori)
Metformin use
Most common anaemia in hospitals
Anaemia of chronic disease (usually normocytic, normochromic). Can be microcytic.
extravascular vs intravascular haemolysis
Extra: enhanced rate of RBC breakdown (eg hyperspelenism) - usually less severe, more gradual
Intra: destruction of RBCs within circulatory system, cytoskeletal defects
Both show increased bili, increased reticulocytes
Intravas also causes haemoglobinuria, haemosiderin in urine
What does sickle cell provide protection against?
Plasmodium falciparum
Why is it important to diagnose beta-thalassaemia trait?
May wrongly be diagnosed with Fe-deficiency anaemia: inappropriate Fe therapy
Why does thalassaemia cause hair on end skull appearance?
Extramedullary haemopoiesis causes (hepatosplenomegaly and) expansion of marrow cavities in cortical bone. also causes more fractures
What are myeloproliferative disorders?
Excessive proliferation of one or more specific cell lines from myeloid pregenitor. These cells retain ability to mature and differentiate normally.
Usually indolent course.
E.g. polycythaemia rubra vera
NON-MALIGNANT (but have potental to evolve into AML)
Which gene mutation is present in myeloproliferative disorders?
JAK2 gene mutation (can differentiate from secondary polycythaemia)
Presentation of polycythaemia rubra vera
Plethora
Splenomegaly/ hepatomegaly
Risk of thrombosis
Define myelodysplastic disorders
Clonal proliferation of myeloid cells that mature abnormally/ incompletely
(usually disease of elderly)
What is acute vs chronic in terms of haem malignancies?
Acute: immature blast cells
Chronic: more mature cells
Why do leukaemias often cause cytopenias?
Marrow being taken up
Most common adult acute leukaemia?
AML
Most common childhood cancer?
ALL
Which malignancy causes alcohol-induced pain?
Pathognomic for Hodgkins
Reed-Sternberg cells are associated with
Hodgkins
Most common adult leukaemia
CLL
Clinical features of multiple myeloma (and mnemonic)
CRAB Calcium Renal (impairment): dehydration, NSAIDs for bone pain, hypercalcaemia, Bence-Jones... anaemia (normochromic, normocytic) Bones
Blood tests you might request in haem malignancies
Serum lactate dehydrogenase
Serum urate
Why give FFP instead of packed red cells?
Clotting factors
In which transfusion reaction can you continue infusing?
Febrile non-haemolytic: fever/ rigors in hours - slow and give paracetamol
What is classed as anaemia
under 13g/dl men, 12 g/dl women
triad in plummer-vinson syndrome (aka Paterson-Kelly-Brown)
iron-deficiency anaemia, oesophageal webs, dysphagia
replace fe and endoscopic dilatation
higher risk of developing oesophageal ca
why should you be careful interpreting iron results in hospital
ferritin is an acute phase protein so may be falsely elevated
what is sideroblastic anaemia
congenital or acquired form of anaemia with dysfunctional erythropoiesis
iron deposition in RBC precursors leads to formation of ringed sideroblasts
iron studies will show high Fe
antifolate drugs
phenytoin, methotrexate, trimethoprim
how to replace folate and B12
folate: 5 mg daily for 3 weeks, followed by weekly dose
B12: loading regime of 6 doses.
then 1 mg every week for 2 weeks
then 1 mg every 3 months
when do you see Heinz bodies?
G6PD deficiency
when do you see prickle cells?
Pyruvate kinase deficiency
what blood abnormality can be caused by heparin?
thrombocytopenia
what will be abnormal in bloods of haemophilia A?
prolonged APTT
reduced factor VIII
which factor is low in haemophilia B?
factor IX
what do bloods show in vWB disease?
prolonged APTT and PT
what do bloods show in vit K deficiency?
prolonged APTT and PT
when are Auer rods seen?
Aml
when are smudge cells seen?
cml
in anaemia, rate for prescribing packed cells?
1 unit at a time, usually over 2h
rate for infusing unit of FFP, cryoprecipitate or platelets
30 mins
universal donor for FFP
AB Rh -
