Haematology Flashcards
What is pernicious anaemia?
B12 deficiency
What cells in the stomach produce intrinsic factor?
Parietal cells
Where is B12 absorbed?
Ileum
What is the pathophysiology of pernicious anaemia?
Autoimmune - antibodies against the parietal cells or intrinsic factor
What are the symptoms of B12 deficiency?
Peripheral neuropathy
Loss of vibration sense or proprioception
Visual changes
Mood or cognitive changes
What is the management for pernicious anaemia?
Oral cyanocobalamin
If severe: IM hydroxycobalamin
If you have folate and B12 deficiency, which one should you treat first?
B12 first: otherwise it can cause subacute combined degeneration of the cord.
What does the Direct Coombs test test for?
Autoimmune haemolytic anaemia
What is the inheritance pattern in hereditary spherocytosis?
Autosomal dominant
What virus can cause an aplastic crisis in hereditary spherocytosis?
Parvovirus
What is the management of hereditary spherocytosis?
Folate supplementation
Splenectomy
Cholecystectomy if gallstones are a problem
What is the inheritance pattern of hereditary elliptocytosis?
Autosomal dominant
What is the inheritance pattern of G6PD deficiency?
X linked recessive. More common in mediterranean and African patients
What can trigger a crisis in G6PD?
Fava beans, antimalarial primaquine, ciprofloxacin, sulfonylureas, sulfasalazine and other sulphonamide drugs, infections.
What are the two types of autoimmune haemolytic anaemia?
Warm type and cold type (what temperature the antibodies attach themselves - agglutination)
What conditions is cold type autoimmune haemolytic anaemia secondary to?
Lymphoma
Leukaemia
SLE
Infections such as: mycoplasma, EBV, CMV, HIV
What is the management of autoimmune haemolytic anaemia?
Blood transfusion
Prednisolone
Rituximab (monoclonal antibody against B cells)
Splenectomy
What is alloimmune haemolytic anaemia?
Foreign red blood cells causing an immune reaction (transfusion or newborn)
What is paroxysmal nocturnal haemoglobinuria?
Genetic mutation in the stem cells
Realists in loss of proteins on the surface of red blood cells that inhibit the complement cascade -> complement cascade is activated and RBCs are destroyed
What is the characteristic presentation of paroxysmal nocturnal haemoglobinuria?
Red urine in the morning
Also:
Anaemia
Predisposed to thrombosis and smooth muscle dystonia (e.g. oesophageal spasm and erectile dysfunction)
What is microangiopathic haemolytic anaemia secondary to?
Haemolytic uraemia syndrome
DIC
Thrombotic thrombocytopenia purpura
SLE
Cancer
Myeloma is a cancer of which cells?
Plasma cells (the B lymphocytes that produce antibodies)
What are Bence Jones proteins
Light chains of antibodies found in the urine of patients with myeloma
What causes renal impairment in patients with myeloma?
High levels of immunoglobulins can block flow
Hypercalcaemia
Dehydration
Bisphosphonates
Raised plasma viscosity in myeloma can cause what?
Easy bruising
Easy bleeding
Reduced or loss of sight due to vascular disease in the eye
Purple discolouration to the extremities
heart failure
What does CRAB stand for in myeloma?
Calcium (elevated
Renal failure
Anaemia
Bone lesions/pain
What are the risk factors for myeloma?
Older age
Male
Black African ethnicity
Family history
Obesity
What investigations do you do for myeloma? (BLIP)
Bence Jones protein (request urine electrophoresis)
L - Serum free light chain assay
I - Serum Immunoglobulins
P- Serum Protein electrophoresis
Bone marrow biopsy
What are the x-ray signs in myeloma?
Punched out lesions
Lytic lesions
‘Raindrop skull’
What is the first line management for myeloma?
Chemo: Bortezomid, Thalidomide, Dexamethasone
VTE prophylaxis if on thalidomide
What is the management for myeloma bone disease?
Bisphosphonates (suppress osteoclasts activity)
Radiotherapy
Orthopaedic surgery
Cement augmentation (injecting cement into vertebral fractures)
What is myelofibrosis?
Fibrosis of the bone marrow, due to cytokines released from he proliferating cells
Why does myelofibrosis cause organomegaly?
Extramedullary haematopoiesis has to happen in the liver and spleen. Can cause portal hypertension or spinal cord compression
What are the signs of polycythaemia vera?
Conjunctival plethora (redness
A ruddy complexion
Splenomegaly
What can a blood film look like in myelofibrosis?
Teardrop-shaped RBCs, varying sizes of RBCs (poikilocytosis) and immature red and white cells.
How do you diagnose myelofibrosis
Bone marrow biopsy: dry bone marrow on aspiration
What is the difference between myeloproliferative disorders and myelodysplastic syndrome?
Myeloproliferative: one stem cell is proliferating much more than it should
Myelodysplastic: myeloid bone marrow cells not maturing properly and so low levels of the cells that should be being produced
What can myelodysplastic and myeloproliferative syndromes transform into?
Acute myeloid leukaemia
What does myelodysplastic syndrome present with?
Anaemia/neutropenia/thrombocytopenia.
Often have a history of chemo or radiotherapy and are over 60.
Confirmed on bone marrow aspiration and biopsy
What is the most common inherited cause of abnormal bleeding?
Von Willebrand disease
What is the inheritance pattern of VWD?
Autosomal dominant
What is VWF?
A glycoprotein
What is the management of VWD?
Desmopressin - can stimulate the release of VWF
Infused VWF +/- factor VIII
Women with heavy periods: tranexamic or mefanamic acid, norethisterone, COCP, Mirena,
What can affect the production of platelets?
Sepsis
B12 or folate def.
Liver failure causing reduced thrombopoietin production
Leukaemia
Myelodysplastic syndrome
What can cause the destruction of platelets?
Medications (sodium valproate, methotrexate, isotretinoin, antihistamines, proton pump inhibitors)
Alcohol
ITP
Thrombotic thrombocytopenia purpura
Heparin-induced thrombocytopenia
HUS
What platelet count is at high risk for spontaneous bleeding?
Below 10 x 10tothe9
What is the pathophysiology of thrombotic thrombocytopaenic purpura?
Tiny blood clots form in the small vessels, using up platelets. A microangiopathy.
These develop due to a shortage in the protein ADAMTS13 (either due to genetic mutation or autoimmune disease).
This protein normally inactivates vWF and reduced platelet adhesion and clot formation.
What is the management for thrombotic thrombocytopaenic purpura?
Plasma exchange
Steroids
Rituximab
What is the pathophysiology of heparin induced thrombocytopenia?
Antibodies are formed against platelets in response to exposure to heparin.
These antibodies activate clotting mechanisms and lead to thrombosis, as well as breaking down platelets.
A surprising picture of a patient on heparin with low platelets forming unexpected blood clots.
