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if a lady has rheumatoid arthritis and a large spleen and is anaemic, what is the diagnosis?
felty's syndrome with pancytopenia
what are fragment cells (schistocytes) and what are the causes of getting them in the blood film?
- damaged RBC which have resealed their cell membrane
- causes: prosthetic heart valve, renal dialysis, microangiopathic haemolytic anaemia eg in DIC
if a boy with lead poisoning is anaemic, what is the diagnosis, explain?
- siderblastic anaemia
- lead inhibits the enzyme involved in HAEM synthesis causing anaemia
what are the causes of sideroblastic anaemia?
- congenital: x-linked, rare
- acquired: myelodysplastic disorder, after chemo or radio, alcohol, lead excess, antiTB drugs
- ineffective erythropoiesis leading to increased iron absorption and iron loading in BM, haemosiderosis (iron deposition in endocrine, liver, heart leading to damage)
what is the blood film and bone marrow film in siderloblastic anaemia?
- blood: hypochromic RBC
- BM: ring sideroblasts - erythroid precursors with iron deposited in mitochondria in a ring around the nucleus
what is the treatment of sideroblastic anaemia?
- treat cause
- repeat blood transfusion if severe anaemia
what is anisocytosis and when is it seen?
- variation in RBC size
- megaloblastic anaemia, thalassaemia, IDA
what is poikilocytosis and when is it seen?
- variation in RBC shape
- IDA, myelofibrosis, thalassaemia
On a blood film, what are pencil cells a feature of?
in which situations is the platelet count likely to DROP?
what is the normal daily iron requirement for adults and where is it absorbed?
what are the characteristic features of myelodysplastic disorders?
increased BM cellularity and dysplasia
what are the main differences between myelodysplastic disrobers and myeloproliferative disorders?
- myelodysplastic: spleen is not enlarged, blood count low, no basophilia
- myeloproliferative: spleen enlarged, high blood count, basophilia
what percent of AML myeloblasts have Auer rods?
what are the symptoms of AML?
- marrow failure: anaemia, infection, bleeding
- infiltration: hepato splenomegaly, gum hypertrophy
why must APML be identified early?
- theres release of thromboplastin (TF + PL) which can set off DIC
- this can be prevented using all-transretinoic acid so good prognosis
what is the translocation of APML?
which age group does AML affect the most?
if there is dietary deficiency of vitamin B12 what is the treatment?
50mcg ORAL hydrocobalamin daily!
why do many patients with HIV have B12 deficiency?
abnormal small intestine flora so less absorption
how long do our body stores of B12 last?
what is b12 needed for?
thymidine synthesis hence DNA
what are the causes of B12 deficiency?
- dietary - vegans
- malabsorption: stomach = pernicious anaemia, gastrectomy, terminal ileum = ileal resection, Crohns, bacterial overgrowth (HIV), tropical strue (tapeworm)
- congenital abnormalities in metabolism
why do you get lemon tinge skin in B12 deficiency
- combo of jaundice from haemolysis
- pallor from anaemia
what is subacute combined degeneration of the spinal cord?
- subacute: insidious onset with peripheral neuropathy due to low B12
- combined: i.e. symmetrical dorsal column loss (sensory and LMN signs) and symmetrical corticospinal tract loss (motor and UMN signs)
what is the triad seen in subacute combined degeneration of the spinal cord?
- extensor plantars (UMN)
- absent knee jerks (LMN)
- absent ankle jerks (LMN)
what are the causes of megaloblastic anaemia?
- B12 deficiency
- folate deficiency
in RA with enlarged spleen, what is the syndrome and what is the cause of anaemia?
- felty's syndrome
- pancytopenia with hypocellular bone marrow
what are 3 causes of avascular necrosis e.g. of femoral head?
- perthes disease
- sickle cell
- steroid use
What are burr cells and when are they seen?
- irregularly shaped cells
- uraemia - kidney
what are howell jolly bodies?
- DNA nuclear remnants in RBCs
- normally removed by spleen
when are howell jolly bodies seen in the circulation?
- post splenectomy
- hyposplenism - e.g. sickle cell disease, coeliac disease, congenital, IBD, myeloproliferative disease, amyloid
What are the causes of a normocytic anaemia?
- anaemia of chronic disease
- renal failure
- bone marrow failure - aplastic anaemia
- acute blood loss
what are the causes of non megaloblastic macrocytic anaemia?
- cytotoxics - hydroxyurea
- haemolysis - reticulocytosis
- marrow infiltration
- antifolate drugs - e.g. phenytoin
what are the causes of warm AIHA?
- autoimmune conditions: SLE
- CLL, lymphomas, methyldopa
what is the treatment of warm AIHA?
- remove cause
how is warm AIHA diagnosed?
direct antiglobulin test (Coombs')
what does the blood film of AIHA look like?
spherocytes as macrophages remove part of RBC membrane
what are the causes of cold AIHA?
- infection: mycoplasma pneumoniae
what are the features of cold AIHA?
what is the treatment of cold AIHA?
which drugs can cause haemolytic anaemia?
- penicillin: binds to RBC membrane and so an antibody to the drug will destroy the RBC
- quinine: production of immune complexes
what is the treatment for APML?
ATRA to reduce DIC, gets through differentiation block
what is the differential diagnosis for parotid gland enlargement?
- ALL infiltration
What are the most common reasons for a hypercoagulable state? inherited or acquired?
acquired: trauma, pregnancy
what are the inherited causes of a thrombophilia state?
- factor V leaden: disrupts action of protein C!
- antithrombin deficiency
- protein C and S deficiency
what are the acquired cause of thrombophilia?
- 1. essential thrombocythaemia: lots of platelets (both ATE and VTE)
- 2. anti-phospholipid syndrome: anti cardiolipin and lupus anticaog (both ATE and VTE)
- 3. homocystinaemia
- 4. polycythaemia: sluggish flow
how can you get a macrocytic anaemia in coeliac disease?
Give some examples of when you would see thrombocytopenic purport
- immune mediated thrombocytopenia: infectious mononucleosis, gold therapy, SLE
- purport in chronic alcoholism: BM suppression so less platelets made
what are the purpura seen in Henoch-Schonlein purpua due to? and where in the body are they typically found?
- small vessel vasculitis
- non blanching
- buttocks and extensor surfaces
who does Henoch-Schonlein purpua normally affect?
where are the features of Henoch-Schonlein purpua?
- joint pain
- acute abdomen
where is folate absorbed?
duodénum and jéjunum
what is the difference between folate stores and B12 stores?
- folate: short - 2-3wks
- B12: long - many months (up to 4 yrs.)
what are the causes of folate deficiency?
- poor diet: low green veg
- malab: coeliac
- drugs: phenytoin, sodium valproate, methotrexate, trimethoprim
what happens if give folate supplements without checking B12 levels?
subacute combined degeneration of the spinal cord
when do you see Heinz bodies? how formed?
- G6PD deficiency (xlinked african and med men)
- formed from oxidised denatured Hb during oxidative crises
what triggers the attacks in G6PD deficiency?
- oxidative stress eg sepsis
- drugs: primaquine (used to treat malaria), sulphonamides, aspirin
- fava beans (med)
what does the blood film of G6PD deficiency look like?
- bite cells: following removal of Heinz
- Heinz bodies: formed from oxidised denatured Hb
- nucleated RBC
which infections are sickle cell patients specifically susceptible to and why?
- encapsulated organisms eg Strep pneumo, H. influenzae and N.Meningitidis
- these are normally removed by spleen
- but in sickle - splenic infarction and some have splenectomy.
name 2 different types of anaemia when you see spherocytes on blood film
- hereditary spherocytosis: auto doom, most common inherited haemolytic anaemia in N.europe
how is the diagnosis of hereditary spherocytosis made?
osmotic fragilité tests: increased RBC osmotic fragility in hypotonic solutions
what are 5 features of hereditary spherocytosis?
- 1. haemolytic crises with bad jaundice
- 2. aplastic anaemia
- 3. folate deficiency due to increased BM requirement
- 4. pigment gall stone
- 5. leg ulcers
which chromosome is B globin on?
what are the features of B thal trait?
- asymp or mild microcytic anaemia
- often confused with IDA
what are the features of B thal intermedia?
- moderate anaemia
- maybe splenomegaly
what are the features of B thal major? (cooleys)
- severe anaemia
- HbA absent
- extramedullary haematopoiesis - frontal bossing,
- life long transfusions needed
- haemochromatosis - DM, hypopit, cardiac, liver toxicity
what are the features of skull XR in B thal major?
hair on end skull XR
which chromosome is a globin on?
what are the features of a thalassaemia with 1 gene deletion?
what are the features of a thalassaemia with 2 gene deletion?
- low MCV
- asymptomatic carrier state
what are the features of a thalassaemia with 3 gene deletion?
- alpha thal major
- HbH disease
- Excess B chains causes formation of B4 tetratmers (HbH)
- moderate anaemia
- leg ulcers
what are the features of a thalassaemia with 4 gene deletion?
- HbBarts - physiologically useless
- death in utero - hydrops fettles
which leukaemia is particularly associated with DIC?
APML (prevent with ATRA)