common cause of anaemia and thrombocytopenia Flashcards
what are the main causes of anaemia
haematinic deficiencies. haemolysis secondary to a chronic condition alcohol, drugs renal impairment -EPO primary marrow disease- malignant, haemoglobin disorder, aplasia, congenital.
causes of macrocytic anaemia
B12, folate, metabolic (e.g. thyroid/liver disease), marrow damage (alcohol, drugs, marrow disease), haemolysis (due to reticulocytosis)- breaking down RBC.
causes of normocytic anaemia
anaemia of chronic disease/inflammatory.
causes of microcytic anaemia
iron deficiency, haemoglobin disorders- sickle cell anaemia, thalassemia
is iron excreted from the body
no
how is iron balance controlled
where is iron levels controlled
gut mucosa
most iron is absorbed in the duodenum
what molecule transfers iron
transferrin
what molecule is iron stored in
ferrtin/haemosiderin
what food products contain iron
red meat chicken contains some iron baked beans boiled eggs canned sardiness, oily fish and mussels. breakfast cereals with added vitamins green leafy vegetables, dried fruit, wholemeal bread, lentils, beans, peas and nuts.
what lab tests establish low iron
FBC and film ferritin- key marker (for iron deficiency) Hypochromic cells serum iron/TIBC marrow.
what can causes anaemia
not individual factors general factors
blood loss- gut, respiratory
increased demand- pregnancy and growth
reduced intake- diet and malabsorption.
in children what are the main causes of anaemia
diet, growth, malabsorption
in young women what are the main causes of anaemia
menustral loss, pregnancy, diet
in the elderly what are the main causes of anaemia
bleeding, GI problems (ulcer, gastritis, aspirin, malignancy, diverticulis, GI surgery of various types)
main side effect of oral iron
stomach upset
main side effect of IM iron
painful
most common cause of megaloblastic change.
B12 and/ Folic acid and deficiency- most common cause.
causes of megalobastic change
alcohol, drugs, haematological malignancy, congenital rarities
pathogenesis of folate and B12 anaemia
DNA= purine and pyrimidine bases.
folate required for DNA base synthesis.
B12 needed for folate synthesis.
so deficiency in either starves DNA bases.
what source does B12 come from
animal source
what cells and factors are involved in B12 absorption
gastric parietal cells
Intrinsic factor produced by parietal cells
receptors in terminal ileum which internalise B12.
most common causes for B12 deficiency
nutritional- vegans
gastric problems- gastrectomy or pernicious anaemia
small bowel problem- terminal ileum resection, crohn’s, jejunal diverticulosis, fish tapeworm.
what sources contain folic acid
green veg, beans, peas, nuts and liver
where is folic acid absorbed
upper small bowel
how long would the body’s store of folic acid last before it runs out
4 months.
main causes of folic acid deficiency
Mainly dietary / malnutrition
Malabsorption / small bowel disease
Increased usage-preganancy, haemolysis and inflammatory conditions, drug use
main cause of B12 deficiency
problem in absorption
symptoms of B12 or folate deficiency.
Megaloblastic anaemia, panctopenia, mild jaundice, glosstiis and angular stomatitis
anoexia
sterility
Lab features of B12 and folate deficiency
• Blood count and film - marrow sometimes • Bilirubin and LDH - ‘haemolysis’ • B12 and folate levels • Antibodies • B12 absorption tests +/- IF- no longer used. • GI investigations: – Crohn’s – malabsorption – blind loop etc
cause of perincious anaemia
B12 deficency
SADC (subacute combined degeneration of the cord) occurs due to
severe B12 deficency.
pathogenesis of subacute combine degeneration of the cord.
Demyelination of dorsal + lateral columns
symptoms of subacute combined degeneration of the cord
- Peripheral neuropathy / Paraesthesiae
- Numbness and distal weakness
- Unsteady walking
- Dementia
treatment for B12 deficiency.
- B12 + Folate until B12 deficiency excluded
- B12 x5 then 3 monthly for life for PA
- Folic acid 5mg daily to build stores
why is it important to give a patient both folic acid and B12 until the cause of anaemia has be diagnosed as one or the other/
Folic acid in isolation without knowing B12 status- can exacerbate B12 neuropathy
define haemolysis
breakdown of RBC
causes of haemolysis inside the RBC
haemoglobinopathy (sickle cell) Enzyme defects (G6PD)
causes of haemolysis in the RBC membrane
Hereditary Spherocytosis / elliptocytosis
causes of haemolysis outside the RBC
Antibodies (warm / cold)
Drugs, toxins
Heart valves
Vascular / vasculitis / ‘microangiopathy’
what tests show that haemolysis is present
anaemia
high MCV, macrocytic.
high reticulocytes
blood film
raised billirubin and LDH- present due to breakdown of RBC an recycle of haemoglobin.
low haptoglobins used in haemolysis
Urinary Haemosiderin- haemoglobin comes out in urine.
what is the treatment for autoimmune haemolytic anaemia
steroids
why is transfusion of blood difficult in autoimmune haemolytic anaemia
blood is difficult to match.
what is the MCV in anaemia of the chronic disease
normal
why do you have reduced RBC production in anaemia of the chronic disease.
Abnormal iron metabolism, poor erythropoetin response and blunted marrow response.
where is hepcidin produced
liver
what is the function of hepcidin
regulator of iron absorption and release from macrophages
diagnosis of anaemia of a chronic disease
- No other causes of anaemia
- No test, so diagnosed by excluding other causes.
- Usually mild anaemia, normal MCV
- Often raised inflammatory markers
- ESR, CRP, PV etc
- Normal/high ferritin + low serum iron
- Normal % Saturation transferrin
treatment for anaemia of the chronic disease.
Erythropoetin (SC)
Iron (IV)
Transfusion in severe cases.
common causes of thrombocytopenia
- ITP (sometimes associated with lymphoma/CLL/HIV)
- Other autoimmune diseases
- Liver disease and / or hypersplenism
- Pregnancy (physiological and a range of complications e.g. eclampsia)
- Haematological / marrow diseases
- Infections acute or otherwise e.g.
- Acute sepsis / HIV / other viral infections (EBV and many others)
- Disseminated Intravascular Coagulation (DIC)
- Range of congenital conditions
is Immune thrombocytopenic purpura (ITP) an immune disorder
yes
treatment for immune thrombocytopenic purpra (ITP)
young children lower than 12 can get bruising, but it is self limiting, but is hemorrhagic can be treated with steroids, doesn’t come back.
What causes immune thrombocytopenic purport in children, but not in adults
post viral infection
common feature os immune thrombocytopenic purpaura in adults
relapsing and remitting.
symptoms of immune thrombocytopenic purpura
bruising and petichae
plalatet count
•
treatament for mmune thrombocytopenic purpura
steroid
IV immunoglobulin- saturating spleen with antibodies so that it cannot get rid of platelets which are coated with antibodies.
Immunosupresants or spleenectomy.
Newer thrombo-mimetics make more paltelets
2 examples of thrombomimetics
- Eltrombopag
* Romiplostin
what symptoms alongside thrombocytopenia indicate thrombotic thrombocyotpenia
- Fever
- Neurological symptoms
- Haemolysis (retics / LDH)
