causes of anaemia/thrombocytopenia Flashcards
what are some examples of causes of anaemia
blood loss, deficiencies (B12, iron, folate), chronic disease, haemolysis (alcohol, drugs, toxins)
what are the names and causes of the classification of MCV (mean cell volume) in RBC’s
normocyte
microcyte (iron deficiency or thalassaemia)
rough macrocyte (liver disease, alcohol, hypothyroidism)
oval macrocyte (magaloblastic anaemia)
what would iron deficiency do to the RBC
microcytic anaemia
what is the most common cause of anaemia
iron deficiency = microcytic anaemia
what is the 3 stage process to treatment of iron deficicency
first establish level - FBC, MCV blood film
establish cause
iron therapy - oral, IM, IV
what are the common causes of iron deficiency in child, young women and older people
children - diet, growth, malabsorption
young women - mentrual loss or pregnancy
older - bleeding or GI problem
what does an older man with iron deificincy at risk of
bowel cancer
describe magloblastic anaemia and the cause
macrocytic anaemia caused by impaired DNA synthesis
RBC bigger, MCV high, lobed nuclei of nucleated blood cells
describe magloblastic anaemia
macrocytic anaemia caused by impaired DNA synthesis
RBC bigger, MCV high, lobed nuclei of nucleated blood cells
what are specific causes of megaloblastic anaemia (macrocytic anaemia)
most common - B12/folate deficiency (folate required for DNA synthesis and B12 essential for cell folate generation)
alcohol and drugs
what is the treatment for megaloblastic anaemia
give B12 and folate until B12 deficiency is ruled out
where do we get vit B12 from
animal sources
describe the absorption of vit B12
easy - absorbed by binding to intrinsic factor made by parietal cells in the terminal ileum
what are some examples of reasons for vit B12 deficiency
nutritional - mainly vegans
gastric - antibodies against intrinsic factor or parietal cells, atrophic gastritis
small bone issues (crohns)
SACDC
what is SACDC
sub acute combined degradation of get cord
severe b12 deficiency - peripheral neuropathy, numbness and weak ness
where do we get folic acid from
green veg, beans, nuts
what causes folic acid deficiency
malnutrition, malabsorption, pregnancy
drugs/alcohol/UTI
what is haemolysis
shortened RBC life ie less than 120 days - problems with cell internal machinery, cell membrane or external factors
what are the 3 causes of haemolysis
intracellular - enzyme defect (G6DP def) or sickle cell
membranous - hereditary spherocytosis (most common)
extracellular - antibodies, dirges, toxins
what investigative clues can be done for haemolysis
anaemia, blood film (look for spherocytes)
raised bilirubin
low haptoglobin
urinary haemosiderin
what is the causes and pathogenesis of normcytic anaemia
suppression of normal BM function
malignacy, infection, inflammation
reduced RBC production due to poor EPO, abnormal iron metabolism
what molecules can cause normocytic anaemia
inflammatory cytokines (IL-1/6, TNF-a)
hepcidin (made in liver) - inhibits iron from endothelial cells = reduced RBC production
what is thrombocytopenia and the common causes
decrease in the number of platelets
drugs, alcohol, toxins ITP (immune thrombocytopenia purpura) liver disease pregnancy infection
what is the presentation of thrombocytopenia and therapy
bruising and low platelet count (below 30)
steroids or IV IG’s
thrombomimics
what is ITP, causes , presentation and theory
immune thrombocytopenic purpura
antibody mediated platelet destruction
children show acute presentations usually with viral infection
bruising and low platelet count
first line T = steroids or Iv IG’s
what is TTP, causes and treatment
rare but severe
thrombocytes thrombocytopenic purpura - vWF issue = cause lots of little thrombi
do not give platelets but give steroids
