hrhodes's version from 2015-11-05 05:41

Anaemia causes

Question Answer
List the 3 main reasons to be anaemic decreased production, increased destruction or bleeding
List the causes of bleedingtraumatic, non-traumatic; acute or chronic
List the causes of decreased productionmegaloblastic, B12/folate def, aplastic, myelodysplasia, marrow disease, CRF
List causes of increased destruction (haemolytic)congenital, spherocytosis, eliptocytosis, G6DP def, sickle cell, acquired autoimmune (cold or warm), MAHA, mechanical trauma, infections, PNH
List ways to define anaemiamicrocytic, normocytic or macrocytic - MCV 80-100

Iron studies

Microcytic anaemia

Question Answer
What is microcytic anaemia? MCV <80
After MCV what is the next thing you look at?RDW, this is the variability in red cell size/width. Normal is <15%
If this is high what do you then look at?Ferritin
If microcytic, RDW is high and ferritin is low what is it?Iron deficiency anaemia
If microcytic, RDW is high, and ferritin is normal?Chronic disease, sideroblastic anaemia
If microcytic, RDW is normal, what do you look at?RBC
If microcytic, RDW normal, RBC high what are the causes?Chronic disease, Vit C deficiency, hypothyroid
If microcytic, RDW Normal, RBC low, what are the causes?Thalasseamia
So for microcytic you look at?1. MCV <70, 2. RDW - High, look at ferritin; Normal, Look at RBC. If High RDW and low ferritin - iron deficinecy, If RDW and ferritin high Sideroblastic or chronic disease, If RDW normal, look at RBC - Low - Vit C , chronic, hypothyroid. If normal Thalassemia
So in brief for MCV <70?RDW, ferritin, RBC

Iron deficiency

Question Answer
Blood resultsLow MCV - <70, RDW >15%, Ferritin low. Also high TIBC and transferrin
Causes of iron deficiency anaemiaGI / GU blood loss; Malabsorption, Pregnancy; Dietary
How is iron deficiency managed?IV Fe if severe anaemia not requiring transfusion, or unable to tolerate PO
What do the iron studies show?Low Fe, Low ferritin, High transferrin, but low transferrin % use, High TIBC - There is not much but the body is trying to make it possible to carry, absorb and store iron


Question Answer
Pattern seen in blood results?Micro (or normo) MCV <70, RDW normal <15%, RBC normal, Also high reticulocytes and erythroblasts
What other things might you see on blood film?Poikilocytosis, anisocytosis, incr no. of erythroid precursors on BM biopsy, nucleated RBC’s, basophilic stippling, target cells
Causes?Reduced rate of production of norma globin chains and haemolysis
What are the different types of Thalassaemia?Alpha - bad, Beta - minor and major
What are the main characteristics of Thal Alpha?more common in SE Asia; HbBarts (4; IU demise); HbH (3; mod disease); trait (2; asymp)
How is Thalasseamia Beta different to Alpha?Beta: more common in Europe; Hetero = minor (asymp); homo = major; more symp than alpha
Whats the worst type of thallaesmia you can have?Thalaessemia Beta Major (homo)
What are the symptoms?Fe overload (hepatosplenomegaly, cardiac disease), Pathological #, bone deformities, paraspinal masses, Endocrine failure, Recurrent infections
How is it managedTreat Fe overload with desferrioxamine; stem cell transplant; often require transfusions

Sideroblastic anaemia

Question Answer
What do you see in the blood results?Low MCV <70, high RDW >15%, High/normal ferritin
What other tests might you find an abnormality?In BM find sideroblasts
List the causes of sideroblastic anaemiaHereditary (may respond to pyridoxine), Lead poisoning, ETOH, Myelodysplastic syndrome / myeloproliferative disease
How is it treated?: Pyridoxine trial 2-3/12

Anaemia of chronic disease

Question Answer
What do you find in blood results?Low MCV <70, RDW high or normal, Ferritin normal, and RBC low


Question Answer
DefineMCV >100
What is the next thing yu look at in macrocytic anaemias?RDW
If macrocytic and RDW is high, list the causes Vit B12 deficiency, folate deficiency
If macrocytic and RDW is normal, list the causesAlcoholism, liver disease, hypothyroidism and myelodysplastic
Vit B12 and folate deficiency can be called?megaloblastic - MCV high and lots of new cells, RDW is high
List the causes of non-megaloblastic macrocytic anaemiaalcoholism, chronic liver disease,hypothyroidism, myelodysplastic disease

Vit B12 deficiency

Question Answer
Typically what is the MCV ?MCV >115 Cause:
List the causes of VIit B12 deficiency 1. decd intake - vegan diet or 2. decd absorption, pernicious anaemia (autoab to parietal cell and intrinsic factor ◊ decr production of IF, prevent formation of complex; mean onset 60 years), stomach resection, ileal resection, achlorhydria (PPI), metformin
What are the complications of B12 deficiency?peripheral neuropathy, SADSC and dementia
List 5 associated diseasesautoimmune thyroiditis, Graves, Addisons, 1Y hypoPT, vitiligo, MG
List 7 symptoms of B12 deficiency Dementia, psychosis, peri neuropathy, subacute degeneration of spinal cord (occurs faster if only folate supplementation; due to demyelination; affects post + lat columns), abnormal gait
What might one exam finding be on clinical exam of mouth?painful smooth tongue
How is it treated?Vit B12 injections; high dose PO vit B12
What do you find on bloods aside from MCV >115, RDW >15%? Incr: LDH; Decr: B12; WBC and plt; holotranscolabalmin II, Hypersegmented neutrophils; Stippling of red cells; Howell Jolly bodies
What specific tests may you order?B12, Antipareital and intrinsic factor antibodies , Schilling test (decr urinary B12 that is incr by giving IF)

Folate deficiency

Question Answer
Causes of folate deficiency1. decd intake 2. decd absorption, coeliacs 3. incr demand - alcoholism, pregnancy, dialysis 4. Medications - sulphasalazine, methotrexate, phenytoin, metformin, dihydrofolate reductase inhibitors - trimethorpim, antimalarials
Treatment 5mg folate OD; vit B12 if def suspected
Blood results show?MCV >115, RDW >15% and low folate


Question Answer
What is normocytic anaemia?MCV normal 80-100
What do you look at after MCV with normocytic?Reticulocytes, then RDW or Coombs
If MCV normal, reticulocyte count is normal and RDW is high list the causesthe deficiency anaemias - Fe, B12 and folate
If MCV normal, Reticulocytes normal and RDW normal?Chronic disease or renal failure
If MCV normal, retics high, Coombs positiveAutoimmune, transfusion reaction, drug reaction
If MCV normal, reticulocytes high and coombs negativeG6PD, sickle cell, spherocytosis, MACA -All the haemolytics
Way to remember the coombs test?if its negative - it can't find anything as you were born with it: sickle cell, G6PD, MAHA, spherocytosis, if positive its new haemolysis: drug, autoimmune, transfusion

Aplastic anaemia

Question Answer
Causes of aplastic anaemiastem cell loss - Idiopathic (50-65%), Fanconi’s syndrome (autosomal recessive), Radiation, viruses, Drugs: Chloramphenicol, gold, sulphur drugs, chlorpromazine, streptomycin Viral infections (eg. hepatitis), SLE; Pregnancy; Graft vs host
Symptoms of aplastic anaemia Decr tissue oxygenation, immunocompromise, bleeding, Fatigue, weakness, No splenomegaly
How is aplastic anaemia managed?supportive; ABx; blood products; immunosupp; G-CSF
What do the bloods show?reduced reticulocytes. can also have low WBC, plt; Hypocellular BM

anaemia of chronic disease

Most common cause of normocytic
Question Answer
WHY does it happen?Due to incr hepcidin, decr erythropoietin, inhibited marrow proliferation, altered Fe distribution, decr RBC life span, incr reticulo-endothelial activity
RA, CRF, Ca, CT disorders
Question Answer
How do you manage?blood transfusion; consider Fe; EPO
Blood resultshigh ferritin; normal reticulocytes and RDW, reduced Fe, transferrin, TIBC


Question Answer
What is spherocytosis caused by?Defect in membrane proteins (spectrin) ◊ decr deformability ◊ haemolysis
What are the symptoms? Usually asymptomatic, Splenomegaly (moderate; 50% young children, 85% adults), Jaundice, gallstones (5% children, 50% adults), Haemolytic crises (usually during infections; mild) Aplastic crises (parvovirus infection), Leg ulcers, spinal cord lesions
How is spherocytosis managed?splenectomy, cholecystetcomy
BloodsNormocytic, Retics high, Features of haemolysis, spherocytes, coombs negative
What tests might you order?Haemolysis screen = haptoglobins, LDH, Coombs (negative), unconj/conj bil, urobilinogen


Question Answer
What is G6PD?X-linked inherited; more common in black males, oxidative stress causing haemolysis
What can trigger oxidative stress in G6PD and lead to haemolysis? infection; sulphonamides, nitrofurantoin, antimalarials, vit K, aspirin
What are the symptoms?Splenomegaly, neonatal jaundice, gallstones
BloodsFeatures of haemolysis + G6PD assay

Sickle cell disease

Question Answer
What is the genetics of SCD?Autosomal recessive; account for 70% congenital Hb disorders; esp in Black (occurs in 8%), Middle East, Indian
How does it have its affect?Defect in Hb production (valine/glycine) ◊ HbS ◊ polymerization when low NO conc ◊ damage to membrane ◊ haemolysis, incr intracellular Ca, rigid RBC’s, activation of thrombosis
What triggers haemolysis?hypoxia, acidosis, 2,3,DPG, vascular stasis, IV vol depletion, infection, dehydration, altitude, cold
Symptoms of SCD? Onset after 6/12 (when HbF gone), Arthralgia, dactylitis (most common <2yrs; periosteal elevation on XR, painful swelling); bone thinning CCF; murmurs in 80%, Jaundice, gallstones, AP, Hepatosplenomegaly (spleen small in adulthood due to recurrent infarction; functional asplenia); incr bil; jaundice; gallstones, Leg ulcers
What is the most common cause of death in SCD ?Sepsis is most common cause of death in children, esp strep pneumoniae
What are the types of crisis SCD people can have?Vasoocclusive crises, Haematological, Aplastic
Give some examples of what happens in vasooccusive crisis? Pain, CVA, pul infarction; acute chest syndrome
What happens in haematologic crises? splenic sequestration – 2nd most common cause death, aplastic, infectious
How is Aplastic crises caused?parvovirus B19 - sudden lethargy, pallor, high output CHF
What bloods?Normocytic, Retics high, coombs negative. Features of haemolysis + Incr: LFT’s, plt; Hb 6-9; HbF 2-20%; RBC survival 10-20/7 (instead of 120); reticulocytes 5-15%
Blood filmSickle cells; Howell Jolly bodies
How is it managed generally?avoid precipitants, BMT (80% cure), hydroxyurea, folic acid, penicillin prophylaxis, pneumococcal etc immunisation, transfusions
In crisis how is it managed?hydration, O2 if hypoxic, analgesia, antibiotics for infection, transfusion, treat underlying


Question Answer
What causes Rouleux formation?Anything that causes a raised ESR and inflammation. Changed rheology and clumpnig of cells mean they stick together. infection, inflammation, malignancy, hyper viscosity, dehydration, liver disease, Multiple myeloma
What causes nucleated red cells?these are essentially reticulocytes - BM struggling to keep up with breakdown. Asplenia, anaemia, hypoxia, inflammatory bowel disease, renal failure
What causes the presence of plasma cells?B cell lymphoma, multiple myeloma, plasmacytoma, TB, hepatitis
What causes Heinz bodies?oxidative stress. G6PD deficiency and drugs such as primaquine, in alpha thallasemia, chronic liver disease and splenectomy
What are target cells and what causes it?Annormal Hb seen in middle of cell. Thalassemia, Hepatic disease with jaundice, Hemoglobin C disorders, Postsplenectomy, SCD, Fe deficiency, lead poisoning
How do you tell a MAHA?Anaemia, schistocytes


Question Answer
ITP is not a MAHA. Why?This is a platelet destruction problem by autoimmune factors. MAHA affects small vessels and micro occlusion
Diffence between TTP and HUS FARTN - Fever, anaemia with schistocytes, Renal failure, Thrombocytopenia, Neuro symptoms (70%pts), HUS - FARTNG everything plus gastro