Anemias - Sideroblastic, Aplastic, Beta-thalassemia major and trait, Hereditary spherocytosis, G6PD deficiency, Macrocytic, Microcytic, IDA, AOCD Flashcards
Sideroblastic anemia
-what is it
-causes
-presentation
-investigations
-management
Body has iron but it’s not put in Hb => Fe deposited in mitochondria, forms a ring around the nucleus (ring sideroblast)
Congenital - delta-aminolevulinate synthase 2 deficiency
Acquired
-myelodysplasia
-alcohol
-lead
-anti-TB meds
FBC - hypochromic microcytic anemia
Fe studies - high ferritin, high Tsats, low TIBC
Blood film - basophilic stippled RBCs
Bone marrow - Prussian blue stained ringed sideroblasts
Supportive
Treat underlying cause
Pyridoxine (B6) needed for delta aminolevulinate synthase 2 function - good in congenital SA
Aplastic anemia
-what is it
-associated conditions
-causes
-presentation
-management
Deficiency of all blood cells due to failure of BM development
Can be the first presenting feature of ALL, AML
Idiopathic
Congenital - Fanconi anemia
Drugs - CYTOTOXICS, CHLORAMPHENICOL, PHENYTOIN
Infection - parvovirus, hepatitis
Radiation
Normochromic, normocytic anemia
Pancytopenia
Supportive - blood products, prevent/treat infection
Medical - Antithymocyte globulin, antilymphocyte globulin
Immunosuppression - ciclosporin
Stemcell transplantaion
Beta-thalassemia major
-what is it
-presentation
-investigations
-management
No b globulin chains - Chromosome 11, recessive
Presents in 1st year of life - failure to thrive, hepatosplenomegaly
Microcytic anemia
HbA absent - Hb with 2a and 2b
HbA2 high - Hb with 2a and 2d
HbF high
Regular transfusion + deferroxamine to remove excess Fe from repeat transfusions
Beta-thalassemia trait/minor
-what is it
-presentation
-investigation
-management
Carrier of recessive b thalassemia - presents in 20-30s
-often symptomatic in pregnancy from dilutional anemia
Anemia - SOB, fatigue
Identified on antenatal screening or through GP/NHS Sickle cell and Thalassemia screening programme
-MILD ANEMIA, SIGNIFICANT MICROCYTIC
-low MCH and MCV
HbA2 high
Check ferritin
-normal => no treatment needed
-low => Fe supplements
Genetic counselling and partner screening
Hereditary spherocytosis
-what is it
-presentation
-investigations
-management
Autosomal dominant affecting RBC cytosksleton => sphere RBC, which is destroyed by the spleen
-Northern European
-Parvovirus can trigger aplastic crisis
Failure to thrive
RBCs destroyed by spleen (EXTRAVASCULAR HEMOLYSIS) => splenomegaly, jaundice, gallstones
FHx
FBC - high mean corpuscular Hb conc (MCHC), high reticulocytes
Blood film - spherocytes
GOLD STANDARD - EMA
Acute hemolytic crisis - supportive, transfusion if needed
Long term - folate to support erythropoeisis
-consider splenectomy to eliminate hemolysis, anemia
G6PD deficiency
-what is it
-presentation
-investigations
-management
X linked recessive => increased susceptibility to oxidative stress
-African, Mediterranean
Hemolysis triggers
-infection
-broad beans
-Drugs - primaquine, cipro, sulpha drugs (sulphonamides, sulfasalaizine, sulfonylureas
Intravascular hemolysis => neonatal jaundice, gallstones
Can have splenomegaly
FBC - anemia
Blood film - Heinz bodies, bite/blister cells
Diagnosis made with G6PD enzyme assay 3 months after acute hemolysis episode
Remove trigger
Transfusion may be needed
Macrocytic anemia
-megaloblastic causes
-normoblastic causes
Due to red blood cell synthesis issue
Megaloblastic
-B12, folate deficiency (can be 2ndary to methotrexate)
Normoblastic
-alcohol
-liver disease
-hypothyroidism
-pregnancy
-myelodysplasia
-cytotoxics
Microcytic anemia causes
Due to haemoglobin production issue
TICS
Thalassemia
Iron deficiency
Chronic disease
Sideroblastic/Lead
Interpretation of haptoglobin
-what does it do
-what can it tell us
Haptoglobin - binds to free Hb so there is reduced oxidative damage to vasculature => transports Hb to spleen for destruction
Intravascular hemolytic anemia => low haptoglobin
-mismatched blood transfusion
-G6PD deficiency
-RBC fragmentation from heart valves, TTP, DIC, HUS
Extravascular hemolytic anemia => low haptoglobin if severe
-sickle cell, thalassemia
-spherocytosis
-hemolytic disease of newborn
Coombs test
-what can it tell you
Can test for the presence of ABs amongst circulating RBCs that induce hemolysis
Direct (DAT) - AB attached to RBCs
-autoimmune hemolytic anemia vs heretidary spherocytosis
-drug induced (methyldopa, penicillin)
Indirect - AB within serum
-used in prenatal testing
-used before blood transfusion
Iron deficiency anemia
-main causes
MOST COMMON CAUSE OF ANEMIA
Excess blood loss
-heavy periods
-GI bleeding => cancer?
Inadequate intake
-VG, V - but can get Fe through dark green leafy greens
Poor absorption
-coeliac, IBDs
Increased iron requirements
-pregnancy - demands from baby + dilutional anemia
Iron deficiency anemia
-presentation
-investigations
-management
Fatigue
SOBOE
Palpitations
Pale
Koilonychia
Hair loss
Atrophic glossitis
Post cricoid webs + IDA + dysphagia - Plummer Vinson
Angular stomatitis
FBC - hypochromic microcytic anemia
Low reticulocytes - not enough Fe to make new RBCs
Iron studies
-low ferritin (but may be raised during inflammation)
-high TIBC
Blood film - anisopoikilocytosis (irregular size and shape), target cells
FIT test
PR exam - r/o PR bleed
Endoscopy, colonoscopy - GI cancer
Conservative if dietary intake inadequate - increase intake
-red meats
-dark leaft grains
-Fe fortified bread
-apricot, prunes, raisins
Medical
1st line - PO ferrous sulfate OD - continue for 3months after deficiency has been corrected
2nd line - reduce PO frequency to alternate days
3rd line - IV iron
Monitor Hb for response in 4wks
-yes => recheck at 2-4months
-no => assess compliance, continue assessments for underlying issues
Anemia of chronic disease
-pathophysiology
-investigations
Normally, when red blood cells are destroyed at the end of their lifecycle, the iron is recycled
But in inflammatory states, your body stores iron away so it cannot be used for new RBC formation
Normocytic
High ferritin
Low transferrin
Low TIBC -
Normocytic anemia causes
Due to impaired RBC production
Loss of RBCs
-acute bleed
-hemolytic anemia
-HS
-G6PD
-sickle cell
Reduced production
-BM failure
-chronic disease
-aplastic
Dilutional
-pregnancy
Interpretation of iron studies
-serum iron
-Tsats
-TIBC
-ferritin
-transferrin
Serum iron - measure of circulating iron, bound and unbound
-low in IDA - not enough Fe
-low in ACD - Fe stored away
Tsats - % of Fe bound to transferrin
TIBC - available Fe binding sites on transferrin
Ferritin - amount of Fe stored in liver, BM, macrophages
Transferrin - amount of Fe transport proteins
