W2: Haemolytic anaemia Flashcards
EASY ONE. What is haemolytic anaemia?
When the red blood cell destruction is so fast we losing RBC faster than we produce it.
RBC are destroyed before or after their normal life span?
Before lah omg. so the RBC is removed within 100 days.
What compensatory mechanism is expected when RBC is destroyed so quickly?
increase in marrow activity lah because we desperately need RBC.
There is heightened reticulocyte percentage (Reticulocytosis)
Name the two types of haemolysis
Intravascular and extravasular
Haptoglobin function?
A protein produced by liver to clear free haemoglobin from circulation
In intravascular haemolysis, RBC is broken down in circulation, increase free haemoglobin, increase haptoglobin. If too much hgb, then the __________
Excess free haemoglobin travels to the urogenital tract and filtered by glomerulus, passed out through urine.
Ferritin and iron together forms hemosiderin in renal tubule and passed out through urine. This is known as____________
Hemosiderinuria
Where does extravascular hemolysis happens?
In the reticuloendothelial system (liver, spleen and bone marrow)
Why is there no haemoglobinaemia or haemoglobinuria in extravascular haemolysis?
Because there is no haemolgobin released in the circulation`
Hyper_______ occurs in extravascular haemolysis
Hyperbilirubinaemia
In extrvascular haemolysis, RBC is phagocytized by macrophage. The lysozyme degrades it into ______ and ______. ______ is further broken down into Fe and _______. The ______ forms unconjugated bilirubin which travels to the hepatocyte to become conjugated and goes into the biliary system.
Heme and globin. Heme is further broken down in Fe and porphyrin. The porphyrin forms unconjugated bilirubin.
Renal failure, renal tubular dysfunction happens in _________
Haemoglobinuria
Splenomegaly and increase urinary urobilinogen happens in ____________
extravascular haemolysis
There is a _______ in serum lactate dehydrogenase for both haemolysis process
Increase, hence it is a marker for haemolysis
There is a decrease in _________ for both haemolysis process
serum haptoglobin
Examples of causes for hereditary haemolytic anemia
- hereditary spherocytosis
2, hereditary eliptocytosis
- G6PD deficiency
- Pyruvate kinase deficiency
- Genetic abnormalities in Hb.
Examples of causes for acquired haemolytic anemia
- Drug associated
- Autoimmune
- Alloimmune such as allografts, transfusion reactions
- Red cell fragmentation syndrome
- Malaria, clostridia
- secondary cause due to liver and renal disease
- Paroxysmal Nocturnal Hemoglobinuria
RBC destroyed prematurely by antibody and/or complement. What is this?
Immune related hemolytic anemia
Explain warm autoimmune haemolytic anaemia (AIHA).
- optimum reaction of antibody with RBC at 37c
- RBC coated with IgG or with complement
- Primary = no underlying disease
- Secondary = due to chronic lymphatic leukaemia, non-Hodgkin lymphoma, SLE , hypothyroidism
Explain the 3 ways RBC are destroyed in warm AIHA.
- Macrophage express receptor for Fc region and trap and ingest the opsonized (with IgG) RBC. Leads to incomplete phagocytosis = spherocyte formation (weak, will lyse)
- Sequestered and phagocytosed by macrophages in spleen
- complement protein C1 bind to RBC, activate classical complement pathway. C3b also come and attach. Then lastly kuppfer cell in liver in phagocytose this RBC.
Clinical feature of warm AIHA include ______, jaundice, ________ sudden onset of severe anemia, fever.
Splenomegaly
Hepatosplenomegaly
Warm AIHA is normocytic, hypochromic anaemia. True or False?
FALSE LAH. Its normochromic, normocytic anaemia.
Complete blood count of warm AIHA is how?
Normal values all the way.
Special test for warm AIHA =
Direct antiglobulin test AKA direct Coombs test = detects sensitized RBC with IgG or C3b
warm AIHA patient is positive = RBC will agglutinate in test