11. What is Hemolysis
- Premature destruction of dead cells.
- Causes hereditary and acquired disorders.
- Hemolysis occurs at two sites:
12. Intravascular
- Hemolysis occurs within systemic
circulation.
- Hemoglobin is released into plasma.
- Hemoglobin is lost through kidneys or
catabolized in the liver.
13. Extravascular
- Trapping of red cells in spleen or liver
sinuses.
- Lyses of trapped red cells.
- Release of lysed hemoglobin and
catabolism within the sequestering organ.
17. C) Hemoglobin defect:
- Thalassemias
- Sickle cell anemia
- Hemoglobin C disease
- Hemoglobin E disease
- Unstable hemoglobin
18. Laboratory Findings
• Chemistry
Hyperbilirubinemia, predominantly unconjugated bilirubin
due to breakdown of heme ring by reticuloendothelial cells
in the liver.
elevated LDH: released from destroyed cells.
Hemoglobinemia: free hemoglobin level increases in
hemolysis esp. intravascular hemolysis: levels of 10-20
mg/dl gives plasma amber color and 50-100 gm/dl reddish
color.
19. Hemoglobinuria: red-brown color of urine due to free
hemoglobin and methamoglobin.
Decreased Heptaglobin level: it is a alpha-2-globin produced
in the liver. It binds free hemoglobin thus level is reduced in
hemolysis.
Hemosidrinuria: it reflects extensive hemolysis for a
prolonged period of time. When hemoglobin is filtered by
nephron, proximal tubular cells metabolize hemoglobin and
iron accumulate in the cells. Cells then exfoliate in the urine
and iron can be detected by Prussian blue reaction.
20. Drug-Induced Acute Hemolysis
•
•
•
•
•
•
•
•
•
Drugs that have been linked to G6PD:
Primaquine (an antimalarial)
Sulphonamide antibiotics
Sulphones (e.g. dapsone, used against leprosy)
Other sulphur-containing drugs: glibenclamide (an anti-diabetic drug)
Nitrofurantoin (an antibiotic often used for urinary tract infections)
Vitamin K analogues
Several others
Henna can cause a hemolytic crisis in G6PD deficient infants
27. Non-Immune Hemolytic Anemias
Hemolytic anaemias due to mechanisms or agents
other than antibodies +/or complement e.g.:
•
•
•
•
•
•
•
Mechanical (traumatic)
Toxins
Infections
Splenomegaly (hypersplenism)
Burn (physical)
Renal failure and liver failure
Chemical
28. Mechanical (Traumatic)
This is due t
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gtm
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(
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)to the RBCs
causing fragmentation of the RBCs & intra-
vascular hemolysis. The fragmented cells can be
seen on peripheral blood smears & are called
(schistocytes).
Due to:
1. Prosthetic valves
2. Patches
3. Valvular diseasse e.g., stenosis
Cont…
29. Mechanical (Traumatic)
(Fragmentation)
(cont…)
1. Microangiopathic: mechanical hemolysis due to
contact between the RBCs & the abnormal intema
of thrombosed, narrowed, necrotic small vessels or
fibrin strand formation.
Caused by many diseases e.g., DIC (disseminated
intravascular coagulation), malignant hypertension,
disseminated malignancies especially mucin
secreting adenocarcinomas, TTP
(thrombocytopenic purpura), hemolytic uremic
syndrome (HUS).
