13. Hemolysis

What is the primary site of extravascular hemolysis?

Spleen, liver, lymph nodes, and bone marrow.

What percentage of hemolysis is extravascular?

90%.

What happens to hemoglobin during extravascular hemolysis?

It is released into macrophages and broken down into heme and globin.

How are globin chains processed after hemolysis?

The amino acids are recycled into the amino acid pool.

What is the role of transferrin?

It transports iron to the bone marrow or storage sites.

What by-product is formed when hemoglobin reacts with hemoxygenase?

Biliverdin.

What does unconjugated bilirubin attach to for transport?

Albumin.

What laboratory finding signifies increased extravascular hemolysis?

Elevated reticulocyte count and polychromasia on peripheral smear.

What occurs during intravascular hemolysis?

Red blood cells are lysed directly in the blood vessel.

What happens to free hemoglobin in the plasma during intravascular hemolysis?

It binds to haptoglobin.

What indicates a decrease in free haptoglobin?

Binding with free hemoglobin in the plasma.

What condition arises as the bone marrow attempts to compensate for hemolysis?

Erythroid hyperplasia.

What laboratory marker increases in plasma during intravascular hemolysis?

Lactate dehydrogenase (LDH).

What can activate complement in hemolysis?

Conditions that predispose to rapid lysis within vessels.

What can be seen in the plasma during hemoglobinemia?

Red- or pink-tinged plasma.

What is hemoglobinuria?

Hemoglobin in urine due to filtration by the kidneys.

What are the typical blood findings in extravascular hemolysis?

Decreased hemoglobin, hematocrit, and red blood cell count.

What is the normal myeloid:erythroid (M:E) ratio in healthy bone marrow?

3:1 to 4:1.

What does a shift in the M:E ratio towards erythroid indicate?

Erythroid hyperplasia.

What visual clue may indicate hemolysis in a peripheral smear?

Polychromasia.

What happens to red blood cells traveling through the spleen during hemolysis?

They may become spherocyte shaped.

What is one consequence of antibody-coated red blood cells in the spleen?

Diminished lifespan of red blood cells.

What happens to serum bilirubin levels during hemolysis?

They are elevated, resulting in jaundice.

What occurs to reticulocyte count during hemolytic events?

It is elevated.

What is one of the shared laboratory findings in both extravascular and intravascular hemolysis?

Decreased hemoglobin and hematocrit.

What is a classic sign of intravascular lysis?

Hemoglobinemia leading to red-tinged plasma.

What kind of hemolysis occurs when RBCs burst directly in circulation?

Intravascular hemolysis.

What is the impact of hemolysis on the kidney?

Hemoglobinuria from free hemoglobin filtration.

What are intrinsic defects of red blood cells related to?

Inherited deficiencies of cell structure or function.

What are extrinsic defects related to in hemolytic anemias?

Events secondary to red blood cell structure and function.

What type of anemia is caused by environmental agents?

Extrinsic defects leading to hemolysis.

What is an example of a hemoglobinopathy?

Sickle cell disease.

What are hereditary spherocytosis and elliptocytosis classified as?

Intrinsic membrane defects.

Which infections can cause hemolytic anemia?

Malaria and Babesiosis.

What does G6PD deficiency represent?

An intrinsic RBC enzyme defect.

What is the main concern with acute hemolytic transfusion reactions?

Rapid intravascular hemolysis.

In what conditions might haptoglobin be markedly decreased?

During hemolytic events.

What is the result of complement activation on red blood cells?

Damage to the red blood cell membrane.

What is a clinical sign of hemolysis?

Pallor, fatigue, and tachycardia.

What is the potential danger of hemoglobinuria?

Risk of significant drop in hematocrit levels.

What is often elevated in the plasma during hemolytic events?

Lactate dehydrogenase (LDH).

What does the analysis of plasma changes help determine?

The type of hemolysis occurring.

What may happen to the spleen in cases of extravascular hemolysis?

It may become enlarged.

What does an elevated reticulocyte count indicate in hemolytic conditions?

Bone marrow's attempt to increase red blood cell production.

What happens to red blood cell lifespan due to hemolytic events?

It is decreased.

What might you observe in a peripheral smear during hemolysis?

Increase in nucleated red blood cells.

What is required for life-threatening hemolytic anemias?

Recognition, evaluation, and management.

What are symptoms of anemia due to hemolysis?

Pallor, fatigue, tachycardia.

What can be a complication during transfusion if ABO compatibility is not respected?

Hemolysis due to complement activation.

What is the significance of hemolysis laboratory tests?

To confirm hemolysis and determine its type.