Question 1

What are the bone marrow findings in hemolytic anemia?

Accepted Answer

Erythropoiesis is increased (erythroid hyperplasia)in the bone marrow in hemolytic anemia,with no change in the production of granulocytes.The M:E ratio will therefore be decreased (i.e.,more erythroid precursors relative to myeloid).Overall cellularity of the bone marrow is increased so that less fat exists.

Question 2

What characteristic red cell shape is associated with extravascular hemolysis?

Accepted Answer

Spherocytes suggest extravascular hemolysis.

Question 3

Which of the following are typical findings in extravascular hemolysis?

Accepted Answer

During the process of extravascular hemolysis,macrophages phagocytize and break down hemoglobin into its various component parts.Unconjugated bilirubin is thus increased.This is taken to the liver,where it is conjugated.Bacteria in the gut oxidize conjugated bilirubin into various water-soluble compounds that together are called urobilinogen.Some of this is reabsorbed into the plasma and because of its water solubility will be filtered by the renal glomerulus and excreted into urine.This results in an increase in urobilinogen in the urine.

Question 4

Unconjugated or indirect bilirubin is normally found in

Accepted Answer

The bilirubin originally released from macrophages after degradation of the protoporphyrin ring is normally found in plasma before conjugation in the liver.

Question 5

Which of the following clinical findings specifically suggests,if it is present,extravascular hemolysis?

Accepted Answer

A chronic extravascular hemolytic process can lead to an enlarged spleen (splenomegaly).All of the other clinical findings listed may be found in anemia because of any cause-they are nonspecific findings.

Question 6

A plasma sample appears hemolyzed or red.Which of the following is true?

Accepted Answer

Plasma hemoglobin can be detected when the concentration of hemoglobin is greater than 50 mg/dL.Free hemoglobin is seen in plasma,giving it its red color when excessive intravascular hemolysis exists.Both haptoglobin and hemopexin will be decreased as an attempt to salvage iron occurs.

Question 7

Which of the following test results suggests red blood cell (RBC)survival is significantly decreased from the normal of 120 days?

Accepted Answer

Glycated hemoglobin increases over the life of the red cell as it (the red cell and thus hemoglobin)is continually exposed to glucose in plasma.In hemolytic disease,the red cells have a shortened survival and thus less exposure to glucose,which results in a lower glycated hemoglobin than normal.Haptoglobin is an acute phase protein and may be normal or even increased even in intravascular hemolysis if the patient has concurrent inflammation;thus a normal haptoglobin does not rule out intravascular hemolysis with a shortened RBC survival.Lactic dehydrogenase is released from lysed red cells and increases when RBC survival is shortened.A T₁/₂ Cr of 30 days is normal.

Question 8

Which of the following suggests ongoing hemolysis in a patient who has not had massive blood loss or been hemodiluted?

Accepted Answer

A drop in the hemoglobin by greater than 1 g/dL/week can signal ongoing hemolysis provided the clinician has ruled out hemorrhage and hemodilution.

Question 9

Which of the following is the most specific indicator of accelerated intravascular red cell destruction?

Accepted Answer

When red cells are destroyed in the circulation,hemoglobin is released into plasma.Haptoglobin binds the free hemoglobin and thus decreases in plasma.This is specific for intravascular hemolysis.

Question 10

Laboratory tests indicate that an female adult has an increased rate of red cell destruction in the circulation.Her hematocrit is 39%.Which of the following describes her hemolytic disorder?

Accepted Answer

This patient is not anemic,so this is a compensated hemolytic disorder.The response to anemia is to increase the rate of red cell production and release to peripheral blood.When the marrow response is robust enough to keep up with the rate of red cell destruction,anemia does not develop and the result is a compensated hemolytic disorder.

Question 11

All of the following are often seen in various types of hemolytic anemia except

Accepted Answer

Hypochromia is present when hemoglobin synthesis is abnormal such as in iron deficiency anemia.It is not observed in hemolytic anemias.

Question 12

A patient develops an immunoglobulin G (IgG)antibody that causes red cells to be destroyed by the spleen.This is what type of hemolysis?

Accepted Answer

Because the patient develops the antibody,this is acquired,not inherited.The antibody is found in plasma,so it is extrinsic to the red cell.Destruction in the spleen is extravascular because it occurs outside the circulation.It is immune because an antibody causes it.

Question 13

An elevated reticulocyte count rules out which of the following?

Accepted Answer

An elevated reticulocyte count is seen after acute blood loss,acute hemolysis,and after successful patient response to iron therapy.It is not observed in an aplastic crisis.

Question 14

Which of the following is decreased in intravascular hemolysis?

Accepted Answer

Haptoglobin will be decreased in intravascular hemolysis as the free hemoglobin is bound in an attempt to salvage the iron.

Question 15

Which of the following tests for hemolysis is easiest and safest for the patient?

Accepted Answer

The easiest and safest test for the patient is the reticulocyte count,which requires nothing more than a blood sample.All the other procedures listed are more invasive and carry more risk to the patient.

Question 16

Which of the following breakdown products of hemoglobin is removed from the body instead of being recycled?

Accepted Answer

The protoporphyrin ring is gradually degraded into bilirubin and eventually excreted from the body.Globin chains are broken down into their component amino acids,which are returned to the amino acid pool for future protein synthesis.Iron is very tightly conserved and recycled.

Question 17

The presence of hemoglobinuria,hemosiderinuria,and hemoglobinemia indicate that hemolysis is

Accepted Answer

When hemolysis is intravascular,red cells are lysed within the circulation releasing hemoglobin;this is called hemoglobinemia.If the renal threshold is exceeded,some hemoglobin may pass through the kidney and thus be found in urine (i.e.,hemoglobinuria).Renal tubular epithelial cells,where the iron is separated from protoporphyrin,take up some hemoglobin passing through the kidney.Some of these renal tubular epithelial cells will gradually be sloughed off into the urine;an iron-specific stain will demonstrate the presence of iron in the form of hemosiderin (as in hemosiderinuria).

Question 18

How are normal red cells removed when they lose the ability to deform?

Accepted Answer

At the end of their 120-day normal life span,red cells are removed from circulation by splenic macrophages.

Question 19

Which of the following is found normally in urine?

Accepted Answer

Bacteria in the gut oxidize conjugated bilirubin into various water-soluble compounds that together are called urobilinogen.A small amount of this is normally reabsorbed into the plasma and because of its water solubility will be filtered by the renal glomerulus and excreted into urine.

Question 20

A urine sediment stains with Prussian blue.The patient probably has

Accepted Answer

When the amount of free hemoglobin exceeds the capacity of plasma salvage systems (e.g.,haptoglobin,hemopexin),free hemoglobin can be found in plasma.This hemoglobin is filtered through the kidney;some of the iron will be released and taken up by renal tubular cells that are eventually sloughed off into the urine.The iron can be detected in these renal tubular epithelial cells by giving a positive Prussian blue stain.

Quiz 23: Introduction to Increased Destruction of Erythrocytes