Anemia quiz
Here’s a little quiz on anemia. Answers are in the first comment following this post.
1. Which of the following is a sign of red cell destruction?
A. ↑ haptoglobin
B. ↓ LDH
C. ↑ bilirubin
D. ↑ reticulocytes
E. ↑ LAP
2. Your patient is a 68 year old male who has very pale, almost bluish fingertips. When you question him about this, he says that it gets worse when he’s out in the cold, and that his doctor says he has some kind of anemia.
Which of the following is probably true?
A.He is making IgG antibodies against his red cells
B. His DAT would be negative
C. The spleen is the major site of red cell destruction in this patient
D. His blood smear would show schistocytes
E. Complement is attacking his red cells
3. What is the defect in hereditary spherocytosis?
A. A point mutation in a hemoglobin chain gene
B. Absence of one or more hemoglobin chain genes
C. Absence of a red cell enzyme
D. A spectrin abnormality
E. Inability to incorporate iron into hemoglobin
4. Your apparently healthy, 75-year-old grandfather was found to have an abnormality on his blood smear during a routine physical. His indices are as follows:
Hgb 8 g/dL (12-16)
MCV 70 fL(80-100)
RDW 15% (12 – 13.5)
RBC 3.5 x 10^12/L (4.5-6.0)
WBC 10 x 10^9/L (4-11)
Plt 300 x 10^9/L (150-450)
What should be done next?
A. Check his blood smear at his next annual physical
B. Give him iron replacement
C. Perform a complete physical, including testing for blood in the stool
D. Give him steroids
E. Do a bone marrow biopsy
5. Your next patient, a 65 year old Finnish bachelor, is a self-proclaimed heavy drinker. He has the following indices:
Hgb 8 g/dL (12-16)
MCV 110 fL(80-100)
RDW 13% (12 – 13.5)
RBC 3.5 x 10^12/L (4.5-6.0)
WBC 7.2 x 10^9/L (4-11)
Plt 420 x 10^9/L (150-450)
What is the most likely diagnosis?
A. Iron-deficiency anemia
B. Thalassemia
C. Megaloblastic anemia
D. Hereditary spherocytosis
E. Sickle cell anemia
November 25th, 2009 at 7:34 am
1. C. Increased bilirubin.
Haptoglobin would be decreased, and LDH increased, in a hemolytic process.
Reticulocytes are a sign of increased production – they are usually increased in a hemolytic process, but are not a sign of destruction in and of themselves.
LAP (Leukocyte alkaline phosphatase) is an enzyme made by neutrophils. It happens to be a good test for telling a benign neutrophilia (like one you’d get with an infection) from CML. In a benign neutrophilia, the LAP is increased (there are tons of neutrophils, and they’re all making LAP). In CML, there are tons of neutrophils, but they’re malignant – and they don’t make LAP. So the LAP would not be increased in CML.
2. E. Complement is attacking his red cells.
This patient’s symptoms are consistent with cold autoimmune hemolytic anemia, in which IgM antibodies bind to red cells and agglutinate them at cold temperatures.
IgG antibodies are produced in warm, not cold AIHA.
The DAT is positive in both warm and cold AIHA.
The spleen destroys the IgG-coated red cells in warm AIHA (in cold AIHA, the red cells get destroyed by complement, and it happens intravascularly).
Schistocytes are present in microangiopathic hemolytic anemia (not AIHA)
3. D. Spectrin abnormality.
Patients with sickle cell anemia (and other hemoglobinopathies) have a point mutation in a hemoglobin chain gene. Patients with thalassemia are often missing one or more hemoglobin chain genes. In alpha thalassemia, patients are missing one or more of the four alpha chain genes. In beta thalassemia, the patient has beta chain genes, but they do not produce the normal amount of beta chains. In both alpha and beta thalassemia, patients do not have enough of one of the types of hemoglobin chains. Patients with G6PD deficiency are missing G6PD, a red cell enzyme. Patients with anemia of chronic disease have an inability to incorporate iron into hemoglobin.
4. C. Perform a complete physical, including testing for blood in the stool
Your grandfather is anemic (hemoglobin is low, RBC is low). The MCV is decreased, so he has a microcytic anemia. There are only two microcytic anemias that we talked about: iron deficiency anemia and thalassemia. In IDA, the RDW is increased (because you have red cells of all sizes – they get successively smaller as the iron deficiency gets worse). In thalassemia, the RDW is normal, and for some reason, the RBC is increased. Weird.
So – your grandfather probably has an iron deficiency anemia. The next thing to do is find out WHY he has this. If IDA occurs in a premenopausal woman with heavy menses, IDA is not concerning. But IDA in a male is always worrisome. You don’t want to just give him iron, because you could miss a slow GI bleed from something like a colon cancer.
5. C. Megaloblastic anemia
This patient is anemic, and his red cells are macrocytic. The only macrocytic anemia on the list is C, megaloblastic anemia. He probably is folate deficient as a consequence of his alcoholism (the diet can suffer in chronic alcoholics).