Module 2 - Microcytic-Hypochromic Anemias - Sideroblastic Anemia

Question 1

What heterogenous group makes up SA?

Answer 1

heterogeneous group of inherited and acquired disorders.

Question 2

What characterizes SA?

Answer 2

anemia of varying severity and the presence of ringed sideroblasts in the bone marrow

Question 3

What are ringed sideroblasts

Answer 3

-erythroblasts that have iron-laden mitochondria arranged in a circle around one-third or more of the nucleus
-these are red blood cells that have iron granules that have not been synthesized into hemoglobin.

Question 4

Individuals with SA have increased levels of this.

Answer 4

Individuals with SA also have increased tissue levels of iron.

Question 5

SA have various causes but they have this similarity.

Answer 5

ll have altered heme synthesis in the erythroid cells in bone marrow.

Question 6

What are the different types of SA?

Answer 6

• Acquired sideroblastic anemias (ASAs)
• reversible sideroblastic anemias (reversible SAs),
• Hereditary (congenital) sideroblastic anemias

Question 7

This is the most common SA, occur as a primary disorder with no known cause?

Answer 7

Acquired sideroblastic anemias (ASAs)

Question 8

What are ASA’s associated with?

Answer 8

myeloproliferative or myeloplastic disorders such as myeloma, polycythemia vera, and leukemias.

Question 9

This type of SA is secondary to conditions such as alcoholism, medication reactions, copper deficiency, and hypothermia.

Answer 9

reversible sideroblastic anemias (reversible SAs)

Question 10

Reversible SA associated with alcoholism results from what?

Answer 10

nutritional deficiencies of folate.

Question 11

What the hypothermia cause?

Answer 11

decreased heme synthesis and incorporation into hemoglobin.

Question 12

This type of SA are rare and occur almost exclusively in males, supporting a recessive X-linked transmission.

Answer 12

Hereditary (congenital) sideroblastic anemias

Question 13

Which type of SA occur almost exclusively in males?

Answer 13

Hereditary (congenital) sideroblastic anemias

Question 14

What is the leading cause of primary ASA?

Answer 14

myelodysplastic syndrome (MDS), is a group of disorders of hematopoietic stem cells demonstrating abnormal growth or cell characteristics.7

Question 15

What are the clinical manifestations of SA anemias?

Answer 15

• moderate to sever
• Hgb 40-100g/L
• cardio and resp symptoms
• signs of overload - hemochromatosis
• mild to moderate enlargement of liver (hepatomegaly) and spleen (splenomegaly)
• Liver function normal or mildly affected
• skin may be bronzed tinted
  -**infants and children - growth and development impairment if severely affected

Question 16

How is SA diagnosed?

Answer 16

bone marrow biopsy

Question 17

What are treatments?

Answer 17

1. identification of cause
2. supportive treatment(transfusion)
3. alchohol abuse and pyroxidine antagonist causes - shows complete response to pyroxidine. Other etiologies does not show same improvement.

Question 18

What is the initial treatment for hereditary SA and how effective is it?

Answer 18

pyroxidine therapy, effective 1/3 of individuals but structural abnormalities does not disappear.

Question 19

What happens to hgb with treatment of pyroxidine?

Answer 19

level can increase but stabilize at less than normal levels

Question 20

What if no response to pyroxidine?

Answer 20

Need blood tranfusion

Question 21

What is treatment for iron overload?

Answer 21

iron depletion therapy to minimize organ damage

Question 22

What is used on individuals with mild to moderate anemia without other complications?

Answer 22

Phlebotomy

Question 23

What is used for severe iron overload?

Answer 23

the use of deferoxamine, an iron-chelating agent, reduces excess iron levels.

Question 24

What type of SA will less likely to respond to pyridoxine

Answer 24

Individuals with acquired SA

Question 25

What are some of the recent treatments for SA’s

Answer 25

• prolonged administration of erythropoietin and stem cell transplant.