RBC Disorders - Microcytic Anemia

Question 0

What are the sources of iron from our diet? Where is it absorbed? What protein transports iron in the blood? How is iron stored intracellularly? how is iron transported across the cell membrane?

Answer 0

Ironman is consumed from both meat and vegetables. Iron is absorbed in the duodenum. Enterpcytes transport iron across the cell membrane via Ferroportin. Transferrin transports iron in the blood and delivers it to liver and bone marrow macrophages for storage where it is bound to ferritin to prevent it from forming free radicals via Fenton.

Question 1

What is the general cause of microcytic anemia? And what are the four types of microcytic anemias?

Answer 1

Microcytic anemia is due to decreased production of hemoglobin. There’s an extra division to maintain hemoglobin concentration. A decrease in heme which is made of iron and protoporphyria can cause microcytic anemia. The four kinds are 1. iron deficiency 2. chronic disease 3. Sideroblastic 4. Thalassemia

Question 2

What causes iron deficiency in infants, children, adults, the elderly?

Answer 2

Infants is breast-feeding. Children is poor diet. Adults is peptic ulcer disease in males and menorrhagia or pregnancy in females. Elderly have colon polyps or carcinoma in the west or hookworm in the developing region.

Question 3

Is it heme or nonheme that is more readily absorbed in entericytes? Which iron state is better absorbed?

Answer 3

Heme form. Fe2+ more than Fe3+.

Question 4

What are the four stages of iron deficiency?

Answer 4

1. Iron storage is depleted low ferritin 2. Serum iron is depleted low serum iron 3. Normocytic anemia 4. Microcytic, hypochromic anemia which is the bone marrow making smaller and fewer RBCs.

Question 5

What are the clinical features of iron deficiency and water some laboratory findings? How is it treated?

Answer 5

Clinical findings are anemia, koilonychua and pica. Laboratory findings are low ferritin, high TIBC high free erythrocyte protoporphyrin and hypochromic RBCs with increased red cell distribution width. Treatment is via supplemental iron.

Question 6

49-year-old police Hooman presents to you with symptoms of anemia and a history of difficulty swallowing. When doing physical examination you noticed that her tongue is really red almost beef red. What does she have and what are some classical findings?

Answer 6

She has plumber – Vinson syndrome which has esophageal web on imaging and atrophic glossitis.

Question 7

How does chronic disease cause microcytic anemia?

Answer 7

Chronic disease increases have site in production. If side and lower siren by a. Limiting iron transfer from macrophages to erythroid precursors b. Suppressing EPO production to prevent bacteria from accessing iron. Low available Iron - low heme -low hemoglobin- microcytic anemia

Question 8

What are the lab findings in anemia chronic disease with ferritin, serum iron, FEP, saturation? What is treatment?

Answer 8

High ferritin, low serum iron, low percent saturation, low TIBC, high free erythrocyte protoporphyria. Treatment involves addressing the underlying issue of chronic inflammation.

Question 9

What causes Sideroblastic anemia? What are the two kinds of sideroblastic anemia and what cause them? What are laboratory findings in sideroblastic anemia?

Answer 9

Psycho plastic anemia due to a defective protoporphyrin synthesis. The two kinds are congenital which involves a LAS enzyme and acquired which is caused by alcoholism, lead poisoning, vitamin B6 deficiency. Lab findings include increased Ferritin; increased serum iron; increased saturation and decreased TIBC.

Question 10

What is the characteristic finding in sideroblastic anemia?

Answer 10

The characteristic finding is a ring of iron filled mitochondria around the nucleus of erythroid precursors.

Question 11

How is protoporphyrin synthesized? How and where is heme made from protoporphyrin?

Answer 11

Succinyl CoA a is converted to ALA using ALAS and vitamin B6 -which is the rate limiting step. ALA is converted to porphobilinogen using ALAD. Porphobilinogen is then converted to protoporhirin. Ferrochelatase attaches protoporphyrin to iron to make heme in the mitochondria.

Question 12

What causes Thalassemia? What are carriers protected against? What are the two classifications of Thalassemia?

Answer 12

Thalassemia is due to decreased synthesis the globin chains. Carriers are protected against Plasmodium falciparum malaria. It is divided into Alpha and Beta thalassemia based on increased production of alpha or beta globin chains.

Question 13

What is the cause of alpha thalassemia ? Which chromosome is it located on? How many Alpha thalassemia are there?

Answer 13

It is due to Jean deletion. Four Alpha genes on chromosome 16.

Question 14

An African-American patient comes to your clinic for alpha thalesmmia treatment. What type of deletion does she have?

Answer 14

Trans deletion.

Question 15

A Chinese patient comes to your clinic for alpha thalesmmia treatment. What type of deletion does she have?

Answer 15

Cis deletion.

Question 16

What are the electrophoresis findings when three genes and four genes are deleted? What causes hydrops fetalis?

Answer 16

Three genes HbH and four genes HB barts. 4 gene deletion. It is lethal in utero. Gamma chains form tetramers the damage red blood cells.

Question 17

What is the cause of beta thalassemia ? Which population is it usually seen in?Which chromosome is it located on? How many Alpha thalassemia are there?

Answer 17

B-thalassemia is due to Gene mutations seen in people of African and Mediterranean descent. Two beta genes on chromosome 11. Mutations resulting absent B0 or diminished B plus production of the beta-globin chain.

Question 18

What is the presentation of Beta thalassemia minor? What would you see on blood smear and hemoglobin electrophoresis?

Answer 18

It is asymptomatic. Blood smear shows microcytic, hypochromic red blood cells and target cells. Hemoglobin electrophoresis shows increased HbA2 and HbF and decreased HbA.

Question 19

At three-month-old girl presents with severe anemia. What do you think she has? Why did she present at three months and not at birth?

Answer 19

She has beta thalassemia major which is the most severe form of disease. High fetal hemoglobin temporarily protects her.

Question 20

How are red blood cells damaged in beta thalassemia major? What massive processes happens? What are some signature findings on the x-ray?

Answer 20

Unpaired alpha chains precipitate and damage red blood cell membrane resulting in ineffective erythropoiesis and extravascular hemolysis. Massive erythroid hyperplasia ensues. Signature findings on x-rays are crewcut appearance and chipmunk facies.

Question 21

What are the manifestations of massive erythroid hyperplasia?

Answer 21

A. Expansion of hematopoiesis into the skull causing crew cut and chipmunk faciea B. Hepatosplenomegaly due to extra medullary hematopoiesis C. Aplastic crisis with parvovirus B 19 infection.

Question 22

How is beta Thalesemmia major treated? What are the risks? What does blood smear show? Electrophoresis?

Answer 22

Chronic transfusions. Increased risk for secondary hemachromatosis. Smear shows microcytic, hypochromic red blood cells with target cells and nucleated red blood cells. Electrophoresis shows little or no HbA, But you have HbA2 and HbF.