Types Of Anemia

The pathogenesis of anemia seen in the patient is due to decreased beta-globin chain synthesis. This means that there is a deficiency in the production of beta-globin chains, which are necessary for the formation of hemoglobin. Hemoglobin is responsible for carrying oxygen in the blood, and a decrease in its production leads to a decrease in the oxygen-carrying capacity of the blood, resulting in anemia. The other options mentioned, such as decreased heme synthesis, abnormal spectrin assembly, clonal stem cell defect, and impaired utilization of iron from storage sites, are not relevant to the specific pathogenesis described in the patient.

B) Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal stem cell disorder that is characterized by abnormal red cells, granulocytes and platelets. The RBCs are abnormally sensitive to the lytic activity of complement due to a deficiency of GPI linked proteins, namely decay accelerating factor (DAF; or CD55), membrane inhibitor of reactive lysis (CD55) or CD59 (a C8 binding protein). Complement is normally activated by acidotic states, such as occur with exercise or sleep. In patients with PNH, the acidotic condition that develops during sleep ( which is usually at night) causes hemolysis of red cells and results in red urine in the morning. The RBCs of these patients lyse in vitrowith acid (sucrose lysis test).
A positive Coombs test suggests immune-related hemolysis.

In homozygous beta-thal (thal major), most of the Hb is of the fetal type (HbF).

B. Correct. Irreversible sickle cells show a rearrangement of phospholipids b/w the outer and inner monolayers of the cell membrane. RBCs are no longer deformable and more adherent to endothelial cells, which predispose to ischemia and thrombosis. Iscehmia leads to severe pain, esp in chest, abdomen and bones.

B. CORRECT. Hereditary spherocytosis is due to an abnormality in RBC cytoskeleton (structural membrane protein spectrin accounts for the abnormality). Negative Coombs test rules out the possibility of auto-immune emolytic anemia.

(B) CORRECT. The form of alpha-thalassemia seen in Southeast Asia has two abnormal alpha globin genes on the same chromosome, so it is possible to inherit two bad sets, leading to a complete lack of alpha globin chain formation, so that fetal hemoglobin cannot be made, and there is a severe anemia.
Incorrect. Sickle cell anemia is seen in persons of African and eastern Arabian ancestry. In perinatal life and in infancy, there is sufficient hemoglobin F to prevent complications.
(C) Incorrect. G6PD disease is most frequent in Africa and Mediterranean regions and can produce a hemolytic anemia when the RBC's are stressed by oxidants
(D) Incorrect. Hereditary elliptocytosis may cause a mild anemia.

(E) CORRECT. He has glucose-6-phosphate dehydrogenase (G6PD) deficiency, which can result in a hemolytic anemia on exposure to oxidizing agents such as certain drugs such as antimalarials. This is an X-linked disorder. The Heinz bodies are denatured hemoglobin.

(A) There is a marked hypocellularity of the bone marrow with aplastic anemia, and resulting pancytopenia. The spleen is of normal size
Spleen in CML can reach massive proportions.
Spleen is often palpably enlarged with infectious mononucleosis, there may be mild anemia, but not marked pancytopenia.
Large cell lymphomas tend to be localized masses that do not fill up the bone marrow to cause pancytopenia.
There is splenomegaly with HS. Removal of the spleen in adults with HS leads to a decrease in problems resulting from spherocytosis.

C. Exposure to benzene, pancytopenia, low reticulocyte count and hypocellular marrow with increased fat – all are pointers for aplastic anemia

B. Correct. Cell membrane of reversible sickle cells are sticky and adhere to capillary endothelium. This is due to an increased expression of adhesion molecules. Also, free Hb is depleted by binding to NO, resulting is further vasoconstriction.

B. Correct. Chronic infections like TB result in impaired utilization of iron from macrophage stores in BM, resulting in a functional iron deficiency. Iron stores may be normal or increased.

(C) CORRECT. The serum iron and iron binding capacity are both low, and reticulocytosis is diminished in spite of the anemia. In this condition, iron is not recycled appropriately.

B. Correct. Spherocytes undergo extra-vascular hemolysis resulting in excessive bilirubin. This results in pigmented gallstones in these patients.

(B) CORRECT. Reduced beta-globin chain synthesis from beta-thalassemia leads to RBC microcytosis, hypochromasia, ineffective erythropoiesis, and excessive iron absorption.

E. Correct. The PBS shows fragmented red cells or schistocytes, which are seen in DIC, TTP, HUS or RBC breakdown due to mechanical trauma.