Extravascular Hemolysis MCQs

Following factors determine the rate at which the polymerization of HbS and consequent sickling take place: Presence of non HbS hemoglobin Intracellular concentration of HbS Total hemoglobin concentration Extent of deoxygenation Acidosis and dehydration Increased concentration of 2, 3 BPG in the red cells Reference: Harsh mohan, 6 th edition, page number-319

Pathogenesis of Sickle cell anemia: Sequence of codon 6 of the Beta-chain changed from GAG in the normal gene to GTG in the sickle cell gene, resulting in substitution of valine for glutamic acid Concept: So if you see, the charge of amino acid is changing from charged (glutamic acid, more negative) to neutral amino acid (valine), so when we do an electrophoresis, the mobility of HbS will be lesser than HbA towards Anode (i.e retarded) (which is positively charged). Reference: Complete review of Pathology 1st/343

This disorder stems from inherited (intrinsic) defects in the red cell membrane that lead to the formation of spherocytes, nondeformable cells that are highly vulnerable to sequestration and destruction in the spleen. Hereditary spherocytosis is usually transmitted as an autosomal dominant trait; a more severe, autosomal recessive form of the disease affects a small minority of patients. The characteristic features are anemia, splenomegaly, and jaundice. The anemia is variable in severity, ranging from subclinical to profound; most commonly it is moderate in degree. Because of their spherical shape, red cells in hereditary spherocytosis show increased osmotic fragility when placed in hypotonic salt solutions, a characteristic that can help establish the diagnosis. Reference: Robbins, 10 th edition, page number445

Hereditary spherocytosis is hemolytic anemia so high reticulocyte count. All others have normal to low reticulocyte count Reference: Wintrobe 1165

Hemolytic anemias have high retic counts. Autosplenectomy can be seen in sickle cell anemia. Reference: Robbins, 10 th edition page number - 111, 117, 488

A decreased Erythrocyte Sedimentation Rate (ESR) can be caused by several factors. Here are some of the common causes: Polycythemia Vera: This is a condition characterized by an increased number of red blood cells Sickle Cell Disease: This is a genetic disorder that affects the shape and functionality of the red blood cells Hyperviscosity Syndrome: This is a group of symptoms triggered by an increase in the viscosity of the blood Hereditary Spherocytosis: This is a condition that leads to an abnormality in the red blood cell membrane, causing the cells to take on a spherical shape Abetalipoproteinemia and Acanthocytosis: These are rare inherited disorders affecting fat absorption and red blood cell shape Reference: Robbins & cotran pathologic basis of diseases, 10 th edition Chapter 14, pg 641

Hemolytic disease of new born results from the passage of IgG antibodies from maternal circulation across the placenta into the circulation of the foetal red cells. Besides pregnancy, sensitization of the mother may result from previous abortions and previous blood transfusions. It occurs from incompatibilities of ABO or RH blood group. Rh incompatibilities results in severe hemolytic disease of new borns. It results in intrauterine death from hydrops fetalis. Moderate disease produce baby born with severe anemia and jaundice due to unconjugated hyperbilirubinemia. When the level of unconjugated bilirubin exceeds 20 mg/dl, it results in deposition of bile pigments in the basal ganglia of CNS called kernicterus and gives permanent brain damage. Reference: Harsh mohan, 6 th edition, page number - 341

The mutation in sickle cell anaemia is an example of missense mutation. Sickle cell disease(scd) is a genetic disorder caused by a mutation in both copies of a person's hbb gene. This gene encodes a component of hemoglobin, the oxygen-carrying protein in red blood cells. The mutation causes hemoglobin molecules to stick together, creating sickle-shaped red blood cells. Reference: Robbins and Cotran Pathologic Basis of Diseases, 10 th ed Pg: 244