Paediatric Anemias MCQs

Human Parvovirus B19, also written as B19V, is notorious for aplastic crisis in chronic hemolytic states. Individuals with chronic hemolytic anemia and increased red blood cell (RBC) turnover, including Sickle Cell Anemia & Hereditary Spherocytosis, are very sensitive to minor perturbations in erythropoiesis. Infection with B19V leads to a transient arrest in RBC production and a precipitous fall in serum hemoglobin, often requiring transfusion. The reticulocyte count drops to undetectable levels, reflecting the lysis of infected erythroid precursors. Humoral immunity is crucial in controlling infection. Specific immunoglobulin (Ig) M appears within 1-2 days of infection and is followed by anti-B19 IgG, which leads to control of the infection, restoration of reticulocytosis, and a rise in serum hemoglobin. Reference: Nelson 21 st Edition, Chapter 278

Sickle cell hemoglobinopathy occurs due to mutation of beta-globin gene situated on short arm of chromosome 11, where adenine is replaced by thymine in base of DNA coding for the amino acid in the sixth position in beta-globin chain. This leads to an amino acid change in beta chain of Hb molecule, from glutamic acid to valine. The result is profound change in the molecular stability and solubility of Hb "S". Reference: IAP Textbook of Pediatrics 5 th Ed/Page 700, OP Ghai 10 th Edition, Page 364

All patients with sickle cell anemia are at increased risk of infection and death from bacterial infection, particularly encapsulated organisms such as Streptococcus pneumoniae Hemophilus influenzae type b Neisseria meningitidis Tags : Topic : BACTERIAL INFECTIONS Difficulty level : GOOD TO KNOW Reference : Nelson textbook of pediatrics, 21 st ed., pg. 2542

Bebtelovimab : This is a monoclonal antibody used for COVID-19 treatment , not related to the management of sickle cell anemia. Disease-Modifying Drugs in ménagement of Sickle cell anemia (A): Hydroxyurea :It increases fetal hemoglobin (HbF) levels, reducing sickling and vaso-occlusive crises. (C): L-Glutamine : Approved for sickle cell disease; reduces oxidative stress and decreases the frequency of pain crises. (B): Voxelotor : A hemoglobin modulator that stabilizes oxygenated hemoglobin, reducing hemoglobin polymerization and improving anemia Crizanlizumab :A monoclonal antibody targeting P-selectin to reduce adhesion of sickled cells to the endothelium. Decreases vaso-occlusive crises Reference: Nelson textbook of paediatrics