sbb final Complete Questions & Answers

A peripheral smear with increased polychromasia, schistocytes and spherocytes is indicative of which condition? A. Aplastic anemia B. Iron deficiency anemia C. Hemolytic anemia D. Megaloblastic anemia - ANSWER C. Hemolytic anemia Megaloblastic anemia would show larger, less mature RBCs on the smear. Iron deficiency anemia would show hypochromasia, and a lower RBC count. Aplastic anemia would show very little amounts of mature RBCs on the smear Hemolytic anemia results in misshapen RBCs and inconsistent RBC appearance because of the rapid RBC destruction. Because the RBCs have as shortened survival, pieces of the membrance can break off resulting in spherocytes and schistocytes. Which of the following treatments is useful when distinguishing between anti-D and anti-Lw? A. Choloroquine B. Cord cells C. Ficin D. Dithiothreitol - ANSWER Answer: Dithiothreitol (DTT) LW antigens require divalent cations (e.g., Mg2+) for expression and have intramolecular disulfide bonds that are sensitive to dithiothreitol (DTT) treatment. DTT treatment is helpful to differentiate anti-LW from anti-D, because the D antigen is resistant to DTT while LW antigen is sensitive to DTT. LW antigens are expressed equally well on group O D-positive and D-negative cord blood red cell. expected reaction with O- cord RBCsexpected reaction with O+ DTT treated RBCsanti-LW+-anti-D-+ The best answer is DTT. Cord cells are not considered a treatment and often used in conjunction with DTT results to confirm the presence of either antibody.