SBB final exam questions and 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 - 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: 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. ficin (breaks down proteins) and chloroquine (dissociates bound antibody from RBCs/ destroys HLA antigens) do not disrupt disulfide bonds. Therapeutic plasma exchange is most useful in treating patients with: A. Circulating immune complexes B. Autoimmune diseases C. high titer IgG anti-D D. Hyperimmune synromes - Correct: Circulating Immune Complexes Plasma exchange is used to help a temporary condition. So an autoimmune disease is better treated with the use of steroids and other medicines that will suppress the autoantibody production. A patient with high titer anti-D is actively producing anti-D. So these patients will also not benefit from plasma exchange since their immune system is just going to produce more anti-D. Patients with hyperimmune syndromes are also actively producing harmful substances, so removing them won't be effective since more will be produced as soon as the procedure is completed. Circulating immune complexes are a condition that is caused by antigen-antibody reaction due to a short lived condition, so the use of plasma exchange is very effective in removing those large complexes. With additional treatment, we can prevent more immune complexes from forming so once the exchange is complete, the condition is most often resolved. Which of the following donors is eligible to donate? A. Wife of a patient with active Hepatitis ; they are living together; last sexual contact was 18 months ago. B. Former prostitute; married with no high-risk behavior for 10 years C. Male who had sex with another male 11 months ago D. Male jailed for 7 days, 15 months ago - Correct: Male jailed for 7 days, 15 months ago AABB standards (32nd ed): Incarceration for more than 72 consecutive hours defers the donor for 12 months from the date of release. Because this donor was released 15 months ago, he is eligible.