Hemolytic Disease of the Newborn Case #3

1. Hemolytic Disease of the Newborn Case #3

2. Scenario Baby Girl Dae two-day old jaundiced newborn girl sample of her blood is submitted to the Blood Bank for an HDN work-up

3. What we know about the Mother • Doris Dae (mother) • mother's first pregnancy • pre-natal type and screen done at 2 months - ADT negative • Blood was tested again at 28 weeks gestation - ADT negative • Received prophylactic antenatal RhIg at 28 weeks • a post-delivery specimen was submitted for an RhIg retest

4. What we know about Baby • Blood type - A pos • Test for Circulating Antibody (reverse type) • shows 1+ reaction with A1 cells, no reaction with B cells • indicates presence of anti-A1 in baby's serum (must be maternal IgG since baby is not producing antibodies yet) • Antibody screen - negative • indicates ABO antibody or rare antibody • DAT - positive at immediate spin (indicates IgG antibody) • NOTE: positive result means that antibody is present on baby's cells; does NOT indicate severity of reaction

5. Elution Results on Baby’s blood • Elution results • Positive for A1 cells (both Rh pos and neg) • indicates that antibody coating the baby's RBCs is ABO, not Rh • At this stage we know that the baby has maternal ABO antibody coating her cells • Most likely culprit is anti-A,B

6. Further work up on Mom • Doris Dae • Post-delivery confirmation of blood type - O negative • Post-delivery antibody screen (ADT) • positive reaction for both screening cells at AHG (1+) • Antibody Detection Panel • most likely antibody: anti-D • can't rule out anti-C, -E, -Cw, -K

7. Is there a serological problem in either the mother or the baby? • Yes - baby is reacting to any antibody from the mother; mother has tested positive for an antibody as well

8. Does the child have HDN? What type of HDN? • Yes - ABO HDN The baby's back typing/test for circulating immune antibody is positive; reacting at the AHG level at a 1+, and the baby's DAT is positive at both the initial spin and at 5 minute incubation. This indicates there has been in vivo sensitization of the baby's RBC's with IgG and/or complement by the mother's cells. The baby's cells are coated with (most likely) IgG antibodies to A from the mother, and are thus being removed from her body via the spleen and liver causing the jaundice

9. What led you to the conclusion of HDN and what is/are the implicated antibodies? • DAT - shows that there is an IgG antibody coating the baby's RBCs • Back type and elution - shows that it is an ABO reaction, not Rh or non-Rh. Weak D reaction is negative • Clinical presentation and patient history also helps • jaundiced baby within 48 hours of delivery • mother's first pregnancy • Mother is type O- and baby is type A+ • Antibody present: most likely anti-A,B

10. How would you explain the testing results to the physician as they relate to the clinical picture of the infant? • Discuss clinical presentation of ABO HDN, both the mother and the newborn’s test results and common treatments • transfusion is rarely needed for ABO HDN • Increasing levels of bilirubincan be treated with phototherapy using a blue light of a specific frequency that breaks down the bilirubin to a water soluble form that is easier for the body to get rid of • the infant’s rising bilirubin levels are seen due to the liver’s immaturity/inability to keep up with the excess free hemoglobin from the lysis of the baby’s IgG coated RBC’s. While inutero, the mother’s liver was clearing the antibody coated infant’s RBC’s, therefore the excess bilirubin was not building up

11. Transfusion indicated treatment in the newborn for HDN ABO • Rapidly increasing bilirubin levels not controlled by the phototherapy • Transfusion with group O Rh- RBC’s may be required

12. What type of red cells, plasma, and platelets should be given if the mother requires blood? • RBC - O neg • Plasma - O preferred, any type will be acceptable • Platelets - O neg Red Cells Recipient type1st Choice 2nd Choice 3rd Choice 4th Choice AB AB A B O A A O B B O O O Platelets, Plasma, and Cryoprecipitate AB AB A A AB (universal plasma donors) B B AB O O Any – Depending on inventory because there is no antigen on the red cells Rh matching is not required with plasma and cryo Platelets must be selected according to Rh D neg or positive type of recipient.

13. What type of red cells, plasma, and platelets should be given if the baby requires blood? • RBC - O neg • Plasma - AB • Platelets - O neg • Baby should be transfused using cells that match the mother’s blood type and Rh. Also O neg is the universal donor type since it has no antibodies on the surface of the red cells

14. Were there any unnecessary tests done? • Back-typing the baby with B cells was not necessary -- baby is not producing antibodies yet, and if maternal ABO crossed the placenta it is most likely anti-A,B (anti-A and anti-B are IgM unless the mother was immunized in some rare scenario)

15. Are there any additional tests that would be useful in solving this problem? • Test baby's eluate or mother's serum for anti-A,B to confirm that it is the antibody causing the reaction • To finish the work-up you should try to rule out the additional antibodies from the mother's antibody panel • Titer in first trimester. • Paternal Testing - phenotyping the father to see if the he has the antigen corresponding to the mother's antibody can help the diagnosis.

16. Should this mother receive RhIg? Why or why not? • yes - mother is Rhneg and the baby is Rh pos and we want to prevent the mother from becoming immunized • the mother's pre-natal and 28 week ADT were both negative • post-natal ADT was positive but weak • Baby RBC elution shows no anti-D • positive post-natal ADT is due to residual RhIg? from the prophylactic treatment at 28 weeks

17. Why is baby only reacting with A? • cells have more A receptors than B receptors - the A response was already pretty weak so the B response may not have been detectable (not high enough titer of antibody?) • mom could have been previously immunized and formed IgG anti-A (rare!)