H EMOLYTIC D ISEASE OF THE N EWBORN C ASE #3

S CENARIO Baby Girl Dae Two-day old jaundiced newborn girl Sample of her blood submitted for HDFN workup

W HAT WE KNOW ABOUT THE M OTHER Doris Dae 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 Post-delivery specimen was submitted for an RhIg retest

S EROLOGICAL R ESULTS FOR B ABY Blood type - A pos Test for Circulating Antibody (reverse type) ABabD [IS]Ctl [IS] IS37 o AHGCCC A 1 cells--1+ B cells---/-+

B ABY ’ S S EROLOGICAL R ESULTS C ONT. Antibody Detection Panel DAT IS37 o AHGCCC I---/-+ II---/-+ IS37 o CCC 1+

E LUTION R ESULTS ON B ABY ’ S BLOOD Elution results At this stage we know that the baby has maternal ABO antibody coating her cells CellsAHGCCC A 1 + cells2+ A 1 – cells2+ B + cells-/-+ B – cells-/-+ O + cells-/-+ O – cells-/-+

S EROLOGICAL R ESULTS FOR M OTHER Post-delivery confirmation of blood type Post-delivery antibody screen (ADT) Antibody Detection Panel Most likely antibody: anti-D Can't rule out anti-C, -E, -Cw, -K ABabDISDIS D 37 o D AHG D CCC Ctl IS Ctl 37 o Ctl AHG Ctl CCC / IS37 o AHGCCC I--1+ II--1+

I S THERE A SEROLOGICAL PROBLEM IN EITHER THE MOTHER OR THE BABY ? Yes - baby is reacting to an antibody from the mother; the mother has tested positive for an antibody as well

D OES THE CHILD HAVE HDN? W HAT TYPE OF HDFN? Yes - ABO HDN Antibody is coating the baby’s cells Baby is showing classic symptoms of a hemolytic reaction Serological testing shows that it is an ABO antibody, not Rh or non-Rh HDFN

W HAT 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 This is the mother's first pregnancy Mother is type O- and baby is type A+ Antibody present: most likely anti-A,B

H OW WOULD YOU EXPLAIN THE TESTING RESULTS TO THE PHYSICIAN ? Discuss clinical presentation of ABO HDN, both the mother and the newborn’s test results and common treatments ABO HDFN usually presents with milder hemolytic symptoms; thus transfusion is rarely necessary Infant’s rising bilirubin levels are due to the liver’s immaturity and inability to keep up with the breakdown excess free hemoglobin due to RBC lysis. In utero, the mother’s liver was clearing the bilirubin before it could accumulate. Increasing levels of bilirubin can be treated with phototherapy using a blue light of a specific frequency that breaks down the bilirubin

T RANSFUSION 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

W HAT TYPE OF B LOOD P RODUCTS SHOULD BE GIVEN TO THE M OTHER ? Blood Products: RBC: O neg Plasma: O preferred, any type will be acceptable Platelets: O neg NOTE: Rh matching is not required with plasma and cryoprecipitate Platelets must be selected according to the Rh status of recipient.

W HAT TYPE OF BLOOD PRODUCTS SHOULD BE GIVEN TO THE BABY ? Blood Products: RBC: O neg Plasma: AB Platelets: O neg NOTE: Baby should be transfused using cells that match the mother’s blood type and Rh status. O neg is the universal donor type since it has no antigens on the surface of the red cells

W ERE THERE ANY UNNECESSARY TESTS DONE ? Back-typing the baby with B cells was not necessary Baby is not producing its antibodies yet 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) Testing with A cells alone would be sufficient to detect anti-A,B or rare anti-A IgG

A RE 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

W HY 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!)

S HOULD THIS MOTHER RECEIVE R H I G ? W HY OR WHY NOT ? yes - mother is Rh neg 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 ?

Q UESTIONS ?