Extended matched intrauterine transfusions reduce maternal Duffy, Kidd, and S antibody formation.

BACKGROUND: Severe alloimmune hemolytic disease of the fetus is treated with intrauterine transfusions (IUTs). Despite C, c, E, e, and K matching between mother and donor, IUT results in new antibodies in approximately 25% of women. Newly formed Fy(a), Fy(b), Jk(a), Jk(b), and S antibodies are in 83% presumably induced by the IUT donor. Therefore, we intentionally extended matching between mother and IUT donor for these additional antigens. The results, after almost 8 years of applying this protocol, are reported.

STUDY DESIGN AND METHODS: Data from February 2007 to August 2014 on IUT patients were retrieved from the Leiden University Medical Center database and from donors from the Sanquin National Donor Database. Maternal data included red blood cell (RBC) antigen profiles, RBC antibodies, and date and consecutive number of each IUT. From the fathers, children, and IUT donors the RBC antigen profiles were retrieved.

RESULTS: A total of 182 fetuses from 159 women were treated with 481 IUTs. Of these, 317 IUTs (66%) were matched for Duffy, Kidd, and S antigens. Only matched IUTs were received by 77 women (48%) and 82 (52%) received (partly) nonmatched IUTs. Evaluable for new antibodies were 142 women. Duffy, Kidd, or S antibodies were formed by three of 69 women (4.3%) after matched IUTs and by eight of 73 women (11.0%) after nonmatched IUTs.

CONCLUSION: Extended matching for all IUTs was not possible for approximately 50% of women. Strict adherence to Duffy, Kidd, and S antigens-matched IUTs decreased immunization against these antigens by 60% compared to nonmatched IUTs.