ABO incompatibility and RhIG immunoprophylaxis protect against non‐D alloimmunization by pregnancy. Issue 7 (6th April 2018)

• Record Type: Journal Article
• Authors: Zwiers, Carolien; Koelewijn, Joke M.; Vermij, Lisa; van Sambeeck, Joost; Oepkes, Dick; de Haas, Masja; van der Schoot, C. Ellen
• Is Part Of: Transfusion. Volume 58:Issue 7(2018)
• Page Start: 1611
• Page End: 1617
• Publication Date: 2018-04-06
• Subjects: Hematology -- Periodicals; Blood -- Transfusion -- Periodicals; Blood Group Antigens -- Periodicals; Blood Preservation -- Periodicals; Blood Transfusion -- Periodicals; 615
• DOI: 10.1111/trf.14606
• Languages: English
• ISSNs: 0041-1132

Abstract

Abstract : BACKGROUND: Hemolytic disease of the fetus and newborn (HDFN) is caused by maternal antibodies against fetal red blood cell antigens, most often anti‐D, ‐K, or ‐c. ABO incompatibility between mother and child and anti‐D immunoprophylaxis (RhIG) are known to reduce the risk of D immunization and subsequent HDFN. However, no immunoprophylaxis has been developed to prevent non‐D immunizations. STUDY DESIGN AND METHODS: We evaluated whether ABO incompatibility has a preventive effect on formation of non‐D alloantibodies, by performing a case‐control study including pregnant women with newly detected non‐D antibodies, identified within a nationwide data set, immunized during their first pregnancy and/or delivery. Subsequently, we assessed a possible protective effect of RhIG in a subgroup with non‐Rh antibodies only. The proportions of previous ABO incompatibility and of RhIG administrations of these women were compared to the known rate of 19.4% ABO incompatibility and 9.9% RhIG administrations (D– women carrying a D+ child) in the general population of pregnant women. RESULTS: A total of 11.9% of the 232 included immunized women had a possible ABO incompatibility in their first pregnancy (vs. expected 19.4%; 95% confidence interval [CI], 7.3‐18.8; p = 0.036). Furthermore, 1.0% women with non‐Rh antibodies were D–, delivered a D+ child, and had therefore received RhIG, whereas 9.9% was expected (95% CI, 0.18‐5.50; p = 0.003). CONCLUSION: We found that ABO incompatibility and RhIG reduce the risks not only for D, but also for non‐Rh immunizations, suggesting that antibody‐mediated immune suppression in this condition is not antigen specific.