[The Value of IgG Anti-A/Anti-B Antibody Titers after Absorption of IgG Anti-AB Antibodies in Predicting ABO Fetal Neonatal Hemolytic Disease]

Objective: To analyze the diagnostic value of IgG anti-A/anti-B antibody titer in the serum of type O pregnant women after absorption of IgG anti-AB antibody for ABO hemolytic disease of fetus and newborn (ABO-HDFN).

Methods: From February 2020 to September 2020, 235 samples of neonatal hemolytic disease whose mother's blood type O from Beijing Blood Center were selected. The titer of IgG anti-A/anti-B antibody in mother's serum before and after absorption of IgG anti -AB antibody was detected by microcolumn gel card, and the incidence of ABO-HDFN was statistically analyzed. The titer level of IgG anti-A/ant-B antibody and the incidence of ABO-HDFN were compared before and after the absorption of IgG anti-AB antibody, and the diagnostic efficacy of the titer level of IgG anti -A/anti-B antibody in the serum of type O pregnant women after the absorption of IgG anti-A and B antibodies on the incidence of ABO-HDFN was analyzed using the receiver's work characteristic (ROC) curve.

Results: Of the 235 neonatal hyperbilirubinemia samples with maternal blood type O, 127 were blood type A, 38 of which were diagnosed as ABO-HDFN; 108 were blood type B, of which 31 were diagnosed as ABO-HDFN. Before and after absorption of IgG anti-AB antibody, there was a significant difference in the titer of IgG anti-A/anti-B antibody (P < 0.05). Among the 69 confirmed cases, the incidence of ABO-HDFN increased with the increase of IgG anti-A/anti-B antibody with or without the IgG anti-AB antibody, but the anti-A/anti-B antibody titer ≥1∶512 before the absorption of IgG anti-AB antibody, while the anti-A/anti-B antibody titer decreased significantly, decreasing by three titers, all≤1∶512. The ROC curve shows that the titers of IgG anti-A/anti-B antibodies before and after absorption of IgG anti-AB antibodies can be used as the efficacy indicators for the diagnosis of ABO-HDFN. However, there was a significant difference in the potency of IgG anti-A/anti-B antibody titer for the diagnosis of ABO-HDFN before and after the absorption of IgG anti-AB antibody (P < 0.05). The AUC values were greater than before absorption, indicating that the IgG anti-A/anti-B antibody after the absorption of IgG anti-AB antibody was better than before absorption (P < 0.05).

Conclusion: The higher the titer of IgG anti-A/anti-B antibody measured after absorbing IgG anti-AB antibody, the higher the incidence of ABO-HDFN. In addition, the efficacy of IgG anti-A/anti-B antibody titer to diagnose ABO-HDFN after absorption of IgG anti-AB antibody is higher than that before absorption.