Irregular RBC antibody detection clinically important for pregnant women: Study

To understand the risk of the production of irregular RBC antibodies during the current pregnancy as a result of gestational alloimmunization, authors performed screens for irregular RBC antibodies in 4983 pregnant women during their late first pregnancy and 13,027 women patients with a history of multiple (two or more) pregnancies, and compared the differences in irregular RBC antibody positivity and specificity between the two groups; these results will be important for guiding clinical practice in maternal and fetal/neonatal blood management.

Using the microcolumn gel antiglobulin method, 18,010 Chinese women with a history of pregnancy and pregnant women were screened for irregular RBC antibodies, and for those with positive test results, antibody specificity was determined. The detection rate and specificity of irregular RBC antibodies in women with a history of multiple pregnancies (two or more) and first-time pregnant women were determined.

In addition to 25 patients who passively acquired anti-D antibodies via an intravenous anti-D immunoglobulin injection, irregular RBC antibodies were detected in 121 (0.67%) of the 18,010 women. Irregular RBC antibodies were detected in 93 (0.71%) of the 13,027 women with a history of multiple pregnancies, and antibody specificity was distributed mainly in the Rh, MNSs, Lewis, and Kidd blood group systems; irregular RBC antibodies were detected in 28 (0.56%) of the 4983 first-time pregnant women, and the antibody specificity was distributed mainly in the MNSs, Rh, and Lewis blood group systems.

The difference in the percentage of patients with irregular RBC antibodies between the two groups was insignificant (χ2 = 1 248, P > 0 05).

Of the 121 women with irregular RBC antibodies, nine had anti-Mur antibodies, and one had anti-Dia antibodies; these antibodies are clinically important but easily missed because the antigenic profile of the reagent RBCs that are commonly used in antibody screens does not include the antigens that are recognized by these antibodies.

The results of this study, which included 18,010 obstetrics and gynecology patients who might require transfusion therapy, showed that except for those with the passive acquisition of anti-D antibodies through intravenous anti-D immunoglobulin injections, the irregular RBC antibody positivity rate among women with a history of multiple (two or more) pregnancies and first-time pregnant women was 0.67%, which was lower than that in previous reports. This is mainly because the prevention of alloimmune anti-D antibody production in RhD-negative pregnant women has gradually been emphasized. In recent years, anti-D immunoglobulin has been widely used in RhD-negative pregnant women in areas such as the Pearl River Delta Region of China, reducing the production of alloimmune anti-D antibodies in RhD-negative pregnant women and thus lowering the irregular RBC antibody positivity rate in those with a history of pregnancy.

In summary, this study showed that although the use of antiD immunoglobulin has resulted in a decreasing trend of irregular RBC antibody positivity in women, the irregular RBC antibody positivity rate in women with a history of pregnancy is still 0.67%, and the specific distribution of antibodies is still dominated by the Rh, MNSs, and Kidd blood group systems, which include clinically important antibodies. During the first pregnancy, irregular RBC antibodies of clinical significance, such as anti-E, anti-Mur, and anti-c antibodies, can be produced, and it is necessary to detect irregular RBC antibodies in first-time pregnant women. Mur and Dia should be included in the antigenic profile of the antibody screening reagent RBCs applied to the Chinese population to avoid the omission of anti-Mur and anti-Dia antibodies, which are two clinically important antibodies.

Source: Shujie Wu, Yinglin Wu, Ganping Guo; Wiley Journal of Pregnancy Volume 2024, Article ID 5539776, 6 pages https://doi.org/10.1155/2024/5539776