Irregular RBC antibody detection clinically important for pregnant women: Study
Irregular red blood cell (RBC) antibodies are antibodies
against blood group antigens other than ABO antigens and can cause difficulties
in blood typing and cross-matching, hemolytic transfusion reactions (HTRs) of
varying severity, and hemolytic disease in the fetus and newborn (HDFN). It is
generally accepted that the irregular RBC antibodies produced by “natural
immunity” are mainly IgM antibodies, which are not clinically important; irregular
RBC antibodies that are clinically important are mainly IgG antibodies, which
are the less common type and are produced due to pregnancy, allogeneic blood
transfusion, allogeneic tissue and organ transplantation, and other forms of
allogeneic immunity. It was previously believed that fetomaternal hemorrhage
occurs mainly in late pregnancy or during delivery; clinically significant
alloimmune irregular RBC antibodies are rarely produced during the first
pregnancy without a history of other alloimmunizations; and clinically
significant irregular RBC IgG antibodies are produced after the second period
of alloimmunization. However, a recent study showed that fetal RBCs can be
detected in maternal blood samples at 6–22 weeks of gestation but there is a
lack of research data to guide the clinical management of maternal and fetal
blood and determine whether fetomaternal hemorrhage can lead to the production
of alloimmune irregular RBC antibodies in pregnant women during their current
pregnancy.
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
