An infant’s blood type is a recognized potential risk factor for hemolytic disease of the fetus and newborn (HDFN), and those with certain types are an elevated risk for the disorder, according to findings from a study conducted in Jakarta, Indonesia, and published in the Medical Journal of Indonesia.
HDFN can be associated with the development of anemia, jaundice, hyperbilirubinemia and even brain damage in a fetus or a newborn. Immunoglobulin G (IgG) is known to be the only antibody that is capable of crossing the placenta. This class of antibodies can be divided into four different subtypes—IgG1, IgG2, IgG3, and IgG4—with each of these subtypes exhibiting a different way in which to destroy red blood cells (RBCs). Although IgG1 and IgG3 both can bind to Fc-phagocyte cell receptors, which, in turn, can lead to hemolysis, IgG3 has a greater ability to do so when compared with IgG1.
Despite the fact that a variety of studies on IgG subtypes have been carried out in numerous countries, which IgG subtypes are associated with the development of HDFN in Indonesia remains to be seen. The researchers sought to establish which subtype of IgG plays a role in the development of HDFN, and thus can lead to clinical symptoms in fetuses and newborns.
Learn more about HDFN testing and diagnosis
A total of 30 pairs of newborns and mothers with different blood types who were being treated in the Division of Perinatology, Department of Obstetrics and Gynecology, Cipto Mangunkusumo Hospital and Budi Kemuliaan Hospital, located in Jakarta, were enrolled in the study. The gestational age of the participants ranged between 36 and 40 weeks. The cutoff bilirubin concentration was 5 to 13 mg/dL over 0 to 48 hours.
The study utilized blood and umbilical cord blood samples from the 30 mother/baby pairs. The samples were divided into two groups: one group included patients with jaundice or hyperbilirubinemia, and the other was a control group.
A self-developed enzyme-linked immunosorbent assay protocol was used for detection of the IgG antibody subtypes. In the samples collected from the mothers and the babies, the IgG subtypes revealed were IgG1, IgG2, and IgG4. The IgG2 subtype was ignored since “it is predominantly responsible for anti-carbohydrate IgG responses against bacterial capsular polysaccharides.”
Results of the study showed that blood type was statistically significantly associated with total bilirubin expression (P =.005). The following statistically significant findings were reported with respect to hyperbilirubinemia in newborns:
- IgG1 anti-A: P =.041
- IgG3 anti-A: P =.013
- IgG4 anti-A: P =.017
- IgG1 anti-B: P =.028
- IgG3 anti-B: P =.001
- IgG4 anti-B: P =.007
“IgG1 and IgG3 were more significant in causing clinical problems. IgG4 suppressed IgG activation, resulting in no destruction of the infant’s RBCs,” the study authors wrote. “[B]esides blood group analysis, we suggest adding an assay for obstetrics and gynecology patients, which is subtype IgG antibody anti-A and anti-B analysis.”
