HDFN Due to Other Antibodies
After anti-D, the antibodies that are most often associated with HDFN include:
- anti-Fya (rarely)
- anti-Jka (rarely)
- anti-M,-N,-S,-s,-U (all rarely)
Of these antibodies, anti-K, anti-c, and anti-E are more common causes. Anti-K typically causes more severe HDFN (hydrops and neonatal death) than the others. Anti-c has also been known to cause severe HDFN.
Antibodies to low frequency antigens have also been known to cause HDFN, albeit rarely. Examples include anti-Mia, -Dia, -Wra and anti-Rd. In such cases the maternal antibody screen is usually negative and the only unexpected test is a positive DAT on the newborn.
In theory any IgG antibodies directed against antigens that are well developed on fetal red cells can cause HDFN. The complete list of antibodies documented to cause HDFN is long and will not be covered in this survey course.