Red blood cell antibodies in pregnancy and their clinical consequences: synergistic effects of multiple specificities.
BACKGROUND
The objective was to determine clinical consequences of various specificities for the infant/fetus. The population was patients referred between 1998 and 2005 to the tertiary center because of detected red blood cell (RBC) alloimmunization. Altogether 455 infants were delivered by 390 alloimmunized women.


METHODS
This was a retrospective cohort study. Data were obtained from the blood bank register and the obstetric and neonatal database. As indicators of hemolytic activity of the antibodies, the frequency of the therapeutic interventions intrauterine transfusion, exchange transfusion, and simple transfusion was used.


RESULTS
Anti-D was the most common antibody (46.6%), followed by anti-K (15.4%). A combination of antibodies was detected in 27%. All three types of therapeutic intervention were significantly more frequent in women with anti-D plus an additional antibody than in women with anti-D as the sole antibody. The anti-D titer closely paralleled the clinical importance of the antibody. One case of anti-s with a titer of 512 required all three types of transfusion.


CONCLUSIONS
Anti-D was the single most frequent and harmful specificity closely followed by anti-K. Combinations of antibody specificities were more harmful than single specificities, and a potentially synergistic effect should be considered.
Nordvall
Maria
M
Obstetric Clinic, Juliane Marie Centre, Copenhagen, Denmark.
Dziegiel
Morten
M
Hegaard
Hanne Kristine
HK
Bidstrup
Mogens
M
Jonsbo
Finn
F
Christensen
Birgit
B
Hedegaard
Morten
M
D001789:Blood Group Antigens / Q000276:immunology*; D004912:Erythrocytes / Q000276:immunology*; D005260:Female; D006801:Humans; D007518:Isoantibodies / Q000097:blood; D011247:Pregnancy; D012189:Retrospective Studies; D018029:Rho(D) Immune Globulin / Q000097:blood
D001789:Blood Group Antigens; D007518:Isoantibodies; D018029:Rho(D) Immune Globulin