The frequency of anti-C plus anti-C in the absence of anti-D in alloimmunized pregnancies

Anti-D+C are often initially identified in sera from alloimmunized women. A nti-G may be present in these samples, mimicking anti-D+C, and therefore th e differentiation of anti-D, -C and -G may be important. Sera from 27 alloimmunized women, initially identified as containing anti-D + anti-C, were analysed by adsorption/elution studies in the presence of p olyethylene glycol (PEG) using R(0)r (D+C-G+) and r'r(D-C+G+) red blood cel ls (RBC). Additionally, 15/27 samples were tested by adsorption in the pres ence of PEG and subsequently warm elution, using r(G)r (D-C-G+) RBC. Anti-G + anti-C, without anti-D, were identified in 4/27 samples (14.8%) and none of the newborn children needed postpartum treatment. The combination of DG, D+C and D+C+G antibodies occurred in 25.9%, 11.1% and 48.1% of the women , respectively. Overall, anti-G was detected in 24/27 samples (88.9%). Preg nant women shown to have anti G+C but not anti-D should receive Ph immune g lobulin. Additionally, the finding of apparent anti D+C during pregnancy in D-negative spouses may lead to paternity testing and therefore a correct a ntibody identification is necessary.