Clinical significance of anti‐G

Abstract

We read with interest the recent article of Palfi et al. (2001) in which they identified anti-G anti-C without anti-D in 4/27 samples from pregnant women; none of the newborns needed postpartum treatment. Among a few other published cases, only Hadley et al. (1996) observed clinical significance of anti-G in a D negative baby. We would like to share our experience by presenting one case of a D negative, C positive newborn with moderate haemolytic disease of the newborn (HDN) delivered by a mother with anti-G anti-C; the clinical significance of anti-G, but not anti-C, was documented.A mother (group 0rr) delivered a group 0r H r baby with a positive direct antiglobulin test. The cord blood haemoglobin level was normal, but the bilirubin level was slightly elevated (3Á45 mg%), and rose on the second (13Á1 mg%) and the fourth day (20Á3 mg%) in spite of phototherapy. The child was discharged from the hospital on the seventh day in a good health without anaemia.An eluate prepared from the newborn's red cells was strongly positive by the indirect antiglobulin test with r H r, R 1 r, R 1 R 1 , weakly positive with R 0 r, R 2 r, R 2 R 2 , but negative with rr, r HH r cells.When examining the maternal serum (obtained just after delivery) with the panel of red cells by the indirect antiglobulin test, the enzyme (papain) and the polybrene test, we found antibodies to react with all but rr and r HH r cells, suggesting anti-D and anti-C. Differential adsorption/elution studies, using r H r and R 2 R 2 red cells, showed anti-C anti-G, but not anti-D. Moreover, the absence of the latter specificity was confirmed by negative reaction of maternal serum with R 2 r G(±) cells, which have D but not C and G antigens.The level and the functional activity of anti-C and anti-G were examined by indirect antiglobulin test (IAGT) and chemiluminescence test (CLT) (Hadley et al., 1991), respectively, using r H r red cells, such as the newborn's phenotype. For anti-C evaluation, anti-G was previously adsorbed from maternal serum using R 2 R 2 red cells; the titre was 8, the score À10 and the CLT result À1Á6%. The results obtained with nonadsorbed serum were 128, 67, and 18%, respectively; thus, the level and the activity of anti-G appeared to be much higher than that of anti-C. The results of CLT with anti-G were similar to the results observed with antibodies of other specificities in a mild/moderate HDN (Hadley et al., 1991;Zupan ska et al., 2001).Overall, our data allow us to say that the anti-G antibodies were responsible for moderate HDN. They confirm that such antibodies can be of clinical significance in pregnancy.

Case report: moderate hemolytic disease of the newborn due to anti-G

“…They concluded that anti-G may cause moderate to severe HDN in those women with greater than 5 IU/mL anti-C+D (approximately 7%) and that HDN caused by anti-G is probably not rare. Similarly Lenkiewicz et al 8 reported a case of moderate HDN due to anti-G+C in a D-C+ newborn with hyperbilirubinemia requiring phototherapy. The levels and functional activities of both anti-G and anti-C were evaluated with the IAT and the CLT.…”

Severe hemolytic disease of the fetus and newborn due to anti-C+G

“…After delivery of a D-baby, anti-C+G was identified in maternal blood by adsorption and elution, but no anti-D was detected. 3 Lenkiewicz and Zupanska reported a pregnancy where anti-C+G antibodies were responsible for moderate hemolytic disease of the newborn, and, based on titration results, anti-G levels were much higher than anti-C. 10 Anti-G is only rarely the single antibody responsible for HDFN, but is more often expressed with anti-D, anti-C, or both. Palfi and Gunnarsson analyzed the D/C/G antibody combinations in 27 pregnancies and found that anti-G was present in 24 cases, and in 4 of the 27 cases, anti-C+G was identified without anti-D; anti-G was not found alone in any of these cases.…”

“…In our laboratory, anti-G is demonstrated and anti-D ruled out with absorption studies performed concurrently with D-C+ and D+Creagent RBCs. In many laboratories, differential absorption and elution is the method of choice, and is recommended for the differentiation of anti-G from anti-D. [2][3][4]6,10,11 Furthermore, rare r G r cells may also be used in titration. 6,7,11 National and international blood group reference laboratories may be of use in cases where antibody identification by in-house methods is challenging.…”