The Rh-D negative pregnancy is commonly associated with alloimmunization against D-antigen. It can be prevented by anti-D prophylaxis in pregnant patients with negative results on antibody screening. Hence, it is essential to exclude alloantibody-D in the presence of multiple alloantibodies. Anti-G antibody is formed after exposure to G antigen in neonate RBCs. Blood-group discrepancy was noted in reverse grouping, and antibody-screening results were positive in our case individual, a 28-year old Odiya Indian woman. We performed antibody identification on serum specimens from this patient, which revealed the pattern of anti-D + anti-C antibody specificity. Blood-group discrepancy was solved using rr (ce/ce)-phenotype pooled cells for reverse grouping. We identified anti-G antibodies by themselves without anti-D and anti-C after performing sequential adsorption of serum with r\'r\' (Ce/Ce) and R2R2 (DcE/DcE) group-O RBCs in the mother, who had rr phenotype and primigravida designation. After completing antibody screening at the first antenatal check-up, we recommended prophylactic anti-D for the mother in any future pregnancies she may have.

Anti-D in individuals with a weak D phenotype is an unexpected finding that may require additional investigation to determine whether the anti-D is an autoantibody or alloantibody. Further investigation may also include assessment of the patient\'s RHD genotype and exclusion of anti-G. We present a case of an 84-year-old man with the weak D type 2 genotype who developed an unexpected anti-D along with anti-C. Individuals with the weak D type 2 genotype are thought not to be at risk for developing alloanti-D, although the distinction between alloanti-D and autoanti-D may be difficult to ascertain. Furthermore, investigations may affect transfusion recommendations. This patient was restricted to crossmatch-compatible, D-C- red blood cells even though the clinical significance of the anti-D was uncertain. This report is one of a few reported cases of an individual with the weak D type 2 genotype with demonstrable anti-D but without evidence for alloanti-D.

Anti-G antibody mimics the reactivity pattern of coexistent anti-D and anti-C. Differentiating between the two is significant in antenatal females where the decision to administer RhD prophylaxis is based on the presence or absence of anti-D antibody. The aim of reporting this serological challenge is to emphasize the need for phenotyping red cells for sourcing appropriate in house red cell reagents and to help transfusion services sharpen problem-solving skills. A 26-year-old pregnant female with a complicated obstetric history and a positive indirect antiglobulin test presented to the hospital for antenatal assessment at 24 weeks. A positive antibody screen warranted identification of the implicating antibodies. Since identification was suggestive of multiple alloantibodies whose specificities could not be confirmed, step-wise sequential adsorption and elution was required. Anti-D, anti-C, and anti-E antibodies were identified in patient plasma with titers of 1024, 4, and 32, respectively. The absence of anti-G was also confirmed. Multiple alloantibodies can pose a challenge to transfusion services. However, with the help of select cells, phenotyping, adsorption elution studies, and phenotyped donor units; solving complex serological cases can be accomplished.

Anti-G is commonly present with anti-D and anti-C and can confuse serological investigations. The differentiation of anti-G from anti-D and anti-C is particularly essential for the accurate diagnosis of hemolytic disease of the fetus and newborn (HDFN) and appropriate administration of anti-D immunoglobulin prophylaxis in Rhesus (Rh) negative women. We reported a rare case of anti-G together with anti-D and anti-C in a pregnant woman and her female neonate. The titers of IgG anti-D, anti-C, and anti-G in the woman were 256, 128, and 32, respectively. While the titers of IgG anti-D, anti-C, and anti-G in the neonate were 16, 8, and 4, respectively. The neonate experienced mild HDFN and only received phototherapy during hospitalization. This report discusses the diagnostic strategy and clinical significance of differentiating anti-G from anti-D and anti-C.

G antigen of Rh blood group system is present either along with D and/or C positive red cells. Hence, [serologically anti-G presents with the similar picture as that of multiple antibodies (anti-D + anti-C). Differentiating them is important as anti-D + anti-C causes severe hemolytic disease of the fetus and newborn than anti-G. In pregnancies with anti-G alone, alloimmunization due to D antigen could be prevented by prophylactic administration of RhIg. Differentiating between anti-D + C from anti-G in alloimmunized pregnant mothers becomes essential. Sera from antenatal mothers, whose antibody identification by 11-cell panel gave a pattern for anti-D and anti-C were selected. Extended phenotyping for Rh system was performed for these antenatal cases. Differential adsorption and elution testing using R2R2 cells initially and r\'r cells subsequently were performed to distinguish anit-G from anti-D + anti-C. Antibody titers of these antibodies were determined and their clinical outcome in the newborn was followed. A pattern suggestive of anti D and anti C on antibody identification were observed in six antenatal cases. On further workup 50 % of them confirmed to have anti G. Antibody titers of anti-G and anti-C were lower than that of Anti-D. All newborns were sensitized in vivo and the antibody specificity in them were confirmed with elution studies. The mothers who had only anti-G were subsequently administered with an appropriate dose of RhIg.Differential adsorption and elution studies help in identifying anti-G and distinguishing it from anti-D plus anti-C, thus helping in better patient management.

The G antigen of Rh blood group system is present in almost all D-positive or C-positive red cells but absent from red cells lacking D and C antigens. The differentiation of anti-D and anti-C from anti-G is not necessary for routine transfusion; however, during pregnancy, it is important because anti-G can masquerade as anti-D and anti-C with initial antibody testing. The false presence of anti-D will exclude the patient from receiving anti-D immunoglobulin (RhIG) when the patient actually is a candidate for RhIG prophylaxis. Moreover, patients with positive anti-D or anti-G are at risk of developing hemolytic disease of the fetus and newborn and need close monitoring. Thus, proper identification allows the clinicians to manage patients properly. This case report highlights a rare case of anti-G together with anti-D and anti-C in a pregnant woman. This report disseminates knowledge on identification of anti-G and its importance in pregnant women.

Anti-G has been reported as a possible cause of hemolytic disease of the fetus and newborn (HDFN), either independently or in association with anti-D, anti-C or both. The antibody mimics the pattern of anti-C and anti-D reactivity in the identification panel and is often present along with either or both of these antibodies. The differentiation of anti-D, -C and-G in routine pretransfusion workup is particularly essential in antenatal cases. We report two antenatal cases where anti-G was identified on advanced immunohematological workup, in addition to other alloantibodies.

BACKGROUND: Anti-G antibodies are rarely found since anti-D, in combination with anti-C, are difficult to discriminate from anti-G antibodies in routine testing.
METHODS: A 22-year-old, gravida-3, para-1, woman with blood group A Rh D neg ccddee and known antibody anti-Jk(b), gave birth to her second child. While anti-Jk(b) could not be detected at birth, a new anti-C was found. Antibody screening tests (IAT) were performed using gel cards and rare G positive rGr erythrocytes. Genotyping for RHD and RHCE was performed using PCR-SSP.
RESULTS: The child\'s blood group was A Rh D neg Ccddee. Genotyping revealed Cde/cde haplotypes. The erythrocytes of the new-born showed a positive direct antiglobulin test with IgG; anti-D and anti-C could be eluted. Erythrocytes with the rare phenotype rGr were reactive with the serum of the mother.
CONCLUSIONS: The presence of anti-D and anti-C in the eluate from then newborn\'s Ccddee erythrocytes proved anti-G or anti-G in combination with anti-D. When anti-C and anti-D are seen during a pregnancy, possibly anti-G is present. This observation is of relevance since women with anti-G can still develop anti-D and require rhesus prophylaxis.