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 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.