Case report: reporting anti-G as anti-C+D may have misleading clinical implications

Four months after a D– male was transfused with four units of D– red blood cells (RBCs), the results of a standard pretransfusion antibody screen and alloantibody identification panel detected anti-C+D in his serum. This report was interpreted by his physician to be evidence of alloimmunization to the D antigen, which triggered concern that the patient had been transfused previously with D+ RBCs as the result of an error in blood typing or personal identification. After a review of hospital records failed to identify such an error, consultation with a reference laboratory technologist confirmed that the serologic reactions resembled those of anti-C+D but were also consistent with antiC + anti-G. Additional testing confirmed that the reactions were due to anti-G, not anti-C+D. One of the four donors was identified to have the C+D– RBC phenotype, which is typically G+, thus identifying the stimulus for anti-G. Routine reporting of the detection of anti-C+D in the serum of D– people, without confirmatory testing or commentary about the possibility that anti-G may resemble anti-C+D, may mislead health care providers who are not familiar with the pertinent blood group serology.