Objective To solve the difficulty of RhD blood group typing in a patient with double population(DP) of red blood cells for RhD antigen by serological and genotyping analysis. Methods Separation of the two populations of red blood cells of the patient was performed using capillary centrifugation method. ABO, RhD and RhCE typing, direct anti-human globulin test (DAT), irregular antibody screening, antibody identification and blood crossmatching of the patient were conducted using the standard serological methods. The hybrid Rhesus zygosity analysis of the RHD gene was performed by PCR-RFLP method. RHD and RHCE genotype of the patients were identified by PCR-SSP method. Results The patient was B type but with DP of red blood cells for RhD, Rhc and RhE antigens. DAT of the patient was positive and the alloanti-D was detected in serum. The RHD zygosity was D-/D- homozygote. PCR-SSP testing showed the RHD gene deletion (RHD * 01N. 01/01N.01 genotype) and Ccee of RHCE genotype in the patient, which was consistent with RHD zygosity analysis. Conclusion This is a special case with D-negative phenotype which was wrongly detected as D-positive type after D-positive red blood cells transfusion in emergency. When the DP of red cells for D antigen encountered like this case, the RhD typing can be accurately determined by using RHD genotyping analysis to provide strong evidence to the clinical blood transfusion.

We report a case of a newborn baby who suffered from hemolytic disease of fetus and newborn (HDFN) caused by anti-Di a. The baby presented with worsening jaundice started at three hours after birth and was transferred to Dongguan Maternal and Child Health Care Hospital. The newborn's hemoglobin (Hb) was 82 and 76 g/L at five and nine hours after birth, and the total bilirubin (TBIL) was 243.2 and 309.8 μmol/L, respectively. Blood samples of the newborn and the parents were collected for HDFN immunohematology test twelve hours after birth. They showed that the newborn and the father's blood type was A and RhDCCee, while the mother was A and RhDCcee. Direct antiglobulin test (DAT) indicateda strong positive for the newborn and negative for the parents. The reaction of the reagent to red blood cells for antibody screening with the patient's plasma, red cells eluate, and the mother's plasma were all negative, but were positive with the father's red blood cells. The newborn was recovered after treating with phototherapy, intravenous immunoglobulins and urgent blood exchange (the exchanged blood was the same ABO and RhD blood type and cross-matched). The newborn's plasma and red cells eluate were collected before blood exchange, and the mother's plasma were used to assess the red blood cells reaction, and IgG anti-Di a was identified in each sample. Di a blood typing was positive for the newborn and the father, and negative for the mother. Therefore, the newborn was diagnosed as HDFN caused by anti-Di a.

Background. Factors influencing the development of alloantibodies against blood group antigens on transfused red blood cells are poorly defined. We hypothesised that transfused platelets may act as a danger signal to recipients and affect humoral immune responses to transfused red blood cells. Materials and methods. Platelet-rich plasma prepared from wild-type C57BL/6 or CD40L knockout donors was transfused into wild-type or CD40L knock-out recipients. Leucoreduced red blood cells from transgenic donors expressing high levels of the human KEL glycoprotein in an erythrocyte-specific manner (KELhi donors) were transfused after the platelets, and anti-KEL responses were measured longitudinally. In some experiments, recipients were treated with poly (I:C), monoclonal CD40L-blocking antibody, or CD4-depleting antibody prior to transfusion. Results. Transfusion of wild-type C57I3L/6 platelets or treatment with poly (I:C) prior to KELhi red blood cell transfusion led to an anti-KEL alloimmune response in wild-type recipients. Transfusion of platelets from wild-type but not C D40L knock-out donors prior to KELhi red blood cell transfusion led to an IgG anti-KEL alloimmune response in CD40L knock-out recipients; unexpectedly, transfusion of platelets from CLI4DL knock-out donors prior to KELhi red blood cell transfusion led to a robust anti-KEL alloimmune response in wild-type recipients. Recipient treatment with MR1 CD40L-blocking antibody or CD4-depleting antibody prevented KEL alloimmunisation altogether. Discussion. Transfused platelets serve as an adjuvant in this T.dependent murine model of anti-KEL red blood cell alloimmunisation, with CD40/CD40L interactions being involved to some degree bdt with additional mechanisms also playing a role. These findings raise questions about the role that transfused or endogenous platelets may play in other innate/adaptive immune responses.