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【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.
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【Objective】 To identify the blood group epitope of a D variant individual and analyze its molecular characteristics. 【Methods】 The saline test and indirect antiglobulin test (IAT) were used to identify the RhD serologically. The anti-human globulin gel card was used for direct antiglobulin test (DAT). RhD epitopes were detected using the epitope detection kit (D-Screen). RhCE antigens were typed using Rh typing Card. The RHD gene zygomorphism was further analyzed by PCR-RFLP. Ten exons of RHD gene were amplified by PCR and analyzed by direct sequencing. 【Results】 DAT test was negative, and the serological results showed weak expression of RhD, which was D variant. The RhD epitope test results showed that the red blood cells of this patient had a weak agglutination with 4 monoclonal anti-D against epD6.4, epD6.1, epD2.1, and epD5.4 (w+ to 2+ ), and reacted negatively with other epitope antibodies. RhCE antigen typing was Ccee; The RHD gene zygomorphism result was D+ /D-, the sequencing of RHD exons revealed that the first exon carried c. 41C>T (p.Pro14Leu) missense mutation, and its genotype was RHD*01W.136/01N.01. 【Conclusion】 This D variant is the first weak D type 136 reported in the Chinese population, and its phenotype is weak partial D.
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【Objective】 To develop a novel screening reagent for -D- phenotype preliminary screening based on the difference in RhD antigen expression level of -D- phenotype and normal RhD phenotype. 【Methods】 RhD antigen expression of -D-phenotype and Rh D-- gene carrier were detected by flow cytometry. By adjusting the concentration of polybrene in the screening system, the red blood cells with high RhD antigen expression level agglutinated, and the preliminary screening of the -D-phenotype and its gene carriers was realized. 【Results】 According to the quantitative results of immunofluorescence intensity (MFI) analysis by flow cytometry, the expression level of RhD antigen in -D- phenotype cells (284 360±16 698, n=3) was about 3 times normal RhD positive cells (98 642±35 908, n=9)(P<0.01), while RhD antigen expression level of RhD-- gene carrier (181 109±39 455, n=4) was about 2 times normal RhD positive cells(P<0.01). RhD antigen expression (144 538±227 445, n=7) of the positive cells screened by 15 μL 3% fresh red blood cell suspension and screening system 35 μL (1 μL IgG anti-D, 29 μL polybrene polybrene, and 5 μL low ionic strength solution) was about 1.5 times normal RhD positive cells. 【Conclusion】 The polybrene preliminary screening system, which can be used for high-throughput screening of -D- phenotype, is a reliable technical method for frequency study of this phenotype.
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【Objective】 To explore the characteristics of the D antigen epitope of individuals with RhD variants and the genetic molecular mechanism of gene mutations in Guangzhou. 【Methods】 A total of 59 samples of RhD variants were collected from blood donors and hospitals in Guangzhou from January to August 2019. Serological characteristics of D epitopes were further analyzed using two kinds of monoclonal anti-D reagents and D epitope detection kits, and RHCE phenotypic typing was performed. QuickGene DNA extraction kit was used to extract the genomic DNA of the samples, and PCR-RFLP method was used to analyze the RHD gene zygote type. The RHD gene sequence was detected by multiple ligation-dependent probe amplification(MLPA) genotyping, and the RHD exon(1~10) Sanger sequencing was performed on the samples still in doubt after the above detection. DNAStar/SeqMan analysis software was used for comprehensive analysis. 【Results】 In this group of individuals with RhD variants in Guangzhou, 27.12%(16/59) were detected from blood donors [accounting for 0.007%(16/232 793) of blood donors in Guangzhou during the same period], and difficult samples of patients sent by hospitals for determination accounted for 72.88%(43/59). RHD genotype detection: 40.68%(24/59) were RHD*weak partial 15, 25.42%(15/59) were RHD* DⅥ.3 and 33.90%(20/59) were rare RHD variants [76.92%(10/13) were RhD variants with 2 different alleles]. Serological D-screen revealed a relatively fixed pattern of RHD*DⅥ.3 in anti-D antibody(clone: P3*212 23B10), while the others was negative. The phenotypic distribution of RhD variant CE was Ccee 38.98%(23/59), ccEe 35.59%(21/59), CcEe 25.42%(15/59). 【Conclusion】 Weak partial D15 and DⅥ.3 were the most common RhD variants in Guangzhou Han population, and DⅥ can be preliminarily identified by serological methods such as D-Screen anti-D reagent, while the remaining RhD variants can only be identified by molecular biological methods, and >95% of the RhD variants were C+ or E+ phenotypes.
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The RhD antigen is expressed only in human red blood cells (RBC).Its immunogenicity and clinical application are only next to ABO blood group system, and is widely used both for blood typing and prevention of hemolytic disease of the newborn. The traditional anti-Rh(D) is derived by fractionation of plasma from individuals who have been sensitized by pregnancy or transfusion, or have been deliberately immunized to produce anti-Rh(D). Because of the limited source of plasma, researchers began the study of monoclonal and recombinant antibody. Monoclonal and recombinant anti-Rh(D) antibodies may provide alternatives to the current plasma derived polyclonal IgG anti-Rh(D), but up to now,none of them have yet proved effective in humans for prevention of RhD immunity and hemolytic disease of the newborn.
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0.05). The absolute counts of RhD(+) cell of 2 patients at 3 different times were 0.124?10 12 /L, 0.245 ?10 12 /L and 0.517?10 12 /L respectively.Conclusion FCM can be used to detect RhD antigen and perform RhD(+) cell counts in patients with RhD(-) who received incompatible blood.