Objective: To analyze the frequency and investigate the causes of unexpected antibodies in D-negative blood donors. Methods: From January 2022 to December 2024, 3 768 D-negative blood donors sent to our laboratory were selected as research subjects. D-negative confirmation test and RhCE phenotype detection were applied by saline tube method and microcolumn gel indirect antiglobulin test (IAT), respectively. Antibody screening and identification were performed using the polybrene method and IAT column agglutination methods. Anti-D, anti-C and anti-G specificities were identified by a two-step adsorption-elution method, and the genotypes of D-negative samples were determined by RHD gene amplification, Sanger sequencing, and PacBio Single Molecule Real-Time (SMRT) sequencing. Results: Among D-negative donors, ccee and Ccee phenotypes accounted for the highest proportion, 55.68% (2 098/3 768) and 29.56% (1 114/3 768), respectively, while CcEE and CCEe phenotypes were the least, with one case detected in each, accounting for 0.03% (1/3 768). A total of 165 cases with D variant phenotype were detected, and the proportion of D variant was 4.38% (165/3 768) in the donors detected by D-negative confirmation test. Antibody screening positive blood donors were identified in 93 cases with a proportion of 2.47% (93/3 768). Antibody specificity was determined in 84 blood donors, and 9 samples showed no clear specificity. Anti-D was detected most frequently (n=68), in which 6 of them were detected having multiple antibodies, anti-D + anti-C (n=2), anti-D + anti-G(n=1), and anti-D + anti-E(n=3). The other antibodies detected were anti-E (n=1), anti-M(n=9), anti-P1 (n=3), anti-Le (n=1), and anti-HI(n=2). Fourteen cases were detected with anti-D in serological D-negative donors with C+ or E+ phenotype, in which three of them were DVI type 3 individuals and 11 cases were D negative individuals. Conclusion: The incidence of unexpected antibodies was higher in D-negative blood donors than in the total donors, with anti-D being the most common. The data provide insights for prevention and monitoring hemolytic disease of the fetus and newborn (HDFN) caused by anti-D. To ensure the safety of blood transfusion, routine unexpected antibody screening for RhD-negative blood donors is recommended to prevent the use of unexpected antibodies positive plasma in the clinic.

[Objective] To retrospectively analyse the serological characteristics of hemolytic transfusion reactions caused by Rh and Kidd antibodies, and to provide reference for safe, timely, and effective blood transfusion. [Methods] Two cases of patients with RhCcEe and Kidd blood type who experienced allogeneic transfusion at Dazhou Central Hospital were selected. A series of immunohematological tests were performed, including ABO, RhDCcEe and Kidd blood typing, unexpected antibody screening and identification, crossmatching, direct antiglobulin test, acid elution test, and capillary centrifugation to separate the patient's own red blood cells from donated red blood cells. [Results] Unexpected antibody screening, antibody identification, and direct antiglobulin test were positive in both patients. Case 1 had anti-Jk in the plasma, but no specific antibodies were found in the eluate. Case 2 had anti-c and E in the plasma, and anti-E was detected in the eluate. High-speed capillary centrifugation revealed corresponding antigen-positive erythrocytes at the distal end of the blood samples of both patients. [Conclusion] Case 1 received Kidd allogeneic red blood cells, and case 2 received RhCcEe allogeneic red blood cells, and both patients developed the corresponding unexpected antibodies, which led to the occurrence of immune haemolytic blood transfusion reaction.

Objective:To explore the molecular mechanism of a case with RhD-phenotype.Methods:A proband with RhD-phenotype who attended the clinic of the First Affiliated Hospital of Zhengzhou University on January 29, 2024 was selected as the study subject. Peripheral blood samples were collected from the proband (8 mL) and her close relatives (father, mother and brother; 3 mL each) for Rh phenotyping and irregular antibodies testing with gel card and test tube methods. Direct agglutination reaction and absorption-elution test were used to detect the c antigen on the red blood cells of the proband. PCR-sequence specific primers (PCR-SSP) typing and gene sequencing were used to determine the RHCE gene of the proband and her relatives. The origin of the proband′s variant was traced by pedigree analysis. Three-dimensional structural models of the wild-type RhCE*cE protein and the RhD-phenotype protein were constructed to predict the alterations of the RhD-phenotype protein caused by the variant. The procedures of this study were approved by the Medical Ethics Committee of the First Affiliated Hospital of Zhengzhou University (Ethics No.: 2023-KY-0870-003). Results:The red blood cells of the proband did not agglutinate with anti-C, anti-c, anti-E, and anti-e. The result of the serum irregular antibody test was negative. The results of direct agglutination reaction and absorption-elution test of the proband were both negative. Her Rh blood group was identified as RhD-. The results of the Rh blood grouping of her close relatives were normal. PCR-SSP detection showed that the RHCE genotypes of the proband and her close relatives were cE/cE and Ce/cE, respectively. Gene sequencing analysis showed that the RHCE genotypes of the proband and her close relatives were RHCE* cE (c.365C>A)/ RHCE* cE (c.365C>A) and RHCE* Ce/ RHCE* cE (c.365C>A), respectively. Pedigree analysis revealed that the variants in the proband were inherited from her father and mother, respectively. Homology modeling of RhCE*cE protein showed that the RhD-type peptide chain with a significantly shortened C-terminal was encoded by only 121 amino acid resides, which was 296 amino acid resides shorter compared to the wild-type RhCE*cE peptide chain encoded by 417 amino acid residues. Conclusion:Above results revealed the molecular biological mechanism of a RhD-phenotype. The c. 365C>A variant in the RHCE gene has rendered the RHCE* cE alleles invalid, which ultimately led to the RhD-phenotype.

Objective:To analyze the diversity of Duffy blood group gene among ethnic Hui population from Henan Province using PacBio long-read sequencing technique.Methods:Randomly select 30 individuals with three generations of Hui ancestry from Henan as the study subjects. Full-length sequences of the Duffy blood group gene were obtained through PacBio long-read sequencing. Distribution of the predicted phenotype and genotype frequency were determined, and the linkage between Duffy haplotypes and variation sites was analyzed. Genetic diversity, natural selection pressure, and population genetic characteristics were evaluated. This study was approved by the Medical Ethics Committee of the Second Affiliated Hospital of Zhengzhou University (Ethics No. 202223).Results:The predicted Duffy blood group phenotype in the Henan Hui population was predominantly Fy(a+ b-). Three novel SNPs in the FY*01 allele were identified, with a total frequency of 13.33%, among which FY*01.NEW1 (c.199C>T) was the most common. A total of 32 variant sites were identified, with 28 located in intronic regions, indicating that genetic diversity was primarily concentrated in introns. The Duffy blood group gene was under negative selection pressure ( dN/ dS < 1, Tajima′s D, Fu and Li′s D*& F* significantly deviated from 0), suggesting overall conservation. The allele frequencies of Duffy blood group in the Henan Hui population was similar to that of the Xinjiang Hui, Xinjiang Kazakh, Inner Mongolia Mongolian, and Yuncheng Han populations, but significantly different from those of most Han and other ethnic groups ( P<0.05). Conclusion:This study revealed the characteristics of the Duffy blood group gene among the Henan Hui population and demonstrated the significant advantages of PacBio long-read sequencing technique in haplotype analysis, genetic diversity study, and novel mutation identification.

OBJECTIVE: To analyze the diversity of Duffy blood group gene among ethnic Hui population from Henan Province using PacBio long-read sequencing technique. METHODS: Randomly select 30 individuals with three generations of Hui ancestry from Henan as the study subjects. Full-length sequences of the Duffy blood group gene were obtained through PacBio long-read sequencing. Distribution of the predicted phenotype and genotype frequency were determined, and the linkage between Duffy haplotypes and variation sites was analyzed. Genetic diversity, natural selection pressure, and population genetic characteristics were evaluated. This study was approved by the Second Affiliated Hospital of Zhengzhou University (Ethics No. 2022223). RESULTS: The predicted Duffy blood group phenotype in the Henan Hui population was predominantly Fy(a+b-). Three novel SNPs in the FY*01 allele were identified, with a total frequency of 13.33%, among which FY*01.NEW1 (c.199C>T) was the most common. A total of 32 variant sites were identified, with 28 located in intronic regions, indicating that genetic diversity was primarily concentrated in introns. The Duffy blood group gene was under negative selection pressure (dN/dS < 1, Tajima's D, Fu and Li's D* and F* significantly deviated from 0), suggesting overall conservation. The allele frequencies of Duffy blood group in the Henan Hui population was similar to that of the Xinjiang Hui, Xinjiang Kazakh, Inner Mongolia Mongolian, and Yuncheng Han populations, but significantly different from those of most Han and other ethnic groups (P < 0.05). CONCLUSION This study revealed the characteristics of the Duffy blood group gene among the Henan Hui population and demonstrated the significant advantages of PacBio long-read sequencing technique in haplotype analysis, genetic diversity study, and novel mutation identification.
Female ; Humans ; Male ; Asian People/ethnology* ; China/ethnology* ; Duffy Blood-Group System/genetics* ; Ethnicity/genetics* ; Gene Frequency ; Genetic Variation ; Haplotypes ; Polymorphism, Single Nucleotide

OBJECTIVE: To explore the molecular mechanism of a case with RhD-- phenotype. METHODS: A proband with RhD-- phenotype who attended the clinic of the First Affiliated Hospital of Zhengzhou University on January 29, 2024 was selected as the study subject. Peripheral blood samples were collected from the proband (8 mL) and her close relatives (father, mother and brother; 3 mL each) for Rh phenotyping and irregular antibodies testing with gel card and test tube methods. Direct agglutination reaction and absorption-elution test were used to detect the c antigen on the red blood cells of the proband. PCR-sequence specific primers (PCR-SSP) typing and gene sequencing were used to determine the RHCE gene of the proband and her relatives. The origin of the proband's variant was traced by pedigree analysis. Three-dimensional structural models of the wild-type RhCE*cE protein and the RhD-- phenotype protein were constructed to predict the alterations of the RhD-- phenotype protein caused by the variant. The procedures of this study were approved by the Medical Ethics Committee of the First Affiliated Hospital of Zhengzhou University (Ethics No.: 2023-KY-0870-003). RESULTS: The red blood cells of the proband did not agglutinate with anti-C, anti-c, anti-E, and anti-e. The result of the serum irregular antibody test was negative. The results of direct agglutination reaction and absorption-elution test of the proband were both negative. Her Rh blood group was identified as RhD--. The results of the Rh blood grouping of her close relatives were normal. PCR-SSP detection showed that the RHCE genotypes of the proband and her close relatives were cE/cE and Ce/cE, respectively. Gene sequencing analysis showed that the RHCE genotypes of the proband and her close relatives were RHCE*cE (c.365C>A)/RHCE*cE (c.365C>A) and RHCE*Ce/RHCE*cE (c.365C>A), respectively. Pedigree analysis revealed that the variants in the proband were inherited from her father and mother, respectively. Homology modeling of RhCE*cE protein showed that the RhD-- type peptide chain with a significantly shortened C-terminal was encoded by only 121 amino acid resides, which was 296 amino acid resides shorter compared to the wild-type RhCE*cE peptide chain encoded by 417 amino acid residues. CONCLUSION Above results revealed the molecular biological mechanism of a RhD-- phenotype. The c.365C>A variant in the RHCE gene has rendered the RHCE*cE alleles invalid, which ultimately led to the RhD-- phenotype.
Humans ; Rh-Hr Blood-Group System/chemistry* ; Female ; Phenotype ; Male ; Alleles ; Pedigree ; Base Sequence ; Molecular Sequence Data ; Adult

Objective:To analyze the diversity of Duffy blood group gene among ethnic Hui population from Henan Province using PacBio long-read sequencing technique.Methods:Randomly select 30 individuals with three generations of Hui ancestry from Henan as the study subjects. Full-length sequences of the Duffy blood group gene were obtained through PacBio long-read sequencing. Distribution of the predicted phenotype and genotype frequency were determined, and the linkage between Duffy haplotypes and variation sites was analyzed. Genetic diversity, natural selection pressure, and population genetic characteristics were evaluated. This study was approved by the Medical Ethics Committee of the Second Affiliated Hospital of Zhengzhou University (Ethics No. 202223).Results:The predicted Duffy blood group phenotype in the Henan Hui population was predominantly Fy(a+ b-). Three novel SNPs in the FY*01 allele were identified, with a total frequency of 13.33%, among which FY*01.NEW1 (c.199C>T) was the most common. A total of 32 variant sites were identified, with 28 located in intronic regions, indicating that genetic diversity was primarily concentrated in introns. The Duffy blood group gene was under negative selection pressure ( dN/ dS < 1, Tajima′s D, Fu and Li′s D*& F* significantly deviated from 0), suggesting overall conservation. The allele frequencies of Duffy blood group in the Henan Hui population was similar to that of the Xinjiang Hui, Xinjiang Kazakh, Inner Mongolia Mongolian, and Yuncheng Han populations, but significantly different from those of most Han and other ethnic groups ( P<0.05). Conclusion:This study revealed the characteristics of the Duffy blood group gene among the Henan Hui population and demonstrated the significant advantages of PacBio long-read sequencing technique in haplotype analysis, genetic diversity study, and novel mutation identification.

Objective:To explore the molecular mechanism of a case with RhD-phenotype.Methods:A proband with RhD-phenotype who attended the clinic of the First Affiliated Hospital of Zhengzhou University on January 29, 2024 was selected as the study subject. Peripheral blood samples were collected from the proband (8 mL) and her close relatives (father, mother and brother; 3 mL each) for Rh phenotyping and irregular antibodies testing with gel card and test tube methods. Direct agglutination reaction and absorption-elution test were used to detect the c antigen on the red blood cells of the proband. PCR-sequence specific primers (PCR-SSP) typing and gene sequencing were used to determine the RHCE gene of the proband and her relatives. The origin of the proband′s variant was traced by pedigree analysis. Three-dimensional structural models of the wild-type RhCE*cE protein and the RhD-phenotype protein were constructed to predict the alterations of the RhD-phenotype protein caused by the variant. The procedures of this study were approved by the Medical Ethics Committee of the First Affiliated Hospital of Zhengzhou University (Ethics No.: 2023-KY-0870-003). Results:The red blood cells of the proband did not agglutinate with anti-C, anti-c, anti-E, and anti-e. The result of the serum irregular antibody test was negative. The results of direct agglutination reaction and absorption-elution test of the proband were both negative. Her Rh blood group was identified as RhD-. The results of the Rh blood grouping of her close relatives were normal. PCR-SSP detection showed that the RHCE genotypes of the proband and her close relatives were cE/cE and Ce/cE, respectively. Gene sequencing analysis showed that the RHCE genotypes of the proband and her close relatives were RHCE* cE (c.365C>A)/ RHCE* cE (c.365C>A) and RHCE* Ce/ RHCE* cE (c.365C>A), respectively. Pedigree analysis revealed that the variants in the proband were inherited from her father and mother, respectively. Homology modeling of RhCE*cE protein showed that the RhD-type peptide chain with a significantly shortened C-terminal was encoded by only 121 amino acid resides, which was 296 amino acid resides shorter compared to the wild-type RhCE*cE peptide chain encoded by 417 amino acid residues. Conclusion:Above results revealed the molecular biological mechanism of a RhD-phenotype. The c. 365C>A variant in the RHCE gene has rendered the RHCE* cE alleles invalid, which ultimately led to the RhD-phenotype.

Objective:To explore the RH genotype for a female with RhD(-) blood type and its molecular basis. Methods:A 26-year-old female who had attended the outpatient clinic of the First Affiliated Hospital of Zhengzhou University in August 2019 was selected as the study subject. Peripheral blood samples were collected from the proband and her parents for Rh phenotyping with gel card method. PCR-sequence-based typing (PCR-SBT) and DNA sequencing were used to determine the RHD zygosity and RH genotype of the proband and her parents. Homology modeling of Rh proteins was performed with bioinformatic software, and protein structural alterations caused by the variant was simulated by molecular dynamics. This study was approved by the Medical Ethics Committee of the First Affiliated Hospital of Zhengzhou University (Ethics No. 2023-KY-0870-003). Results:Serological tests showed that the proband and her father both had weakened e antigen of the Rh phenotype. PCR-SBT and DNA sequencing showed that the genotypes of the proband and her parents were dce/ dCE, dce/ DcE and dCE/ DcE, respectively. And the genotypes of the RHD and RHCE of the proband were RHD*01N.01/ RHD*01N.16, RHCE*01.01/RHCE*04, respectively. Protein simulation and molecular dynamics analysis revealed that the ce_16C variant resulted from RHCE* ce (c.48G>C) may alter the structure of intracellular and extracellular loops, mainly affecting the mobility of extracellular loops 2, 6 and intracellular loops 3, 4. Conclusion:Variant of the RHCE* ce allele c. 48G>C probably underlay the weakened e antigen in this proband.

Objective To analyze the application of serological test results in the diagnosis and treatment of anti-M-in-duced hemolytic disease of the fetus and newborn(HDFN),and to explore HDFN prevention strategies.Methods The se-rological test results of 12 cases of HDFN caused by anti-M diagnosed in our laboratory from January 2017 to December 2023 were retrospectively analyzed,including blood group identification of mothers and children,serum total bilirubin/hemoglo-bin/antibody titer test,and three hemolysis tests in newborns.Clinical data of the children and mothers were collected,in-cluding pregnancy history,blood transfusion history,prenatal antibody testing,history of intrauterine blood transfusion and gestational week of delivery,and the prognosis of the children was followed up.Results All 12 cases of fetal neonatal he-molytic disease due to anti-M were RhD+MN phenotype newborn born to RhD+NN mother,with maternal-fetal incompati-blility in MN blood groups.In the ABO blood group system,ABO incompatibility between mother and child accounted for 41.7%(5/12).None of the mothers had a history of blood transfusion,and the median titer of the test at 4℃was 32,and the median titer at 37℃was 4.The mothers of 3 cases had a history of multiple intrauterine blood transfusions,with an inci-dence of 25%(3/12).One case had an abnormal first pregnancy,with an incidence of 8.3%(1/12),and seven cases had an abnormal pregnancy with a miscarriage,with an incidence of abnormal pregnancy and birth history of 58.3%(7/12).There were 6 cases of premature labor,with an incidence of 50%(6/12).The mothers in three cases underwent regular ob-stetric examination and the specificity of the antibodies was determined,accounting for 25%(3/12).Twelve children had free antibodies with a median titer of 6 at 4℃and 2 at 37℃.Two children had anti-M antibodies that were not reactive at 37℃,with a negative rate of 16.7%(2/12).The positive rate of DAT and elution test was respectively 8.3%(1/12)and 16.7%(2/12)in the children.The median minimum hemoglobin value was 75 g/L,and all 12 children received blood transfusions.The median peak total bilirubin value was 157.5 μmol/L,and none of them reached the threshold for blood ex-change.The rate of delayed anemia was16.7%(2/12),the postnatal mortality rate was8.3%(1/12),and 11 children was free of growth and neurodevelopmental delay in prognosis.Conclusion Anti-M can cause severe HDFN,which can also oc-cur in primigravida.The intensity of antibody titer does not correlate with the severity of the disease,and it is prone to cause delayed anemia,which should be monitored regularly according to the serological characteristics of anti-M and clinical symp-toms,and should be treated timely.