Tumor-Specific Histo-Blood Group Antigens: Apropos of Two Cases

Cancer cells with immunogenic properties having altered protein glycosylation, modified blood group substances have been widely studied. Due to the genetic instability occurring during carcinogenesis the glycosyltransferases may suffer from posttranslation sequence modification. The author describes 2 autopsy cases, where in the background of the unusual metastatic tumor presentation, incompatible blood group antigenic determinants have been demonstrated using blood group specific lectins and monoclonal antibodies (mAb). In the first case, reported here, a 10-year-old girl developed an acute myeloid leukemia and died in a septic endotoxin shock after successful cytostatic treatment of a juvenile signet ring cell cancer of her colon. At autopsy there were no signs of tumor except bilateral apple-sized mucinous ovarian (Krukenberg) metastases. While she had erythrocyte phenotype of blood group A, the signet ring adenocarcinoma cells expressed blood group B incompatible antigenic determinants with lectin/mAb. In the second case, the autopsy of a 78-year-old female resulted in no macroscopic tumor sign except a moderately enlarged, ham hard spleen. Light microscopy revealed adenocarcinomatous infiltration in the splenic sinusoids. The patient had blood group O, while the metastatic cells in the spleen reacted with Breast Carcinoma Antigen (BioGenex) and incompatible anti-B Banderiaeasimplicifolia agglutinin I and anti-B mAb. It proved to be a case of an occult, completely regressed breast cancer. Based on these observations the expression of tumor specific incompatible blood group antigens might occur from time to time, mostly in adenocarcinomas. Accordingly, blood group-based specific immuno-oncotherapy could be considered in some cancer cases.

Significant association between ABO blood group and pancreatic cancer

AIM:To evaluate whether the ABO blood group is related to pancreatic cancer risk in the general population of the United States.METHODS:Using the University of Pittsburgh's clinicalpancreatic cancer registry,the blood donor database from our local blood bank (Central Blood Bank),and the blood product recipient database from the regional transfusion service (Centralized Transfusion Service) in Pittsburgh,Pennsylvania,we identified 274 pancreatic cancer patients with previously determined serological ABO blood group information.The ABO blood group frequency was compared between these patients and 708842 individual,community-based blood donors who had made donations to Pittsburgh's Central Blood Bank between 1979 and 2009.RESULTS:The frequency of blood group A was statistically significantly higher amongst pancreatic cancer patients compared to its frequency amongst the regional blood donors [47.63% vs 39.10%,odds ratio (OR)=1.43,P=0.004].Conversely,the frequency of blood group O was significantly lower amongst pancreatic cancer patients relative to the community blood donors (32.12% vs 43.99%,OR=0.60,P=0.00007).There were limited blood group B (n=38) and AB (n=17) pancreatic cancer patients;the overall P trend value comparing patient to donor blood groups was 0.001.CONCLUSION:The ABO blood group is associated with pancreatic cancer risk.Future studies should examine the mechanism linking pancreatic cancer risk to ABO blood group.

Association of ABO blood groups with the severity of coronary artery disease: a cross-sectional study

Objective To investigate whether ABO blood groups is associated with the severity of coronary artery disease(CAD). Methods Between January 2015 and December 2017, 1425 first diagnosed CAD patients confirmed by selective coronary angiography were recruited into this cross-sectional study, and their baseline characteristics, ABO blood groups, Gensini score were collected. Multiple linear regression analysis was performed to test the association between the severity of CAD and ABO blood groups. Results The Gensini score was significantly higher in the blood group A than in the non-A groups(41.2 ± 32 vs. 38 ± 27;P = 0.026). After adjusting for age, male, smoking, family history of CAD, hypertension, diabetes mellitus and hypercholesterolemia, multivariate linear regression indicated that blood group A was associated with the severity of CAD(β= 3.298, 95% CI: 0.91–6.505, P = 0.044). In diabetes group, A blood type was also associated with increased Gensini score(P = 0.02) after adjusting for age, male, family history of CAD, hypercholesterolemia, smoking and hypertension. Conclusion In this cross-sectional study, the data indicated that blood group A was an independent risk factor of severity of CAD in Chinese population and Chinese patients with type 2 diabetes.

Identification and Characterization of Peptide Mimics of Blood Group A Antigen

In order to investigate peptide mimics of carbohydrate blood group A antigen, a phage display 12-mer peptide library was screened with a monoclonal antibody against blood group A antigen, NaM87-1F6. The antibody-binding properties of the selected phage peptides were evaluated by phage ELISA and phage capture assay. The peptides were co-expressed as glutathione S-transferase （GST） fusion proteins. RBC agglutination inhibition assay was performed to assess the natural blood group A antigen-mimicking ability of the fusion proteins. The results showed that seven phage clones selected bound to NaM87-1F6 specifically, among which, 6 clones bore the same peptide sequence, EYWYCGMNRTGC and another harbored a different one QIWYERTLPFTF. The two peptides were successfully expressed at the N terminal of GST protein. Both of the fusion proteins inhibited the RBC agglutination mediated by anti-A serum in a concentration-dependent manner. These results suggested that the fusion proteins based on the selected peptides could mimic the blood group A antigen and might be used as anti-A antibody-adsorbing materials when immunoabsorption was applied in ABO incompatible transplantation.

Association of ABO blood group and Plasmodium falciparum malaria in Dore Bafeno Area,Southern Ethiopia

Objective:To assess the distribution of ABO blood group and their relationship with Plasmodium falciparum(P.falciparum) malaria among febrile outpatients who sought medical attention at Dore Bafeno Health Center,Southern Ethiopia.Methods:A total of 269 febrile outpatients who visited Dore Bafeno Health Center,Southern Ethiopia,were examined for malaria and also tested for ABO blood groups in January 2010.The blood specimens were collected by finger pricking,stained with Geimsa,and examined microscopically.Positive cases of the parasitemia were counted.CareStart^(TM) Malaria PflPv Combo was also used to test the blood specimens for malaria.ABO blood groups were determined by agglutination test using ERYCLONE antisera.Data on socio-demographic characteristics and treatment status of the participants were also collected.Chi-square and ANOVA tests were used to assess the difference between frequencies and means,respectively.Results:Out of a total of 269 participants,178(66.2%) febrile patients were found to be infected with Plasmodium parasites,among which 146(54.3%),28(10.4%),and 4(1.5%) belonged to P.falciparum,P.vivax,and mixed infections,respectively.All febrile patients were also tested for ABO blood groups and 51.3%,23.5%,21.9%and 3.3%were found to be blood types of 0,A,B and AB,respectively.Both total malaria infection and P.falciparum infection showed significant association with blood types(P<0.05).The proportion of A or B but not 0 phenotypes was higher(P<0.05) in individuals with P.falciparum as compared with non-infected individuals.The chance of having P.falciparum infection in patients with blood groups A,B and AB was 2.5,2.5 and 3.3times more than individuals showing blood 0 phenotypes,respectively.The mean P.falciparum malaria parasitemia for blood groups A,B,AB,and 0 were 3 744/μ L,1 805/ μ L,5 331/μ L,and1 515/μ L,respectively(P<0.01).Conclusions:The present findings indicate that individuals of blood groups A,B and AB are more susceptible to P.falciparum infection as compared with individuals of blood group O.Nevertheless,further in depth studies are required to clearly establish the role that ABO blood group plays in P.falciparum malaria.

ABO blood group is a predictor of survival in patients with laryngeal cancer

Background: Whether the ABO blood group is associated with the survival of patients with laryngeal cancer remains unknown. The purpose of this study was to investigate the association between the ABO blood group and clinico?pathologic characteristics of patients with laryngeal cancer and assess whether the ABO blood group was associated with prognosis.Methods: We analyzed the records of 1260 patients with laryngeal cancer who underwent curative treatment at Sun Yat?sen University Cancer Center between January 1993 and December 2009. The Chi?square test was used to assess the relationship between the ABO blood group and clinicopathologic characteristics. The Kaplan–Meier method was used to estimate 3?, 5?, and 10?year overall survival(OS) rates. The Cox proportional hazards model was used in univariate and multivariate analyses of OS.Results: No signiicant association was found between the ABO blood group and clinicopathologic characteristics except for primary tumor site. The median OS for patients with blood groups A, B, AB, and O were 87.0, 80.0, 90.0, and 72.5 months, respectively. The 3?, 5?, and 10?year OS rates were 82.4%, 76.0%, and 67.5% for patients with blood group A; 77.4%, 69.8%, and 58.4% for patients with blood group B; 82.2%, 73.1%, and 65.6% for patients with blood group AB; and 71.7%, 66.4%, and 55.5% for patients with blood group O, respectively. Univariate and multivariate analyses showed that the ABO blood group had signiicant efects on prognosis in patients with laryngeal cancer.Conclusions: The ABO blood group is associated with survival in patients with laryngeal cancer. Patients with blood group O had signiicantly shorter OS than patients with other ABO blood groups.

Blood group type antigens in pancreatic intraductal papillary mucinous neoplasms

BACKGROUND: There are few data on blood group(BG) types and types of pancreatic cancers. The aims of this study were to study BG types and BG-antigens in pancreatic intraductal papillary mucinous neoplasms(IPMNs). METHODS: BG type and tumor BG-antigen(glycoprotein) expression(studied by immunohistochemistry on tissue microarrays) were analyzed with regard to characteristics of 101 surgically resected pancreatic IPMNs. RESULTS: Non-O BG type predicted invasive carcinoma independently from high serum CA19-9 and male gender. BG type A was observed more frequently in women than in men. Chronic pancreatitis was more frequently seen in patients with BG type B or AB. Aberrant tumor expression(with regard to BG type) of loss of A antigen expression type occurred in 15.0% of IPMNs and of loss of B antigen expression type in 62.5% of IPMNs. Intraneoplasm BG-antigen expression was not related to dysplasia grade or invasion. CONCLUSION: The results of the study suggest that in pancreatic IPMN, non-O BG type predicted invasive carcinoma, whereas for intratumor BG-antigen expression no specific patterns were detected with regard to the progression of glandular epithelial dysplasia or invasion.

Seroprevalence of Helicobacter pylori in dyspeptic patients and its relationship with HIV infection,ABO blood groups and life style in a university hospital,Northwest Ethiopia

AIM： To determine the prevalence of Helicobacter pylori （H pylori） among dyspeptic patients and to assess the relationship between Hpylori infection, blood group, HIV infection and life style of the patients. METHODS： In a hospital-based cross-sectional study, patients attending Outpatient Department of University of Gondar Hospital were enrolled. Socio-demographic information was collected using questionnaires. Serum was analyzed for anti-H pylori IgG antibodies using a commercial kit. HIV serostatus was determined by enzyme-linked immunosorbent assay （ELISA）. Blood grouping was performed by slide agglutination tests. RESULTS： A total of 215 dyspeptic patients were included in the study. One hundred and sixteen patients （54%） were females and 99 （46%） were males. Anti-H pylori IgG antibodies were detected in sera of 184 （85.6%） patients. The prevalence was significantly higher in patients aged 50 years and above. Twenty point five percent of the patients were found to be seropositive for HIV. No significant association was found between sex, ABO blood groups, consumption of spicy diets, socioeconomic status and seropositivity for Hpylori. However,alcohol consumption was significantly associated with H pylori serology. CONCLUSION： The prevalence of H pylori infection is associated with a history of alcohol intake and older age. The effect of different diet, alcohol and socioeconomic status as risk factors for H pylori infection needs further study.

Comparison of Blood Group Molecular Genotyping to Traditional Serological Phenotyping in Patients with Chronic or Recent Blood Transfusion

Objectives: Accurately identifying the Antigens (Ags) on recipient red blood cells (RBCs) is critical in prevention of RBC alloimmunization in chronically transfused patients. The goal of this study was to compare RBC molecular genotyping to serological phenotyping in those patients. Methods: Serological phenotyping and molecular genotyping methods were used to study blood samples from 18 healthy blood donors and 16 transfused patients. Reticulocyte harvesting or hypotonic cell separation was added to recheck RBC phenotypes of the patients with discrepancies between phenotyping and genotyping. Results: No discrepancies were found between the two genotyping methods in all the donors and patients. 1 of 9 sickle-cell disease (SCD) patients and all 3 thalassemia patients demonstrated discrepancies in multiple blood groups between phenotyping and genotyping, which were not corrected by reticulocyte harvesting or hypotonic cell separation. Conclusions: These findings suggest that RBC molecular genotyping is superior to serological phenotyping in chronically transfused SCD or thalassemia patients.

Relationship between ABO blood groups and carcinoma of esophagus and cardia in Chaoshan inhabitants of China

AIM:To study the relationship between ABO blood groups and carcinoma of esophagus and cardia in Chaoshan inhabitants of China, which is a unique Littoral high-risk area of esophageal carcinoma in China. The poor communication and transportation in the past has made Chaoshan a relatively closed area and kept its culture and custure of old China thousand years ago. METHODS: Data on age, sex, ABO blood type and X-ray or pathological diagnose of the patients with carcinoma of esophagus or cardia were collected from the Tumor Hospital. First Affiliated Hospital, Second Affiliated Hospital of Shantou University Medical College; and the Central Hospital of Shantou and the Central Hospital of Jieyang. A total of 6685 patients with esophageal carcinoma (EC) and 2955 patients with cardiac cancer (CC) in Chaoshan district were retrospectively assessed for their association with ABO blood groups. RESULTS: The distribution of ABO blood groups in patients with EC or CC was similar to the normal local population in Chaoshan. However, blood group B in male patients with CC and in the patients with carcinoma in the upper third esophagus was 2.3% and 4.7% higher than the corresponding controls. The relative risk B O was 1.1415 (P【0.05) and 1.2696 (P【0.05), respectively. No relationship was found between ABO blood groups and tumor differentiation. CONCLUSION: ABO blood group B is associated with the incidence of CC in male individuals and carcinoma in the upper third esophagus. The distribution of ABO blood groups varies in the different geographical and ethnic groups. As a result, proper controls are very important for such studies.

Duffy blood group genotypes among malaria Plasmodium vivax patients of Baoulch population in southeastern Iran

Objective:To determine the distribution of Duffy blood group genotypes in Balouch population as a major ethnic group that living in a sub-tropical area in south East of Iran.Methods:In this study,the Duffy blood group FY phenolypes were determined using indireet anti-globulin technique and also genotype by PCR-RFLP in 160 vivax malaria patients and 160 control individuals.Results:The results showed that the most common Duffy geitolype was FYA/FYB(46.6%)followed by FYA/FYA(15.3%),FYA/FYO(14.4%),FYB/FYO(11.9%,),FYB/FYB(10%)and FYO/FYO(1.9%).In case individuals,frequency of FY A.FYB and FYO alleles were 0.471,0.431and 0.097,respectively compaired to 0.444,0.353 and 0.203,respectively in control(non-infected)group.Conclusions:This data provide evidence that individuals with the FYA/FYB genotype have higher susceptibility to malaria and there are significant associations between Duffy blood group variants and susceptibility or resistance to vivax malaria.

Relationship of A,B,H blood group antigens with pathomorphological grading and prognosis of transitional-cell carcinoma of the urinary bladder

After being labelled with monoclonal antibodies against A,B, H blood group antigens,100 specimens of transitional-cell carcinoma of the urinary bladder were studied with ABC immunohistochemical technique and the cases were followed up.It was found that the overall positive rate of A,B,H antigens was 63%. The mortality rate and recurrence were significantly lower in the positive group than in the negative group(P<0.01)and 5-years survival rate was higher in the positive than in the negative(P<0.01).The findings suggest that the expression of blood group antigens is more effective for the prognosis of transitional-cell bladder carcinoma than the pathomorphological grading.

The Patterns of Blood Groups and Its Association with Blood Donation in Saudi Arabia

Background: Blood groups system has key importance for transfusion safety and clinical practice. Therefore, the objective of the present study was to evaluate the distribution of ABO blood groups and its association with blood donation in Saudi Arabia. Methodology: In this study, we collected information regarding blood donation from 715 Saudi volunteers living in the city of Hail, Northern Saudi Arabia. Data about blood donation were obtained from 715 Saudi volunteers living in the city of Hail. Results: The majority of the study population was found with group B+ representing 174 participants, followed by A+, O+, AB+, B-ve, A-ve, AB-ve and O-ve, representing 165, 153, 47, 29, 20, 9, and 7 participants, in this order. Conclusion: The major blood group among Saudi population is group B+ followed by group A+ and O+. Individuals with rare blood groups were less likely to participate in blood donation programs, which necessitate the need for educational programs using motivating factors.

Prevalence of Malaria Infection and ABO Human Blood Group in Dar-es-Salaam, Tanzania

The main objective of this study was to determine the relationship between occurrence of malaria infection with that of human blood group in Dar-es-Salaam Tanzania. The study was based on data collected randomly from the patients who were screened for malaria of all age groups for a period of three months at Mission Mikocheni Hospital. During this time period, a total of 430 blood samples were collected. From the study findings, it is clear that more than 50% of the patients tested were positive for malaria. Further analysis revealed that about 50% of malaria positive patients were type “O” blood group.

Genetic screening of 5 blood group systems of Li ethnic group in Hainan province and establishment of rare blood group bank

Objective:To screen the blood group system genes of Duffy,Lutheran,Kidd,Diego,Dombrock blood group systems of Li ethnic group in Hainan Province and provide laboratory data for the rare blood group database in this area.Methods:The alleles of Duffy,Lutheran,Kidd,Diego,Dombrock blood group systems of 300 voluntary participants of Li ethnic group in Hainan were detected by sequence-specific primer polymerase chain reaction,and the polymorphism was analyzed.Results:The allele frequencies of Duffy,Lutheran,Kidd,Diego,Dombrock blood group systems of Li ethnic groups in Hainan Province are 0.9583 for Fy^(a),0.0417 for Fy^(b),0.8350 for Au^(a),0.1650 for Au^(b),0.4500 for Jk^(a),0.5500 for Jk^(b),0.0667 for Di^(a),0.9333 for Di^(b),0.1017 for Doa and 0.8983 for Dob,respectively.The antigen incompatibility rates of Fy^(a)/Fy^(b),Au^(a)/Au^(b),Jk^(a)/Jk^(b),Di^(a)/Di^(b),Doa/Dob of Duffy,Lutheran,Kidd,Diego,Dombrock blood group systems were 7.67%,23.76%,37.25%,11.67%and 16.60%,respectively.Conclusion:The gene frequencies of Duffy,Lutheran,Kidd,Diego,Dombrock blood group systems of Li ethnic group in Hainan Province are polymorphic,and the antigen incompatibility rates of alleles are higher,which is quite different from that of other nationalities in China and with unique ethnic distribution characteristics.It is of great significance to establish the rare blood group database in this region.

EFFICACY OF ACUPUNCTURE THERAPY ON A, B AND O BLOOD GROUPS ──Relationship between A, B, O blood groups and the acupuncture therapy

Efficacy of acupuncture therapy varies in patients with similar ailments. The present study was undertaken to search for a marker for better efficacy of acupuncture therapy. The study was made in 224 patients including osteoarthritis 141 (62.94 %), polyarthritis 23 (10.26 %), Bursitis & synovitis 15 (6.69 %) and others 45 (20.08 %). ABO blood groups were tested for each patient. It appears that patients belonging to group AB and B responded well to acupuncture therapy in proportionately more number. Good result was achieved in 47.82 % cases in group AB and 46.04 % cases in group B, whereas patients of group A and O showed good result in 27.65 % and 26.15 % cases respectively. Apparently it may be concluded that patients of AB & B blood groups would respond comparatively well to acupuncture therapy.

Blood groups, hemoglobin phenotypes and clinical disorders of consanguineous Yansi population

AIM:To study frequency of blood groups,prevalence of sickle-cell anemia trait and glucose-6-phosphate dehydrogenase deficiency(G6PD),among consanguineous Yansi tribe.METHODS:A total of 525 blood samples were collected,of which 256 among the Yansi population,and269 for the unrelated control group in the Bandunduprovince of Democratic Republic of Congo.Blood group antigens were determined in the following systems:ABO,Rh,Kell,Duffy,Kidd and MNS.Blood grouping and extended phenotype tests were performed according to standard immunohematological procedures.Spot tests and tandem mass spectrometry were used respectively for the assessment of G6PD and sickle-cell anemia trait.RESULTS:The frequency of ABO phenotypes conformed to the following order O>A>B>AB with notably 62.5%,23.8%,12.1%and 1.6%for the Yansi,and 54.6%,27.5%,14.1%and 3.7%for the unrelated control group,respectively(P=0.19).As for the Rh phenotypes,the most frequent were cc D.ee,cc D.Ee,Cc D.ee,corresponding to 71.5%,12.1%and 12.1%for the Yansi,and 70.6%,15.6%and 8.2%,for the unrelated control group(P=0.27).The frequency of MN and Ss phenotypes were statistically different between groups(P=0.0021 and P=0.0006).G6PD was observed in 11.3%of subjects in the Yansi group,and in 12.4%of controls(P=0.74).The sickle-cell anemia trait was present in 22.4%of Yansi subjects and 17.8%in the control group(P=0.24).Miscarriages and deaths in young age were more common among Yansi people.CONCLUSION:This study shows a significant difference in MNS blood group distribution between the Yansi tribe and a control population.The distribution of other blood groups and the prevalence of hemoglobinopathies did not differ in the Yansi tribe.

ABO Blood Groups and Their Relationship with Coagulation Factor VIII in Healthy Adults

Background: ABO blood group distribution defers with racial and geographic variations. They are related to diseases like cardiovascular diseases, cerebral thromboembolism. ABO blood group system may influence coagulation factor VIII which may increase the future risk of thrombosis. Aim: To assess the relation of ABO blood group with coagulation factor VIII in healthy adults. Material and Methods: A prospective type of analytical cross-sectional study was conducted in the Department of Physiology, Dhaka Medical College, Dhaka from July 2019 to June 2020. After obtaining ethical clearance, a total of 190 healthy adults were selected from different areas of Dhaka city based on inclusion and exclusion criteria, with ages ranging from 18 - 45 years. The subjects were interviewed and detailed history regarding personal, family, medical and drug were taken. Prior to sample collection, informed written consent was taken from the participants. Individuals of blood group A were selected as group A, blood group B as group B, blood group AB as group AB and blood group O as group O. Coagulation factor VIII was measured in the Department of Hematology and BMT Unit, Dhaka Medical College Hospital, Dhaka. Blood grouping was done in the Department of Physiology, Dhaka Medical College, Dhaka. Statistical Analysis: For statistical analysis, ONE way ANOVA followed by Bonferroni test were considered using SPSS 25.0 version. Results: In this study, blood group B was most common (33.2%). Coagulation factor VIII was significantly higher (p < 0.001) in blood group A (105.76% ± 11.82%), B (112.00% ± 15.02%), AB (109.80% ± 11.93%) than blood group O (82.00% ± 12.86%). No significant difference was observed among A, B and AB blood groups regarding coagulation factor VIII. Conclusions: It can be concluded that blood group A, B, AB individuals may have more chance of thrombosis due to significantly higher coagulation factor VIII than blood group O individuals.

Clinical significance of the detection of Rh blood group antigens and irregular antibodies in pregnant women with a second pregnancy

Objective:To investigate the phenotype distribution of five antigens of Rh blood group system and the specificity of Rh blood group irregular antibodies in pregnant women with second child.To analyze the relationship between Rh blood group antibody and hemolytic disease of the newborn(HDN)in second-child pregnant women,and to provide laboratory basis for the diagnosis and treatment of hemolytic disease of the newborn(Rh-HDN).Methods:500 pregnant women with second child were collected as the study group and 500 pregnant women with first pregnancy as the control group(all pregnant women underwent obstetric examination in the integrated obsteric clinic of our hospital from January 2020 to January 2021).To detectethe Rh blood group antigens(D,C,c,E,e)of the two groups of samples,screene the irregular antibodies,identify the specificity of irregular antibodies,determine the titer and record the hemolytic disease of the newborn of pregnant women with positive Rh blood group antibodies.Results:There were 11 Rh phenotypes in the pregnant women with second child in the study group:CCDee(152cases,30.4%),CcDEe(136cases,27.2%)CcDee(84cases,16.8%),ccDEE(30cases,6%),ccDee(31cases,6.2%),CCDEe(14cases,2.8%),ccDEe(9cases,1.8%),cc dee(18cases,3.6%),CCDEE(2cases,0.4%),CcdEe(12cases,2.4%),Ccdee(6cases,1.2%),CCd ee(6cases,1.2%).A total of 42 cases(8.4%)in the pregnant women with second child were negative for RhD.There were 10 Rh phenotypes in the pregnant women with first pregnancy in the control group:CCDee(144cases,28.8%),CcDEe(138cases,27.6%),CcDee(90cases,18%),ccDEE(42cases,8.4%),ccDee(28cases,5.6%),CCDEe(10cases,2%),ccDEe(8cases,1.6%),cc dee(19cases,3.8%),CCDEE(1cases,0.2%),CcdEe(11cases,2.2%),Ccdee(9cases,1.8%).A total of 39 cases(7.8%)in the pregnant women with first pregnancy were negative for RhD.In the pregnant women with second child in the study group,the positive rate of irregular antibody screening was 4.0%(20/500),and the specificity of Rh blood group antibodies was found as follows:anti-E 1.8%(9/500),anti-D 1.4%(7/500),anti-C 0.4%(2/500)and anti-Ec 0.4%(2/500).The positive rate of irregular antibody screening in the pregnant women with first pregnancy in the control group was 0,and the difference between the two groups was statistically significant(P<0.05).Rh-HDN was found in 10 newborns(2%)of the 20 women with positive irregular antibodies in the pregnant women with second child,and the antibody titer during pregnancy was more than 32.No Rh-HDN occurred in newborns in the pregnant women with first pregnancy,and the difference between the two groups was statistically significant(P<0.05).Conclusion:Pregnancy stimulation can increase the probability of irregular antibodies in pregnant women,and irregular antibodies in Rh blood group can easily cause Rh-HDN,so attention should be paid to routine detection of five antigens of Rh blood group and irregular antibody screening during prenatal examination.It is helpful for the early detection of Rh-blood irregular antibodies and the assessment of fetal or neonatal risk of Rh-HDN.