OBJECTIVE: This study was aimed to provide ideas for identifying the antibodies to high-frequency antigens by analyzing a female case of high-frequency antigen antibody (anti-Ku) using serological and sequencing method.
METHODS: The methods for identification of blood group, erythrocyte antigen, screening and identification of antibody were used to detect the blood type and antibody in the proband. The proband\'s serum and reagent screening cells treated with Sulfhydryl reagent were applied to judge the type and characteristics of this antibodies when reacted with the regaent screening cells or proband\'s serum respectively. Gene sequencing was used to determine the genotype of the proband\'s blood group.
RESULTS: The proband\'s red blood cells were determined as O type RhD positive, whose serum showed strong positive reaction to antibody-screening cells and antibody identification cells with the same intensity in saline and IAT medium, however, the self-cells showed negative effect. The Direct Antihuman Globulin of proband\'s red blood cells also showed weak positive reaction, and the other blood types were CcEe, Jk(a+b-), P1-, Le(a-b -), Lu (a-b +), K-, k-, Kp(a-b-). Serum of the proband treated with 2-ME still react with three groups of screening cells in IAT medium. The reaction intensity of proband\'s serum was also unchanged with the cells modified with papain and bromelain, but showed negative effect when the cells were treated with sulfhydryl agents including DTT and 2-ME. Gene sequencing revealed that the KEL genotype of the patient was KEL*02N.24 . This patient had a rare K0 phenotype.
CONCLUSIONS: The rare Kell-null blood group (also known as K0) were identified by serological and molecular tests in the proband who produced both IgG and IgM type of antibody to high-frequency antigen (anti-Ku). These two methods are of great significance in the identification of this rare blood group as well as the antibody to high frequency antigen.
UNASSIGNED: 抗Ku及其他高频抗原抗体的鉴定思路.
UNASSIGNED: 通过对一例女性高频抗原抗体（抗-Ku）病例进行血清学鉴定及血型基因测序分析，为高频抗原抗体的鉴定提供一定思路。.
UNASSIGNED: 运用血型鉴定、患者红细胞抗原鉴定、抗体筛选、抗体鉴定等方式检测该患者的血型及抗体。以巯基试剂处理后的血清与筛选细胞反应、患者血清与酶或巯基试剂处理的筛选细胞反应的方式来判断该抗体的类型及特点，采用基因测序的方法确定患者血型的基因型。.
UNASSIGNED: 该患者血型为O型RhD+，其血清与抗体筛选细胞及抗体鉴定细胞在间接抗人球及盐水介质中的反应呈强反应性，且强度一致，自身阴性，直接抗人球蛋白弱阳性；其他血型为CcEe、Jk(a+b-)、P1-、Le(a-b-)、Lu（a-b+）、K-、k-、Kp(a-b-)。血清经2-ME处理后，在间接抗人球介质中仍与3组筛选细胞反应；血清与经木瓜酶、菠萝酶修饰后的筛选细胞反应强度不变，与巯基试剂DTT、2-ME处理后的筛选细胞反应为阴性。基因测序显示该患者KEL 基因型为KEL*02N.24 ，为罕见的K0表型。.
UNASSIGNED: 血清学试验和分子生物学实验鉴定出该患者为罕见的Kel-null血型（又称K0），该患者体内产生了IgG及IgM性质的高频抗原抗体抗-Ku。血清学方法及分子生物学方法在此类稀有血型及高频抗原抗体的鉴定中具有重要意义。.

OBJECTIVE: To analyze the distribution characteristics of Rh phenotype in pregnant and postpartum women in Chongqing area, and to explore the clinical significance of Rh phenotype in pregnant and postpartum women and the feasibility of Rh phenotype compatible blood transfusion.
METHODS: The ABO blood group and Rh phenotype of 65 161 pregnant and postpartum women were detected by microcolumn gel method, and 48 122 males in the same period were taken as controls. The data were analyzed by Chi-square test.
RESULTS: There were 112 870 cases (99.64%) of RhD+ in 113 283 samples. In RhD+ cases, CCDee (48.39%) and CcDEe (32.88%) were the main phenotypes. The first case of D-- phenotype in Chongqing area was detected. 413 cases (0.36%) of RhD- were detected, with ccdee (52.78%) and Ccdee (33.41%) as the main phenotypes. Compared with RhD- group, RhD+ group showed statistically significant difference in Rh phenotype distribution (P < 0.01). Among 65 161 maternal samples, the positive rate of 5 antigens of Rh blood group from high to low was D > e > C > c > E, and there was no significant difference compared with male samples (P >0.05). There was no significant difference in the distribution of Rh phenotype between males and pregnant/postpartum women, as well as between pregnant/postpartum women with different ABO blood groups (P >0.05). In pregnant and postpartum women, there was no significant difference in distribution of Rh phenotype among the normal pregnancy population, the population with adverse pregnancy history, the population using human assisted reproductive technology (ART) and the population with infertility (P >0.05). There was no significant difference in the distribution of Rh phenotype between the 4 populations mentioned above and the inpatients in the local general Grade A hospitals and the blood donors (P >0.05). In RhD positive pregnant and postpartum women, the probability of finding compatible blood for CcDEe phenotype was 100%, the probability of finding compatible blood for CCDee, CcDee and CCDEe phenotypes was 45%-60%, the probability of finding compatible blood for ccDEE, ccDEe and CcDEE phenotypes was 5%-10%, and the probability of finding compatible blood for other phenotypes was lower than 0.5%. The supply of blood with CCDee and ccDEE phenotypes can meet the compatible transfusions requirements of 7 Rh phenotypes in more than 99% of patients.
CONCLUSIONS: Rh phenotype detection should be carried out for pregnant and postpartum women, and it is feasible to carry out Rh phenotype-matched or compatible blood transfusion for pregnant and postpartum women who need blood transfusion.
UNASSIGNED: 孕产妇Rh表型分布特征及相容性输血的可行性探讨.
UNASSIGNED: 分析重庆地区孕产妇Rh表型分布特征，探讨Rh表型在孕产妇中的临床意义及实行Rh表型相容性输血的可行性。.
UNASSIGNED: 采用微柱凝胶法对65 161例孕产妇进行ABO血型和Rh表型检测，以同期48 122例男性为对照，通过χ2检验对数据进行比较分析。.
UNASSIGNED: 113 283例样本中，RhD+ 112 870例（99.64%），以CCDee（48.39%）和CcDEe（32.88%）为主要表型，并检出重庆地区首例Rh缺失型D--表型；RhD-413例（0.36%），以ccdee（52.78%）和Ccdee（33.41%）为主要表型；RhD+组与RhD-组的Rh表型分布差异有统计学意义（P < 0.01）。在65 161例孕产妇中，Rh 5种抗原的阳性率由高到低为D>e>C>c>E，与男性相比差异无统计学意义（P >0.05）；孕产妇Rh表型分布与男性相比差异无统计学意义（P >0.05）；不同ABO血型的孕产妇间Rh表型分布差异无统计学意义（P >0.05）。在孕产妇中，正常妊娠人群、有不良流产史人群、采用人类辅助生殖技术人群和不孕症患者人群间Rh表型分布无明显差异（P >0.05）， 4个孕产妇人群与本地区综合性三甲医院住院患者和献血者相比，Rh表型分布差异无统计学意义（P >0.05）。RhD阳性孕产妇中，CcDEe表型找到相容性血液的概率为100%，CCDee、CcDee和CCDEe表型找到相容血液的概率为45%-60%，ccDEE、ccDEe、CcDEE表型找到相容血液的概率为5%-10%，其余表型的相容概率均低于0.5%；提供CCDee和ccDEE两个表型的血液即可满足99%以上患者7种Rh表型相容性输血需求。.
UNASSIGNED: 应对孕产妇进行Rh表型检测，对需要输血的孕产妇推行Rh表型相同或相容性输血是切实可行的输血举措。.

Anti-f is produced by exposure to the compound antigen ce (f) on red blood cells (RBCs), expressed when both c and e are present on the same protein (cis position). Although anti-f was discovered in 1953, there are few cases reported worldwide because the presence of anti-f is often masked by anti-c or anti-e and is not generally found as a single antibody. In the present case, anti-f was identified by using three-cell screening and 11-cell identification panels. The identification of anti-f was further supported by additional testing, including (1) Rh antigen typing; (2) antibody identification panels (enzyme-treated panel [ficin] and an in-house-constructed Rh panel); (3) look-back and phenotyping of donor RBC units, which were responsible for alloimmunization; and (4) molecular testing of the patient\'s RBCs.

The high number of D variants can lead to the unnecessary use of Rh immune globulin, overuse of D- RBC units, and anti-D allommunization. D variant prevalence varies among ethnic groups, and knowledge of the main variants present in a specific population, their behavior in serologic tests, and their impact on clinical practice is crucial to define the best serologic tests for routine use. The present study aimed to explore the serologic profile of D variants and to determine which variants are most associated with false-negative D typing results and alloimmunization. Donor samples were selected in two study periods. During the first period, D typing was performed on a semi-automated instrument in microplates, and weak D tests were conducted in tube or gel tests. In the second period, D typing was carried out using an automated instrument with microplates, and weak D tests were performed in solid phase. Samples from patients typed as D+ with anti-D were also selected. All samples were characterized by molecular testing. A total of 37 RHD variants were identified. Discrepancies and atypical reactivity without anti-D formation were observed in 83.4 percent of the samples, discrepant D typing results between donations were seen in 12.3 percent, and D+ patients with anti-D comprised 4.3 percent. DAR1.2 was the most prevalent variant. Weak D type 38 was responsible for 75 percent of discrepant samples, followed by weak D type 11, predominantly detected by solid phase. Among the D variants related to alloimmunization, DIVa was the most prevalent, which was not recognized by serologic testing; the same was true for DIIIc. The results highlight the importance of selecting tests for donor screening capable of detecting weak D types 38 and 11, especially in populations where these variants are more prevalent. In pre-transfusion testing, it is crucial that D typing reagents demonstrate weak reactivity with DAR variants; having a serologic strategy to recognize DIVa and DIIIc is also valuable.

This review aims to provide a better understanding of when and why red blood cell (RBC) genotyping is applicable in transfusion medicine. Articles published within the last 8 years in peer-reviewed journals were reviewed in a systematic manner. RBC genotyping has many applications in transfusion medicine including predicting a patient\'s antigen profile when serologic methods cannot be used, such as in a recently transfused patient, in the presence of autoantibody, or when serologic reagents are not available. RBC genotyping is used in prenatal care to determine zygosity and guide the administration of Rh immune globulin in pregnant women to prevent hemolytic disease of the fetus and newborn. In donor testing, RBC genotyping is used for resolving ABO/D discrepancies for better donor retention or for identifying donors negative for high-prevalence antigens to increase blood availability and compatibility for patients requiring rare blood. RBC genotyping is helpful to immunohematology reference laboratory staff performing complex antibody workups and is recommended for determining the antigen profiles of patients and prospective donors for accurate matching for C, E, and K in multiply transfused patients. Such testing is also used to determine patients or donors with variant alleles in the Rh blood group system. Information from this testing aides in complex antibody identification as well as sourcing rare allele-matched RBC units. While RBC genotyping is useful in transfusion medicine, there are limitations to its implementation in transfusion services, including test availability, turn-around time, and cost.

BACKGROUND: Autoimmune hemolytic anemia disease often produces a large number of various autoantibodies, and some autoantibodies may be related to Rh blood group. In rare cases, autoantibodies can specifically target Rh antigen, thus interfering with the identification of Rh blood group.
METHODS: A case of systemic lupus erythematosus (SLE) with inconsistent RhD blood group identification results in different periods was reported and the reasons were analyzed.
RESULTS: Some autoantibodies can completely block D antigen on red blood cells, resulting in no redundant D sites on red blood cells binding to reagent anti D. In addition, the immunity of the body is extremely low, and the expression of red blood cell blood group antigens in part of the body is inhibited, which will cause the weakening of the expression of Rh antigen in red blood cells. Therefore, when testing the RhD blood type of the patient, the reagent anti D does not agglutinate with the patient\'s red blood cells, and a false negative result of the initial screening appears. Through the RhD negative confirmation test, the patient\'s blood type is a serologically weak D phenotype.
CONCLUSIONS: If the result of serological preliminary screening test is RhD negative or RhD variant, the recipient should be treated as RhD negative, and RhD negative red blood cells should be transfused during blood transfusion. Conditional laboratories can implement RHD genotyping, which is conducive to improving the precise blood transfusion management level of RhD negative blood recipients, saving rare blood resources and improving the treatment efficiency of patients.

BACKGROUND: The need for blood during a surgical procedure is greater than what blood banks are able to provide. There is an excessive amount of blood being ordered for elective surgeries, surpassing the actual requirements. Only 30% of the cross matched blood is actually used in these surgeries. The accuracy of estimating the transfusion needs before a surgical procedure can be determined by looking at the cross match to transfusion ratio and the transfusion index. \"These indicators play a crucial role in developing the maximum surgical blood ordering schedule; in this study, these indicators were tested.\"
OBJECTIVE: Is to determine the efficiency of blood ordering and transfusion practices for patients undergoing elective surgeries.
METHODS: This study is a prospective cross-sectional hospital-based study done at Omdurman Teaching Hospital-Sudan. Conducted for the duration of 6 months period from July to December 2019.The study participants were patients who underwent elective surgical procedures in general surgery and Urology departments as total coverage sample over a period of study duration. Ethical clearance obtained from ethical committee of Sudan Medical Specialization Board.
RESULTS: Two hundreds seven patients included in this study, the amount of blood units requested were 443-unit, cross matching for 98.6% (n 437) of units were done. Only 100 unit were Transfused (22,8%). The calculated CT ratio was 4.4, transfusion index was 1.6 and transfusion probability was 29.9%.
CONCLUSIONS: Transfusion probability and transfusion index of the present study were optimal but comparatively higher than the standard guidelines as most of the cross matched blood was not utilized.

UNASSIGNED: Red blood cell antigens are numerous in structural and functional diversity; some are proteins while others are carbohydrates. The international society of blood transfusion currently recognized 43 blood group systems containing 349 red cell antigens. It also acknowledged 9 blood group systems (ABO, Rhesus, Kell, Duffy, Kidd, MNS, P, Lewis, and Lutheran) that are clinically significant and associated with hemolytic transfusion reactions as well as hemolytic disease of fetuses and newborns. The objective of this study was to assess the distribution of minor blood group antigens and their phenotype among voluntary blood donors in Ethiopian blood and tissue bank service in Addis Ababa.
UNASSIGNED: A cross-sectional study was conducted from January to March 2022 among 260 volunteer blood donors to determine minor blood group antigens and their phenotype at EBTBS, Addis Ababa, Ethiopia. Tests were performed using Galileo Neo Immucor, which is fully automated Immunohematology analyzer.
UNASSIGNED: A total of 260 blood donors were screened of which 153 (59%) were males. The antigen frequencies of minor blood group systems were: Fy(a), Fy(b), Jk(a), Jk(b), k, S, s were 33.5%, 43.5%, 97.7%), 40.4%), 100%, 45%, 90%, respectively. Regarding phenotype distribution, the most common phenotypes were: Duffy Fy (a-b+) 36.9%, MNS S-s+ 55% and Kidd Jk (a+b-) 59.6%.
UNASSIGNED: This study highlights the frequencies of Fy(a), Fy(b), Jk(a), Jk(b), k, S and s blood group antigens and their phenotypes in volunteer blood donors at EBTBS, Addis Ababa. For the management of alloimmunization cases in transfused patients, knowledge of these minor blood group antigens is relevant.

This extraordinary case showcases the identification of a rare anti-Ena specificity that was assisted by DNA-based red blood cell antigen typing and collaboration between the hospital blood bank in the United States, the home blood center in Qatar, the blood center Immunohematology Reference Laboratory, as well as the American Rare Donor Program (ARDP) and the International Society for Blood Transfusion (ISBT) International Rare Donor Panel. Ena is a high-prevalence antigen, and blood samples from over 200 individuals of the extended family in Qatar were crossmatched against the patient\'s plasma with one compatible En(a-) individual identified. The ISBT International Rare Donor Panel identified an additional donor in Canada, resulting in a total of two En(a-) individuals available to donate blood for the patient.

OBJECTIVE: This study aims to report two unrelated individuals with the same novel CisAB blood type and confirm this rare blood type using a comprehensive approach that combines serological and molecular biology techniques.
METHODS: Peripheral blood samples were collected from two patients and their family members. ABO blood typing and antibody detection were performed using conventional tube methods. Molecular biology techniques were employed to amplify and sequence the 6th and 7th exons of the ABO gene, with reference to gene mutation databases provided by NCBI and ISBT.
RESULTS: The genotypes of the two unrelated individuals were identical and were confirmed as a new genotype through ISBT gene database comparison. Serological testing results showed different antigen reaction patterns, especially in terms of reverse typing. Gene sequencing identified a series of mutation points, and both unrelated individuals and one of their daughters had mutations at 297 A>G, 526 C>G, 657 C>T, 703 G>A, 803 G>C, and 930 G>A. According to the comprehensive results from The Blood Group Antigen Gene Mutation Database provided by NCBI, the genotype was determined as Bw37. However, based on the results from Names for ABO (ISBT 001) blood group alleles v1.1 171023, the sequencing results indicated a novel mutation combination not found in the ISBT database. Considering the serological reactions of all three individuals, the final determination was CisAB.
CONCLUSIONS: This study confirmed the novel CisAB blood type in two individuals through the comprehensive application of serology and molecular biology techniques. The identified gene mutation points were not recorded in known databases, emphasizing the uniqueness of CisAB blood types. This research provides important insights into the genetic basis of ABO subtypes and the characteristics of CisAB blood types, and the relevant results have been submitted to the ISBT website for further research.