1
|
Yin Q. DEL variants: review of molecular mechanisms, clinical consequences and molecular testing strategy. Funct Integr Genomics 2023; 23:318. [PMID: 37840046 DOI: 10.1007/s10142-023-01249-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/04/2023] [Accepted: 10/05/2023] [Indexed: 10/17/2023]
Abstract
Patients with DEL phenotype, a D variant with a low number of D antigens per red blood cell, are routinely typed as RhD-negative in serology testing and are detectable only by adsorption and elution techniques or molecular methods. DEL is of clinical importance worldwide, as indicated by its genotype-phenotype discrepancies among different populations and its potential to cause anti-D alloimmunization when DEL phenotype individuals are inadvertently managed as RhD-negative. This narrative review summarized the DEL alleles causing DEL phenotype and the underlying mechanisms. The clinical consequences and current molecular testing approach were discussed to manage the transfusion needs of patients and donors with DEL phenotype.
Collapse
Affiliation(s)
- Qinan Yin
- Henan Engineering Research Center of Digital Pathology and Artificial Intelligence Diagnosis, The First Affiliated Hospital of Henan University of Science and Technology, Luoyang, China.
- Precision Medicine Laboratory, School of Medical Technology and Engineering, Henan University of Science and Technology, Luoyang, China.
| |
Collapse
|
2
|
Ji Y, Luo Y, Wen J, Sun Y, Jia S, Ou C, Yang W, Chen J, Ye H, Liu X, Liang Y, Lu Z, Feng Y, Wu X, Xiao M, Mo J, Zhou Z, Wang Z, Liao Z, Chen J, Wei L, Luo G, Santoso S, Fichou Y, Flegel WA, Shao C, Li C, Zhang R, Fu Y. Patients with Asian-type DEL can safely be transfused with RhD-positive blood. Blood 2023; 141:2141-2150. [PMID: 36638337 PMCID: PMC10273079 DOI: 10.1182/blood.2022018152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 01/03/2023] [Accepted: 01/05/2023] [Indexed: 01/15/2023] Open
Abstract
Red blood cells (RBCs) of Asian-type DEL phenotype express few RhD proteins and are typed as serologic RhD-negative (D-) phenotype in routine testing. RhD-positive (D+) RBC transfusion for patients with Asian-type DEL has been proposed but has not been generally adopted because of a lack of direct evidence regarding its safety and the underlying mechanism. We performed a single-arm multicenter clinical trial to document the outcome of D+ RBC transfusion in patients with Asian-type DEL; none of the recipients (0/42; 95% confidence interval, 0-8.40) developed alloanti-D after a median follow-up of 226 days. We conducted a large retrospective study to detect alloanti-D immunization in 4045 serologic D- pregnant women throughout China; alloanti-D was found only in individuals with true D- (2.63%, 79/3009), but not in those with Asian-type DEL (0/1032). We further retrospectively examined 127 serologic D- pregnant women who had developed alloanti-D and found none with Asian-type DEL (0/127). Finally, we analyzed RHD transcripts from Asian-type DEL erythroblasts and examined antigen epitopes expressed by various RHD transcripts in vitro, finding a low abundance of full-length RHD transcripts (0.18% of the total) expressing RhD antigens carrying the entire repertoire of epitopes, which could explain the immune tolerance against D+ RBCs. Our results provide multiple lines of evidence that individuals with Asian-type DEL cannot produce alloanti-D when exposed to D+ RBCs after transfusion or pregnancy. Therefore, we recommend considering D+ RBC transfusion and discontinuing anti-D prophylaxis in patients with Asian-type DEL, including pregnant women. This clinical trial is registered at www.clinicaltrials.gov as #NCT03727230.
Collapse
Affiliation(s)
- Yanli Ji
- Institute of Clinical Blood Transfusion, Guangzhou Blood Center, Guangzhou, China
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Yalin Luo
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Jizhi Wen
- Institute of Clinical Blood Transfusion, Guangzhou Blood Center, Guangzhou, China
| | - Yuanfan Sun
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
- RNA Biomedical Institute, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Shuangshuang Jia
- Institute of Clinical Blood Transfusion, Guangzhou Blood Center, Guangzhou, China
| | - Chunquan Ou
- State Key Laboratory of Organ Failure Research, Department of Biostatistics, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China
| | - Wenbing Yang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
- RNA Biomedical Institute, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Jingwang Chen
- Institute of Clinical Blood Transfusion, Guangzhou Blood Center, Guangzhou, China
| | - Hanshen Ye
- Department of Blood Transfusion, Guangdong Provincial People's Hospital, (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Xiangfu Liu
- Department of Blood Transfusion, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Yongneng Liang
- Department of Blood Transfusion, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Zhigang Lu
- Department of Blood Transfusion, ZhuJiang Hospital of Southern Medical University, Guangzhou, China
| | - Ying Feng
- Department of Blood Transfusion, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xinzhong Wu
- Department of Blood Transfusion, Guangdong Province Traditional Chinese Medical Hospital, Guangzhou, China
| | - Muzhou Xiao
- Department of Blood Transfusion, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jiankun Mo
- Department of Blood Transfusion, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Zhenhai Zhou
- Department of Blood Transfusion, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Zhen Wang
- Institute of Clinical Blood Transfusion, Guangzhou Blood Center, Guangzhou, China
| | - Zhijian Liao
- Institute of Clinical Blood Transfusion, Guangzhou Blood Center, Guangzhou, China
| | - Junhu Chen
- Guangdong Provincial Institute of Biological Products and Materia Medica, Guangzhou, China
| | - Ling Wei
- Institute of Clinical Blood Transfusion, Guangzhou Blood Center, Guangzhou, China
| | - Guangping Luo
- Institute of Clinical Blood Transfusion, Guangzhou Blood Center, Guangzhou, China
| | - Sentot Santoso
- Institute of Clinical Blood Transfusion, Guangzhou Blood Center, Guangzhou, China
| | - Yann Fichou
- University of Brest, Inserm, EFS, UMR1078, GGB, Brest, France
- Laboratory of Excellence GR-Ex, Paris, France
| | - Willy Albert Flegel
- Department of Transfusion Medicine, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda, MD
| | - Chaopeng Shao
- Department of Blood Transfusion, The Second People's Hospital of Shenzhen, Shenzhen, China
| | - Chengyao Li
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Rui Zhang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Yongshui Fu
- Institute of Clinical Blood Transfusion, Guangzhou Blood Center, Guangzhou, China
- School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| |
Collapse
|
3
|
Yin Q, Flegel WA. DEL in China: the D antigen among serologic RhD-negative individuals. J Transl Med 2021; 19:439. [PMID: 34670559 PMCID: PMC8527646 DOI: 10.1186/s12967-021-03116-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Accepted: 09/21/2021] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Providing RhD-negative red cell transfusions is a challenge in East Asia, represented by China, Korea, and Japan, where the frequency of RhD-negative is the lowest in the world. FINDINGS Among 56 ethnic groups in China, the RhD-negative frequency in Han, the prevalent ethnicity, is 0.5% or less, similar to most other ethnic groups. The Uyghur ethnic group has the highest reported RhD-negative frequency of up to 4.7%, as compared to 13.9% in the US. However, an estimated 7.15 million RhD-negative people live in China. The RhD-negative phenotype typically results from a loss of the entire RHD gene, causing the lack of the RhD protein and D antigen. The DEL phenotype carries a low amount of the D antigen and types as RhD-negative in routine serology. The DEL prevalence in RhD-negative individuals averages 23.3% in the Han, 17% in the Hui and 2.4% in the Uyghur ethnicities. The Asian type DEL, also known as RHD*DEL1 and RHD:c.1227G > A allele, is by far the most prevalent among the 13 DEL alleles observed in China. CONCLUSION The purpose of this review is to summarize the data on DEL and to provide a basis for practical strategy decisions in managing patients and donors with DEL alleles in East Asia using molecular assays.
Collapse
Affiliation(s)
- Qinan Yin
- Laboratory Services Section, Department of Transfusion Medicine, NIH Clinical Center, National Institutes of Health, Bethesda, MD, 20892, USA
- Henan University of Science and Technology, Luoyang, Henan, China
| | - Willy Albert Flegel
- Laboratory Services Section, Department of Transfusion Medicine, NIH Clinical Center, National Institutes of Health, Bethesda, MD, 20892, USA.
- Huazhong University of Science and Technology, Wuhan, Hubei, China.
| |
Collapse
|
4
|
Flegel WA. Proceed with care: the "uncommon" serologic weak D phenotypes. BLOOD TRANSFUSION = TRASFUSIONE DEL SANGUE 2021; 19:272-276. [PMID: 34704554 PMCID: PMC8297679 DOI: 10.2450/2021.0147-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Willy Albert Flegel
- Department of Transfusion Medicine, NIH Clinical Center, National Institutes of Health, Bethesda, MD, United States of America
- Huazhong University of Science and Technology, Wuhan, Hubei, China
| |
Collapse
|
5
|
Zhang Y, Xu H, Wang X, Wang L, Liu R, Li L, Zhou H. Single‑strained DNA aptamers mask RhD antigenic epitopes on human RhD+ red blood cells to escape alloanti‑RhD immunological recognition. Mol Med Rep 2020; 21:1841-1848. [PMID: 32319623 PMCID: PMC7057830 DOI: 10.3892/mmr.2020.10985] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Accepted: 01/24/2020] [Indexed: 02/07/2023] Open
Abstract
Rhesus D‑ (RhD‑) individuals should receive Rh‑matched blood to prevent hemolytic anemia. However, there is a shortage of RhD‑ blood. This study aimed to generate RhD antigen‑specific single‑stranded DNA (ssDNA) aptamers, and test their efficacy in masking RhD antigens on RhD+ red blood cells (RBCs) to prevent their immunoreactivity in vitro. In the present study, ssDNA aptamer candidates were synthesized as a central randomized sequence of 40 nucleotides (nt) flanked by 21‑nt primer hybridization sequences. The functional aptamers were screened using the cell‑based systematic evolution of ligands by exponential enrichment technique and RhD+ RBCs. Two bioactive ssDNA aptamers significantly inhibited the binding of an anti‑RhD antibody to RhD+ RBCs and bound to RhD antigens with high affinity (dissociation constant values of 580.5±142.0 and 737.7±161.8 nM, respectively). Furthermore, treatment with both ssDNA aptamers (500 pmol) effectively masked RhD antigens on 4,000,000 RhD+ RBCs to prevent human anti‑RhD alloantibody‑mediated binding, RBC agglutination and monocyte recognition in vitro. Collectively, such data suggested that these ssDNA aptamers may be feasible for masking RhD antigens on RBCs, and thus valuable for prevention or at least amelioration of RhD+‑related hemolytic anemia in RhD‑ individuals.
Collapse
Affiliation(s)
- Yinze Zhang
- Department of Transfusion, International Cancer Center, Shenzhen University General Hospital, Shenzhen University Clinical Medical Academy, Shenzhen, Guangdong 518055, P.R. China
| | - Hua Xu
- Shaanxi Blood Center, Institute of Transfusion Medicine, Xi'an, Shaanxi 710061, P.R. China
| | - Xin Wang
- Department of Transfusion, International Cancer Center, Shenzhen University General Hospital, Shenzhen University Clinical Medical Academy, Shenzhen, Guangdong 518055, P.R. China
| | - Lin Wang
- Department of Transfusion, International Cancer Center, Shenzhen University General Hospital, Shenzhen University Clinical Medical Academy, Shenzhen, Guangdong 518055, P.R. China
| | - Ruiqi Liu
- Department of Transfusion, International Cancer Center, Shenzhen University General Hospital, Shenzhen University Clinical Medical Academy, Shenzhen, Guangdong 518055, P.R. China
| | - Lu Li
- Department of Transfusion, International Cancer Center, Shenzhen University General Hospital, Shenzhen University Clinical Medical Academy, Shenzhen, Guangdong 518055, P.R. China
| | - Huayou Zhou
- Department of Transfusion, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| |
Collapse
|
6
|
Kim TY, Hong YJ, Kim MJ, Kim H, Kim TS, Park JS, Park KU, Han KS. Recommendations Regarding Practical DEL Typing Strategies for Serologically D-Negative Asian Donors. Transfus Med Hemother 2019; 47:88-93. [PMID: 32110199 DOI: 10.1159/000500098] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 03/31/2019] [Indexed: 12/25/2022] Open
Abstract
Background DEL, the weakest D variant, is mistyped as D-negative by routine serological assays. Transfusion of red blood cells expressing the DEL phenotype has the potential to elicit anti-D alloimmunization in D-negative recipients. The goal of this study was to recommend DEL typing strategies for serologically D-negative Asian donors. Methods RhCE phenotyping and the adsorption-elution test were performed on 674 serologically D-negative samples. RHD genotyping using real-time polymerase chain reaction and melting curve analysis were also undertaken to identify DEL alleles. Costs and turnaround time of RhCE phenotyping, the adsorption-elution test, and RHD genotyping were estimated. Results Sensitivity and specificity of the adsorption-elution test for serologically D-negative samples were 94.9% (93/98) and 91.5% (527/576), respectively. C+ phenotypes were detected in all 98 samples with DEL alleles. Despite comparable costs, RHD genotyping was more accurate and rapid than the adsorption-elution test. Conclusions Two practical DEL typing strategies using RhCE phenotyping as an initial screening method were recommended for serologically D-negative Asian donors. Compared with DEL typing using RHD genotyping, serological DEL typing using adsorption-elution test is predicted to increase the incidence of anti-D alloimmunization and decrease the D-negative donor pool without having any cost-competitiveness but can be used in laboratories where molecular methods are not applicable.
Collapse
Affiliation(s)
- Tae Yeul Kim
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Yun Ji Hong
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.,Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Mi Jung Kim
- Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Hyungsuk Kim
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Taek Soo Kim
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Jeong Su Park
- Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Kyoung Un Park
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.,Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Kyou-Sup Han
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Republic of Korea.,Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| |
Collapse
|
7
|
Shi J, Luo Y. Effects of RHD gene polymorphisms on distinguishing weak D or DEL from RhD- in blood donation in a Chinese population. Mol Genet Genomic Med 2019; 7:e00681. [PMID: 30950221 PMCID: PMC6565595 DOI: 10.1002/mgg3.681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 03/05/2019] [Accepted: 03/07/2019] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Weak D or DEL red blood cell units may be mistyped as RhD- by current serology assays, which can lead to incompatible transfusion to RhD- recipients and further cause anti-D immunization. Molecular RHD blood group typing is a very effective method for overcoming current technical limits. The purpose of this study was to identify RHD single-nucleotide polymorphisms (SNPs) and compare the genotype prevalence among confirmed RhD- individuals in a Chinese population as well as explore effective biomarkers for current weak D or DEL detection before blood transfusion. METHODS In the present study, 125 weak D (1, 2, 3, and 4.1) or DEL and 185 RhD- blood samples from donors detected by current standard serology were collected. Genotyping system was used to analyze the SNPs of RHD in each sample. RESULTS Seven SNPs (rs592372, rs11485789, rs6669352, rs3118454, rs1053359, rs590787, and rs3927482) were detected in the RHD region. Rs3118454, rs1053359, rs590787, and rs3927482 showed significant differences between the weak D (1, 2, 3 and 4.1) or DEL and RhD- groups. Further combined analysis of the allelic distribution of these four SNPs revealed their higher frequencies in the RhD- group. CONCLUSION The SNPs rs3118454, rs1053359, rs590787, and rs3927482 in RHD showed a significantly higher frequency among an RhD- Chinese population and are potential biomarkers.
Collapse
Affiliation(s)
- Jie Shi
- Nanjing Red Cross Blood Center, Nanjing, Jiangsu, P. R. China
| | - Ying Luo
- Nanjing Red Cross Blood Center, Nanjing, Jiangsu, P. R. China.,Division of Nephrology and Rheumatology, Center for Nephrology and Metabolomics, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, P. R. China
| |
Collapse
|
8
|
Sandler SG, Chen L, Flegel WA. Serological weak D phenotypes: a review and guidance for interpreting the RhD blood type using the RHD genotype. Br J Haematol 2017; 179:10-19. [PMID: 28508413 PMCID: PMC5612847 DOI: 10.1111/bjh.14757] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Approximately 0·2-1% of routine RhD blood typings result in a "serological weak D phenotype." For more than 50 years, serological weak D phenotypes have been managed by policies to protect RhD-negative women of child-bearing potential from exposure to weak D antigens. Typically, blood donors with a serological weak D phenotype have been managed as RhD-positive, in contrast to transfusion recipients and pregnant women, who have been managed as RhD-negative. Most serological weak D phenotypes in Caucasians express molecularly defined weak D types 1, 2 or 3 and can be managed safely as RhD-positive, eliminating unnecessary injections of Rh immune globulin and conserving limited supplies of RhD-negative RBCs. If laboratories in the UK, Ireland and other European countries validated the use of potent anti-D reagents to result in weak D types 1, 2 and 3 typing initially as RhD-positive, such laboratory results would not require further testing. When serological weak D phenotypes are detected, laboratories should complete RhD testing by determining RHD genotypes (internally or by referral). Individuals with a serological weak D phenotype should be managed as RhD-positive or RhD-negative, according to their RHD genotype.
Collapse
Affiliation(s)
- S. Gerald Sandler
- Department of Pathology and Laboratory Medicine, MedStar Georgetown University Hospital, Washington, DC
| | - Leonard Chen
- Department of Pathology and Laboratory Medicine, MedStar Georgetown University Hospital, Washington, DC
| | - Willy A. Flegel
- Department of Transfusion Medicine, NIH Clinical Center, National Institutes of Health, Bethesda, MD, United States
| |
Collapse
|
9
|
Kwon DH, Sandler SG, Flegel WA. DEL phenotype. Immunohematology 2017; 33:125-132. [PMID: 29043831 PMCID: PMC5676463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
DEL red blood cells (RBCs) type as D- by routine serologic methods and are transfused routinely, without being identified as expressing a very weak D antigen, to D- recipients. DEL RBCs are detected only by adsorption and elution of anti-D or by molecular methods. Most DEL phenotypes have been reported in population studies conducted in East Asia, although DEL phenotypes have been detected also among Caucasian individuals. Approximately 98 percent of DEL phenotypes in East Asians are associated with the RHD*DEL1 or RHD*01EL.01 allele. The prevalence of DEL phenotypes has been reported among D- Han Chinese (30%), Japanese (28%), and Korean (17%) populations. The prevalence of DEL phenotypes is significantly lower among D- Caucasian populations (0.1%). Among the 3-5 percent of African individuals who are D-, there are no reports of the DEL phenotype. Case reports from East Asia indicate that transfusion of DEL RBCs to D- recipients has been associated with D alloimmunization. East Asian immigrants constitute 2.1 percent of the 318.9 million persons residing in the United States, and an estimated 2.8 percent are blood donors. Using these statistics, we estimate that 68-683 units of DEL RBCs from donors of East Asian ancestry are transfused as D- annually in the United States. Given the reports from East Asia of D alloimmunization attributed to transfusion of DEL RBCs, one would expect an occasional report of D alloimmunization in the United States following transfusion of DEL RBCs to a D- recipient. If such cases do occur, the most likely reason that they are not detected is the absence of active post-transfusion monitoring for formation of anti-D.
Collapse
Affiliation(s)
- Dong H Kwon
- Department of Pathology and Laboratory Medicine, MedStar Georgetown University Hospital
| | - S G Sandler
- Professor of Pathology and Medicine, Georgetown University School of Medicine, and Medical Director, Transfusion Service, Department of Laboratory Medicine, MedStar Georgetown University Hospital
| | - Willy A Flegel
- Chief, Laboratory Services Section, Department of Transfusion Medicine, NIH Clinical Center, Bethesda, MD, and Professor of Pathology (adjunct), Georgetown University School of Medicine
| |
Collapse
|
10
|
Kulkarni S, Parchure DS, Gopalkrishnan V, Madkaikar M. Screening for DEL phenotype in RhD negative Indians. J Clin Lab Anal 2017. [PMID: 28643361 DOI: 10.1002/jcla.22288] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND DEL phenotype represents a very weak form of D variant detected only by adsorption and elution technique. DEL phenotype individuals mistyped as RhD-negative can lead to alloimmunization after transfusion or pregnancy. Molecular techniques have now been used to identify DEL variants. They are commonly encountered in the East Asian population with RHD(K409K) being the most frequent allele. RHD(M295I) is the most common DEL allele in Caucasians. As there is a paucity of data on DEL phenotype in the Indian population, the study aims to screen RhD negative individuals for two most common DEL mutations. MATERIAL AND METHODS EDTA blood was collected from 900 RhD negative individuals. Serological analysis included testing for the five major Rh antigens- C, c, D, E, and e by tube technique. Samples showing negative reaction for the presence of D antigen by Indirect Antiglobulin test were further tested for DEL phenotype by adsorption and elution technique. Molecular analysis involved DNA extraction and testing by PCR-SSP for RHD(K409K) and RHD(M295I) DEL alleles. RESULTS Rh phenotyping showed 153 Rh negative individuals with r'r, ten with r''r and 737 with rr phenotype. All the samples tested negative for RhD antigen by adsorption and elution method. The two common DEL mutations RHD(K409K) and RHD(M295I) were also not detected in the study population. CONCLUSION The study population showed the absence of the two common DEL alleles, concluding the variant to be rare. A comprehensive study with a larger sample size to look for other DEL mutations should be performed.
Collapse
Affiliation(s)
- Swati Kulkarni
- Department of Transfusion Medicine, National Institute of Immunohaematology, Mumbai, India
| | - Disha S Parchure
- Department of Transfusion Medicine, National Institute of Immunohaematology, Mumbai, India
| | - Vidya Gopalkrishnan
- Department of Transfusion Medicine, National Institute of Immunohaematology, Mumbai, India
| | - Manisha Madkaikar
- Department of Transfusion Medicine, National Institute of Immunohaematology, Mumbai, India
| |
Collapse
|
11
|
Molecular basis of DEL phenotype in the Chinese population. BMC MEDICAL GENETICS 2014; 15:54. [PMID: 24884404 PMCID: PMC4024116 DOI: 10.1186/1471-2350-15-54] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 04/30/2014] [Indexed: 12/05/2022]
Abstract
Background Rh blood group system is the most complex and immunogenetic blood group system. Prevalent RHD alleles vary in different populations. We conducted the present study to examine the genotype of DEL individuals and to elucidate whether novel alleles exist in the Chinese population. Methods DEL phenotype was identified by a serologic adsorption-elution method. The nucleotide sequences of ten RHD exons and exon-intron boundary regions were evaluated by RHD gene-specific PCR-SSP and sequencing. Results Of 42306 samples from individual donors and patients, 165 samples were typed as D-negative. Among these D-negative samples, 41 DEL individuals were observed. Thirty-seven DELs were confirmed to have the RHD1227A allele. Two DELs seemed to have RHD-CE-D hybrid alleles, including one RHD-CE (4–7)-D and one RHD-CE (2–5)-D. Two novel RHD alleles were found among the rest of the DEL samples, including one RHD93T > A and one RHD838G > A. Conclusion In this study, about 24.85% (41/165) of the apparent D-negative Chinese individuals were DEL. RHD1227G > A is the most frequent allele in Chinese DEL phenotypes, accounting for 90.24% (37/41). The RHD-CE-D hybrid allele might be the second most frequent DEL allele in the Chinese population. Our study would contribute to the understanding of the molecular mechanism underlying D antigen expression of DEL individuals and provide useful information for designing suitable genotyping strategies in RhD-negative individuals in Asia.
Collapse
|
12
|
Analysis of density and epitopes of D antigen on the surface of erythrocytes from DEL phenotypic individuals carrying the RHD1227A allele. BLOOD TRANSFUSION = TRASFUSIONE DEL SANGUE 2013; 12:244-9. [PMID: 24333082 DOI: 10.2450/2013.0091-13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 08/28/2013] [Indexed: 11/21/2022]
Abstract
BACKGROUND The characteristics of the D antigen are important as they influence the immunogenicity of D variant cells. Several studies on antigenic sites have been reported in normal D positive, weak D and partial D cases, including a comprehensive analysis of DEL types in Caucasians. The aim of this study was to assess D antigen density and epitopes on the erythrocyte surface of Asian type DEL phenotypic individuals carrying the RHD1227A allele in the Chinese population. MATERIALS AND METHODS A total of 154 DEL phenotypic individuals carrying the RHD1227A allele were identified through adsorption and elution tests and polymerase chain reaction analysis with sequence-specific primers in the Chinese population. D antigen density on the erythrocyte surface of these individuals was detected using a flow cytometric method. An erythrocyte sample with known D antigen density was used as a standard. Blood samples from D-negative and D-positive individuals were used as controls. In addition, D antigen epitopes on the erythrocyte surface of DEL individuals carrying the RHD1227A allele were investigated with 18 monoclonal anti-D antibodies specific for different D antigen epitopes. RESULTS The means of the median fluorescence intensity of D antigen on the erythrocyte membrane surface of D-negative, D-positive and DEL individuals were 2.14±0.25, 193.61±11.43 and 2.45±0.82, respectively. The DEL samples were estimated to have approximately 22 D antigens per cell. The samples from all 154 DEL individuals reacted positively with 18 monoclonal anti-D antibodies specific for different D antigen epitopes. DISCUSSION In this study, D antigen density on the erythrocyte surface of DEL individuals carrying the RHD1227A allele was extremely low, there being only very few antigenic molecules per cell, but the D antigen epitopes were grossly complete.
Collapse
|