The American Rare Donor Program

The American Rare Donor Program (ARDP), headquartered in Philadelphia, Pennsylvania, maintains a comprehensive database of donors with “rare blood types.” The ARDP secures blood and blood products for difficult-to-transfuse patients. Remarkably, a significant number of physicians, both in the United States and abroad, remain unaware of the unique and critical services that the ARDP provides to critical care specialists and their patients.     

Challenges in the transfusion management of a 15-month-old pediatric patient with Bombay blood group phenotype

Bombay blood group phenotype is often mistyped as O group which can lead to hemolytic transfusion reactions. There are a very few case reports of Bombay blood group phenotype in pediatric age group. Herein, we report an interesting case of Bombay blood group phenotype in a fifteen-month-old pediatric patient who presented with features of raised intracranial pressure and required an emergency surgery. The Bombay blood group was detected on detailed immunohematology work up which was further confirmed by molecular genotyping. The challenges faced in developing countries for transfusion management of such a case have been discussed.     

上海地区人群中部分稀有血型筛选

目的了解上海地区人群中部分稀有血型的频率和分布情况,用于解决临床上稀有血型的用血问题。方法利用稀有单克隆、多克隆抗血清,对Kell血型系统的K0,Miltenberger血型系统的Mur ,Duffy血型系统的Fya-,高频率抗原中的Lan-、Vel-进行筛选;用2 mol/L尿素进行Kidd血型系统的Jk(a-b-)表型筛选。筛选方法包括试管法间接抗人球蛋白试验(IAT),U型96孔微量板IAT和U型96孔微量板盐水直接离心法试验。结果从24 093名献血者中发现1例K0表型;在2 970名献血者中检出15例Mur ;从200名献血中,检出1例Fya-;从6 153名献血者中发现2例Vel-;在300名献血者中发现了1例Lan-;在102 760名献血者中,成功检出4例Jk(a-b-)。结论Mur 、Lan-、Jk(a-b-)表型频率明显高于白种人;Fya-表型频率低于白种人。     

上海地区人群中部分稀有血型筛选

目的了解上海地区人群中部分稀有血型的频率和分布情况,用于解决临床上稀有血型的用血问题。方法利用稀有单克隆、多克隆抗血清,对Kell血型系统的K0,Miltenberger血型系统的Mur＋,Duffy血型系统的Fya-,高频率抗原中的Lan-、Vel-进行筛选;用2 mol/L尿素进行Kidd血型系统的Jk（a-b-）表型筛选。筛选方法包括试管法间接抗人球蛋白试验（IAT）,U型96孔微量板IAT和U型96孔微量板盐水直接离心法试验。结果从24 093名献血者中发现1例K0表型;在2 970名献血者中检出15例Mur＋;从200名献血中,检出1例Fya-;从6 153名献血者中发现2例Vel-;在300名献血者中发现了1例Lan-;在102 760名献血者中,成功检出4例Jk（a-b-）。结论Mur＋、Lan-、Jk（a-b-）表型频率明显高于白种人;Fya-表型频率低于白种人。     

中国壮族人群Lutheran缺失表型的EKLF／KLF1基因多态性研究

目的针对中国壮族人群中的Lu（a—b－）表型,检测其相关的EKLF／KLF1调控基因,以揭示其分子机理和遗传背景。方法对4527名壮族人群中筛查出的22名Lu（b－）表型的先证者进行家系调查,血清学筛查家系中Lu（a—b－）个体,扩增其EKLF／KLF1调控基因的3个外显子,测序分析其遗传背景。结果在22个家系中包括先证者共检测出Lu（a—b－）表型57名。其中19个家系共51名个体的EKLF／KLF1基因中均发现同样的519．525dupcGGcGcc杂合突变;其余3个家系Lu（a—b－）表型的EKLF／KLF1基因中均发现895C〉G杂合突变。结论中国壮族Lu（a—b－）血型的分子背景可能与EKLF／KLF1基因的特异性杂合突变密切相关,且绝大多数为519-525dupCGGCGCC的杂合突变类型。     

上海地区汉族人群红细胞稀有血型系统抗原基因的多态性研究

目的研究上海地区汉族临床输血人群8个红细胞稀有血型系统19种抗原基因多态性分布,提高配合性输注的能力。方法应用PCR-SSP方法进行血型抗原基因分型。结果Diego,Dombrock,Duffy血型系统抗原基因频率分别为：Di^a=0.0351,Di^b=0.9649;Do^a=0.0614,Do^b=0.9386;Fy^a=0.9649,Fy^b=0.0351,Fy=0;均具有多态性。而Kell,Yt,Scianna,L-W,Colton血型系统抗原基因频率分布为单态性。经χ2检验,均符合Hardy-weinberg遗传定律。结论上海地区汉族临床输血人群Diego、Dombrock、Duffy血型系统抗原基因频率具有多态性,随机临床输血抗原不合率分别是0.0654、0.1086、0.0654,应引起高度重视。     

Using droplet digital PCR to screen for rare blood donors: Proof of principle

BackgroundDigital droplet PCR (ddPCR) is a very sensitive high throughput genotyping methodology. To date, the use of ddPCR in immunohematology is restricted to fetal genotyping of red blood cell antigens. Our hypothesis is that this technology could be applied to screen for rare red blood cell genotypes, such as Di(b-).MethodsNucleic acid of 3168 donors was extracted for viral screening routine in pools of 6, which were converted into three types of 48-donor pools: control pools (only DI*B/*B samples), pools with varying amount of DI*A/*B samples (n = 1–5) and a pool with one rare DI*A/*A sample. Pools were genotyped using ddPCR to detect and quantify DI*A and DI*B alleles.ResultsDI*A allele was accurately detected in all pools containing Di(a + b+) samples and in the pool containing one Di(a + b-) sample. No copies were detected in the control pools (n = 60). The ratio between the number of DI*A and DI*B copies varied significantly between the pools and the triplicates.ConclusionThe proposed ddPCR assay was accurate in identifying the rare DI*A allele in large pools of donors and can be applied to screen for Di(b-) phenotype. The strategy can potentially be extended to search for other rare RBC phenotypes.     

Molecular characterization of a rare Rh phenotype Dc-from the Indian subcontinent

Unusual Rh phenotypes such as Rh_null, D-- and Dc- etc. are rarely encountered in routine blood bank testing. The Rh_null phenotype is characterized by the absence of all Rh antigens, D-- phenotype does not express any RhCcEe antigens whereas Dc- phenotype individual lacks expression of antithetical E /e antigens. These individuals may produce multiple Rh antibodies against missing antigens. An old woman (B RhD positive) from Bangladesh with end-stage renal disease developed severe anaemia. Cross-matching with ABO and RhD compatible blood units showed +3 agglutination reaction. Detailed immunohaematological investigations showed a lack of C, E and e antigens, thus identifying the rare Rh variant as Dc-. Antibodies against C and e antigens were also detected in the patient’s serum. PCR-SSP confirmed the absence of the molecular region defining the C, E and e antigens. Copy number analysis by QMPSF revealed the homozygous state of (RHCE-D(4-9)-CE) allele at the RHCE gene locus. This is the first report of the rare Dc- variant individual from the Indian subcontinent.     

A Canadian perspective on the use and preparation of cryopreserved red cell concentrates

Canadian Blood Services (CBS) operates a national rare blood program to meet the needs of a highly diverse Canadian civilian population. This program manages the frozen inventory of red blood cell products maintaining upwards of 800 units of strategically identified phenotypes for patient use. Red cell concentrates (RCCs) are collected from identified donors with rare blood types as whole blood and are further processed into leukocyte reduced red cell concentrates in SAGM. These units can be stored for up to 21 days prior to glycerolization and frozen storage. The use of the ACP 215, a closed system cell processor, for cryopreservation using the high glycerol method allows for an extended expiry date of 14 days post deglycerolization when RBCs are suspended in AS-3 and stored hypothermically prior to transfusion. This method produces units that meet all Canadian regulatory standards. Introduction of extended outdates has allowed CBS to decrease operational costs and improve cryopreserved RCC product quality.     

Molecular genotyping of Indian blood group antigens amongst regular voluntary blood donors of Surat city,Gujarat, India

BackgroundThere is paucity of data related to the prevalence of the rare blood group antigens amongst South Gujarat blood donor population due to unavailability and high cost of antisera. Therefore it is difficult to screen donors for such rare antigens by gold standard haemagglutination assay. The single nucleotide polymorphism (SNPs) of In^a and In^b antigens is the base of the PCR based detection methods that help to detect these alleles in regular voluntary blood donors.Materials & methodsBlood samples of 200 unrelated regular voluntary blood donors wee collected. DNA was extracted using phenol-chloroform method and genotyped for Indian (In^a/IN*01, In^b/IN*02) blood group alleles by Sequence Specific PCR. In^a antigen positivity was confirmed by serology test.ResultsFour donors were found heterozygous for In^a antigen i.e. In (a + b+) by SS-PCR and their In^a positivity were confirmed by in-house polyclonal Anti-In^a reagent. SS-PCR was standardized using known heterozygous sample of a blood donor. The frequency of In^a antigen (2.0 %) was higher than Caucasians, lower than Iranians and Arabs while comparable to those reported among Indians of Mumbai city.ConclusionIn absence or unavailability of antisera particularly for low frequency alleles like In^a, such PCR based method would be extremely helpful to prepare rare donor registry by screening blood donors’ at large scale. Red cells of In^a positive donors can be used as in-house reagent red cells for screening and identification of corresponding antibody.     

Application of Blood Group Genotyping by Next-Generation Sequencing in Various Immunohaematology Cases

BackgroundNext-generation sequencing (NGS) technology has been recently introduced into blood group genotyping; however, there are few studies using NGS-based blood group genotyping in real-world clinical settings. In this study, we applied NGS-based blood group genotyping into various immunohaematology cases encountered in routine clinical practice.MethodsThis study included 4 immunohaematology cases: ABO subgroup, ABO chimerism, antibody to a high-frequency antigen (HFA), and anti-CD47 interference. We designed a hybridization capture-based NGS panel targeting 39 blood group-related genes and applied it to the 4 cases.ResultsNGS analysis revealed a novel intronic variant ({"type":"entrez-nucleotide","attrs":{"text":"NM_020469.3","term_id":"1482586037","term_text":"NM_020469.3"}}NM_020469.3:c.29-10T>G) in a patient with an A_el phenotype and detected a small fraction of ABO*A1.02 (approximately 3–6%) coexisting with the major genotype ABO*B.01/O.01.02 in dizygotic twins. In addition, NGS analysis found a homozygous stop-gain variant ({"type":"entrez-nucleotide","attrs":{"text":"NM_004827.3","term_id":"1519311581","term_text":"NM_004827.3"}}NM_004827.3:c.376C>T, p.Gln126*; ABCG2*01N.01) in a patient with an antibody to an HFA; consequently, this patient''s phenotype was predicted as Jr(a−). Lastly, blood group phenotypes predicted by NGS were concordant with those determined by serology in 2 patients treated with anti-CD47 drugs.ConclusionNGS-based blood group genotyping can be used for identifying ABO subgroup alleles, low levels of blood group chimerism, and antibodies to HFAs. Furthermore, it can be applied to extended blood group antigen matching for patients treated with anti-CD47 drugs.     

少见部位骨软骨瘤1例

骨软骨瘤非常多见,但生长在尺桡骨间者报道极少.本院收治1例,报道如下: 患儿,女,8岁.因左前臂不能旋转3个月,前来就诊.查体见左前臂不能做旋前及旋后运动.X线片:左尺骨干见一骨性突起,带蒂,邻近桡骨受压硬化,诊为骨软骨瘤.术中见病变呈典型骨软瘤结构(骨性基底、软骨帽、纤维膜).术后病理诊断"骨软骨瘤".随访2年未复发.     

SSOP HD试剂HLA高分辨分型结果不确定的原因分析

目的使用SBT法对SSOP HD试剂分型结果不确定的22份样本进行检测,分析可能的原因。方法对血液样本抽提DNA,按照SSOP HD试剂进行分型检测;针对结果不确定的样本采用SBT法复检,根据SBT法的测序结果分析22份样本SSOP结果不确定的可能原因。结果 2 000份样本经SSOP HD试剂检测后,结果不确定样本共有22份,A位点有6份,B位点有12份,DRB1位点有4份;SBT法检测均为明确的高分辨结果;分析原因可能为磁珠的假阳性或假阴性反应影响软件结果判读;或HLA基因型为罕见型;或试剂的局限性导致两种基因型不能区分。结论 SSOP HD可完成大批量样本的HLA高分辨检测工作;对罕见基因型和磁珠假性反应调整后的结果,应结合SBT法进行核实,保证HLA基因高分辨分型结果的准确性。     

上海地区部分人群Jk(a-b-)、Di~b-、Wr~b-、K_0、Ena-、Tja-、Ge-稀有血型筛选

目的　了解上海地区人群中部分稀有血型的分布 ,以解决临床稀有血型用血问题。方法　采用 2M尿素对受检红细胞进行Kidd血型系统的Jk(a -b - )表型筛选 ;利用稀有单克隆、多克隆抗血清 ,对Diego血型系统的Dib-、Wrb- ,Kell血型系统的K、K0 ,MNS血型系统的Ena - ,P血型系统的Tja - ,Miltinberger血型系统的Murf,Gerbich血型系统的Ge -进行筛选。筛选方法采用试管法间接抗人球蛋白试验 (IAT) ,U型 96孔微量板IAT和盐水直接离心法试验。结果　在 6 4 5人中筛选到Di(a +b - ) 1例 ,90 0人中筛选到Mur(+) 6例 ,10 0 5 7人中筛选到K(+) 7例 ,4 84 0 0人中筛选到Jk(a -b - ) 2例 ,而在 4 0 0 0人的筛选中未发现Wrb-、K0 、Ge -和Ena -表型。结论　上海地区人群中Dib-、Mur+、Jk(a-b - )的红细胞表型明显高于白种人和黑人。     

罕见病诊治思考与展望

近年来,随着医学技术的高速发展,罕见病的诊治取得了巨大进步,高通量测序技术在罕见病临床诊断中发挥了重要作用.通过基因诊断,临床医生对罕见病的基因突变谱系、临床表型等都有了新的认识,可采取有针对性的治疗和预后管理.文章结合"基因组技术与罕见病诊治"专题中的多篇报道,从罕见病表型分析、检测技术的合理应用、遗传检测结果及其临...     

A rare case report: SCARF syndrome

SCARF syndrome is a very rare syndrome that so far only two cases have been reported in the papers. In this article, a 3‐month‐old female who exhibited SCARF syndrome presented with multiple congenital abnormalities and problems at Imam Hossein hospital of Shahroud.