分子生物学鉴定急性白血病患者ABO血型抗原

目的:应用分子生物学方法鉴定急性白血病患者ABO血型抗原,确定患者ABO血型正反定型不符的原因。方法:选取临床正反定型不一致白血病患者,常规血清学ABO血型正反定型;直接和间接抗人球蛋白试验检测不规则抗体;吸收放散法鉴定弱血型抗原;PCR方法扩增ABO基因的7个外显子及侧翼内含子,扩增产物进行测序及序列分析。结果:患者正定型为AB亚型,反定型为AB型;直抗和间抗为阴性;吸收放散试验证明红细胞上存在弱A和B抗原;ABO基因扩增产物测序结果表明其基因型为ABO*A102/B101。结论:该白血病患者经分子生物学方法确定为正常AB型,其血型抗原减弱由白血病所致。基因分型法可以正确区分血型抗原减弱或亚型。     

再障引起A型血型抗原减弱1例

正确的ABO血型鉴定,是临床安全输血的关键。临床上某些疾病如再障、实体瘤、白血病等可以造成ABO抗原减弱或缺乏,影响血型的准确鉴定。现将1例再障患者血型抗原减弱的病例报告如下。1资料与方法1.1资料患者,女,72岁,无近期输血史,在本院住院治疗,诊断为再生障碍性贫血。因病情需要申请输血,在ABO血型鉴定时发现正反定型不符。故进一步检查鉴定其血型。1.2血型血清学检查1.2.1试剂与方法抗-A、抗-B(长春博德);抗-AB、抗-H,抗人球蛋白试剂(上海生物技术有限公司);ABO试剂细胞本室自制;筛选细胞(上海血液中心)。1.2.2 ABO血型鉴定正反…     

幼儿血型B抗原性减弱的分析及探讨

目的:分析2例幼儿血型B抗原减弱的原因,为今后婴幼儿血型的进一步研究提供实验性数据。方法:对2017年2例13个月龄患儿血型B抗原性减弱的样本进行血清学和Sanger双碱基DNA分子测序分析。结果:2例样本其中1例ABO血型基因型为ABO*B101,另1例为Bw型。结论:本次研究提示,幼儿血型抗原减弱可能是红细胞上血型抗原表达减弱导致,血型基因并未发生突变;也有可能是由于血型亚型造成,在儿童血型鉴定时尤其要重视。     

A1B309亚型的血清学鉴定及基因序列分析

目的:通过探讨ABO亚型,提高红细胞输注有效性。方法:ABO血型鉴定,基因测序。结果:血型血清学结果表现为AB亚型,A抗原表现正常,B抗原减弱;基因直接测序结果表现为A1B309亚型。结论:正确检测红细胞血型,能够提高红细胞输注的有效性。     

A1B309亚型的血清学鉴定及基因序列分析

目的:通过探讨ABO亚型,提高红细胞输注有效性。方法:ABO血型鉴定,基因测序。结果:血型血清学结果表现为AB亚型,A抗原表现正常,B抗原减弱;基因直接测序结果表现为A1B309亚型。结论:正确检测红细胞血型,能够提高红细胞输注的有效性。     

骨髓增生异常综合征ABO血型鉴定观察

目的:研究46例骨髓增生异常综合征(MDS)病程中ABO血型检定及抗体的变化。方法:采用血型血清学试验检测ABO血型抗原强度变化。结果:血型抗原减弱或丢失者占17例(37.0%),A抗原最容易减弱或丢失,ABO抗体也可以减弱。结论:吸收放散试验、血型物质检测及家系调查可以防止误定ABO血型。     

台州市献血者血液ABO正反定型不符检测结果分析

目的:对2012年台州地区无偿献血者血型正反不一致的结果进行分析,以保障临床用血的安全。方法:对抗凝标本分别采用纸板法、微量板法做正反定型试验;抗体筛选及鉴定试验以检测ABO以外的抗体。结果:38 279人份标本中有32例出现ABO血型正反不符,其中血清特异性意外抗体或非特异性凝集23例,主要为抗-M和冷凝集素;红细胞抗原减弱5例包括ABO亚型4例和类孟买型1例;血清抗体减弱4例。结论:对ABO血型正反不符的标本应进行严格的筛查和血型鉴定,确认每个献血者ABO血型。     

急性非淋巴细胞白血病分型与红细胞AB抗原表达强度相关性研究4例报告及文献复习

目的:分析研究急性非淋巴细胞白血病(ANLL)分型与红细胞AB抗原表达强度相关性。方法:临床诊断ANLL患者红细胞AB抗原表达强度减弱4例,并复习国内近26年文献中完整资料77例病例报告一起进行分析。结果:81例ANLL中红细胞A抗原、B抗原、AB抗原同时表达减弱分别为51.85%、39.51%、8.64%。在ANLL中M2型最为多见,其次依次为M1型、M5型、M3型。结论:在进行ANLL患者红细胞ABO血型鉴定时,必须应用高效价抗血清试剂(≥128)进行正定型鉴定,以防止由于患者红细胞AB血型抗原表达减弱所致血型误判。     

健康献血者及疾病患者ABO正反定型不符比较研究

目的：分析比较健康献血者及疾病患者ABO血型正反定型不符的原因及特点，为解决ABO疑难血型鉴定提供依据及思考方向。方法：分析研究近3年来本中心检验科及柳州市县各医院因ABO血型正反定型不符而送本中心输血研究室进行疑难血型鉴定的47例健康献血者及60例疾病患者疑难血型鉴定记录。结果：送检的健康献血者及疾病患者AB0正反定型不符血样本在血型构成比上差异无统计学意义，均为B型〉A型〉O型〉AB型。导致健康献血者及疾病患者ABO正反定型不符的原因构成差异有统计学意义。健康献血者及疾病患者ABO正反定型不符原因，A型与B型比较均有显著差异。结论：克服冷凝集素对ABO正反定型的干扰可解决较大部分健康献血者及疾病患者ABO正反定型不符样本的难题。疾病患者抗原减弱或缺乏，抗体减弱或缺乏常与疾病相关，而健康献血者抗原减弱常常是亚型原因。     

红细胞浓度对固相法血型鉴定的影响

目的:探讨红细胞抗原浓度对固相法ABO血型正定型及Rh(D)血型鉴定的影响。方法:随机选取健康成人O型Rh(D)阴性和AB型Rh(D)阳性个体各5例,采集静脉血3~5ml置于EDTA抗凝管中,将O型和AB型血液配制成不同高低浓度的红细胞悬液,并用固相法进行ABO血型正定型及Rh(D)血型鉴定,同时以10%浓度的红细胞浓度作为对照参考,观察假阳性和假阴性出现的情况及假性结果出现时的红细胞抗原浓度。结果:红细胞抗原浓度超过25%易出现假阳性;红细胞抗原浓度低于2%易出现假阴性;低浓度红细胞抗原对抗B、抗D的影响更明显;高浓度红细胞抗原对抗A的影响更明显。结论:红细胞浓度对对固相法ABO血型正定型及Rh(D)血型鉴定有影响,且高、低浓度对不同单克隆抗体结合抗原的能力影响不尽相同。     

Determination of Salivary ABH-Blood Group Antigens by Rocket Affinoelectrophoresis

Abstract. A rocket affinoelectrophoretic assay system was used to detect and quantify the human salivary ABH-blood group antigens of 155 individuals. In this system blood group antigens precipitated as rockets in agarose gels containing different lectins, with the rocket height being correlated to the antigen concentration. This technique was compared with the classical hemagglutination inhibition method for determination of salivary blood group antigens, and it was demonstrated that salivary A, B and H blood group antigens were detected with the lectins from Helix pomatia, Bandeiraea simplicifolia and Ulex europeus , respectively. The technique was rapid and sensitive, with a detection limit of 0.1 μl saliva. This technique can also be used for determination of blood group antigens derived from other body fluids, tissues and cells.     

Identification of a defect in the intracellular trafficking of a Kell blood group variant.

Blood group polymorphisms have been used as tools to study the architecture of the red blood cell (RBC) membrane. Some blood group variants have reduced antigen expression at the cell surface. Understanding the underlying mechanism for this reduced expression can potentially provide structural information and help to elucidate protein trafficking pathways of membrane proteins. The Kp(a+) phenotype is a variant in the Kell blood group system that is associated with a single amino acid substitution (R281W) in the Kell glycoprotein and serologically associated with a weakened expression of other Kell system antigens by an unknown mechanism. We found by immunoblotting of RBCs that the weakening of Kell antigens in this variant is due to a reduced amount of total Kell glycoprotein at the cell surface rather than to the inaccessibility of the antigens to Kell antibodies. Using a heterologous expression system, we demonstrate that the Kpa mutation causes retention of most of the Kell glycoprotein in a pre-Golgi compartment due to differential processing, thereby suggesting aberrant transport of the Kell protein to the cell surface. Furthermore, we demonstrated that single nucleotide substitutions into the coding region of the common KEL allele, as predicted by the molecular genotyping studies, was sufficient to encode three clinically significant low incidence antigens. We found that two low incidence antigens can be expressed on a single Kell protein, thus showing that the historical failure to detect such a variant is not due to structural constraints in the Kell protein. These studies demonstrate the power of studying the molecular mechanisms of blood group variants for elucidating the intracellular transport pathways of membrane proteins and the requirements for cell surface expression.     

ABO blood group antigens on human plasma von Willebrand factor after ABO-mismatched bone marrow transplantation.

von Willebrand factor (vWF) is synthesized exclusively by endothelial cells and megakaryocytes, and stored in the intracellular granules or constitutively secreted into plasma. ABO blood group antigens are covalently associated with asparagine-linked sugar chains of plasma vWF. The effect of ABO-mismatched bone marrow transplantation (BMT) or blood stem cell transplantation (BSCT) on the expression of ABO blood group antigens on the vWF was examined to obtain information on the origin of these antigens. In ABO-mismatched (HLA-matched) groups, 8 cases of BMT and 4 cases of BSCT were examined. In all cases, the ABO blood groups on red blood cells were gradually converted to the donor's type within 80 to 90 days after the transplantation. The blood group antigens on the vWF were consistent with the recipient's blood group for the period monitored by enzyme-linked immunosorbent assay (ELISA). When vWF was isolated from normal platelets and examined for the blood group antigens using ELISA or immunoblotting, it showed few antigens. However, vWF extracted from veins expressed blood group antigens. These findings indicate that platelet (megakaryocyte)-derived vWF does not contain blood group antigens and that these antigens may be specifically associated with vWF synthesized in endothelial cells and secreted into plasma. Furthermore, it is possible that the persistence of the recipient's blood group antigens on plasma glycoproteins such as vWF, independent of the donor-derived erythrocytes, after ABO-mismatched stem cell transplantation, may influence the immunological system in the production of anti-blood group antibodies resulting in the establishment of immunological tolerance in the recipient plasma.     

Disulfide bonds are a requirement for Kell and Cartwright (Yta) blood group antigen integrity

S ummary . We have investigated the effect of dithiothreitol (DTT) upon the Kell blood group system and other red cell antigens. All Kell blood group antigens studied (K, k, Kp^a, Kp^b, Js^a, Js^b and Ku) as well as the Cartwright (Yt^a) antigen were completely denatured after treatment with DTT. The Gerbich antigen was substantially weakened but not completely denatured. The Js^a and Js^b antigens appear to have an exquisite sensitivity to treatment with DTT and can be completely denatured using very low concentrations (≤2 m m ) whereas other Kell system antigens require much higher concentrations of DTT for their denaturation (100–200 m m ). Of 38 other blood group antigens investigated, only the Yt^a antigen was completely denatured using 200 m m DTT. Furthermore, the Yt^a antigen was denatured within the same concentration range as Kell and one can speculate that this indicates some biochemical relationship between these two blood group systems. From our results, we conclude that: (1) at least two distinct disulfide (S–S) bonds are required for maintenance of the Kell blood group antigen system; (2) Js^a and Js^b antigens are distinctly different from other Kell system antigens based upon sensitivity to treatment with DTT; these antigens may be located on a different antigenic domain; and (3) the Yt^a antigen requires at least one disulfide bond for its maintenance of antigen integrity. Although the Gerbich antigen was not completely denatured, results indicate that disulfide bonds may also be important structural determinants for these antigens.     

Inactivation of Kell blood group antigens by 2-aminoethylisothiouronium bromide

Human red cells incubated with a solution containing 6% 2-aminoethyl-isothiouronium bromide (AET) lose activity of antigens that are part of, or related to, the Kell blood group system. However, Kx antigen is not inactivated. Studies on a wide range of other blood-group antigens show no other evidence of changes and AET appears to react specifically with red-cell membrane structures that have Kell activity. The AET procedure produces an artificial K₀ red cell that can be used in blood group serology, and allows easy recognition of antibodies that are associated with the Kell system.
AET has been used by other workers to produce a red cell that has many serological and biochemical characteristics of a PNH cell. Our studies on red cells from PNH patients have not shown any changes in Kell blood-group antigens.     

Unmasking of Kx antigen by reduction of disulphide bonds on normal and McLeod red cells

We have investigated the effect of dithiothreitol (DTT) treatment of human red cells upon the Kx blood group antigen. At low concentrations of DTT (less than or equal to 2 microM) there is enhancement of the Kx antigen concomitant with the complete denaturation of the Jsa and Jsb antigens of the Kell blood system. This unmasking of the Kx antigenic site is near maximal using 2 microM DTT. At this concentration of DTT, only the Jsa and Jsb antigens are completely denatured; all other Kell system antigens tested (K, k, Kpb, Ku) are essentially unaffected. These results argue against the Kx antigen serving strictly as a carbohydrate precursor substance involved in a sequential biosynthetic pathway of Kell blood group antigens. Also, McLeod red cells, after treatment with DTT, were found to contain Kx antigen, although in much lower density than normal red cells, indicating that, although not a typical carbohydrate precursor substance, Kx may, nevertheless, be essential for the serological expression of Kell related antigens. It is hypothesized that the Kx structure and the Kell blood group antigen structure are two separate subunits associated in a quaternary conformation involving at least one interchain S-S bond. Our results should allow for a clearer understanding of the relationship between the serological expression of the Kx antigen and the serologically observed reactivity of the Kell blood group antigens of individuals having normal, Ko and McLeod phenotypes.     

Miltenberger Subsystem of the MNSs Blood Group System: Review and Outlook

The Miltenberger (Mi) classes represent a group of phenotypes for red cells that carry low frequency antigens associated with the MNSs blood group system. The antigens of this system are known to be located on two sialoglycoproteins denoted as glycophorin A (GP A) and GP B. The structural alterations of seven (classes I, II, III, V, VI, VII, VIII) Mi variants and a related variant (J.L.) have been elucidated. Based on these data and yet incomplete studies of the Mi antigens, the approximate structural alterations in class IV and IX may be predicted. In addition, knowledge of the various structures and partial characterization of the Mi antigens allows one to propose detailed hypotheses concerning the epitopes recognized by the various antibodies that define the Mi subsystem. The understanding of the Mi subsystem at the molecular level paves the way for future studies aimed at a more detailed elucidation of epitopes of Mi-related antibodies, the characterization of novel Mi variants and a search for hypothetical, hitherto unknown Mi-related antibodies.     

Tissue types as prognostic risk factor in hepatitis B virus infection.

OBJECTIVES: Outcome after acute hepatitis B virus (HBV) infection may be determined by the host immune system. We studied the distribution of major histocompatibility (MHC) antigens in patients who developed natural immunity against HBV and those with chronic hepatitis B. METHODS: Thirty patients positive for IgG anti-HBs and anti-HBc ('naturally immune'), 30 patients with HBsAg-positive chronic hepatitis and 30 subjects with no serological markers of HBV infection (controls) were studied. MHC class-I antigens were detected by the standard Terasaki microlymphocytotoxicity test and the MHC class-II antigens by a polymerase chain reaction using sequence-specific primers. RESULTS: In the naturally immune group, A11, B73, CW3, DRB1*16 and DQB1*05 antigens were significantly more frequent than in the control group, and B73, DRB1*04 and DRB1*13 antigens were more frequent than in the chronic hepatitis group. In the chronic hepatitis group, CW6, DRB5 and DQB1*05 antigens were significantly more frequent than in the control group, and B8, CW7, DRB1*03 and DQB1*02 antigens were more frequent than in the naturally immune group. CONCLUSIONS: Differences in alleleic frequencies of HLA among persons with natural immunity against HBV and those with chronic hepatitis B may suggest a genetic basis for persistence of HBV infection and occurrence of chronic liver disease.     

A combination of the effects of rare genotypes at the XK and KEL blood group loci results in absence of Kell system antigens from the red blood cells

The 22 antigens of the Kell blood group system are located on a red blood cell (RBC) membrane glycoprotein that shows sequence homology with a family of metalloendopeptidases. Expression of the Kell system antigens is partially governed by XK, an X-linked gene that encodes the Kx protein; absence of Kx results in reduced Kell antigen expression. Almost total absence of Kell antigens from the RBCs of a German man with no symptoms of neuroacanthocytosis could not be due to the Kell- null phenotype, Ko, because his RBCs had very weak expression of Kx antigen and his three children were Kp(a + b+). Kell antigens were normal on the RBCs of his son but weak on those of his two daughters. An Nla III restriction fragment-length polymorphism within the KEL gene showed the Kpa/Kpa genotype in the propositus. Sequencing of his XK gene showed a single base change within the donor splice consensus sequence of intron 2. A BsaAl restriction fragment-length polymorphism showed the mutation in both of his daughters but not in his son. The extreme depression of the Kell antigens of the propositus must be due to a combination of effects, ie, homozygosity for Kpa and deficiency of Kx protein, each of which is capable of causing some degree of weakening of Kell antigens.     

Abomasal lymph node responses to Haemonchus contortus intestinal antigens established in kid goats by infection or immunization with intestinal antigens

Immune responses to Haemonchus contortus intestinal antigens were evaluated using abomasal lymph node (ALN) lymphocytes from kid goats protected against challenge infection by immunization with parasite intestinal antigen, and from kids that were challenged after immunization with ovalbumin. ALN lymphocytes from the intestinal antigen-immunized group produced significantly higher antibody levels against intestinal antigens than the ovalbumin group, supporting the theory that immunization contributed to that ALN response. In contrast, intestinal lysates and membrane enriched preparations from intestinal cells stimulated significant proliferation of ALN lymphocytes in both groups. The proliferation was antigen-dependent, since intestinal antigens failed to stimulate proliferation in ALN lymphocytes from unimmunized and uninfected kids. For both the intestinal antigen and ovalbumin immunized groups, CD4+ T lymphocytes predominated in ALN lymphocytes that were stimulated to proliferate by intestinal antigens. The results indicate that H. contortus infection alone can induce ALN lymphocyte responses to intestinal antigens. In contrast to ALN lymphocyte responses, serum antibody against intestinal antigens was generally low to undetectable in ovalbumin-immunized kids following infection. Abomasal mucus from an H. contortus infected lamb was probed with a monoclonal antibody that binds to a periodate sensitive determinant on numerous H. contortus intestinal membrane and secreted proteins. Numerous bands of reactivity were detected, indicating that multiple parasite intestinal antigens were released into abomasal mucus during infection. The results, challenge the general concept that H. contortus intestinal antigens are 'hidden' from the host immune system during an infection. On the contrary, parasite intestinal proteins may be relatively abundant antigens presented to the host during infection. In addition, ALN T lymphocytes appear to provide a more sensitive measure than serum antibody to detect presentation of these antigens to the host immune system.