血小板悬浮血浆ABO血型抗体效价与保存时间消长性研究

目的研究单采血小板悬浮血浆中的抗-A和抗-B效价及其与保存时间的相关性。方法应用盐水凝集法检测血浆IgM抗-A、抗-B效价;应用2-巯基乙醇(2-Me)破坏IgM抗体后,抗人球蛋白法检测血浆IgG抗-A、抗-B效价。结果在保存期内A、B、O型单采血小板悬浮血浆中抗-A(IgM或/和IgG)或/和抗-B(IgM或/和IgG)效价间相互比较差异无统计学意义(P>0.05),其效价不随保存时间延长而降低(P>0.05);10%O型单采血小板悬浮血浆中抗-A和抗-B效价均较高。结论单采血小板输注时可不进行血液交叉配合试验,但须同型输注;尤其是O型悬浮血浆含较高的抗-A或/和抗-B(IgM或/和IgG)效价时,不能输注给其他血型患者。     

High titers of anti-A1 and anti-B antibodies among Peruvian group O platelet donors

Critical antibody titers have been described as factors associated with hemolysis in ABO plasma-incompatible platelet (PLT) transfusions. This study was carried out to describe the frequency of high-titers anti-A and antiB IgM and IgG antibodies in group O apheresis platelet donors, and to explore differences according to the donor characteristics. A cross-sectional study was carried out at the Blood Bank of a National Hospital in Peru from January to March 2019. IgM and IgG antibodies against A1 and B antigens were quantified in 339 platelet donors using the direct hemagglutination technique and the solid-phase adherence technique, respectively. For analysis purposes, two cut-off points; ≥128 and ≥64, were used to define a critical titer for IgM due to a lack of consensus. An IgG titer of ≥256 was also defined as critical. Of the donors, 22.1 % had critical IgM titers when the cut-off point was defined as ≥128. However, when the IgM cut-off was ≥64, the frequency of platelet donors with critical titers increased to 54.0 %. The frequency of donors with critical IgG titers was 23.5 %. Higher IgG titers were associated with female donors while higher IgM titers were negative associated with age. One in two or three platelet donors, depending on the cutoff point used to define a critical IgM titer, had at least one critical titer of anti-A or anti-B antibodies. Early identification of platelet donors with critical antibody titers could prevent passive transfusion of ABO antibodies to non-isogroup recipients.     

Genetics of anti-A and anti-B levels

Hemolysins and agglutinins anti-A and anti-B were measured in 401 blood group O individuals belonging to 74 families. Levels of hemolysins and saline agglutinins reached a peak during childhood and decreased thereafter. Incomplete agglutinins showed a relative increase after childhood. Hemolysins and agglutinins were higher in blacks than in whites. Whites had higher anti-A than anti-B levels and the levels were higher in females than in males. In blacks the anti-B levels were almost as high as were the levels of anti-A and little sex difference was found. Levels of hemolytic anti-A and saline anti-A were closely correlated as were hemolytic anti-B and saline anti-B but low correlations were found between anti-A and anti-B levels. Anti-A and anti-B hemolysin and agglutinin levels were positively correlated with serum IgM levels but anti-A levels were not. Isoantibody levels were not correlated with IgA, IgD, and IgE levels. Correlation and regression analysis among relatives disclosed that from 20 to 30 per cent of the total phenotypic variation in isoantibody levels was accounted for by genetic variation. Age of the individual also contributed markedly to the variation in hemolysins and saline agglutinins, but about one-half of the total variation remained unaccounted for.     

正常O型人血清ABO血型抗体主要类别的分析

目的通过检测O型及A/B型人血清中IgM类及IgG类抗体的效价,分析正常O型人血清中ABO血型抗体的主要类别。方法分别以盐水介质法和间接抗人球蛋白法检测O型及A/B型人血清中IgM类和IgG类抗A或抗B抗体的效价。结果 O型人血清中IgM类抗A/抗B抗体效价均显著高于IgG类抗A/抗B抗体（均P〈0.01）;O型人血清中IgM类抗A/抗B抗体效价与B/A型人比较无显著性差异（均P〉0.05）,而IgG类抗A/抗B抗体效价显著高于B/A型人（均P〈0.01）;O型人血清中IgG类与IgM类抗A/抗B抗体效价的比值均显著高于B/A型人（均P〈0.01）。结论 O型人ABO血型抗体仍以IgM类为主,但其IgG类抗体效价及在血清中所占的比例要明显高于A/B型人。     

Antibodies to histo-blood group substances A and B: agglutination titers, Ig class, and IgG subclasses in healthy persons of different age categories

Isotypes and IgG subclasses of ABO antibodies from sera of 235 healthy blood donors were determined by an enzyme-linked immunosorbent assay (ELISA). Synthetic A and B trisaccharide-bovine serum albumin glycoconjugates were used for coating and monoclonal antibodies for the detection of heavy chain isotypes. Hemagglutination titers were determined in addition. Blood donors were between 20 and 67 years old, and at least 10 sera per 10-year age category and ABO blood group were included in this study. Antibody concentrations were expressed as a percentage of an internal standard, and sera with subclass-restricted anti-A and/or anti-B (anti-A/B) responses were used to normalize the ELISA values of IgG subclasses. A good correlation between the sum of the four subclasses and the total anti-A/B IgG values (rs = 0.81 for anti-A and 0.84 for anti-B) was obtained. IgG1 and IgG2 were the most predominant subclasses, but were found in various proportions in different individuals. Donor-to-donor variation exceeded age-related changes for all measured parameters. The correlation of anti-A IgM, IgG, IgA, and their sum with the agglutination titers was significant and revealed rs values of 0.70, 0.65, 0.65, and 0.80, respectively. For anti-B as well, the correlation of ELISA values with the agglutination titer was best when all three isotypes were added. We conclude that anti-A/B IgA, together with IgM and IgG, substantially contributes to the agglutination reaction. Potentially autoreactive antibodies were detected in sera of blood groups A, B, and AB.     

MB-P对血浆部分细胞因子与ABO血型抗体活性影响

目的研究亚甲蓝光化学病毒灭活法(MB-P)对血浆SCF、TPO、PF4与GPⅡb/Ⅲa活性与ABO血型抗体活性的影响。方法应用ELISA方法对MB-P制备前后血浆SCF、TPO、PF4与GPⅡb/Ⅲa活性进行检测;应用血型血清学检测方法对MB-P制备前后血浆IgM抗-A、IgM抗-B与IgG抗-A、IgG抗-B活性进行检测。结果 MB-P制备血浆SCF、TPO、PF4与GPⅡb/Ⅲa活性均有不同程度下降,分别为2.59±2.71,248.54±49.01,12.02±3.21,10.21±9.97;与制备前相互比较有统计学意义(P0.05)。另外,MB-P制备后血浆红细胞IgM抗-A、IgM抗-B与IgG抗-A、IgG抗-B效价也有不同程度下降,与制备前相互比较有统计学意义(P0.05)。结论应用MB-P制备血浆须高度重视部分细胞因子与红细胞ABO血型抗体变化情况,确保临床输血安全性与有效性。     

Removal of anti-A/B antibodies for successful kidney transplantation between ABO blood type incompatible couples

A growing shortage of cadaveric donors has prompted expansion of the criteria for acceptable living donors. Because of this, ABO-incompatible kidney transplantation has been carried out. To remove anti-A and/or anti-B antibodies, the recipients received one or two sessions of double filtration plasmapheresis (DFPP) and three or four sessions of immunoadsorption prior to transplantation until the anti-A IgG/IgM titers and/or anti-B IgG/IgM titers decreased to 1:16 or less. Our immunosuppressive protocol involved treatment with the drugs methylprednisolone, cyclosporine, azathioprine, anti lymphocyte globulin and deoxyspergualin. The patient survival was 98% at 1 month, 98% at 3 months, 94% at 6 months, and 92% at 1-5 years. Graft survival was 92% at 1 month, 88% at 3 months, 85% at 6 months, 81% at 1 year, and 76% at 5 years. Both DFPP and/or immunoadsorption eliminated anti-ABO antibodies from ABO-incompatible kidney transplant recipients effectively and safely. The results of the ABO-incompatible kidney transplantation were acceptable and not different from those of ABO-compatible cases.     

ABO antibody titer performance characteristics and correlates between two automated platforms

BackgroundAABB standards require a policy for assessing transfusing ABO-incompatible plasma. After a fatal hemolytic event with incompatible plasma, our institution instituted platelet donor population titer method for ABO antibodies on the PK7300, with high-titer being defined as having isohemagglutinin titers greater than 256. We recently switched titering platforms to the Neo Iris and we seek to determine the equivalent isohemagglutinin high-titer cutoff on the Neo Iris as compared to the PK7300.MethodsWe measured the titers on 299 apheresis platelet donors and compared its performance characteristics at various cutoffs to the PK7300 reference standard. Discrepant results were manually diluted and retested on the Neo Galileo. Furthermore, since the Neo Iris is able to determine isotype and antigen specific titers, we also characterized these features in our donor population.ResultsIgM titer of 128 on the Neo Iris has better accuracy compared to the titer of 64 (94 % vs 93.6 %). Eleven of sixteen discordant results were in agreement with Neo Iris. Blood group O had the highest IgG antibody titers for both anti-A and anti-B (p = 8.4E-17 and 4.3E-09, respectively). Additionally, group O donors exhibited lower anti-A2 than anti-A1 IgG titers.DiscussionThe Neo Iris titer cut-off of 128 had the best overall accuracy and correlation with a 256 cut-off on our laboratory developed test on the PK7300 platform. Additionally, we found that group O donors had the highest titer antibodies, with typically higher IgG titers than IgM, and generally multiple dilution levels greater than other blood types.     

Studies on IgA class circulatory red cell antibodies--I. Preparation and identification of IgA class anti-A,anti-B

To elucidate the role of IgA class alloantibodies in transfusion practice, anti-A,anti-B was prepared using pooled serum from healthy group O donors. IgG was removed by protein A and protein G, whilst IgM was extracted by concanavalin A and anti-human mu chain. The final preparation contained both IgA1 and IgA2; it had an IgA concentration similar to the original serum pool and an environment as near to normal as possible; the absence of IgG and IgM was confirmed by sensitive enzyme-linked antiglobulin tests, and extensive haemagglutination studies showed that anti-A,anti-B was the only red cell antibody present.     

Preparation of single donor platelet with low antibody titers for all patients

Platelet concentrates from ABO-identical donors are the components of choice for patients. However, since inventories are generally insufficient and because there is usually a relative abundance of group O donors, perfect matches are not always possible. It is therefore the accepted practice for platelets to be transfused out of the ABO group when ABO-identical platelets are unavailable. Notwithstanding, the transfusion of platelets containing high titers of antibodies to the antigens on the red blood cells of the patient can cause clinically significant hemolysis. The way to improve the safety of group O platelets has focused on defining a safe level of antibodies or reducing the volume of incompatible plasma. In the current study, 107 group O single donor platelets (SDP) were modified after collecting the platelet pellet in a bag. The AB plasma was added instead of the donor's own plasma. The direct agglutination titers of anti-A/anti-B in the original group O SDPs' plasma were performed by doing a gel test, resulting in from 1:4 to 1:1024. The prevalence of high titers (i.e., at least 1:64 in our study) was relatively high, ～63% for anti-A and 78% for anti-B. The titer of residual anti-A/anti-B in the modified SDPs ranged from negative to 1:8. In most of the modified SDPs anti-A/anti-B could not be detected in the plasma (58.9% and 52.3%, respectively). The results indicate that our modified SDPs have very low titers; that is, acting as a universal SDP which is safe for all ABO patients. This modified SDP form is a more convenient way to overcome the risk from incompatible plasma or loss of platelets during the process of volume reduction and can help effectively manage our inventory.     

探讨微柱凝胶法在检测孕妇ABO血型IgG抗体效价中的应用

目的初步探讨微柱凝胶法技术在检测O型血孕妇血清中IgG抗A（B）血型抗体水平中的应用价值,以预防新生儿溶血病的发生。方法应用微柱凝胶法技术和抗球蛋白法分别测定O型血孕妇IgG抗A（B）抗体效价。结果 1 798例夫妻中,微柱凝胶法和抗球蛋白法检测O-A组合IgG抗A效价≥1∶64者分别为53例、51例;O-B组合IgG抗B效价≥1∶64者分别为32例、29例;O-AB组合IgG抗A抗B效价均≥1∶64者分别为6例、7例,2种方法差异无统计学意义（P〉0.05）。结论微柱凝胶免疫检测法可快捷准确检测O型血孕妇血清IgG抗A（B）抗体的效价,对预防新生儿溶血病的发生具有重要临床意义。     

Significant numbers of apheresis-derived group O platelet units have "high-titer" anti-A/A,B: implications for transfusion policy

Transfusion of group O single-donor apheresis PLTs (SDP) to group A recipients has resulted in intravascular hemolysis and mortality. Owing to low availability of type-specific SDPs, transfusion services sometimes issue ABO-mismatched PLTs. After observing two cases of acute hemolysis following infusion of O SDPs to group A patients, where both recipient eluates revealed anti-A specificity, a prospective study to determine the prevalence of "high-titer" anti-A/A,B in group O SDPs was commenced. One hundred group O SDP samples were tested. Titers of at least 64 and/or 256 from either buffered (generally reflective of IgM antibodies) or anti-IgG gel cards, respectively, were considered critically high. Twenty-eight and 39 percent of samples revealed critically high anti-A/A,B IgM and IgG titers, respectively. IgM titers were at 1:64 (18%), 128 (6%), and 256 (4%), whereas IgG titers were at 1:256 (28%), 512 (7%), 1024 (2%), and 2048 (2%). The prevalence of critical anti-A/A,B titers in group O SDPs is relatively high. Thus, the risk of minor side ABO mismatch and potential intravascular hemolysis during group O SDP transfusion to group A recipients may be significant. Based on these data, a policy was instituted to test anti-A/A,B titers in O SDPs prior to "out-of-group" transfusion.     

Effect of ABO mismatching on a radioimmunoassay for platelet compatibility. Successful adsorption of ABO alloantibodies with synthetic A and B substance

IgG and IgM anti-A and/or -B agglutinin titers were determined on 17 serum samples (5 group 0, 7 group A, 5 group B) to range from 8 to 1024. The presence of hemolysins was also evaluated. Single adsorptions with solid-state synthetic A and B substances greatly reduced or eliminated anti-A and -B titers but did not adsorb known platelet antibodies. Unadsorbed and adsorbed serum samples were crossmatched with ABO-compatible and -incompatible platelets by a radioimmunoassay employing 125I-labeled monoclonal antibodies specific for human gamma, mu, and C3d antigens. IgG and IgM crossmatch incompatibility was directly related to ABO alloantibody titers greater than or equal to 64. The use of adsorbed serum in the crossmatch eliminated or greatly reduced incompatible results that were due to ABO alloagglutinins alone, thus allowing the reliable detection of platelet and/or HLA antibodies.     

A Comparative Observation of the Presence of Anti-Tja-like Hemolysins in Relation to Obstetric History, Distribution of the Various Blood Groups and the Occurrence of Immune Anti-A or Anti-B Hemolysins Among Aborters and Nonaborters

Four hundred and twenty-two mothers with histories of spontaneous abortion and 300 mothers without such histories were examined for their various red cell blood groups, substances in salivary secretions and for the presence of immune anti-A and anti-B hemolysins. These factors in the 722 patients were compared with the occurrence of anti-Tj^a-like hemolysins among aborters in Western Australia. Of significance was the observation that the presence of anti-Tj^a-like hemolysins was associated only with abortion while the presence of immune anti-A or anti-B hemolysins occurred more often in mothers with histories of stillbirths and neonatal deaths. The lower pregnancy rate observed among mothers possessing immune anti-A or anti-B hemolysins also suggests that infertility could be associated with the presence of these hemolysins.     

Age dependency of ABO histo-blood group antibodies: reexamination of an old dogma

Current textbooks for transfusion medicine state that anti-A and/or anti-B (anti-A/B) agglutination titers–and thus the respective antibody concentrations–reach their maximum in individuals 5 to 10 years old and then gradually decline with the increasing age of the individual. This statement is largely based on a study by Thomsen and Kettel that dates to 1929. In the present article, ABO antibodies in sera of 175 healthy persons aged 61 to 97 years, as well as sera of 170 newborn infants and children aged 0 to 17 years, were analyzed. Microhemagglutination tests were performed with all sera and complemented by ABO enzyme-linked immunosorbent assays to measure the immunoglobulin class (IgM, IgG, and IgA) of the anti-A/B. As in a previous study using sera of persons aged 20 to 67 years, individual differences exceeded age-related changes for all variables. Median values of IgG and IgA anti-A/B were elevated in elderly persons of blood group O, whereas no significant changes were observed in other variables. In particular, the decrease in agglutination titers with the increasing age of the individuals was far less pronounced than previously described; even in sera of persons aged 90 to 97 years, median agglutination titers of 128 were found. Results in the sera of children confirm previously reported data that agglutination titers and IgM anti-A/B reached adult levels at the age of 5 to 10 years.     

Cryofiltration apheresis for major ABO-incompatible kidney transplantation.

The barrier of ABO-incompatible kidney transplantation is the presence of anti-A and anti-B antibodies in the recipient's circulating blood. Double filtration plasmapheresis (DFPP) is usually used to eliminate those antibodies. We tried cryofiltration apheresis (CRYO) in 2 recipients. Patient 1 was a 45-year-old male with B, Rh(+). The titers of IgM anti-A antibody were only reduced from x64 to x32 by the end of 3 sessions of standard CRYO. Renal allografting was not performed. Case 2 was a 29-year-old male with B, Rh(+). CRYO was introduced for 3 sessions. The initial IgM and IgG titers were x128 and negative, respectively. The standard CRYO system was modified by temperature, treated volume, and filter pore size. The IgM anti-A antibody titer was markedly reduced to x2 after the final session of CRYO. The donor was a 56-year-old father with A, Rh(+). Tacrolimus, azathioprine, methylprednisolone, and antilymphocyte globulin were used as the introductory immunosuppression therapy.     

Rapid quantitation of immunoglobulin G antibodies specific for blood group antigens A and B by surface plasmon resonance

BACKGROUND: The measurement of immunoglobulin (Ig) G blood group A/B antibody(anti-A/B) levels is important for ABO-unmatched organ recipients because the effective removal of the antibodies improves their prognosis. Currently existing methods to detect IgG anti-A/B suffer limitations owing to high costs, low throughput, and poor adaptability to automation. STUDY DESIGN AND METHODS: We have developed a rapid means to quantitate IgG anti-A/B by surface plasmon resonance (SPR). To investigate the accuracy, a serially diluted plasma sample from a donor was measured with the SPR method. Moreover, IgG anti-A/B titers in 45 healthy volunteers were measured both by the SPR and by the standard tube test (TT) method, as were plasma samples from two ABO-unmatched organ recipients. RESULTS: The change in titers when the same plasma was diluted was precisely reflected by the SPR method. The coefficients of correlation between SPR and TT methods for IgG anti-A and anti-B were 0.85 and 0.56, respectively. The SPR values also paralleled the TT values, which showed a decline in titers after the removal of antibodies by double-filtration plasmapheresis or plasma exchange. CONCLUSION: This SPR method can be used to measure IgG anti-A/B titers in the plasma very quickly and quantitatively.     

Apheresis therapy for living-donor liver transplantation: experience for apheresis use for living-donor liver transplantation at Kyoto University.

Liver transplantation is a fundamental treatment for patients with end-stage hepatic failure. In order to perform living-donor liver transplantations under safer conditions, apheresis plays a major role in Japan due to the prevalence of living-donor liver transplantation wherein later retransplantation is difficult. In our department, the roles of apheresis in liver transplantation are as follows: as bridge therapy to liver transplantation (n = 45); as a supplement to the graft liver until the recovery of hepatic function (n = 77); as treatment for multiple organ failure including posttransplantation renal failure (n = 15); and as a means with which to reduce antibody titers for antibodies such as anti-A or anti-B in persons with ABO blood type = incompatible liver transplantation (n = 23). In our department, we have performed 822 liver transplantations at present. Of those cases, 183 were selected wherein apheresis was performed around the time of the operation. In all cases, transplantation with sufficient apheresis was performed before the surgical operation, however, 22 patients (48.9%) died after undergoing surgery. Among the patients who underwent the postoperative apheresis, those in the nonsurvivor group had lower grafted liver weights compared to those of the survivor group. The kidney was the organ that most frequently failed due to postoperative complications. In cases of ABO blood type-incompatible liver transplantations, patients with high preoperative anti-A/B IgM antibody titers sustained bile duct complications, patients with high preoperative anti-IgG antibody titers sustained hepatic necrosis, and patients with high postoperative anti-A/B IgM and anti-IgG antibody titers sustained hepatic necrosis most frequently.     

ABO新生儿溶血病与O型孕妇血清中IgG及其亚类含量的相关分析

目的探讨O型孕妇血清IgG抗体及其亚型含量与新生儿溶血病(HDN)的关系。方法采用血型血清学方法,对317名夫妇血型不合的O型孕妇作IgG抗体效价检测,并对其中有妊娠史的287名孕妇作IgG抗体水平比较;采用ELISA法对71名HDN患儿及其母亲、65名健康O型孕妇和51名健康新生儿的IgG亚类作定量分析。结果1)317名新生儿中发生ABOHDN71例(22.4%),其中抗-A46例、抗-B25例;2)随着妊娠次数的增加,IgG抗体效价≥64者的比例和ABO-HDN发病率升高,>2次妊娠与第2次妊娠间有统计学差异;3)患儿及其母亲体内IgG抗体的含量显著高于正常对照组,且以IgG1抗体为主,患儿体内的IgG1比例(61.9%)高于母体(52.8%)。结论新生儿ABOHDN的发病率随其母亲体内IgG抗体效价的升高而升高,且与母亲体内IgG1呈正相关。夫妇血型不合的O型孕妇应定期检测IgG抗体及其亚类含量。     

O型孕妇血型抗体效价与新生儿溶血发病率的关系分析

目的：研究。型RhD阳性孕妇（其丈夫为非O型）血清IgG抗-A（抗-B）抗体效价与新生儿溶血病（HDN）的关系。方法：应用微柱凝胶技术对382例O型RhD阳性孕妇进行了免疫性IgG抗A（B）抗体效价检测及对其新生儿进行HDN（①新生儿ABO、Rh系统定型;②新生儿直抗实验;③游离IgG测定;④放散实验）的检测。结果：382例O型RhD阳性孕妇中IgG抗-A（B）效价〈64者330例（占总数86．39％）,抗体效价≥64者13．61％。其中发生HDN5例,抗-A3例,抗-B12例,总发生率1．31％。结论：夫妇血型不合应及时检测孕妇IgG抗体,随着孕妇体内IgG抗体效价的增高,新生儿ABO溶血病的发病率也随之升高。孕妇产前应定时进行IgG抗体检测,了解效价与新生儿溶血病发病率之间的关系,对于预防新生儿溶血病极为有效。