摘要:

BACKGROUND: In patients in whom autoantibodies of broad specificity (panagglutinins) are present in the serum, adsorption studies are often necessary to identify alloantibodies that are simultaneously present. STUDY DESIGN AND METHODS: Samples from 138 patients in whom the direct antiglobulin test was positive and antibody was present in the serum were studied. When antibody identification studies before or after initial adsorption suggested the presence of an alloantibody, additional alloadsorptions were performed. RESULTS: Among the samples from 138 patients, 71 contained only panagglutinating autoantibody, and another 19 contained either autoantibodies or alloantibodies that were not accompanied by panagglutinins. The remaining 48 samples contained both panagglutinins and a total of 62 antibodies that appeared to be alloimmune in nature. Alloadsorption with antigen‐negative red cells showed that 29 (47%) of the apparent alloantibodies were in fact partially adsorbed autoantibodies that mimicked alloantibodies by their reactions. CONCLUSION: Initial autoadsorption often left unadsorbed alloantibodies and autoantibodies with mimicking specificities. Initial alloadsorption more often left only true alloantibodies unadsorbed. From the screening tests, it appeared that 43 percent of the 138 patients were alloimmunized. Recognition of the mimicking nature of the partially adsorbed autoantibodies found that the real incidence of alloimmunization in the patients was 23 percent. Recognition of this phenomenon considerably simplifies the selection of blood for transfusion to these patient

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36696269503.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

BACKGROUND: The polyethylene glycol indirect antiglobulin test for detection of red cell antibodies was compared with a proven, highly sensitive test system using papain. STUDY DESIGN AND METHODS: Parallel, prospective testing of 1508 samples with polyethylene glycol and with albumin and papain evaluated the sensitivity and specificity of polyethylene glycol. Retrospective analysis of antibody specificities was performed for the 2 years before and the 2 years after the institution of polyethylene glycol testing. RESULTS: Of 1508 prospective screens, 53 (3.5%) had discordant results: 5 were positive only in polyethylene glycol and 48 were positive only in albumin and papain. Upon antibody identification, the 5 samples that were positive only in polyethylene glycol showed 1 anti‐D, 2 warm autoantibodies, and 2 false‐positive results. The 48 samples that were positive only in albumin and papain showed 1 each of the following: anti‐Le(b); anti‐P1; anti‐S; high‐titer, low‐avidity antibody; and cold autoantibody; there were 43 false‐positive results. False‐positive results totaled 12 (0.8%) with polyethylene glycol and 53 (3.5%) with albumin and papain. The retrospective analysis of antibody specificity with polyethylene glycol showed a significant increase in the detection of Fy(a) and/or Fy(b) (p<0.0002) and Jk(b) (p<0.0002) antibodies and a decrease in the detection of Le(a) and/or Le(b) antibodies (p<0.0002). CONCLUSION: Polyethylene glycol retained the high sensitivity of the albumin and papain, while significantly lowering the number of false‐ positive results and decreasing the detection of antibodies of doubtful cl

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36696269504.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

BACKGROUND: The Kell blood group system is complex, consisting of five sets of alleles and expressing high‐ and low‐incidence antigens and at least 11 other independently expressed antigens. The molecular basis of two sets of alleles: KEL1 (K) and KEL2 (k) and KEL6 (Jsa) and KEL7 (Jsb) have been elucidated as single‐base mutations leading to amino acid changes. The molecular basis for the KEL3 (Kpa), KEL4 (Kpb), and KEL21 (Kpc) alleles, the KEL11(Cote) and KEL17(Wka) alleles, and for KEL10 (UIa) is now reported. STUDY DESIGN AND METHODS: Genomic DNA from unrelated individuals with KEL:3,‐4,‐21 [Kp(a+b‐c‐)], KEL:‐3,‐4,21 [Kp(a‐b‐c+)], KEL:17,‐11, and KEL:10 (UIa) phenotypes was amplified by polymerase chain reaction (PCR) with primers for the 19 exons of KEL. The PCR products were sequenced and compared to the DNA sequences of a common Kell system phenotype, KEL:‐3,4,‐21,‐17,‐10. Base mutations found were confirmed by restriction fragment length polymorphism analysis in which DNA of unrelated persons with similar red cell phenotypes was used. RESULTS: In all cases, single‐base mutations were responsible for the expression of the various antigens. In KEL3 (Kpa), KEL4 (Kpb), and KEL21 (Kpc), point mutations at the same codon in exon 8, encoding amino acid residue 281, distinguish the three genes. KEL4 has the CGG codon for arginine, KEL3 has the TGG codon for tryptophan, and KEL21 has the CAG codon for glutamine. KEL17 has a T1025C mutation in exon 8, encoding a valine‐to‐alanine amino acid change at residue 302. KEL10 has an A1601T mutation in exon 13, encoding a glutamic acid‐ to‐valine change at residue 494. In all cases, the point mutations created restriction enzyme sites, and PCR‐based restriction fragment length polymorphisms confirmed that these point mutations occurred in unrelated persons with the same red cell phenotype. CONCLUSION: Single‐ base substitutions characterize the KEL3, KEL21, KEL17, and KEL10 genes. The allelic relationship of KEL3, KEL4, and KEL21 was confirmed because the mutations occur in the same codon, expressing different amino acids. PCR‐based restriction fragment length pol

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36696269505.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

BACKGROUND: Kell is a major antigenic system in human red cells, with more than 20 identified antigens. KEL1 and KEL2 are two opposing low‐ and high‐frequency alleles. Immunization to KEL1 is clinically significant, because anti‐KEL1 can cause severe reactions to transfusion of incompatible blood, as well as hemolytic disease of the newborn. At the nucleotide level, the difference between the KEL2 and KEL1 alleles is a single‐base change within exon 6 that results in the substitution of methionine (ATG) for threonine (ACG) at position 193. STUDY DESIGN AND METHODS: An assay using polymerase chain reaction and sequence‐specific primers to genotype for the KEL1 and KEL2 alleles has been developed. It uses two allele‐specific forward primers for either KEL1 or KEL2 and a single reverse‐consensus primer. RESULTS: A validation study of 42 serologically typed samples (5 KEL:1,‐2 [K+k‐]; 23 KEL:1,2 [K+k+]; and 14 KEL:‐1,2 [K‐k+]) was performed. A concordance rate of 100 percent (42/42 samples) was observed between polymerase chain reaction with sequence‐specific primers and serologic typing. CONCLUSION: This rapid, nonradioactive, Kell system genotyping assay does not require the additional steps of probe hybridization or restriction enzyme digestion. This application of polymerase chain reaction with sequence‐specific primers should prove particularly useful in Kell system genotyping of amniotic cells to identify pregnancies at risk for hemolyt

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36696269506.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

BACKGROUND: The major cause of fetal hemolytic disease is maternal immunization to D in D‐incompatible pregnancies. To prevent complications, D‐incompatible pregnancies are monitored for the level of maternal anti‐D. At present, the monitoring of anti‐D levels is performed by the indirect antiglobulin test complemented by quantitation by the technique used in an automated antibody detection and quantitation instrument. STUDY DESIGN AND METHODS: Flow cytometry was used to quantitatively determine the level of anti‐D in serum and to analyze the IgG subclass distribution and the presence of IgM anti‐D in these samples. The results were compared to the indirect antiglobulin test titer and to the results obtained by the technique used in an automated antibody detection and quantitation instrument. RESULTS: Flow cytometry allowed sensitive and accurate determinations of anti‐D levels with low interassay and intra‐assay variability, both for serum samples and standard curves. CONCLUSION: Flow cytometry is a simple, rapid, and reliable method for determining the serum levels of D antibodies and their Ig subclass distribution. It is therefore well suited for the monitoring of women during D‐incompa

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36696269507.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

BACKGROUND: Almost all red cells that carry D and/or C antigens also express the G antigen (Rh12). A study was conducted on the molecular background of the G epitope. STUDY DESIGN AND METHODS: Two unrelated donors with the rare ccDEe, G‐ phenotype and one donor with the ccEe, G+ phenotype were studied. Genomic DNA and cDNA of these donors were studied with polymerase chain reaction, Southern blot, and sequence analysis, with special focus on exon 2, because it is only in this exon that there are supposed to be similarities between RHD and the RHC allele, but not between RHD and the RHc allele. RESULTS: In both ccDEe, G‐ donors, a nucleotide substitution was found in exon 2 of RHD; T307 was replaced by C307, which predicted a Ser‐>Pro substitution at amino acid position 103 of the D polypeptide. The ccEe, G+ donor carried the complete exon 2 of RHD. Moreover, despite the absence of all known D epitopes, this donor also carried RHD characteristics in exons 1 to 3 and exon 9 and further downstream. CONCLUSION: Ser103, encoded by exon 2 of the RH genes, is involved in G epitope form

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36696269508.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

BACKGROUND: Historically, classification of U‐ and U variant (U+var) individuals has been made by hemagglutination and adsorption and elution studies performed with polyclonal U antisera. Molecular studies and serologic tests with a potent monoclonal anti‐He have shown that U+var red cells, some of which are He+, possess an altered form of glycophorin B. STUDY DESIGN AND METHODS: Seventeen sera, previously determined to contain anti‐U, were tested with a panel of red cells of common and rare MNS types. RESULTS: Five sera contained anti‐U only, and 12 sera contained broadly reactive antibodies with apparent, but inseparable, anti‐U,He or anti‐U,N,He specificities. CONCLUSION: The majority of antibodies produced by S‐s‐U‐ individuals are anti‐U plus anti‐glycophorin B and are analogous to the broadly reactive antibodies produced by En(a‐) individuals whose red cells lack glycophorin A or have altered glycophorin A. To avoid further immunization of patients with anti‐U, sera used for classification of S‐s‐U‐ donors should be selected to detect S‐s‐ red cells that pos

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36696269509.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

BACKGROUND: Antibodies of the Knops system have been referred to as nonneutralizable because they cannot be inhibited with serum, saliva, or urine. Because the Knops system antigens have been located on complement receptor 1 (CR1), the question of whether the antibodies could be neutralized with soluble CR1 (sCR1) produced by recombinant DNA techniques was studied. STUDY DESIGN AND METHODS: First, radiolabeled immunoprecipitation techniques were used to test sCR1 for the expression of the high‐incidence Knops system antigens. Then, a total of 45 antibodies were neutralized with sCR1, including the following: one each of anti‐Cr(a), ‐Dr(a), ‐Do(b), ‐Hy, ‐Ge, ‐Jr(a), ‐ Sc1, ‐Jk(a), ‐Cs(a), and ‐Kp(b); two each of anti‐Lu(b), ‐Yt(a), and ‐ JMH; three each of anti‐McC(a), ‐Rg, and ‐Sl(a); and four each of anti‐ Ch, ‐Kn(a), ‐Yk(a), ‐Kn/McC. In addition, two examples of anti‐Kn(a) + K, one example of anti‐Sl(a) + K + Fy(a), and one example of anti‐Yk(a) + E were tested. The sCR1 was added to each test serum and 6‐percent albumin was added to the control; this was followed by neutralization incubation for 5 minutes at 25 degrees C. The antibody samples were then tested by a low‐ionic‐strength solution, anti‐human globulin technique. RESULTS: The sCR1 expressed Kn(a), McC(a), Sl,a and Yk(a). All Knops system antibodies (n = 22) were neutralized by the sCR1, but none of the other 23 alloantibodies decreased in reactivity. The samples containing antibodies of two specificities showed inhibition of the Knops system antibody but not of the second antibody. CONCLUSION: This neutralization method, in which recombinant protein is used, provides an expedient and d

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36696269510.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

BACKGROUND: Very little is known about the determinants of blood transfusions in patients undergoing coronary artery bypass graft surgery. STUDY DESIGN AND METHODS: To identify factors that influenced the transfusion of red cells, platelets, plasma, and cryoprecipitate, statistical methods were used to study 2476 consecutive diagnosis‐ related group 106 and 107 patients in five teaching hospitals who underwent coronary artery bypass surgery between January 1, 1992, and June 30, 1993. RESULTS: The likelihood of red cell transfusion was significantly associated with 10 preoperative factors: 1) admission hematocrit, 2) the patient's age, 3) the patient's gender, 4) previous coronary artery bypass surgery, 5) active tobacco use, 6) catheterization during the same admission, 7) coagulation defects, 8) insulin‐dependent diabetes with renal or circulatory manifestations, 9) first treatment of new episode of transmural myocardial infarction, and 10) severe clinical complications. Platelet and/or plasma transfusions were strongly associated with the dose of red cells transfused. Transfusion requirements and other in‐hospital outcomes were associated with patient characteristics, surgical procedure (reoperation vs. primary procedure), and the conduits used for revascularization (venous graft only, venous and internal mammary artery graft, or internal mammary artery graft only). Blood resource use and donor exposures were evaluated with respect to the risk to patients of contracting hepatitis C virus and human immunodeficiency virus infections. CONCLUSION: The classification of coronary artery bypass graft patients on the basis of attributes known preoperatively and by conduits used yields subsets of patients with distinctly different transfusion requirements and in‐ hospital o

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36696269511.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

BACKGROUND: Most published reviews and audits of blood and blood component transfusion have focused on the issue of overtransfusion and on the inappropriate use of red cell components. There is growing concern that efforts to curb unnecessary transfusions may result in a trend toward undertransfusion of patients. There is little published information that addresses this issue or the magnitude of this practice. STUDY DESIGN AND METHODS: Undertransfusion was evaluated by examining the transfusion records from a 3‐month period for 55 patients who met the study criteria of having either a hemoglobin level<7 g per dL or a platelet count of<10 × 10(9) per L. If the identified patient did not receive a transfusion within 24 hours of the reported hemoglobin level or platelet count, the medical record was reviewed by a resident physician. RESULTS: A total of 213 individual hemoglobin levels and platelet counts, representing the 55 patients, met our transfusion criteria. All except 8 of the identified patients received red cells and/or platelet transfusions. Reasons for not transfusing red cells included the patient's response to nutritional support and iron supplementation, refusal of blood, and noncompliance. Reasons for not transfusing platelets included falsely low platelet count because of platelet clumping in vitro, contraindication based on clinical diagnosis (e.g., immune thrombocytopenic purpura), and the patient's death before transfusion. CONCLUSION: Red cell and platelet transfusions were appropriately ordered for all patients who met the transfusion criteria. Undertransfusion is not a problem at this institution according to the criteria established. It is recommended that other institutions expand their blood utilization audits to include investigation for evidence of undertransfusion. Further research regarding the issue of undertransfusion is warranted and could be expanded to include other componen

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1996.36696269512.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY