摘要:

SUMMARY.The clinical and immunological data of 12 Danish cases of post‐transfusion purpura (PTP) are summarized. All patients but one were women. All except one had thrombocytopenic purpura which occurred 4–11 days after transfusion, usually with a nadir of the platelet count below 10times1091‐1. The typical haemorrhagic symptoms were cutaneous bleedings, melena and haematuria lasting from 3 to 12 days. The time until normalization of platelet count varied from 3 to 50 days after onset. One patient had recurrence of PTP and one patient died due to intracranial haemorrhage.Ten of the HPA‐la negative patients (83%) had platelet‐specific HPA‐la antibodies and two HPA‐lapositive individuals had anti‐HPA‐lbantibodies. In 10 patients, HLA antibodies were also detectable and in one patient a delayed haemolytic transfusion reaction due to anti‐E was seen.All of seven patients investigated had anti‐HPA antibodies of both IgGl and IgG3 subclasses during the thrombocytopenic period while all of 10 patients had anti‐HPA of only the IgGl subclass after recovery from PTP Thus, the destruction of autologous platelets in PTP seems to be associated with the presence of anti‐HPA of the IgG3 subclass which may be of importance i

ISSN:0958-7578    

DOI:10.1111/j.1365-3148.1994.tb00236.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:0958-7578    

DOI:10.1111/j.1365-3148.1994.tb00272.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SUMMARY.Currently, five platelet alloantigen (alloAg) systems have been established (HPA‐1, ‐2, ‐3, ‐4, ‐5). Three of these are expressed on the glycoprotein (GP) IIb‐IIIa complex, HPA‐1, HPA‐3 and HPA‐4, inherited in an autosomal codominant mode. Recent investigations of the molecular basis of these platelet alloantigen systems have shown that only one nucleic acid base substitution in the genes encoding for GP IIb and GP IIIa is responsible for the polymorphism. This substitution is reflected in a difference in restriction enzyme recognition allowing platelet alloantigen typing by restriction fragment length polymorphism (RFLP) analysis of DNA amplified by the polymerase chain reaction (PCR). To validate the PCR technology for platelet typing, we have compared PCR‐RFLP with monoclonal‐antibody‐specific immobilization of platelet antigens (MAIPA). For this purpose, we have studied different Glanzmann thrombasthenic families and particularly heterozygous individuals, who are not lacking GP IIb‐IIIa, as a model to detect the occurence of discrepancies between these two technologies. In two families, we have found differences between molecular biology and serological methods with the lack of expression of one antigen on the platelet membrane surface. In the first family, the abnormality is related to the HPA‐1 alloantigen system with three informative members; in the second, the HPA‐3 alloantigen system is concerned with two informative members. Considering these results, there may not always be a perfect correlation between molecular biology and serological methods, as an unknown molecular defect could interfere with the PCR results and lead to false platelet typing. In cases of suspected post‐transfusion purpura (PTP) or fetuses at risk for neonatal alloimmune thrombocytopenia (NAITP), great care must be taken in the interpretation of the results if on

ISSN:0958-7578    

DOI:10.1111/j.1365-3148.1994.tb00237.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SUMMARY.Prenatal typing for the human platelet antigens‐1 (HPA) permits identification of a fetus at risk for neonatal alloimmune thrombocytopenia (NAITP) in cases of HPA‐1 incompatibility in which the father is heterozygous for the HPA‐la antigen. Diagnostic cordocentesis and phenotyping of the fetal platelets are used for this purpose. We applied allele‐specific restriction enzyme analysis on polymerase chain reaction (PCR)‐amplified DNA purified from amniocytes. This assay allows early second trimester typing for HPA‐1 alleles. We were able to determine the genotype of three fetuses at risk. Iatrogenic fetal loss is lower with amniocentesis than with cordocentesis. Therefore, this technique is a welcome addition to the antenatal manageme

ISSN:0958-7578    

DOI:10.1111/j.1365-3148.1994.tb00238.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SUMMARY.A simplified method for large‐scale HPA‐la phenotyping of platelets was developed for use in an antenatal screening programme for fetomaternal alloimmune thrombocytopenia (FMAIT). The test was based on the MAIPA assay, which was modified for antigen‐typing with a well‐characterized anti HPA‐la reagent. The resulting assay gave reliable results, was inexpensive and allowed testing of large batches using semiautomated

ISSN:0958-7578    

DOI:10.1111/j.1365-3148.1994.tb00239.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SUMMARY.The expression of Fc‐gamma‐R (FcR) classes on circulating leucocyte lineages (lymphocytes, monocytes, granulocytes) was determined by flow cytometry in 46 fetuses at 18–35 weeks of gestation and in 11 full‐term neonates, and compared to that in 20 adults. Classes of FcR present on adult leucocytes could be detected on the corresponding fetal cells as early as 18 weeks of pregnancy. Generally, in the fetus, FcR expression was lower than in the adult while in the neonate it approached values found later in life. However, percentages of Fc‐gamma‐RIII‐positive fetal/new‐born monocytes, and those of FcR‐positive new‐born granulocytes were considerably raised above adult levels. The modified pattern of FcR expression on fetal/new‐born leucocytes is likely to influence their IgG‐mediated effector activities towards targets such as

ISSN:0958-7578    

DOI:10.1111/j.1365-3148.1994.tb00240.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SUMMARY.Three cohorts of elective surgical patients were reviewed in order to develop a method in which the discharge haematocrit can serve as a clinical indicator for a subsequent study of the use of blood transfusion therapy. Three different levels of discharge haematocrit were evaluated: 36, 33, and 30% for ‘generous’, ‘intermediate’, and ‘strict’ criteria, respectively. Discharge haematocrits (%, mean ± SD) for patients not transfused were 29.6±4.6, 33.7 ± 5.0, and 33.6 ± 3.4 for three different surgical groups (cardiac, orthopaedic, and urological surgical patients). When discharge haematocrits greater than 33% (‘intermediate’) were considered excessive due to previous transfusion, the prevalence of patients identified was 9, 6.5 and 13%, respectively. We found no relationship between the length of stay in hospital and the number of blood units transfused or patient discharge haematocrit levels. When the length of stay of patients identified by exceeding the clinical indicator was compared to that of patients not identified, orthopaedic and urological surgical patients showed no difference; however, cardiac surgical patients who exceeded the clinical indicator had shorter hospital stays compared to patients who were not so identified. We conclude the following:1The discharge haematocrit can be used as a clinical indicator for a subsequent review of use in order to evaluate the appropriateness of blood transfusion therapy.2The prevalence of patients identified who exceeded the clinical indicator, among three elective surgical patient groups, suggests that this indicator is applicable across elective surgical categories in order to target transfusion medicine education programmes and clinical outcome studies.3Additional factors important to the ‘transfusion trigger’, such as blood lost during hospitalization, may need to be included with the discharge haematocrit as clinical indicators in order to evaluate blood transfusion

ISSN:0958-7578    

DOI:10.1111/j.1365-3148.1994.tb00241.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SUMMARY.To improve the appropriateness of blood‐component prescribing, a mandatory haematologist pretransfusion approval programme of all non‐red‐cell components was instituted. This was associated with a 33% decrease in the units of fresh frozen plasma (FFP) transfused. Platelet transfusions increased but utilization of both platelets and FFP are now the lowest of the six comparable blood transfusion regions in New Zealand.A subsequent concurrent audit, using preset criteria, of FFP, cryoprecipitate and platelet usage over a 3‐month period showed that further reductions in blood component usage could still be achieved, despite the continuing pretransfusion approval policy. This audit showed that 33% of FFP and 30% of cryoprecipitate units transfused were inappropriately given, despite prior haematologist approval.Hospital transfusion practices can be improved by mandatory blood‐component pretransfusion approval but concurrent auditing of this programme is required to identify and correct continuing inappropriate blood‐component prescribing. Haematologists need to agree on blood‐component indications prior to instituting a pretransfusion approval programme in order to provide optim

ISSN:0958-7578    

DOI:10.1111/j.1365-3148.1994.tb00242.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SUMMARY.The aim here was to determine the effectiveness of a transfusion medicine educational intervention in a medicine core clerkship program.Third‐year medical students enrolled in their medicine core clerkship rotations at tertiary care hospitals affiliated with our institution underwent a two‐part educational intervention that incorporated a transfusion medicine curriculum within the context of the medicolegal, ethical and educational elements of informed consent. Part one was a 1‐h didactic session on standards of practice for red blood cell transfusion. Part two was a 90‐min multidisciplinary workshop on informed consent. The effectiveness of the educational intervention was analysed by an objective structured clinical evaluation.The student group receiving the educational intervention scored significantly higher than in the comparison group (65.8 ± 9.2 vs. 54.1 ± 10.56,P<0.001). When student scores were used to determine changes in student response patterns over time, the largest change occurred in identifying possible other options to allogeneic blood transfusion.These results suggest that a transfusion medicine curriculum using an informed consent model can be used effectively as an educational intervention in a medicine core clerkship

ISSN:0958-7578    

DOI:10.1111/j.1365-3148.1994.tb00243.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SUMMARY.This study compared plateletpheresis on the Haemonetics PCS Plus (PCS Plus) and the Baxter Autopheresis C (Auto C) using the same 100 selected donors. The number of packs meeting UK BTS/NIBSC specification (>2.2 times 1011platelets per pack) was achieved by 99% of PCS Plus and 82% of Auto C procedures. The positive correlation found between donor precount and final platelet yield was better for the PCS Plus. Both machines met U.K. specification for white‐cell contamination but this was significantly greater for the Auto C. Plasma yields were similar.As a result of this study we chose to use the PCS Plus for routine plateletpheresis in our unit. This has enabled us not only to comply with UK BTS/NIBSC specifications for apheresis platelets easily and cost effectively but also to meet our own higher specification (2.75 times 1011platelets per pack) using existing staff and without extending the working da

ISSN:0958-7578    

DOI:10.1111/j.1365-3148.1994.tb00244.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY