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Biomedical subjects

W N Erber

Publications and source records attributed to W N Erber.

At least 19 recordsLinked to original sources
PubMed2006

The utility of an automated electronic system to monitor and audit transfusion practice.

BACKGROUND AND OBJECTIVES: Transfusion laboratories with transfusion committees have a responsibility to monitor transfusion practice and generate improvements in clinical decision-making and red cell usage. However, this can be problematic and expensive because data cannot be readily extracted from most laboratory information systems. To overcome this problem, we developed and introduced a system to electronically extract and collate extensive amounts of data from two laboratory information systems and to link it with ICD10 clinical codes in a new database using standard information technology. MATERIALS AND METHODS: Three data files were generated from two laboratory information systems, ULTRA (version 3.2) and TM, using standard information technology scripts. These were patient pre- and post-transfusion haemoglobin, blood group and antibody screen, and cross match and transfusion data. These data together with ICD10 codes for surgical cases were imported into an MS ACCESS database and linked by means of a unique laboratory number. Queries were then run to extract the relevant information and processed in Microsoft Excel for graphical presentation. We assessed the utility of this data extraction system to audit transfusion practice in a 600-bed adult tertiary hospital over an 18-month period. RESULTS: A total of 52 MB of data were extracted from the two laboratory information systems for the 18-month period and together with 2.0 MB theatre ICD10 data enabled case-specific transfusion information to be generated. The audit evaluated 15,992 blood group and antibody screens, 25,344 cross-matched red cell units and 15,455 transfused red cell units. Data evaluated included cross-matched to transfusion ratios and pre- and post-transfusion haemoglobin levels for a range of clinical diagnoses. Data showed significant differences between clinical units and by ICD10 code. CONCLUSION: This method to electronically extract large amounts of data and linkage with clinical databases has provided a powerful and sustainable tool for monitoring transfusion practice. It has been successfully used to identify areas requiring education, training and clinical guidance and allows for comparison with national haemoglobin-based transfusion guidelines.

Adult↗
PubMed2005

Primary and isolated anaplastic large cell lymphoma of the bone marrow.

Anaplastic large cell lymphoma (ALCL) is a T-cell lymphoma in which the majority of patients present with advanced stage III or IV disease. Here we report a case of ALCL where bone marrow was the only site of disease, in a 60-year-old man with pyrexia and pancytopenia. The diagnosis of ALCL was made on detection of CD30-positive anaplastic cells in the bone marrow, together with prominent hemophagocytosis. Genetics confirmed the clonal nature of the disease and showed it to be anaplastic lymphoma kinase (ALK) negative. Primary isolated bone marrow ALCL should be considered in the diagnosis of pancytopenia associated with hemophagocytosis.

Bone Marrow↗
PubMed2005

The role of RhD agglutination for the detection of weak D red cells by anti-D flow cytometry.

Anti-D flow cytometry is an accurate method for quantifying feto-maternal haemorrhage (FMH). However, weak D red cells with <1000 RhD sites are not detectable using this methodology but are immunogenic. As quantitation of RhD sites is not practical, an alternative approach is required to identify those weak D fetal red cells where anti-D flow cytometry is inappropriate. We describe a simple algorithm based on RhD agglutination and flow cytometry peak separation. All weak D (n = 34) gave weak agglutination with RUM-1 on immediate spin (grading </=2.5). In Diamed-ID Diaclon ABO/D or ABO/Rh for Newborn cards two subgroups of weak D were observed. In one subgroup, weak agglutination (grading 3) was observed and the red cells were undetectable by flow cytometry. In the second subgroup, agglutination was strong (grading 4) and the red cells were detectable by anti-D flow cytometry. The accuracy of the quantitation was dependent on adequate separation of the weak D and RhD-negative peaks as in seven of 11 samples <1.11% of an expected 2% red cells were detectable. Monitoring RhD agglutination and flow cytometric peak separation are pivotal if anti-D flow cytometry is to be maintained as the primary technique for FMH quantitation in the routine laboratory.

Agglutination Tests↗
PubMed2005

Molecular genetic analysis of haematological malignancies: I. Acute leukaemias and myeloproliferative disorders.

Molecular genetic techniques are now routinely applied to haematological malignancies within a clinical laboratory setting. The detection of genetic rearrangements not only assists with diagnosis and treatment decisions, but also adds important prognostic information. In addition, genetic rearrangements associated with leukaemia can be used as molecular markers allowing the detection of low levels of residual disease. This review will concentrate on the application of molecular genetic techniques to the acute leukaemias and myeloprolferative disorders.

Biomarkers, Tumor↗
PubMed2005

Case report: immune anti-D stimulated by transfusion of fresh frozen plasma.

FFP has occasionally been reported to generate an immune response to RBC antigens (e.g., anti-D and anti-Fya). The Council of Europe requires that each unit of FFP have less than 6 x 10(9)/L RBCs. However, there is considerable variation internationally in the method of production and the level and assessment of RBC contamination of FFP. This study reports the case of a 63-year-old group B, D- man who received multiple transfusions of D- blood products over a 4-month period. Seven months later the patient's antibody screen remained negative and he was transfused with seven units of D- RBCs and six units of FFP, four of which were D+. Two months later anti-D, -E, and -K were detected in his plasma. Although the anti-E and anti-K could have resulted from transfusion of antigen-positive RBCs, the anti-D could have resulted only from transfusion of the D+ FFP. The D status of FFP is currently not considered when selecting products for transfusion even though the D antigen is highly immunogenic and the level of RBC contamination of FFP is not always known. This case highlights that transfusion of FFP is a stimulus for RBC antibodies and that when a patient has had a recent transfusion of FFP, consideration should be given to obtaining a sample for pretransfusion testing within 3 days before a scheduled RBC transfusion. In addition, the D status of FFP should be considered before administering FFP to premenopausal D- women.

Adenocarcinoma↗
PubMed2004

A community profile of alpha thalassaemia in Western Australia.

OBJECTIVE: To investigate the current prevalence of alpha-thalassaemia in the population of Western Australia, which has received substantial immigration from South-East Asia during the last 30 years. METHOD: Over a 1-year period commencing July 2002, alpha-thalassaemia DNA testing was performed on 920 blood samples received from the Migrant Health Service, referring doctors or pathology laboratories in Western Australia. Molecular testing for alpha-thalassaemia was performed on extracted DNA for single and double alpha-globin gene deletions and mutations by PCR. RESULTS: An alpha-globin gene abnormality was detected in 35.4% (326/920) of samples. There were 177 cases (50.6%) with a single gene deletion alpha(+)-thalassaemia, most commonly -3.7 kb, and 102 cases (31.2%) with double alpha-gene deletions (alpha(0)-thalassaemia), including 7 cases of HbH disease. CONCLUSION: Overall, the findings amount to 1.7 new cases of alpha-thalassaemia per 10,000 population in the 12-month period and demonstrate that alpha-thalassaemia is an increasingly common disorder in the Western Australian population. This has important implications for community outreach programmes, genetic counselling and the screening of at-risk populations.

Adolescent↗
PubMed2004

The effect of haemodilution on antithrombin concentration during cardiac surgery.

The effect of haemodilution on antithrombin concentration was investigated in 73 patients undergoing elective cardiac surgery with and without cardiopulmonary bypass. In patients who required cardiopulmonary bypass (n = 45), the antithrombin concentration fell to 52% of baseline during surgery (24.2 mg.dl(-1) to 12.6 mg.dl(-1)), and the haemoglobin level fell to 55% (136 g.l(-1) to 75 g.l(-1)). In patients who did not require cardiopulmonary bypass (n = 28), the antithrombin concentration fell to 82% of baseline (23.7 mg.dl(-1) to 19.5 mg.dl(-1)), and the haemoglobin concentration fell to 78% (141 g.l(-1) to 109 g.l(-1)). The overall correlation coefficient (r) for changes in antithrombin and haemoglobin concentrations was 0.76. The results indicate that most of the decrease in concentration of antithrombin during cardiac surgery is a consequence of cardiopulmonary bypass and is due to haemodilution. This data demonstrates that the percentage decrease in haemoglobin concentration can be used to estimate the percentage decrease in antithrombin concentration that occurs during cardiac surgery, if blood products that might effect the results are not administered between measurements.

Antithrombin III↗
PubMed2002

Comparison of low ionic diluents for use with the Diamed antiglobulin gel test.

Microtube column systems, although widely used in transfusion serology for the detection of red cell antibodies, may not detect weak Fy(a), Jk(a), S and K antibodies. A number of low ionic diluents are used to shorten the incubation time required for red cell antibody detection in the antiglobulin test. However, there are no published reports to show whether these low ionic diluents vary in their ability to detect red cell antibodies using microcolumn detection systems. Three low ionic diluents, Diamed ID-CellStab, Diamed ID-Diluent2 and an in-house produced low ionic strength solution (LISS), were assessed using the Diamed-ID LISS/Coombs microtube column system (in accordance with the manufacturer's instructions), to ascertain whether the choice of diluent influences red cell antibody detection. Two hundred and seventy patient samples were screened for red cell antibodies. The reaction strength was increased in 50% of the samples with detectable red cell antibodies using LISS as the diluent compared with ID-CellStab. Of the 51 red cell antibodies directed against Rhesus, Duffy, Kidd or Kell antigens, 21% reacted more strongly in LISS compared with Diamed ID-CellStab with a difference in grading of > or =1. Minimal disparity was found between ID-Diluent2 and LISS. Biochemical analysis of pH, osmolality, sodium, potassium and phosphate were comparable for ID-CellStab, ID-Diluent2 and LISS. Measurement of conductivity in each low ionic diluent was performed as a measure of ionic strength in the final reactant mix, as the same amount of low ionic diluent was used for each test. The conductivity was 3 x 5 mS cm for LISS and ID-Diluent2, and 5 x 8 mS cm for ID-CellStab; the acceptable range being 3 x 7 +/- 0 x 3 mS cm as cited in the Guidelines for the Blood Transfusion Services in the United Kingdom. This evaluation suggests that ID-CellStab is a suboptimal low ionic diluent for red cell antibody detection using Diamed-ID LISS/Coombs gel cards. The poorer performance of ID-CellStab compared with LISS may be explained by its higher ionic strength.

Antibodies↗
PubMed2002

Gene frequencies of human platelet antigens 1-5 in indigenous Australians in Western Australia.

The frequencies of human platelet antigen (HPA) systems vary between different racial groups; however, HPA frequency data for some racial groups are still incomplete. We report the distribution of HPA 1-5 systems in Australian Aborigines from a remote community in the north-west of Australia and compare our findings with HPA observed in a Western Australian blood donor population. Using a polymerase chain reaction (PCR) with sequence-specific primers, 185 indigenous Australians and 1000 Western Australian blood donors were genotyped for each of the HPA 1-5 systems. Comparison of gene frequencies of alleles from HPA-1, -2, -3 and -5 systems showed significant differences between Aboriginal people and Western Australian blood donors (P < 0.001). In particular, the frequency of HPA-3b (0.068) in the Australian Aboriginals, from this study, was one of the lowest reported, whilst the frequency of HPA-5b (0.246) was one of the highest for this allele. Gene frequencies were similar to those reported for central Australian Aborigines but with no other ethnic group. In conclusion, this study confirms significant differences in HPA distributions between indigenous Australians, Australian blood donors and other racial groups. These results indicate a higher potential risk of alloimmunization to HPA-1, -2 and -3 in Australian Aborigines receiving transfusion therapy from a Caucasian blood donor population, thereby having practical implications for transfusion and pregnancy risks in people of Aboriginal origin.

Antigens, Human Platelet↗
PubMed2001

Factor V(LEIDEN) and cardiopulmonary bypass: investigation of haemostatic parameters and the effect of aprotinin using an ex vivo model.

It has been suggested that aprotinin results in significantly increased risk for perioperative thrombotic complications in patients with Factor V(LEIDEN) (F5L) due to its ability to competitively inhibit activated protein C (APC) function in vitro. No clinical studies have been performed to assess the effect of aprotinin on APC function of F5L in vivo. We developed an ex vivo model to mimic the effects of cardiopulmonary bypass with the exclusion of the patient in order to assess APC function. Blood from normal (n = 2) and F5L heterozygous donors (n = 2) was treated with aprotinin or placebo (saline). The blood was heparinized, added to the prime and circulated at 2 l/min through a modified cardiopulmonary bypass circuit. After 60 min of circulation, the heparin was neutralized with protamine sulfate. Blood samples, drawn at specific time points, were analysed for APC ratio. Results showed a decrease in APC ratio for both F5L and normal bloods with the addition of aprotinin (18% and 40%, respectively). APC ratios also decreased with the commencement of extracorporeal circulation for all bloods, resulting in an APC ratio of 1.35 in normal placebo-treated blood and 0.67 in F5L placebo-treated blood. The combined effect of aprotinin and extracorporeal circulation resulted in APC ratios of 0.90 for normal blood and 0.63 for F5L blood, corresponding to a severe dysfunction of APC intraoperatively (reference range 1.9-4.0). The data from this model predict an increased risk of perioperative thrombosis due to inhibition of APC function in cardiac surgical patients heterozygous for the F5L mutation. Aprotinin further compounds the severity of APC dysfunction, though the effect is more severe in normal blood. The ex vivo model employed was an effective tool for the investigation of the haemostatic effect of aprotinin. This model may be exploited for other applications such as the investigation of novel or emerging haemostatic agents prior to clinical trial.

Aprotinin↗
PubMed2000

Detection of massive transplacental haemorrhage by flow cytometry.

Flow cytometry has been shown to be a more accurate and sensitive method than the Kleihauer-Betke test for the measurement of feto-maternal haemorrhage in Rh(D) incompatibility. This report describes the successful use of flow cytometry to detect and monitor the management of a massive transplacental haemorrhage (105 ml) of fetal Rh(D) positive cells in a Rh(D) negative woman. The report highlights the accuracy and reproducibility of the test and the stability of a blood sample when transferred 596 kilometres to a central testing facility.

Adolescent↗
PubMed2000

HPA-1, 3, 5 genotyping to establish a typed platelet donor panel.

Platelet antigen typing of blood donors is not routinely performed. Usually, ABO-matched platelets are transfused. In situations where the recipient has a human platelet-associated (HPA) antibody resulting in refractoriness to platelet transfusions, post-transfusion purpura or neonatal alloimmune thrombocytopenia, HPA-typed platelets may be required. Having a panel of HPA-typed donors would be helpful. This study utilised PCR-RFLP and PCR-SSP methods to determine the HPA-1, 3, 5 genotypes of 1,000 blood donors to establish a panel of HPA homozygous donors who could donate platelets for patients with anti-HPA-antibodies. The study demonstrates the HPA genotype frequencies in a Western Australian blood donor population and has identified donors who are homozygous for the "aa" and "bb" genotypes for HPA-1, 3 and 5. The Australian Red Cross Blood Service-NW Region can now use these data to develop a panel of HPA-1, 3 and 5 "aa" and "bb" homozygous platelet donors, which can be accessed for patients with HPA antibodies requiring platelet transfusion.

Antigens, Human Platelet↗
PubMed1998

White cells in fresh-frozen plasma: evaluation of a new white cell-reduction filter.

BACKGROUND: Fresh-frozen plasma (FFP) has generally been regarded as an acellular component. Recently, viable lymphocytes have been detected in this component and the question of irradiation of FFP for certain patients has been raised. Whether the numbers of white cells (WBCs) in FFP are sufficient to require WBC-reduction of acellular components for patients receiving WBC-reduced cellular components has not been determined. WBC numbers in FFP were examined, and the performance of a new commercial WBC-reduction filter for FFP was assessed. STUDY DESIGN AND METHODS: WBC numbers in plasma processed for use as FFP and in thawed FFP were counted before and after WBC-reduction filtration by the use of flow cytometry Fast and slow filtration was used to simulate laboratory and bedside filtration, respectively. Three different methods for plasma harvesting (soft-spin, hard-spin, and second-spin methods) were assessed. The filter capacity was also examined. RESULTS: The numbers of WBCs in plasma covered a three-log10 range (soft-spin method, 0.04-3.6 x 10(6); hard-spin method, 0.47-45.4 x 10(6); second-spin method, 0.4-37.2 x 10(6)). For the hard-spin and second-spin methods which produced the greatest plasma yields, 92 percent and 85.7 percent of bags, respectively, had counts >1 x 10(6) and 43 percent (hard-spin method) and 45.7 percent (second-spin method) had counts >5 x 10(6). There was no significant difference between the counts obtained in plasma and thawed FFP. The filter reduced WBC numbers to <1 x 10(5) in all but 3 of 49 bags. In the remaining three, there were <2 x 10(5) WBCs. Five bags of plasma could be processed effectively through each filter. CONCLUSION: FFP may contain WBC numbers above the threshold at which the use of WBC-reduction filters for cellular components in some patients is necessary. Confirmation of these findings and similar investigations on plasma prepared by other methods may help in defining a role for the use of WBC-reduction filters for FFP

Blood Component Removal↗
PubMed1998

The effect of minimum luminal nutrition on mucosal cellularity and immunity of the gut.

Many catabolic patients can only consume small volumes of enteral nutrients. The aim of this study was to evaluate markers of cellularity and immunity in the small intestine of rats randomized to receive 6 days of parenteral nutrition, 25% enteral and 75% parenteral nutrition (i.e. minimum luminal nutrition) or enteral nutrition. The same glutamine-enriched solution was used for both parenteral and enteral nutrition. Enteral nutrition was associated with the least amount of jejunal atrophy (P<0.01), with the results from the minimum luminal nutrition group approximating those of the parenteral nutrition group. Parenteral nutrition was associated with the greatest number of CD2+ cells (P< 0.05) and the lowest CD4/CD8 cell ratio (P< 0.01) in the jejunal mucosa. In essence, we failed to demonstrate that there are any appreciable benefits associated with the enteral consumption of 25% of a nutrient load.

Animals↗