When and why is blood crossmatched? A prospective survey of transfusion laboratory practice in two regions in the north of England.

BACKGROUND AND OBJECTIVES: This study was undertaken to provide data relating to the timing of laboratory crossmatch procedures, and the source of requests for out of hours crossmatch, to support interpretation of error reports originating in the transfusion laboratory, received by the Serious Hazards of Transfusion haemovigilance scheme. MATERIALS AND METHODS: Data on the timing, origin and urgency of all crossmatch requests were collected in 34 hospitals in northern England over a 7-day period in 2008. Additional data on clinical urgency were collected on crossmatches that were performed out of hours. RESULTS: Data were obtained on 2423 crossmatches, including 610 (25.2%) performed outside core hours. 30.3% of out of hours crossmatch requests were for transfusions that were set up outside 4 h of completion of the crossmatch. CONCLUSION: 2008 Serious Hazards of Transfusion data showed that 29/39 (74%) of laboratory errors resulting in 'wrong blood' occurred out of hours whilst our audit shows that only 25% of crossmatch requests are made in that time period, suggesting that crossmatching performed outside core hours carries increased risks. The reason for increased risk of error needs further research, but 25 laboratories had only one member of staff working out of hours, often combining blood transfusion, haematology and coagulation work. A total of 25% of out of hours requests were not clinically urgent. Hospitals should develop policies to define indications for out of hours transfusion testing, empower laboratory staff to challenge inappropriate requests and ensure that staffing and expertise is appropriate for the workload at all times.

Current uses of transfusion administration sets: a cause for concern?

There is potential for inappropriate use of transfusion administration sets when used in combination with modern infusion pumps with consequences for patient safety. The aims of our study were to (i) establish if the design and testing of transfusion sets specified in International Standard ISO 1135-4 are adequate for their current applications, (ii) identify if infusion pumps currently supplied in the UK for blood component administration are suitable for this purpose and (iii) determine the additional control measures needed to be applied by manufacturers and users to ensure patient safety. Keyword literature search was carried out to review and correlate important transfusion parameters with resultant adverse effects. Units for occlusion pressure, flow rate and haemolysis were standardised for ease of comparison. A sample of transfusion set instructions for use was reviewed. Principal suppliers of infusion pumps to the UK market were surveyed to identify those sold for blood transfusion, their recommended operating parameters and compatible transfusion sets. Previous work showed clinically unacceptable haemolysis at pressures above 40 kPa. Modern infusion pumps operate under negative pressures of up to 210 kPa. ISO 1135-4 design and test requirements do not match this performance and in particular omit testing under negative pressure. Transfusion sets surveyed did not indicate flow or pressure restrictions or specify the blood components with which they had been validated. ISO 1135-4 requires updating and has been initiated. Meanwhile, recommendations are made for transfusion set manufacturers concerning pressure limitations and restrictions on blood component type and for users concerning purchase, configuration and validation of infusion pumps and disposables.

Massive transfusion--evaluation of current clinical practice and outcome in two large teaching hospital trusts in Northern England.

BACKGROUND AND OBJECTIVES: Although numerous guidelines exist for the management of massive blood loss, there have been few data confirming whether these guidelines are observed in practice or whether compliance results in improved outcome. We have performed a retrospective audit of cases of massive transfusion in two major teaching hospital trusts in Northern England to investigate the use of blood components and patient outcome. MATERIALS AND METHODS: The massive transfusion population was electronically derived from a list of all blood component transfusions in 2006. Data from the intensive care and patient administration databases established hospital outcome. Factors independently predictive of survival were identified by logistic regression. Data are presented as medians and interquartile ranges. Odds ratios (OR) are given with 95% confidence intervals. RESULTS: Two hundred and four patients had a massive transfusion. Although only 1.3% of all transfused patients, the massive transfusion group used 10% of the total blood products. Their mortality rate was 34%. Factors independently predictive of survival were: a ratio of fresh frozen plasma: red blood cells > 1.1, OR 7.22 (1.95-26.68), and elective surgery, OR 4.56 (1.88-11.05). Factors independently predictive of death were: age (per year), OR 0.97 (0.95-0.99), liver disease, OR 0.25 (0.09-0.70), male gender, OR 0.41 (0.19-0.89), vascular surgery, OR 0.34 (0.12-0.96) and number of adult packs of platelets transfused, OR 0.69 (0.57-0.83). CONCLUSION: Massive transfusion occurs rarely but has a high mortality and requires a disproportionate amount of blood products. An increased ratio of fresh frozen plasma to red blood cells was associated with improved outcome.

Detection and quantitation of the CBFbeta/MYH11 transcripts associated with the inv(16) in presentation and follow-up samples from patients with AML.

We have developed a competitor-based RT-PCR technique which will detect and quantitate the CBFbeta/MYH11 transcripts associated with inv(16)(q22;p13) and have used it to study presentation and follow-up samples of acute myeloid leukaemia (AML). The levels of the leukaemia-specific transcripts are expressed as a ratio to a ubiquitously expressed mRNA species (Abl) which controls for RNA degradation. This technique has been applied to 75 consecutive patients presenting with either de novo AML or tMDS; 6/75 patients analysed were positive for the inv(16), all were confirmed by conventional cytogenetics. The inv(16) has a strong association with M4Eo, but we found only 2/6-positive patients to have this diagnosis (two patients with M2, one patient M1 and one patient had MDS). At presentation the levels of CBFbeta/MYH11 transcripts were 0.1-10/Abl transcript (mean 3.3/Abl transcript). Seventeen follow-up samples were available on 5/6 of these patients, and on two further patients in whom stored material was available. Following the first cycle of chemotherapy the level of transcripts was at least 10(-2) lower (0.1-10 x 10(-2)/abl transcript) than their presentation sample. Subsequent samples on these patients when in remission gave transcript levels in the range (1.0 x 10(-4) - 2 x 10(-3)/abl transcript), and three long-term follow-up samples were negative. We have developed a quantitative test which opens the possibility of predicting relapse by detecting changes in the numbers of leukaemia-specific transcripts.

Leucodepletion of blood products by filtration.

The leucocytes present in red cell and platelet components have been implicated in several important immunological and infective complications of blood transfusion. Recent developments in blood filtration technology allow the production of leucodepleted blood products (residual leucocytes < 5 x 10(6) per transfused unit) in the laboratory or at the bedside with the potential to prevent these adverse effects. Quality assurance remains an important problem, particularly for bedside filtration. Prestorage filtration may have significant advantages for red cell and platelet production. There is strong clinical evidence that 3 log10 leucodepletion prevents or delays febrile reactions in patients receiving multiple red cell transfusions and can reduce cytomegalovirus transmission. Leucodepletion to prevent HLA alloimmunisation, platelet refractoriness and febrile reactions in patients receiving red cell and platelet support remains controversial. Transfused leucocytes induce 'immunosuppressive' changes in the recipient, but recent studies cast doubt on the association with cancer recurrence after surgery. However, leucodepleted blood may reduce the incidence of postoperative infection. Leucodepletion by filtration is expensive and there is a requirement for well-designed prospective clinical studies focusing on appropriate filtration technology (and alternatives), clinical outcome and cost-effectiveness.

Changes in plasma fibronectin during allogeneic bone marrow transplantation.

Plasma fibronectin concentrations were measured serially in nine patients undergoing allogeneic bone marrow transplantation. Concentrations were reduced by conditioning treatment and episodes of bacterial infection. Acute graft versus host disease may exacerbate or prolong this process. Reduced plasma fibronectin concentrations impair the function of the mononuclear phagocyte system and the maintenance of capillary endothelial integrity and may thus contribute to the morbidity and mortality in patients undergoing bone marrow transplantation.

Changes in plasma beta 2 microglobulin concentrations after allogeneic bone marrow transplantation.

Plasma concentrations of beta 2 microglobulin (B2M), the light chain of the class I major histocompatibility complex, were measured serially in 26 patients undergoing allogeneic bone marrow transplantation (BMT). The concentrations fell after conditioning treatment, and recovered when the marrow was transplanted. Bacterial infection did not influence B2M concentration, but nine of 22 episodes of acute graft versus host disease were associated with raised concentrations. Increased plasma B2M concentrations were also a feature of eight episodes of chronic graft versus host disease, and these fell after treatment. Reactivation of herpes simplex, varicella zoster, or cytomegalovirus infections were also accompanied by raised B2M concentrations. Three patients with cytomegalovirus pneumonitis had high concentrations of plasma B2M, the rise starting between five and 22 days before onset of symptoms. Although it is non-specific, serial measurement of plasma B2M in patients undergoing BMT may be clinically useful in monitoring chronic graft versus host disease.

Cell surface expression of beta 2-microglobulin (beta 2m) correlates with stages of differentiation in B cell tumours.

Cell surface beta 2-microglobulin (beta 2m) densities of malignant B cells were determined by enzyme immunoassay in 97 cases of immunologically defined lymphoproliferative disease. Absolute beta 2m densities were found to depend on disease category with the lowest levels found on cells from chronic lymphocytic leukaemia (mean = 5.6 ng/10(6) cells, n = 27); atypical chronic lymphocytic leukaemia (mean = 5.9 ng/10(6) cells, n = 8); and prolymphocytoid chronic lymphocytic leukaemia variant (mean = 6.0 ng/10(6) cells, n = 16). beta 2m densities for B non-Hodgkin's lymphoma (n = 14) and B prolymphocytic leukaemia (n = 17) cases were 8.1 and 10.0 ng/10(6) cells, respectively, and the highest densities were found on cells from "late-B cell" tumours (mean = 14.3 ng/10(6) cells). Plasma cells from cases of Ig secreting tumours expressed unexpectedly low beta 2m densities (mean = 9.3 ng/10(6) cells; n = 6).

DNA Genotypic Conservation During Phenotypic Switch from T-cell Acute Lymphoblastic Leukaemia to Acute Myeloblastic Leukaemia.

This communication reports a case of T-cell acute lymphoblastic leukaemia (T-ALL) which, after treatment and remission induction, relapsed 17 months after apparent disease-free remission as acute myeloblastic leukaemia (AML). Extensive immunophenotypic, analysis an initial presentation revealed a typical T-ALL phenotype (HLA-Dr(-), TdT(+), CD2(+), CD3(+), CD4(-), CD5(+), CD7(+), CD8(-), CD19(-), CD13/33(-)) that was unusual in that the majority of blasts expressed membrane TCR γδ chains but not TCR αß chains. Similarly, the morphological (Auer rods +), cytochemical (MPO(+) and SBB(+)) and phenotypic characteristics at relapse were unequivocably consistent with a diagnosis of AML. In contrast to previous case studies of "phenotypic switch" or "metachronous bilineal leukaernia", Southern blot analysiis of TCR and Ig gene rearrangements at presentation and relapse were able, because of an unusual genotypic pattern (TCR ß +, TCR γ +, TCR δ + and JH), to confirm the common clonal origin of the two leukaemias. It is suggested that the transition from T-ALL to AML may not be a "random" phenomenon but may rather reflect subclonal domination by mycloid blasts with relative drug resistance (i.e. synchronous bilineal differentiation with an undetectable myeloid component), or therapy-induced alterations in the balance of (myelosuppressive) factors.

Persistent clonal expansions of CD3+TCR gamma delta+ and CD3+TCR alpha beta+CD4-CD8- lymphocytes associated with neutropenia.

This communication reports the clinical and cellular features of five elderly female patients with persistent moderate to severe neutropenia and concomitant relative expansions of CD3+TCR gamma delta+ (n = 4) or CD3+TCR alpha beta+CD4-CD8- (n = 1) lymphocyte populations. In clinical terms, severe neutropenia was the main contributing factor to patient symptoms although two additionally had long-standing histories of rheumatoid arthritis. The absolute lymphocyte counts did not exceed the normal upper limit in these patients, and morphologically the lymphocytes were not typically of large granular lymphocyte (LGL) type although LGL-associated BLT-esterase staining was consistently increased. Expression of NK-associated (NKa) membrane determinants (CD16, CD56 and CD57) were variable but there was an apparent correlation between weak membrane CD8 and CD16 expression. DNA genotypic studies confirmed that the four CD3+TCR gamma delta+ cases were clonal in nature and add further support to an emerging impression that expansions of these lymphocyte subpopulations may frequently be clinically associated with autoimmune phenomena in general and neutropenia in particular.

Anaemia in children following cardiac transplantation: treatment with low dose human recombinant erythropoietin.

Anaemia is common in children following cardiac transplantation. In a series of 5 children with anaemia beyond the immediate post-operative period one had a hypochromic, microcytic anaemia which corrected with oral iron. The other four had normochromic, normocytic anaemias unresponsive to iron or folate supplementation and associated with inappropriately low levels of erythropoietin. Subcutaneous administration of low dose human recombinant erythropoietin to these four patients resulted in correction of their anaemia. Our findings suggest that erythropoietin deficiency is an important cause of anaemia in transplant recipients and should be sought in cases of anaemia refractory to conventional haematinic therapy. In cases of proven erythropoietin deficiency, treatment with erythropoietin is effective, acceptable to patients and preferable to repeated blood transfusion.

Re-establishment of erythropoietin responsiveness in end-stage renal failure following renal transplantation.

Re-establishment of erythropoietin (EPO) secretion following renal transplantation is poorly understood. The development of sensitive EPO radioimmunoassay has enabled further study of this phenomenon. Forty-one adult patients were studied during the first 16 weeks following renal transplantation. Twenty six received cyclosporin monotherapy and 15 also received prednisolone and azathioprine. Serum creatinine, haemoglobin (Hb), ferritin and EPO were assayed pre-operatively, daily for 1 week, weekly for 1 month, and fortnightly to 16 weeks. An expected EPO value, for any Hb level, was derived by linear regression analysis in 144 patients with iron deficiency anemia. An observed to expected ratio (O/E) was calculated, a value of 1.0 implying appropriate responsiveness. Hb increased from 8.6 +/- 2.0 (SD) to 12.3 +/- 2.1 g/dl (p < 0.001) over 16 weeks, an increase unaffected by ferritin status. Mean EPO concentration increased during the first week with a peak at day 4 (22.1 +/- 13.3 to 44.6 +/- 40.0 mu/ml, p < 0.05), a change apparent only in patients with immediate graft function (24 cases). There was no correlation between EPO and Hb pre-operatively; however a significant inverse relationship was established by week 16 (r = -0.404, p < 0.02). The median O/E ratio (0.22) at baseline increased progressively to 1.0 at 16 weeks (p < 0.001); ratios were significantly greater in the immediate versus delayed function group throughout (p < 0.05). In the former group an O/E ratio of 1.0 was reached at 10 weeks when mean serum creatinine was 142 +/- 48 mumol/l. Patients with poor ongoing renal function (9 cases, serum creatinine > 250 mumol/l at 16 weeks) had impaired Hb recovery (10.1 +/- 1.6 vs 12.7 +/- 2.0 g/dl at 16 weeks, p < 0.05). EPO values were not different in those patients but median O/E ratios were significantly depressed (p < 0.05) throughout, the maximum O/E ratio being 0.75. Recovery of renal function is accompanied by a beneficial Hb response driven by EPO synthesis in the transplant. The O/E ratio provides a useful index to assess EPO responsiveness. Appropriate secretion was achieved during the first 4 months and optimized by immediate and satisfactory graft function.

Postoperative autologous transfusion in cardiac surgery. A prospective, randomised study.

To investigate the safety and efficacy of postoperative autologous blood transfusion (AT) using the Shiley hardshell venous reservoir, a prospective, randomised, controlled study was carried out in two matched groups of twenty patients undergoing elective coronary artery bypass surgery. The mean volume of shed mediastinal blood reinfused in the first 6 h postoperatively was 371.7 +/- 63.23 ml. Use of homologous blood was reduced from 760.5 +/- 108.37 ml in the control patients to 466.25 +/- 87.44 ml in the AT patients, a reduction of 38.7% (p less than 0.05). There was no statistically significant difference in the clinical outcome, overall blood loss, use of platelets, fresh frozen plasma and colloids, haematological indices, renal and hepatic functions, or clotting mechanism, although there was a reduction in the fibrinogen level in the patients who received AT (p less than 0.05). Mediastinal blood did not clot and was defibrinogenated. It contained significant levels of haemoglobin (8.175 +/- 0.506 g/dl), platelets (96.55 +/- 10.39 per mm3 10(3)), protein (42.5 +/- 1.13 g/l), calcium (2.385 +/- 0.054 mmol/l) and was well oxygenated (PO2 = 20.46 +/- 0.81 kPa). No patients developed bacteraemia or had any AT-related infections. We conclude that postoperative autologous transfusion using the Shiley hardshell venous reservoir is a safe and efficient method for reducing postoperative homologous blood requirement after coronary artery bypass surgery.

Haemochromatosis: a time for guidelines?

Hereditary haemochromatosis is an autosomal recessive metabolic abnormality which causes excessive absorption of dietary iron. Iron accumulation leads to potentially fatal damage to organs such as the heart, liver and pancreas. Normal life expectancy can be restored simply by therapeutic venesection. Discovery of the gene, HFE, has rekindled interest in pathogenesis, management and screening strategies.

American fresh frozen plasma for neonates and children.

From the spring of 2004 the United Kingdom Blood Services have been importing fresh frozen plasma from United States donors for all neonates and children born after 1 January 1996. The decision to mandate the use of American plasma in this age group was taken by the Department of Health in 2002 as part of its precautionary approach to the risk of transfusion transmitted variant Creutzfeldt-Jakob disease. In this article we explain the background to this decision and explore some of the implications it raises for clinical practice.

Pernicious anaemia and hypogammaglobulinaemia in a patient with severe infantile kyphoscoliosis.

A 27-year-old man with severe infantile kyphoscoliosis suffered from recurrent respiratory tract infections during childhood and early adult life. He deteriorated and was found to have pernicious anaemia and common variable immunodeficiency with hypogammaglobulinaemia and impairment of cell-mediated immunity. Marked clinical improvement has followed the institution of effective gamma-globulin replacement.