RBC alloantibody prevalence and specificity in a Western Norwegian tertiary hospital.

BACKGROUND AND OBJECTIVE: Although several studies focus on red blood cell (RBC) alloantibody distribution in selected patient populations, few address the specificity and frequency in all relevant groups. This study reports alloantibody frequency, distribution and the relationship to age and gender in blood donors, pregnant women and potential recipients of blood products. METHODS: This historical cohort study included 55 462 consecutive antibody screening tests from a tertiary Western Norwegian Hospital. Descriptive statistics were performed, and the results were compared with the literature. RESULTS: The detection and immunisation frequency for the whole cohort were 0·39 and 0·51%, respectively, whereas the RBC alloantibody prevalence was 0·73%. The most frequent RBC alloantibodies were anti-E (20·1%), anti-M (18·7%), anti-K (9·8%), anti-D (8·9%) and anti-Fy(a) (7·0%). In pregnant women, the most frequent RBC alloantibodies were anti-M, anti-D and anti-Le(a) (20·8, 18·9 and 18·9%, respectively), whereas there was no anti-K detected. Anti-E and anti-M were the dominating RBC alloantibodies in the pre-transfusion testing of in-hospital patients (24·1 and 17·1%, respectively). Eighteen (9·2%) persons in the total cohort had two RBC alloantibodies, six persons had three alloantibodies, and two persons had four alloantibodies. Rh and K typing to prevent future immunisations was only performed in 21·0% of the individuals who presented with a new alloantibody; despite that, 50·5% of the detected alloantibodies had such specificities. CONCLUSIONS: The immunisation frequency and the level of anti-K are low compared to national and international studies. Rh and K phenotype-matched blood transfusions might be a feasible future strategy to further decrease RBC alloantibodies.

Massive transfusion: changing practice in a single Norwegian centre 2002-2015.

OBJECTIVES: To describe the change in massive transfusion (MT) practice in a single Norwegian centre throughout the period 2002-2015. BACKGROUND: MT support for traumatic haemorrhage has changed since the mid-2000s. However, life-threatening haemorrhage may occur in other clinical specialties. In 2007, Haukeland University Hospital (HUS) introduced a universal MT programme including education, Acute Transfusion Packages (ATPs) and thromboelastography. METHODS/MATERIALS: A retrospective review was performed of all MT episodes defined as ≥10 red cell concentrates (RCC) in 24 h. Episodes were identified using the laboratory information system. Patient records were reviewed manually for demographics, transfusion indication, haemostatic drugs and mortality. The ATPs contained six units RCC, six units Octaplas and two platelet concentrates (four buffy coats/apheresis in platelet additive solution (PAS)). RESULTS: A total of 410 episodes were identified in 410 patients. The mean patient age was 60 years (9-94), with a male predominance (64%); 87·1% of MT episodes were in support of surgery (cardiac services 42·7%; trauma 17·6%), and 29·8% of MTs involved platelet inhibitors, with 82·6% of these undergoing cardiac procedures. MT accounted for 2·8% of all RCCs and 3·4% of platelets issued. The mean ratio of blood components RCC: plasma: platelets changed from 1·0 : 0·37 : 0·39 in 2002-2006 (n = 149) to 1·0 : 0·79 : 0·85 in 2008-2015 (n = 241, P < 0·001). A sub-analysis showed that cardiac specialities used proportionally more plasma and platelets. CONCLUSION: The MT programme changed transfusion practice, resulting in greater use of plasma and platelets. MT was primarily used in major surgery. The practice in cardiac surgery may reflect changes in antiplatelet medication.

Thromboelastography may predict risk of grade 2 bleeding in thrombocytopenic patients.

BACKGROUND AND OBJECTIVES: Platelet count is used as a prophylactic platelet transfusion trigger, although evidence suggests that it is a poor predictor of bleeding. Thus, alternative tests are required. The primary objective of this study was to compare thromboelastography (TEG) parameters on days with and without bleeding symptoms. The secondary objectives were to investigate the relationship between TEG parameters and haematological variables, fever, C-reactive protein (CRP) and platelet transfusion. MATERIALS AND METHODS: This is a prospective, observational pilot study of 13 thrombocytopenic, haemato-oncologic patients, over 17 cycles of chemotherapy. Bleeding assessment was performed daily together with a total platelet count (TPC), reticulated platelet per cent (RPP) and count (RPC), haemoglobin, mean platelet volume, white blood cell count (WBC), CRP and temperature. TEG analyses were performed on weekdays. RESULTS: TEG alpha angle was significantly lower on days with World Health Organization (WHO) grade 2 bleeding than on days without bleeding. Haematologic variables, CRP and platelet transfusion the previous day were associated with the outcome of TEG analysis, but fever was not. CONCLUSION: We found a highly significant correlation between the TEG alpha angle and WHO grade 2 bleeding. This finding suggests that fibrinogen-platelet interactions may affect the bleeding risk in thrombocytopenic patients.

A prospective observational study on effects of fever on red cell transfusion outcome.

The effects of fever on red cell transfusions are not well documented. In this pilot study, we have compared the outcome of red-blood-cell transfusions in haematologic patients with and without fever. The results indicate that haemoglobin increment per unit is significantly lower in febrile patients receiving red cell transfusions than in patients without fever. These findings are in line with earlier findings in preclinical studies. Larger studies are necessary to confirm our results, and laboratory studies should be conducted to investigate the underlying mechanisms.

Experiences with semi-routine production of riboflavin and UV-B pathogen-inactivated platelet concentrates in three blood centres.

BACKGROUND: For a clinical platelet (PLT) transfusion trial conducted in three countries, the production of PLT concentrates (PCs) that were pathogen inactivated with the Mirasol technology was set up and validated. While the Mirasol procedure is applied to an established PLT product, the PLT processing procedure still had to be modified to ensure a treated PC was of sufficient quality. Further, the effect of simulated transport conditions and the effect of ambient light on Mirasol-treated PCs was determined. STUDY DESIGN AND METHODS: Platelet concentrates in plasma were made from pooled buffy coats followed by Mirasol treatment. To mimic transport conditions, units were left unagitated for 6 h at room temperature. To mimic ambient light exposure, units were held unagitated for 4 h in direct fluorescent tube light. RESULTS: Measures had to be taken to allow 7-day storage of treated concentrates. In one site, PCs made from five buffy coats with >450 × 109 PLTs were removed from inventory. Another site went from five to four buffy coats per pool. Interruption of agitation for 6 h on day 3 did not induce meaningful changes in in vitro measures, even when stored up to 7 days. Exposure to ambient light for 4 h, either on day 3 or 6, had no effect on in vitro measures. CONCLUSION: The Mirasol pathogen inactivation process can be implemented in routine, but changes to current PLT processing methods might be needed. Transport conditions and 4-h-long ambient light exposure have no negative effect on the in vitro quality of Mirasol-treated PCs.

Implementing a patient blood management program in Norway: Where to start?

Norway has recently established a working group to implement a national patient blood management (PBM) program. Although benchmarking regarding blood usage is challenging in Norway due to legal barriers, a survey was sent to different hospitals to identify possible areas to be prioritized in the first phase of the PBM program. Among them, optimizing the patient's hemoglobin level before elective surgery and implementing electronic check-lists for the indication of transfusion when ordering blood products are two measures that may have a considerable impact on blood usage. The results of the survey also showed that patients may receive a red blood cell transfusion at hemoglobin levels that are higher than those internationally recommended. Since there are no national guidelines for the use of blood products, agreement regarding hemoglobin thresholds is essential to reduce variation in transfusion practice. To achieve these goals, the transfusion specialist plays a key role in promoting the principles behind the PBM concept at the local hospital.

A prospective, active haemovigilance study with combined cohort analysis of 19,175 transfusions of platelet components prepared with amotosalen-UVA photochemical treatment.

BACKGROUND AND OBJECTIVES: A photochemical treatment process (PCT) utilizing amotosalen and UVA light (INTERCEPT(™) Blood System) has been developed for inactivation of viruses, bacteria, parasites and leucocytes that can contaminate blood components intended for transfusion. The objective of this study was to further characterize the safety profile of INTERCEPT-treated platelet components (PCT-PLT) administered across a broad patient population. MATERIALS AND METHODS: This open-label, observational haemovigilance programme of PCT-PLT transfusions was conducted in 21 centres in 11 countries. All transfusions were monitored for adverse events within 24 h post-transfusion and for serious adverse events (SAEs) up to 7 days post-transfusion. All adverse events were assessed for severity (Grade 0-4), and causal relationship to PCT-PLT transfusion. RESULTS: Over the course of 7 years in the study centres, 4067 patients received 19,175 PCT-PLT transfusions. Adverse events were infrequent, and most were of Grade 1 severity. On a per-transfusion basis, 123 (0.6%) were classified an acute transfusion reaction (ATR) defined as an adverse event related to the transfusion. Among these ATRs, the most common were chills (77, 0.4%) and urticaria (41, 0.2%). Fourteen SAEs were reported, of which 2 were attributed to platelet transfusion (<0.1%). No case of transfusion-related acute lung injury, transfusion-associated graft-versus-host disease, transfusion-transmitted infection or death was attributed to the transfusion of PCT-PLT. CONCLUSION: This longitudinal haemovigilance safety programme to monitor PCT-PLT transfusions demonstrated a low rate of ATRs, and a safety profile consistent with that previously reported for conventional platelet components.

Hyperleukocytosis and leukocytapheresis in acute leukaemias: experience from a single centre and review of the literature of leukocytapheresis in acute myeloid leukaemia.

BACKGROUND: Hyperleukocytosis is usually defined as leukocyte count >100 × 10(9) L(-1) and can be seen in newly diagnosed leukaemias. Hyperleukocytic leukaemia is associated with a risk of organ failure and early death secondary to leukostasis. Mechanical removal of leukocytes by the apheresis technique, leukocytapheresis, is a therapeutic option in these patients. METHODS: During a 16-year period, 16 patients were treated with leukocytapheresis (35 apheresis procedures) for hyperleukocytosis/leukostasis. We present our experience, and in addition we review previous studies of hyperleukocytosis/leukocytapheresis in patients with acute myeloid leukaemia (AML). RESULTS: We used a highly standardised approach for leukocytapheresis in leukaemia patients with hyperleukocytosis. The average leukocytapheresis number for each patient was 2·2 (range 1-6). Median leukocyte count before apheresis was 309 × 10(9) L(-1) (range 104-935); the mean leukocyte count reduction was 71%, corresponding to a mean absolute reduction of 219 × 10(9) L(-1). No serious side effects were seen during or immediately after apheresis. CONCLUSIONS: The data suggest that our standardised technique for leukocytapheresis effectively reduced the peripheral blood leukaemia cell counts. Previous studies in AML also support the conclusion that this is a safe and effective procedure for the treatment of a potentially life-threatening complication, but apheresis should always be combined with early chemotherapy.

Evaluation of noninvasive methods for the estimation of haemoglobin content in red blood cell concentrates.

OBJECTIVES: Red blood cell concentrates (RCCs) are the major blood component transfused to patients. There is a great variability in patient response, depending on both the patient's blood volume and haemoglobin content in the RCC. Standardisation of transfusion practice is needed to improve the prediction of patient outcome. AIM: We hypothesise that labelling of RCCs with haemoglobin content will add possibilities for the standardisation of transfusion practice. METHODS: Data from multiple international transfusion services regarding haemoglobin content and weight or volume of RCC were collected and analysed. RESULTS: We demonstrate a strong and highly significant correlation between haemoglobin content with both weight and volume of the RCCs. A linear regression model was used to assess these relationships, and it demonstrates how haemoglobin content can be estimated for different cell production processes. CONCLUSIONS: We recommend the use of weight or volume of the RCCs as the basis of estimating haemoglobin in the RCC and postulate that this can be used in future studies to explore the effects of a haemoglobin dose-based transfusion system. As the weight - and sometimes the volume - of the blood bag is easily accessible, in contrast to direct haemoglobin measurements from each individual unit, this method is feasible and simple.

A pilot study of the possibility and the feasibility of haemoglobin dosing with red blood cells transfusion.

BACKGROUND AND OBJECTIVES: Red blood cell concentrates (RBCs) are the major blood component transfused. Although the haemoglobin content is variable, the transfusion dose is prescribed as units of red cell concentrates. Thus, by chance, large volume patients may receive a low haemoglobin dose and low volume patients may be transfused with haemoglobin-rich RBCs. The aim of this study was to evaluate whether the haemoglobin increment (grams per litre) in the patient can be predicted from the haemoglobin dose (in grams) transfused, with and without correction for estimated blood volume. If this is true, it may be possible to achieve the predicted transfusion outcome by selecting RBCs for each patient. MATERIALS AND METHODS: Haemodynamically stable patients scheduled for day treatment with transfusion of RBCs were recorded. A total of 52 transfusions episodes, 27 for women and 25 for men, were recorded. Blood volumes were estimated, haemoglobin content in the RBCs was measured before transfusion, and pre- and post-transfusion haemoglobin concentrations were obtained. RESULTS: The haemoglobin content of the RBCs prepared for transfusion showed a wide range, varying from 38.7 g/unit to 69.0 g/unit. There were statistically significant correlations between haemoglobin concentration in the RBCs and haemoglobin increment in patients. CONCLUSION: Post-transfusion increment in circulating haemoglobin can be predicted from the haemoglobin content of transfused cells, but knowledge of the patient's blood volume improves the accuracy of prediction. It may be feasible to select the high haemoglobin content RBC for patients with largest blood volume and vice versa.

Effect of iron supplementation on iron status during the first week after blood donation.

INTRODUCTION: Frequent blood donations may lead to a negative iron balance. Iron depletion may be prevented by iron supplementation after whole blood donations. The aim of this study was to compare the short time changes in iron status after donation in two groups randomized to iron supplementation or no additional iron. A second objective was to evaluate the effect of iron supplementation in donors having HFE-variants compared to HFE wild types. METHODS: Subjects of both genders (199 women, 200 men) were randomised to receive iron supplementation or no additional iron after donation. Iron status, defined by the concentration of haemoglobin, serum ferritin, soluble transferrin receptor, concentration of haemoglobin in reticulocytes (CHr) and percent hypochrome mature red blood cells, was determined at the start of donation and 8 +/- 2 days after donation. HFE genotyping was performed at reappearance. RESULTS: There was a significant difference between the two study groups on all the iron status parameters. CHr was an efficient, early marker of ongoing synthesis of haemoglobin. Heterozygosity for the HFE variants C282Y and H63D had no statistically significant influence on the iron status. The donor's baseline serum ferritin value may be basis for an individual iron supplementation regimen, as donors with serum ferritin >50 microg/l do not seem to utilize the iron supplementation, but prefer endogenous iron to restore the loss of haemoglobin. CONCLUSION: Iron supplementation had a significant positive impact on the restoration of iron status one week after donation.

Monitoring and treatment of anti-D in pregnancy.

Prophylactic anti-D is a very safe and effective therapy for the suppression of anti-D immunization and thus prevention of haemolytic disease of the foetus and newborn. However, migration from countries with low health standards and substantial cuts in public health expenses have increased the incidence of anti-D immunization in many "developed" countries. Therefore, this forum focuses on prenatal monitoring standards and treatment strategies in pregnancies with anti-D alloimmunization. The following questions were addressed, and a response was obtained from 12 centres, mainly from Europe.

Iron status in Norwegian blood donors: comparison of iron status in new blood donors registered in 1993-1997 and in 2005-2006.

BACKGROUND AND OBJECTIVES: The impact of a poor iron status on the difficulties to keep recruitment of new donors at pace with the ongoing increased demand for blood transfusions was studied by comparing the iron status of new donors recruited in 1993-1997 and in 2005-2006. MATERIALS AND METHODS: Iron status was defined by haemoglobin and serum ferritin. Inclusion criteria for approving new donors were haemoglobin >/= 12.5 g/dl for women and >/= 13.5 g/dl for men, and serum ferritin > 15 microg/l for both genders. Data were gathered retrospectively from 943 subjects (55% women) in the 1990 ties and prospectively from 1013 subjects (63% women) 10 years later. RESULTS: In women, there was a significant fall in haemoglobin and serum ferritin mean values from 13.2 to 13.1 g/dl and from 30.9 to 26.9 microg/l, respectively. Rejection due to low haemoglobin was significantly increased from 14% to 24%. In men, there were minor changes that did not affect rejection rates. CONCLUSION: Iron status of women who want to serve as blood donors has deteriorated in the last 10 years, leading to an increased rejection due to haemoglobin below the inclusion criterion for blood donors.

The effect of blood donation frequency on iron status.

INTRODUCTION: The effects of blood donation on iron status in donors without iron supplementation were studied. Analysing interactions between donations and iron status markers may predict these effects. MATERIALS AND METHODS: Haemoglobin (Hb) and serum ferritin were analysed in 893 donors over 1 year. Serum transferrin receptor (sTfR) was measured at the first and last donation. RESULTS: Prolonged intervals prevented decrease in Hb in women and in ferritin for both genders. In women, a high TfR-F index (sTfR/log ferritin) predicted fall in Hb. CONCLUSION: Adjusting the donation intervals is a way to prevent iron deficiency in blood donors.

Monocyte phagocytosis of opsonized Neisseria meningitidis serogroup B.

The chemiluminescence (CL) was examined when peripheral blood monocytes were incubated with opsonized Neisseria meningitidis, serogroup B, serotype 15:P1.16 or serotype 2a:P1.2. The monocytes were separated from a mononuclear cell suspension by an immunomagnetic negative selection technique using magnetic polystyrene microspheres coated with monoclonal antibodies specific for T and B lymphocytes. More than 90% of the lymphocytes were removed, yielding a suspension containing 93% monocytes. Optimal sensitivity for phagocytosis was obtained using 1% serum (10 microliters), 72 bacteria per monocyte cell, and 7.5 min opsonization and incubation time during continuous agitation at 37 degrees C. The CL was amplified by lucigenin. Preliminary experiments suggest that convalescent sera from patients with group B meningococcal disease induced increased CL responses compared to acute sera. Sera from volunteers immunized with an outer membrane complex vaccine from serogroup B, serotype 15:P1.16 or 2a:P1.2 meningococci also induced increased CL activity compared to preimmune sera. No such response was shown when a group B capsular polysaccharide vaccine was given. This response pattern was also demonstrated by a flow cytometric phagocytosis technique (FCM). Internalization of meningococci by monocytes was demonstrated by a FCM quenching technique and by transmission electron microscopy. CL and FCM represent rapid and reproducible methods for the measurement of opsonophagocytosis of meningococci by monocytes and may be performed with minute amounts of sera.

Large-volume leukapheresis yields more viable CD34+ cells and colony-forming units than normal-volume leukapheresis, especially in patients who mobilize low numbers of CD34+ cells.

BACKGROUND: Large-volume leukapheresis (LVL) differs from normal-volume leukapheresis (NVL) by increased blood flow and altered anticoagulation regimen. LVL is now regarded as a safe procedure for collection of peripheral blood progenitor cells (PBPCs), but it is not known whether the procedure will alter CD34+ cell quality or will be useful for patients who mobilize few CD34+ cells into peripheral blood. STUDY DESIGN AND METHODS: The results from 82 LVL and 125 NVL (4.0-5.3 and 2.7-3.5 times the patients' blood volumes processed, respectively) were retrospectively analyzed in altogether 112 consecutive patients with malignant diseases. RESULTS: The LVL yielded significantly more CD34+ cells (4.2 x 10(6) vs. 3.1 x 10(6)/kg, p = 0.006, all patients; and 1.8 x 10(6) vs. 1.3 x 10(6)/kg, p = 0.004, bad mobilizers) and significantly higher colony-forming units (77 x 10(4) vs. 33 x 10(4)/kg; all patients and 33 x 10(4) vs. 20 x 10(4)/kg, p < 0.001, both groups). Significantly fewer leukapheresis procedures were required to obtain 2 x 10(6) CD34+ cells per kg (one vs. two, p = 0.001, all patients; and two vs. three, p = 0.009, bad mobilizers). No significant differences in CD34+ cell viability and time to hematologic recovery were observed between the patients who received PBPCs harvested by NVL and LVL. CONCLUSION: Although a median platelet loss of 36 percent can be expected, LVL can be recommended as the standard apheresis method for PBPC collections in patients with malignant diseases. LVL is particularly useful in patients who mobilize a low number of CD34+ cells into the peripheral blood.

High prevalence of IgE antibodies among blood donors in Sweden and Norway.

BACKGROUND: Reactions after a blood transfusion could be allergic because of passive transfer of immunoglobulin E (IgE) antibodies from allergic donors. AIMS OF THE STUDY: To compare spectrum and prevalence of IgE antibodies in blood donors from Sweden and Norway. METHODS: Using the ImmunoCAP method, serum samples from 1002 blood donors from Sweden and 500 from Norway were analysed for IgE antibodies to common inhalant and food allergens and allergens common in a hospital environment, such as penicilloyl G and latex. RESULTS: As many as 23.6-27.3% of the donors had IgE antibodies to at least one of the 14 allergens tested. Of these 6.8-16.7% had extremely high concentrations, i.e. >35 kU(A)/l corresponding to 100 times the cut-off for a positive allergy test. Most donors were sensitized to pollens, dander and mite but several had very high levels of IgE antibodies to penicilloyl G, latex and peanut. The pattern of sensitizing allergens differed between Sweden and Norway. CONCLUSIONS: High serum levels of IgE antibodies to various allergens are common among blood donors and the degree of sensitization and spectrum of involved allergen varies between geographical regions. Present routines to identify IgE sensitized, potential risk, donors are not satisfactory; the sensitivity of selection procedures is about 25%.

Calcium homeostasis in pregnancy and lactation.

This paper discusses different aspects of calcium homeostasis in pregnancy: the calcium demands of the mother, regulation mechanisms and the risk factors for demineralization. Special care should be paid to patients lying in bed for long periods and patients given heparin prophylaxis. One to two grams of calcium and 400 IU of vitamin D daily should be given orally to patients who are being treated for deep vein thrombosis. In addition, bone density should be checked to detect osteoporosis. The period of heparin prophylaxis must be as short as possible and bed rest must not be unnecessarily prolonged.

Effects of normal platelets on proliferation and constitutive cytokine secretion by human acute myelogenous leukaemia blasts.

The effects of soluble E-selectin, P-selectin and normal platelets on acute myelogenous leukaemia (AM L) blasts were investigated in vitro. We investigated effects on spontaneous and cytokine-dependent blast proliferation, and constitutive blast secretion of different cytokines. The presence of normal platelets during in vitro culture caused a dose-dependent increase in both spontaneous and cytokine-dependent AML blast proliferation. Addition of platelets also increased constitutive blast secretion of Interleukin 1beta (IL1beta ), IL6, GM-CSF and TNFalpha, whereas platelets had no effect on the release of IL1 receptor antagonist. The effects of platelets on constitutive cytokine secretion were also detected when platelets and AML blasts were cultured in different chambers separated by a permeable membrane, and a further enhancement was achieved when blasts and platelets were cultured together. Soluble P-selectin had no effect on constitutive AML blast cytokine secretion or the platelet-induced enhancement of the secretion. However, both soluble E- and P-selectin altered AML blast proliferation for a minority of patients. We conclude that normal platelets can modulate the function of human AML blasts in vitro.