Novel method for determining when a field-collected donor unit is sufficiently full

BACKGROUND

Whole blood (WB) collections can occur downrange for immediate administration. An important aspect of these collections is determining when the unit is sufficiently full. This project tested a novel method for determining when a field collection is complete.

METHODS

The amount of empty space at the top of WB units, destined to become LTOWB or separated into components, that were collected at blood centers or hospitals was measured by holding a WB unit off the ground and placing the top of a piece of string where the donor tubing entered the bag. The string was marked where it intersected the top of the column of blood in the bag and measured from the top. The WB units were also weighed.

RESULTS

A total of 15 different bags, two of which were measured in two different filling volumes, from 15 hospitals or blood centers were measured and weighed. The most commonly used blood bag, Terumo Imuflex SP, had a median string length of 9 mm (range: 2-24 mm) and weighed a median of 565.1 g (range: 524.8-636.7 g).

CONCLUSION

Pieces of string can be precut to the appropriate length depending on the type of bag before a mission where field WB collections might be required and a mark placed on the bag before the collection commences to indicate when the unit is full.

The healthy donor effect and survey participation, becoming a donor and donor career

BACKGROUND

The healthy donor effect (HDE) is a selection bias caused by the health criteria blood donors must meet. It obscures investigations of beneficial/adverse health effects of blood donation and complicates the generalizability of findings from blood donor cohorts. To further characterize the HDE we investigated how self-reported health and lifestyle are associated with becoming a blood donor, lapsing, and donation intensity. Furthermore, we examined differences in mortality based on donor status.

STUDY DESIGN AND METHODS

The Danish National Health Survey was linked to the Scandinavian Donations and Transfusions (SCANDAT) database and Danish register data. Logistic- and normal regression was used to compare baseline characteristics and participation. Poisson regression was used to investigate future donation choices. Donation intensity was explored by the Anderson-Gill model and Poisson regression. Mortality was investigated using Poisson regression.

RESULTS

Blood donors were more likely to participate in the surveys, OR = 2.45 95% confidence interval (2.40-2.49) than non-donors. Among survey participants, better self-reported health and healthier lifestyle were associated with being or becoming a blood donor, donor retention, and to some extent donation intensity, for example, current smoking conveyed lower likelihood of becoming a donor, OR = 0.70 (0.66-0.75). We observed lower mortality for donors and survey participants, respectively, compared with non-participating non-donors.

CONCLUSION

We provide evidence that blood donation is associated with increased likelihood to participate in health surveys, possibly a manifestation of the HDE. Furthermore, becoming a blood donor, donor retention, and donation intensity was associated with better self-reported health and healthier lifestyles.

Hospital red blood cell and platelet supply and utilization from March to December of the first year of the COVID-19 pandemic: The BEST Collaborative Study

Background

At the start of the coronavirus disease 2019 (COVID‐19) pandemic, widespread blood shortages were anticipated. We sought to determine how hospital blood supply and blood utilization were affected by the first wave of COVID‐19.

Study Design and Methods

Weekly red blood cell (RBC) and platelet (PLT) inventory, transfusion, and outdate data were collected from 13 institutions in the United States, Brazil, Canada, and Denmark from March 1st to December 31st of 2020 and 2019. Data from the sites were aligned based on each site's local first peak of COVID‐19 cases, and data from 2020 (pandemic year) were compared with data from the corresponding period in 2019 (pre‐pandemic baseline).

Results

RBC inventories were 3% lower in 2020 than in 2019 (680 vs. 704, p < .001) and 5% fewer RBCs were transfused per week compared to 2019 (477 vs. 501, p < .001). However, during the first COVID‐19 peak, RBC and PLT inventories were higher than normal, as reflected by deviation from par, days on hand, and percent outdated. At this time, 16% fewer inpatient beds were occupied, and 43% fewer surgeries were performed compared to 2019 (p < .001). In contrast to 2019 when there was no correlation, there was, in 2020, significant negative correlations between RBC and PLT days on hand and both percentage occupancy of inpatient beds and percentage of surgeries performed.

Conclusion

During the COVID‐19 pandemic in 2020, RBC and PLT inventories remained adequate. During the first wave of cases, significant decreases in patient care activities were associated with excess RBC and PLT supplies and increased product outdating.

Investigation of circulating DNA integrity after blood collection

Method summary

Concentrations of circulating DNA in blood plasma were compared using NanoDrop, Qubit, quantitative PCR and Bioanalyzer, and DNA integrity was evaluated with the Bioanalyzer according to the time of plasma preparation.

Is tranexamic acid use in patients with a hip fracture safe?

AIMS

To assess the safety of tranexamic acid (TXA) in a large cohort of patients aged over 65 years who have sustained a hip fracture, with a focus on transfusion rates, mortality, and thromboembolic events.

METHODS

This is a consecutive cohort study with prospectively collected registry data. Patients with a hip fracture in the Region of Southern Denmark were included over a two-year time period (2015 to 2017) with the first year constituting a control group. In the second year, perioperative TXA was introduced as an intervention. Outcome was transfusion frequency, 30-day and 90-day mortality, and thromboembolic events. The latter was defined as any diagnosis or death due to arterial or venous thrombosis. The results are presented as relative risk (RR) and hazard ratio (HR) with 95% confidence intervals (CIs).

RESULTS

A total of 3,097 patients were included: 1,558 in the control group and 1,539 in the TXA group.31% (n = 477) of patients had transfusions in the control group compared to 27% (n = 405) in the TXA group yielding an adjusted RR of 0.83 (95% CI 0.75 to 0.91). TXA was not associated with increased 30-day mortality with an adjusted HR of 1.10 (95% CI 0.88 to 1.39) compared to the control group as well as no association with increased risk of 90-day mortality with a per protocol adjusted HR of 1.24 (95% CI 0.93 to 1.66). TXA was associated with a lower risk of thromboembolic events after 30 days (RR 0.63 (95% CI 0.42 to 0.93)) and 90 days (RR 0.72 (95% CI 0.52 to 0.99)). A subanalysis on haemoglobin demonstrated a median 17.7 g/L (interquartile range (IQR) 11.3 to 27.3) decrease in the control group compared to 17.7 g/L (IQR 9.7 to 25.8) in the per protocol TXA group (p = 0.060 on group level difference).

CONCLUSION

TXA use in patients with a hip fracture, was not associated with an increased risk of mortality but was associated with lower transfusion rate and reduced thromboembolic events. Thus, we conclude that it is safe to use TXA in this patient group. Cite this article: Bone Joint J 2021;103-B(3):449-455.

Reduced prevalence of SARS-CoV-2 infection in ABO blood group O

Identification of risk factors for contracting and developing serious illness following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is of paramount interest. Here, we performed a retrospective cohort analysis of all Danish individuals tested for SARS-CoV-2 between 27 February 2020 and 30 July 2020, with a known ABO and RhD blood group, to determine the influence of common blood groups on virus susceptibility. Distribution of blood groups was compared with data from nontested individuals. Participants (29% of whom were male) included 473 654 individuals tested for SARS-CoV-2 using real-time polymerase chain reaction (7422 positive and 466 232 negative) and 2 204 742 nontested individuals, accounting for ∼38% of the total Danish population. Hospitalization and death from COVID-19, age, cardiovascular comorbidities, and job status were also collected for confirmed infected cases. ABO blood groups varied significantly between patients and the reference group, with only 38.41% (95% confidence interval [CI], 37.30-39.50) of the patients belonging to blood group O compared with 41.70% (95% CI, 41.60-41.80) in the controls, corresponding to a relative risk of 0.87 (95% CI, 0.83-0.91) for acquiring COVID-19. This study identifies ABO blood group as a risk factor for SARS-CoV-2 infection but not for hospitalization or death from COVID-19.

Frequent blood donation and offspring birth weight-a next-generation association?

BACKGROUND

The prevalence of iron depletion is high among premenopausal women who donate blood frequently. Studies in nondonor populations indicate that iron deficiency anemia is associated with an increased risk of low birth weight. This prompts concerns that iron deficiency induced by frequent blood donation might impair subsequent fetal development.

STUDY DESIGN AND METHODS

The aim of this study was to assess whether prepregnancy donation intensity affects the birth weight of singletons born at term (gestational week 38 or later) to nulliparous female donors in Denmark. We identified 293,897 first live singleton births to Danish women between 1997 and 2012 with complete information on gestational age, birth weight, child sex, parental age, maternal smoking status during pregnancy, and parental education length and annual income. Linear regression analysis was applied, with birth weight as outcome, number of donations within the 3 years before pregnancy as the explanatory variable, and confounding variables as described.

RESULTS

Birth weight among children of low-intensity donors (n = 22,120) was 12.6 g (95% confidence interval, 6.7-18.6) higher than nondonors (n = 268,253) after controlling for the above-mentioned factors. The higher birth weight among low-intensity donors can be explained by the healthy donor effect. In fully adjusted analyses, birth weight among children of high-intensity donors (n = 3,524) was 20.2 g (95% confidence interval, 5.1-35.3 g) lower compared with low-intensity donors. This reduced birth weight among high-intensity donors compared to low-intensity donors may reflect blood donation-induced iron deficiency.

CONCLUSIONS

Our results show that high prepregnancy donation intensity is inversely associated with birth weight of singletons born at term to nulliparous women.

Epidemiology of chronic red-cell transfusion recipients in Sweden and Denmark-a 10 year follow-up study

BACKGROUND AND OBJECTIVES

Chronic red-cell transfusions may be an indispensable part of patient treatment and may require early intervention to avoid adverse transfusion effects. The population of chronic transfusion recipients including common diagnoses and survival remains poorly characterised. Thus, the objective was to examine the complete range of chronic transfusion recipients, including demographic and patient characteristics and survival.

MATERIALS AND METHODS

All patients who received their first transfusion in Sweden or Denmark from January 1, 2002 to December 31, 2010 were followed up for subsequent transfusion episodes until December 31, 2012. Data on patient characteristics at time of the first and subsequent transfusions were retrieved from the national registers. We estimated the proportion of transfused patients who experienced 20 or more red-cell transfusion episodes (with an episode defined as all transfusions received 4 days or less apart) and characterised this patient population with respect to diagnoses, demographics and survival.

RESULTS

Among 893 117 first time red-cell transfusion recipients, 6157 (0·7%) experienced 20 or more episodes in total. The most common diagnoses among these patients were haematologic malignancies followed by non-haematologic malignancies and non-malignant blood and immune system related diseases. On average, chronically transfused patients had a median survival of less than 1 year following their 20th transfusion episode.

CONCLUSION

This study provides an overview of patient characteristics related to repeat red-cell transfusions and of the amount of red-cell transfusion episodes administered during a 10-year period in two countries. Patients who become chronically transfused suffer from diseases with poor prognosis.

Searching for unknown transfusion-transmitted hepatitis viruses: a binational cohort study of 1.5 million transfused patients

BACKGROUND

Both hepatitis B and C viruses were transmitted through blood transfusion before implementation of donor screening. The existence of additional, yet unknown transfusion transmittable agents causing liver disease could have important public health implications.

METHODS

Analyses were based on the Scandinavian Donations and Transfusions (SCANDAT2) database. Cox regression models were used to estimate the hazard ratio (HR) of developing chronic liver disease in recipients of blood from donors who later developed any chronic liver disease compared to recipients who received blood transfusion from healthy donors. We also studied whether the risk of liver disease was increased in patients who received units from 'high-risk' donors, defined as donors who had a higher than expected occurrence of liver disease amongst their previous recipients. All analyses were stratified before and after 1992 to account for the effect of screening for hepatitis C virus.

RESULTS

A total of 1 482 922 transfused patients were included in the analyses. Analyses showed evidence of transfusion transmission of liver diseases before, but not after the implementation of hepatitis C virus screening in 1992, with HRs for any liver disease of 1.38 [95% confidence interval (CI), 1.30-1.46] and 0.99 (95% CI, 0.91-1.07), before and after 1992, respectively. Similarly, blood components from 'high-risk' donors conferred increased risks before, but not after 1992.

CONCLUSIONS

Our data provide no evidence for transfusion transmission of agents causing liver disease after the implementation of screening for hepatitis B and C, and suggest that if such transmission does occur, it is rare.

Introduction of national guidelines for restrictive blood transfusion threshold for hip fracture patients--a consecutive cohort study based on complete follow-up in national databases

Background

Randomized controlled trials have demonstrated that a restrictive red blood cell (RBC) transfusion strategy lowers transfusion frequency without affecting mortality. However, the external validity of these trials has not been tested in a large cohort. The purpose was to estimate the effect of introducing a National Clinical Guideline (NCG) for a restrictive hemoglobin transfusion threshold on transfusion frequency and mortality in hip fracture patients > 65 years old.

Methods

A consecutive cohort study of hip fracture patients > 65 years old residing in the southern region of Denmark was conducted using prospectively gathered data from registers during two separate 1-year time periods. The first period from October 1, 2012, to September 30, 2013, included 1494 patients and used a liberal transfusion threshold, whereas the second period from October 1, 2015, to September 30, 2016, including 1414 participants used a restrictive threshold from the NCG. Participant data for age, sex, body mass index, Charlson Comorbidity Index, time to surgery, and death were retrieved from the Danish Interdisciplinary Registry of Hip Fractures and were merged with RBC transfusion and medication data extracted from the Danish Transfusion and Odense Pharmacoepidemiological Databases, respectively. Cox proportional hazards models were used to test relative mortality risk for the restrictive group compared with the liberal group at 30 and 90 days.

Results

Overall RBC transfusions decreased from 42 to 30% (p < 0.001). The 30-day mortality rate (95% CI) was 9% (8;11) in the restrictive group and 13% (11;14) in the liberal group (p < 0.008), whereas the adjusted relative mortality risk was 0.72 (0.57;0.91). The 90-day mortality rate was 15% (13;17) in the restrictive group and 19% (17;21) in the liberal group, whereas the adjusted relative mortality risk was 0.78 (0.65;0.94).

Conclusion

These data suggest that the introduction of an NCG on restrictive blood transfusion leads to lower transfusion frequency in hip fracture patients > 65 years old. Even though this reduction is associated with decreased mortality at both 30 and 90 days, it may be explained by other issues than restrictive transfusion strategy. There has been an improvement in the mortality of hip fracture patients in Denmark, and we suggest that a restrictive transfusion strategy does not lead to increased mortality.

Blood Sample Transportation by Pneumatic Transportation Systems: A Systematic Literature Review

BACKGROUND

Pneumatic transportation systems (PTSs) are increasingly used for transportation of blood samples to the core laboratory. Many studies have investigated the impact of these systems on different types of analyses, but to elucidate whether PTSs in general are safe for transportation of blood samples, existing literature on the subject was systematically assessed.

METHODS

A systematic literature review was conducted following the preferred reporting items for systematic reviews and metaanalyses (PRISMA) Statement guidelines to gather studies investigating the impact of PTS on analyses in blood samples. Studies were extracted from PubMed and Embase. The search period ended November 2016.

RESULTS

A total of 39 studies were retrieved. Of these, only 12 studies were conducted on inpatients, mainly intensive care unit patients. Blood gases, hematology, and clinical chemistry were well investigated, whereas coagulation, rotational thromboelastometry, and platelet function in acutely ill patients were addressed by only 1 study each. Only a few parameters were affected in a clinically significant way (clotting time parameter in extrinsic system thromboelastometry, pO2 in blood gas, multiplate analysis, and the hemolysis index).

CONCLUSIONS

Owing to their high degree of heterogeneity, the retrieved studies were unable to supply evidence for the safety of using PTSs for blood sample transportation. In consequence, laboratories need to measure and document the actual acceleration forces in their existing PTS, instituting quality target thresholds for these measurements such as acceleration vector sums. Computer modeling might be applied to the evaluation of future PTS installations. With the increasing use of PTS, a harmonized, international recommendation on this topic is warranted.

Changes in plasma unit distributions to hospitals over a 10-year period

BACKGROUND

There are many influences on a hospital's demand for plasma. Pharmaceuticals are now being administered for many indications instead of plasma, although trauma resuscitation now emphasizes increased and early intervention with plasma. This multinational study evaluated changes in blood center plasma unit distributions over a 10-year period.

STUDY DESIGN AND METHODS

Data on the total number and the ABO groups of plasma unit distributions were obtained from nine American blood collectors (ABCs) and nine national or provincial blood services (NPBS) from 2007 through 2016. Plasma distributions to trauma hospitals by five ABCs and four NPBS were also analyzed.

RESULTS

The overall number of plasma unit distributions from ABCs decreased by 23.1% from 2007 to 2016, but the relative proportion of distributed AB plasma units increased during the same period. The NPBS (excluding the Japanese Red Cross [JRC]) also had a 35.4% decrease in the overall number of plasma unit distributions with an increase in the relative proportion of AB plasma distributions between 2007 and 2016. The JRC, however, reported an increase in the overall number of plasma distributions by 13.5% in 2016 compared to 2007. The proportion of low-titer A plasma distributions increased to 1.6% of total plasma distributions by ABCs in 2016. There was a trend of distributing increasing proportions of group AB plasma units to trauma hospitals over the 10-year period.

CONCLUSION

Although the number of plasma unit distributions has decreased at many blood collectors over time, the proportion of AB units has increased at both ABCs and NPBS.

Storage time of platelet concentrates and risk of a positive blood culture: a nationwide cohort study

BACKGROUND

Concern of transfusion-transmitted bacterial infections has been the major hurdle to extend shelf life of platelet (PLT) concentrates. We aimed to investigate the association between storage time and risk of positive blood cultures at different times after transfusion.

STUDY DESIGN AND METHODS

We performed a nationwide cohort study among PLT transfusion recipients in Denmark between 2010 and 2012, as recorded in the Scandinavian Donations and Transfusions (SCANDAT2) database. Linking with a nationwide database on blood cultures (MiBa), we compared the incidence of a positive blood culture among recipients of PLTs stored 6 to 7 days (old) to those receiving fresh PLTs (1-5 days), using Poisson regression models. We considered cumulative exposures in windows of 1, 3, 5, and 7 days.

RESULTS

A total of 9776 patients received 66,101 PLT transfusions. The incidence rate ratio (IRR) of a positive blood culture the day after transfusion of at least one old PLT concentrate was 0.77 (95% confidence interval [CI], 0.54-1.09) compared to transfusion of fresh PLT concentrates. The incidence rate of a positive blood culture was lower the day after receiving one old compared to one fresh PLT concentrate (IRR, 0.57; 95% CI, 0.37-0.87). Three, 5, or 7 days after transfusion, storage time was not associated with the risk of a positive blood culture.

CONCLUSION

Storage of buffy coat-derived PLT concentrates in PAS-C up to 7 days seems safe regarding the risk of a positive blood culture. If anything, transfusion of a single old PLT concentrate may decrease this risk the following day.

Management of an acute outbreak of diarrhoea-associated haemolytic uraemic syndrome with early plasma exchange in adults from southern Denmark: an observational study

BACKGROUND

Diarrhoea-associated haemolytic uraemic syndrome in adults is a life-threatening, but rare multisystem disorder that is characterised by acute haemolytic anaemia, thrombocytopenia, and renal insufficiency. We aimed to assess the success of management of this disorder with plasma exchange therapy.

METHODS

Patients diagnosed with diarrhoea-associated haemolytic uraemic syndrome in southern Denmark were treated with daily plasma exchange by centrifugation and substitution with fresh frozen plasma. Stool culture and serological testing was done to identify the cause of disease, and the success of management with plasma exchange therapy was assessed from change in platelet count, glomerular filtration rate, and lactate dehydrogenase.

FINDINGS

During May 25-28, 2011, five patients with a median age of 62 years (range 44-70) presented with diarrhoea-associated haemolytic uraemic syndrome, which was caused by an unusual Shiga-toxin-producing Escherichia coli serotype O104:H4. Strains of E coli showed a high resistance to third-generation cephalosporins because the strains had extended-spectrum β lactamases. After plasma exchange, median platelet count and glomerular filtration rate increased, median lactate dehydrogenase concentration decreased, and neurological status improved. The time interval from onset of bloody diarrhoea to start of plasma exchange had an inverse correlation with reduction of lactate dehydrogenase concentrations by plasma exchange (p=0.02). All patients were discharged with normal neurological status at 7 days (range 5-8) after starting plasma exchange.

INTERPRETATION

Early plasma exchange might ameliorate the course of diarrhoea-associated haemolytic uraemic syndrome in adults. However, this finding should be verified in randomised controlled trials

FUNDING

None.

Management of an acute outbreak of diarrhoea-associated haemolytic uraemic syndrome with early plasma exchange in adults from southern Denmark: an observational study

BACKGROUND

Diarrhoea-associated haemolytic uraemic syndrome in adults is a life-threatening, but rare multisystem disorder that is characterised by acute haemolytic anaemia, thrombocytopenia, and renal insufficiency. We aimed to assess the success of management of this disorder with plasma exchange therapy.

METHODS

Patients diagnosed with diarrhoea-associated haemolytic uraemic syndrome in southern Denmark were treated with daily plasma exchange by centrifugation and substitution with fresh frozen plasma. Stool culture and serological testing was done to identify the cause of disease, and the success of management with plasma exchange therapy was assessed from change in platelet count, glomerular filtration rate, and lactate dehydrogenase.

FINDINGS

During May 25-28, 2011, five patients with a median age of 62 years (range 44-70) presented with diarrhoea-associated haemolytic uraemic syndrome, which was caused by an unusual Shiga-toxin-producing Escherichia coli serotype O104:H4. Strains of E coli showed a high resistance to third-generation cephalosporins because the strains had extended-spectrum β lactamases. After plasma exchange, median platelet count and glomerular filtration rate increased, median lactate dehydrogenase concentration decreased, and neurological status improved. The time interval from onset of bloody diarrhoea to start of plasma exchange had an inverse correlation with reduction of lactate dehydrogenase concentrations by plasma exchange (p=0.02). All patients were discharged with normal neurological status at 7 days (range 5-8) after starting plasma exchange.

INTERPRETATION

Early plasma exchange might ameliorate the course of diarrhoea-associated haemolytic uraemic syndrome in adults. However, this finding should be verified in randomised controlled trials

FUNDING

None.

ABO-incompatible kidney transplantation

INTRODUCTION

Kidney transplantation is the optimal treatment for many patients with end-stage renal disease (ESRD). Due to shortage of donor kidneys in Denmark, there is a need to expand the possibilities for donation. At the Odense University Hospital (OUH), we have introduced ABO-incompatible kidney transplantation. We used antigenspecific immunoadsorptions to remove blood group antibodies and anti-CD20 antibody (rituximab) to inhibit the antibody production. The aim of introducing the ABO-incompatible kidney transplantation at the OUH was to increase the rate of living donor kidney transplantation without increasing rejection or mortality rates.

MATERIAL AND METHODS

Retrospective evaluation. Eleven patients received ABO-incompatible kidney transplantation. The patients were followed for 3-26 months.

RESULTS

One patient had an antibody-mediated rejection, one patient suffered T-cell-mediated rejection, and one patient died of myocardial infarction with a functioning graft on the third post-operative day. Both rejections were treated effectively. Among the patients, the average serum creatinine level was 128 micromol/l.

CONCLUSION

The rejection and mortality rates for ABO-incompatible kidney transplantation at the OUH are similar to the results from ABO-compatible kidney transplantations performed at the OUH and at other hospitals.

One-year period prevalence of blood transfusion

Transfusion practice is reported to differ considerably between countries. Comparisons often rely on transfusion rates, incidence - or prevalence rates. In this paper, the one-year period prevalence rate (1-YPPR) of transfusion of red cells (RBC) is presented. Transfusion data, demographic data and patient data were retrospectively combined to calculate sex and diagnosis specific and age standardized 1-YPPR s of RBC transfusion for the complete population in a Danish county. During the calendar year of 2006, 4427 patients received RBC transfusion in Funen County. The crude 1-YPPR of RBC transfusion was 9.2/1000 citizens. Most of the transfused patients had a main diagnosis of neoplasm (22% of recipients), diseases of the circulatory system (15%), the digestive system (15%), injuries (13%) and diseases of the blood (8%). Age standardization reversed the relation between sex specific 1-YPPRs, yielding a statistically significantly higher 1-YPPR in males (6.8/1000) vs. females (6.3/1000). The method for calculating a diagnosis specific 1-YPPR of transfusion of RBC is presented and proposed as an option for comparison of transfusion practice with other transfusion centres. The crude and the diagnosis specific 1-YPPR s are found to increase with age. Thus, age standardization of crude prevalence rates is necessary for meaningful comparisons between populations.

Blood transfusion exposure in Denmark and Sweden

BACKGROUND

Although essential for the evaluation of blood transfusion safety, the prevalence of blood transfusion in the general population is not presently known. This study estimated the exposure to blood transfusion in the general Scandinavian population.

STUDY DESIGN AND METHODS

Population-based registry data of more than 600,000 transfusion recipients and general population data from 2000 to 2002 in Denmark and 1996 to 2002 in Sweden were reviewed. Outcome measures were the unit exposure rate, the 1-year period prevalence, the incidence rate, and the prevalence of exposure to blood transfusion.

RESULTS

The unit exposure rate was 71.9 per 1000 population per year in Denmark and 60.9 in Sweden, corresponding to 29 percent more blood units being transfused in Denmark than in Sweden. The 1-year period prevalence was 8.8 and the incidence rate was 7.2 per 1000 population per year in Denmark, being 37 and 25 percent higher than in Sweden, respectively. The prevalences of blood transfusion in Danish males at 20, 40, 60, and 80 years of age were 1.9, 3.1, 7.6, and 18.1 percent, respectively. In Danish females, the corresponding prevalences were 1.6, 5.9, 11.1, and 20.5 percent. A similar but slightly lower prevalence was found in Sweden.

CONCLUSION

Exposure to blood transfusion is frequent in Denmark and Sweden. At age 80 years, approximately one in five persons in the general population had received blood at least once.

Survival after blood transfusion

BACKGROUND

Long-term survival of transfusion recipients has rarely been studied. This study examines short- and long-term mortality among transfusion recipients and reports these as absolute rates and rates relative to the general population.

STUDY DESIGN AND METHODS

Population-based cohort study of transfusion recipients in Denmark and Sweden followed for up to 20 years after their first blood transfusion. Main outcome measure was all-cause mortality.

RESULTS

A total of 1,118,261 transfusion recipients were identified, of whom 62.0 percent were aged 65 years or older at the time of their first registered transfusion. Three months after the first transfusion, 84.3 percent of recipients were alive. One-, 5-, and 20-year posttransfusion survival was 73.7, 53.4, and 27.0 percent, respectively. Survival was slightly poorer in men than in women, decreased with increasing age, and was worst for recipients transfused at departments of internal medicine. The first 3 months after the first transfusion, the standardized mortality ratio (SMR) was 17.6 times higher in transfusion recipients than in the general population. One to 4 years after first transfusion, the SMR was 2.1 and even after 17 years the SMR remained significantly 1.3-fold increased.

CONCLUSION

The survival and relative mortality patterns among blood transfusion recipients were characterized with unprecedented detail and precision. Our results are relevant to assessments of the consequences of possible transfusion-transmitted disease as well as for cost-benefit estimation of new blood safety interventions.

Improving health profile of blood donors as a consequence of transfusion safety efforts

BACKGROUND

Transfusion safety rests heavily on the health of blood donors. Although they are perceived as being healthier than average, little is known about their long-term disease patterns and to which extent the blood banks' continuous efforts to optimize donor selection has resulted in improvements. Mortality and cancer incidence among blood donors in Sweden and Denmark was investigated.

STUDY DESIGN AND METHODS

All computerized blood bank databases were compiled into one database, which was linked to national population and health data registers. With a retrospective cohort study design, 1,110,329 blood donors were followed for up to 35 years from first computer-registered blood donation to death, emigration, or December 31, 2002. Standardized mortality and incidence ratios expressed relative risk of death and cancer comparing blood donors to the general population.

RESULTS

Blood donors had an overall mortality 30 percent lower (99% confidence interval [CI] 29%-31%) and cancer incidence 4 percent lower (99% CI 2%-5%) than the background population. Mortality rates and cancer incidence were lowest for outcomes that are recognized as being related to lifestyle factors such as smoking or to the selection criteria for blood donation. Blood donors recruited in more recent years exhibited a lower relative mortality than those who started earlier.

CONCLUSION

Blood donors enjoy better than average health. Explicit and informal requirements for blood donation in Scandinavia, although mostly of a simple nature, have successfully refined the selection of a particularly healthy subpopulation.

A survey of the demographics of blood use

Epidemiological information was obtained by a series of questions to experts in the field of epidemiology of transfusion from the United States, England, Australia and Denmark. Although it became clear that the methods for collecting the data had differed between the countries, useful information was obtained for all questions. The data highlighted some major differences between the countries: the incident rate for red cell transfusion varied from 44.7 to 54.1 units, for platelets from 2.0 to 6.0 units and for plasma from 4.8 to 13.8 units transfused per 1000 population per year. Age and sex distribution of transfused patients was similar in all countries. Most of the red cell products are transfused to older recipients, and the distribution between men and women is approximately equal. The distribution for platelets is over a wider age range, and the difference between men and women is marked, with men predominating in all countries. The distribution for plasma is also directed to the elderly, and there is a predominance of men. The relationship between the disease or surgical procedure and the use of blood products was similar between countries. The use of red cells in cardiovascular surgery predominated. Neoplasms and digestive disorders were also prevalent. Neoplasms, including those relating to haematology, were the main use for platelets, but cardiovascular surgery was also important. In all countries, plasma is largely used in cardiovascular surgery. Two countries provided data relating to the number of units per transfusion episode including information relating to massive transfusion. In Australia, red cell use of >or=50 units per episode was largely associated with multiple traumas. In Denmark, it was associated with gastrointestinal bleeding and various medical requests.

Risk of cancer after blood transfusion from donors with subclinical cancer: a retrospective cohort study

BACKGROUND

Although mechanisms for detection of short-term complications after blood transfusions are well developed, complications with delayed onset, notably transmission of chronic diseases such as cancer, have been difficult to assess. Our aim was to investigate the possible risk of cancer transmission from blood donors to recipients through blood transfusion.

METHODS

We did a register-based retrospective cohort study of cancer incidence among patients who received blood from donors deemed to have a subclinical cancer at the time of donation. These precancerous donors were diagnosed with a cancer within 5 years of the donation. Data from all computerised blood bank registers in Sweden and Denmark gathered between 1968 and 2002 were merged into a common database. Demographic and medical data, including mortality and cancer incidence, were ascertained through linkages with nationwide, and essentially complete, population and health-care registers. The risk of cancer in exposed recipients relative to that in recipients who received blood from non-cancerous donors was estimated with multivariate Poisson regression, adjusting for potential confounding factors.

FINDINGS

Of the 354 094 transfusion recipients eligible for this analysis, 12,012 (3%) were exposed to blood products from precancerous donors. There was no excess risk of cancer overall (adjusted relative risk 1.00, 95% CI 0.94-1.07) or in crude anatomical subsites among recipients of blood from precancerous donors compared with recipients of blood from non-cancerous donors.

INTERPRETATION

Our data provide no evidence that blood transfusions from precancerous blood donors are associated with increased risk of cancer among recipients compared with transfusions from non-cancerous donors.

A population-based binational register for monitoring long-term outcome and possible disease concordance among blood donors and recipients

BACKGROUND AND OBJECTIVES

Even with appropriate donor deferrals and advanced screening tests, the risk of disease transmission through blood transfusion cannot be completely disregarded. Efficient monitoring of possible disease transmission between blood donors and recipients should be an important component of a comprehensive haemovigilance system.

MATERIALS AND METHODS

We assembled the Scandinavian Donations and Transfusions (SCANDAT) database, with data on virtually all blood donors and recipients who have been registered at least once in any of the computerized local blood bank databases in Sweden and Denmark since the start of computerized registration in 1966. The records of these individuals, with their entire computerized donation and/or transfusion histories and all donor-component-recipient connections, were linked to nationwide population and health registers to attain essentially complete follow-up for up to 36 years regarding reproduction, hospital morbidity, cancer, and death.

RESULTS

After data cleaning, the database contained 1,134,290 blood donors who contributed 15,091,280 records of donations and 1,311,079 recipients who received 11,693,844 transfusions. The data quality in the existing data sources was satisfactory. From the data obtained from local blood banks, 4.6%, 1.6%, and 6.4% of the person, donation, and transfusion records, respectively, had to be discarded after review of the legitimacy of recorded values, and comparisons with independent, external databases.

CONCLUSION

It is possible to use existing computerized data, collected in routine health care, in haemovigilance systems for monitoring long-term outcome and disease concordance in blood donors and transfusion recipients.

Cesarean section: is pretransfusion testing for red cell alloantibodies necessary?

BACKGROUND

Routine pretransfusion testing for red cell alloantibodies (RBCab) in cesarean patients is standard practice in many obstetric centers. The objective of the present study was to evaluate the usefulness of this test.

METHOD

A retrospective study was conducted using computerized registers to extract data on blood transfusions and the occurrence of RBCab in cesarean patients.

RESULTS

A total of 4434 admissions for cesarean section were identified. Only 10 patients (0.23%) had clinically significant RBCab, which had not been previously detected. Blood transfusions were required in relation to 147 cesarean sections (3.3%). A number of preoperative conditions, traditionally believed to be risk factors for preoperative and postpartum hemorrhage, occurred more frequently in transfused patients than in nontransfused. The probability of a cesarean patient having a previously undetected clinically significant RBCab and receiving a blood transfusion during admission for delivery was estimated to be 9.0 x 10(-5) (1 in 11 050 cesarean sections). Analyses of the time relationships between cesarean sections and initiation of blood transfusions indicated that most often there would be enough time for postoperative antibody screening and/or cross matching if the routine pretransfusion testing was omitted.

CONCLUSION

These findings suggest that routine pretransfusion testing in cesarean patients can be omitted.

Monitoring transfusion practice--a computerized procedure

As the description of transfusion practice over time requires the handling of massive amounts of data, and because the majority of records have until now been paper-based, little is known about the epidemiology of blood transfusion. Furthermore, most previous studies have collected data manually from patient records or from computerized registers created solely for study purposes. We describe a procedure for monitoring transfusion practices based exclusively upon the collection of data from the existing computerized registers. During the calendar years 1997 and 1998, more than 750 000 data records were collected from the blood transfusion registers, diagnosis and procedure registers, and clinical biochemistry registers at two university hospitals. Linking of the data required a unique and consistent identification of all data records. This was made possible by the national Personal Identification Number. In this way more than 98% of all transfusions could be identified and approximately 95% (77 950) could be connected to a principal diagnosis. The described procedure creates new opportunities for studies of transfusion practices both on a large scale and in richness of detail, and we propose to establish a network where transfusion practices data are available and comparable for individual departments, hospitals, whole regions, and possibly nations.

Monitoring transfusion practices at two university hospitals

BACKGROUND AND OBJECTIVES

Considering the clinical importance of blood transfusions, the limited knowledge of transfusion practices is remarkable. New methods are needed to elucidate the observed variation of transfusion practices.

MATERIALS AND METHODS

All patients transfused or pretransfusion tested (i.e. at risk for blood transfusion) at two tertiary teaching hospitals during the full years of 1997 and 1998 were included in the study.

RESULTS

The observed practices contained substantial variance at the level of hospitals. The contributions to the total variance of the different specialities were highly significant, as was the contribution of hospitals to the variance in plasma and platelet transfusions. Significant interactions between hospitals and specialities were observed in transfusion of red cells, plasma and platelets.

CONCLUSION

To our knowledge this is the first survey of this size to combine transfusions, diagnoses and biochemical tests, exclusively based on an existing computerized register. The aim is to establish a basis for comparison of local transfusion practices with other commensurate hospitals and regions at a national (and international) level.

Detection of irregular red cell antibodies: more than 3 years of experience with a gel technique and pooled screening cells

BACKGROUND AND OBJECTIVES

The purpose of this study was to evaluate more than 3 years of experience with a gel technique in combination with pooled screening cells for the detection of irregular red cell antibodies.

MATERIALS AND METHODS

Conventional serologic methods were used for blood typing, antibody screening and cross-matching until the end of 1992. We introduced the gel technique as a routine assay for antibody detection and identification in 1993.

RESULTS

After the tube technique had been abandoned, the number of false-positive antibody screening tests was reduced by 71%, positive antibody screening tests by 33%, enzyme agglutination by 100% and rouleaux reactions and cold-reacting antibodies by more than 50%. There was a 40% increase in first-time detection of clinically relevant antibodies. We saw no increase in delayed haemolytic transfusion reactions.

CONCLUSIONS

For the detection of irregular red cell antibodies, pooled screening cells in combination with a gel technique are at least as efficient and safe as a conventional tube technique with unpooled test cells.

The isolation and characterization of an insulin-releasing tetrapeptide from urines of patients with lipoatrophic diabetes

The tetrapeptide pyroGlu-Glu-Asp-GlyOH and its gamma-amide have been isolated from the urines of lipodystrophic patients with insulin-resistant diabetes. Both peptides induce insulin release only at high blood glucose levels.

A synthetic hexadecapeptide derived from allergen M imposing allergenic and antigenic reactivity

A solid phase synthesis (SPPS) hexadecapeptide corresponding to residues 49-64 of allergen M from cod was found to bind specifically IgE antibodies from sera of cod-allergic individuals. The SPPS peptide was similarly reactive in IgG-mediated reactions; it could interfere with Allergen M line precipitate in rocket-line immunoelectrophoresis, giving a distinct deflection. It is the only reported synthetic polypeptide imposing allergenic and antigenic reactivity. The hexadecapeptide is composed of two homologous tetrapeptides located at its terminai, tentatively concluded to be mutually critical for the immunological specificity. The data obtained confirmed the predicted reactivity of the Ca2+-binding CD loop of the intact Allergen M.

Patterns of peptides and protein-associated-peptide complexes in psychiatric disorders

Peptidic neurones may be considered as multisignal intergrators and transducers. When formation or release of peptide outstrips genetically determined breakdown capacity, overflow of peptides to the body fluids and urine may be expected. In this paper, pathological urinary chromatographic patterns of peptides are shown for genetic, functional and mixed disorders. Part symptoms of the disorders may be induced with the biologically isolated and purified peptides as well as with chemically synthesized peptides.

Cyclic peptides of sarcosine. Syntheses and conformation

A series of cyclic peptides of sarcosine with the general formula c-Sar-n, n=2-8, has been synthesized and conformational studies carried out both in solution and in the solid. The rings are conformationally very homogeneous and contain both cis and trans amide bonds. Their barriers to ring inversion are high; in the smaller rings this is attributed to steric hindrance, caused by the N-methyl-groups, whilst in the larger rings the folding of the chain in helical segments plays an important role.