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OBJECTIVES: This was a laboratory exercise designed to determine whether combined antibody titrations in the presence of multiple antibodies achieve a critical level earlier or at the same time as antibodies having individual antibody titrations. BACKGROUND: Management of haemolytic disease of the fetus and newborn involves monitoring maternal antibody concentration by antibody titration. Separate titrations are generally performed for each antibody. METHOD: Thirty-one samples containing combinations of two different Rh and/or non-Rh antibodies were examined with separate titres for each antibody and one single combined titration. RESULTS: Of 31 samples, 19 (61.3%) showed an increased combined titre. Of 12 samples that showed no increase, 10 contained a separate titre of <1 for either one or both antibodies. Where both antibodies had a separate titre of ≥1, 15 of 17 (88.2%) showed an increased combined titre. In contrast to the separate titration method, no decrease in titre level was observed using the combined method. CONCLUSION: Where two antibodies are present, titrations performed by a combined method will produce titre levels equal to or higher than antibodies titred individually. Therefore, a combined titration can be expected to reach a critical titre level as early as, or earlier in gestation than, antibodies monitored by a single titration method. Further studies relating fetal outcomes to titration methodology would be valuable in determining the validity of this approach for prenatal management. Cost-effectiveness of this approach to prenatal screening should also be assessed.

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Despite the existence of long-standing, well-organized programs for Rh immune globulin (RhIG) prophylaxis, immune anti-D continues to be detected in the D­ perinatal population. Between 2006 and 2008, 91 prenatal patients, found to have a previously unidentified anti-D, were followed up with a survey to their treating physician and with additional serologic testing where possible. The physician survey requested pregnancy and RhIG history information, including recent or distant potential alloimmunizing events, and the physicians were asked their opinion on the likely cause for the anti-D. Based on survey responses, updated RhIG information, and results of follow-up serology, anti-D was determined to be attributable to previously unreported RhIG in 44 of 91 (48.3%) cases and to active immunization (immune anti-D) in 36 of 91 cases (39.6%). A probable cause for alloimmunization was reported in 14 of 52 (26.9%) returned surveys. Anti-D alloimmunization continues to occur in our prenatal population despite a comprehensive approach to RhIG therapy. Observations from this prospective patient management strategy include the need for improved application of guidelines for RhIG administration and improved quality of information provided to laboratories assessing RhIG eligibility. A laboratory process for prospective follow-up when unexpected anti-D is detected in pregnancy is recommended.

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BACKGROUND: RhIG prophylaxis for D- pregnant women prevents hemolytic disease of the newborn and typically depends on results of serologic D typing. Interpretation and follow-up of weak D serology is variable. Recent recommendations promote genotyping for RHD status determination in those with weak D serology. Canadian Blood Services performs comprehensive serologic prenatal testing in four provinces. Genotyping is used to determine D typing in patients with weak D. STUDY DESIGN AND METHODS: A serologic algorithm identified which patients require genotyping for RHD determination. Genotyping was performed on one of two commercially available platforms. RESULTS: Only 0.4% of D- patients met criteria for genotyping. Sixty-one percent were weak D Type 1, 2, or 3. Thirty percent had a partial or weak D other than Type 1, 2, or 3. Eleven had variants which remained unresolved. Seventeen were D+ and four were D-. CONCLUSIONS: Genotyping of patients with weak D serology led to an identified genotype in most patients. RhIG administration was avoided in 66% who were weak D Type 1, 2, or 3 or were D+. The use of a serologic algorithm to select patients for RHD genotyping identifies a majority of patients with weak D types not at risk for alloimmunization. This approach limits the number of genotyping investigations and the cost of providing classification for weak D types.

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OBJECTIVE: The goals of this study were to determine the prevalence and relative frequencies of red blood cell antibodies in a Canadian prenatal population, and to evaluate the fetal and neonatal outcomes of affected pregnancies. METHODS: We conducted a retrospective review of pregnancies that screened positive for red cell antibodies between 2006 and 2010. The following antibodies were included: anti-D, -C, -c, -E, -e, -Fya, -Fyb, -Jka, and-Jkb. Cases of anti-Kell as the sole antibody were excluded. Fetal and neonatal outcome data were then collected and analyzed. RESULTS: The population prevalence of a positive antibody screen was 0.36%. Anti-E was the most frequent antibody at 48.5%, followed by anti-c and anti-Jka. Anti-D made up 6.8% of cases, but had significantly higher titres and was responsible for the majority of severely affected fetuses. Sixteen cases in our series experienced severe adverse fetal or neonatal outcomes. All severe outcomes occurred in cases that had a maximum titre of ≥ 8. CONCLUSION: Despite the decreasing incidence of anti-D alloimmunization, anti-D remains responsible for the majority of severe cases of hemolytic disease of the fetus and newborn.

Objectif : Cette étude avait pour objectif de déterminer la prévalence et la fréquence relative des anticorps anti-érythrocytaires au sein d'une population prénatale canadienne, et d'évaluer les issues fœtales et néonatales des grossesses affectées. Méthodes : Nous avons mené une analyse rétrospective portant sur les grossesses qui ont obtenu des résultats positifs au dépistage des anticorps anti-érythrocytaires entre 2006 et 2010. Les anticorps suivants ont été inclus : anti-D, -C, -c, -E, -e, -Fya, -Fyb, -Jka et -Jkb. Les cas où l'anti-Kell constituait le seul anticorps ont été exclus. Des données sur les issues fœtales et néonatales ont par la suite été recueillies et analysées. Résultats : La prévalence populationnelle de l'obtention d'un résultat positif au dépistage des anticorps a été de 0,36 %. L'anti-E a été l'anticorps le plus fréquent à 48,5 %, suivi de l'anti-c et de l'anti-Jka. Bien que l'anti-D n'ait constitué que 6,8 % des cas, ses titres étaient considérablement accrus et il a été à l'origine de la majorité des cas de fœtus gravement affecté. Dans le cadre de notre série, seize cas ont connu des issues indésirables fœtales ou néonatales graves. Toutes les issues graves ont été constatées dans les cas qui présentaient un titre maximum de ≥ 8. Conclusion : Malgré l'incidence décroissante de l'allo-immunisation anti-D, l'anti-D demeure à l'origine de la majorité des cas graves de maladie hémolytique du fœtus et du nouveau-né.

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The medical literature is replete with articles addressing the diagnosis and management of patients with a positive direct antiglobulin test (DAT). However, there is scant information addressing the management of blood donors and blood donations found to have a positive DAT. Practices vary considerably between countries and blood suppliers within countries, and there is no standardized approach to the management of these blood donors or the blood products prepared from their donations. Recent evidence from Israel suggests that the finding of a positive DAT in a blood donor may not be as benign as previously thought. Therefore, it may be prudent for blood collection agencies to periodically reexamine their approach to the management of blood donors with a positive DAT and their donations. This article reviews the available literature and explores options for the management of DAT-positive blood donors and their blood donations.

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BACKGROUND: The first case describing the SARAH (SARA) antigen occurred in 1990, in an Australian blood donor. Hemolytic disease of the fetus and newborn (HDFN) due to anti-SARA has not been previously described. CASE REPORT: We report a case of HDFN in a multiparous female. The pregnancy was unremarkable except that she was involved in a seemingly minor motor vehicle accident at 25 weeks' gestation. Routine prenatal antibody screening was negative throughout the pregnancy. She presented at 37 weeks' gestation because of decreased fetal movements. Labor was induced and a 2702-g infant male was delivered. The infant's hemoglobin was 49 g/L and the bilirubin was 153 µmol/L. RESULTS: Blood samples from the parents and infant were referred to Canadian Blood Services National Immunohematology Reference Laboratory and subsequently to the Australian Red Cross Red Cell Reference Service. The father's and infant's red blood cells were confirmed to be SARA positive, and the mother's plasma contained anti-SARA. CONCLUSION: The infant was successfully treated with a double-volume exchange transfusion. This is the first example of HDFN associated with this antibody.

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Preserving cell viability and function is an essential component in the translation and delivery of existing and emerging cell-based therapeutics from the research lab to the patient bedside. This workshop provided a summary of the advances and challenges that currently face the preservation sciences, together with a glimpse at the future applications and instrumentation that will enhance our ability to process, preserve, and store red blood cells (RBCs), platelets, and stem cells. It is clear from the presentations made during the workshop and the discussions that ensued after that, for us to overcome the challenges that face blood biopreservation, it will require a concerted effort from clinicians, scientists, and engineers from a variety of disciplines. Through this interdisciplinary research effort, significant progress will be made to improve the safety, quality, and potency of the blood products that are used in reparative medicine. As the need for effective preservation technologies will be the motivation for more concerted efforts in the biopreservation sciences, there are encouraging prospects for the future applications of biopreserved blood cells.

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Transfusion-related acute lung injury is a relatively uncommon transfusion-associated adverse effect occurring during or soon after an allogeneic blood transfusion. Transfusion-related acute lung injury is a complex syndrome that has many manifestations and has only recently been identified to be an important cause of transfusion-associated morbidity and mortality. But despite its increasing recognition, much about the pathogenesis, treatment, and prevention is poorly understood and often controversial. The purpose of this consensus conference was to bring together international experts in an effort to try to standardize a case definition, which could be used to enhance future understanding of transfusion-related acute lung injury including its epidemiology, pathogenesis, management, prevention, and research. These proceedings are being provided with a view to making available to the transfusion medicine community the considerable amount of important information presented at this consensus conference by the invited international panel of experts.

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Since the identification, in 1996, of the first case of variant Creutzfeldt-Jakob disease (vCJD) in humans various approaches have been implemented and/or proposed to prevent this disease from being transfusion transmitted. In addition, a variety of possible laboratory-based approaches have been developed and will continue to be developed for the vCJD screening of blood donors. Various issues related to the implementation of such vCJD testing is likely to assume greater importance as diagnostic tests for vCJD becomes available for the potential screening of blood donors. The purpose of this Consensus Conference was to bring together international experts in an effort to determine which principles should guide the introduction of such testing. These experts provided the scientific and biological background of bovine spongiform encephalopathy (BSE) and vCJD, an understanding of their current epidemiology, as well as the ethical and legal issues that would impact on the implementation of a screening test for preventing the transfusion transmission of vCJD. This contentious issue is of potential considerable importance to transfusion medicine personnel worldwide, as well as to future recipients of allogeneic blood components.

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BACKGROUND: Unaccustomed intense endurance exercise is associated with short-term suppression of natural immunity. However, it is not established whether intensified endurance training alters resting immune status or increases the risk of upper respiratory infection (URI). PURPOSE: This study examined the effect of intensified endurance training for performance enhancement on resting immune status in nine healthy, male competitive cyclists. DESIGN: Data were collected during 4 weeks of usual training (baseline), followed by prescribed cycle training that consisted of volume-building at customary training intensity (V phase, 6 weeks), unaccustomed very high intensity interval training at 100% maximal heart rate (I phase, 18 days), and an unloading taper (U phase, 10 days). METHODS: The main performance criterion was a simulated 20 km time-trial. Aerobic capacity measures included power output at ventilatory threshold (POT(vent)) and maximal oxygen uptake (VO(2max)). Markers of immune status (lymphocyte subset counts, serum cytokine levels, and new URI cases) and physiological indicators of training stress (cycling economy, 24-hour urinary cortisol excretion, and serum testosterone concentration) were evaluated in the rested state, 36 to 44 hours postexercise, during baseline, and after each training phase. RESULTS: Time-trial performance, POT9(vent), VO(2max), and cycling economy improved significantly (p < 0.001) after the V phase, and remained higher than baseline (p < 0.001) after the I and U phases. As compared with the V phase, performance time was faster after the U phase (p < 0.01). In contrast, lymphocyte counts, cytokine levels, incidence of URI, cortisol excretion, and serum testosterone concentration were not significantly different from baseline in any phase. CONCLUSIONS: Cycling efficiency and performance improved while resting immune status was maintained throughout the 10-week training program. This study provides encouraging data in support of immunological robustness during intensified endurance training.

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