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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.

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., (Copyright © 2012 Elsevier Inc. All rights reserved.)

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.

A variety of pretransfusion tests have been developed to improve the safety and effectiveness of transfusion. Recently, a number of traditional tests have been shown to offer limited clinical benefit and have been eliminated in many facilities. A survey of pretransfusion test practices was distributed to 116 hospital transfusion services. Routine test practices and facility size were analyzed. Ninety-one responses were received. Many smaller laboratories include tests such as anti-A,B, an autocontrol, and DAT, and immediate spin and 37 degrees Celsius microscopic readings. Nine percent never perform an Rh control with anti-D typing on patient samples. Various antibody screening and crossmatch methods are utilized. Individual laboratory test practices should be periodically assessed to ensure that they comply with standards, represent the recognized best practice, and are cost-effective. The survey responses indicate that many laboratories perform tests that are not necessary or cost-effective. These facilities should review their processes to determine which tests contribute to transfusion safety. Smaller facilities may be reluctant to change or lack the expertise necessary for this decision making and often continue to perform tests that have been eliminated in larger facilities. Consultation with larger hospital transfusion services may provide guidance for this change.

Instructions included with monoclonal Rh(D) typing reagents do not require routine use of an Rh control as immunoglobulin-coated red blood cells (RBCs) rarely yield falsely positive results with low protein reagents. However, the American Association of Blood Banks (AABB) Technical Manual recommends a concurrent control be performed on patients' RBCs that type as group AB, D(+). Proficiency testing surveys presented sensitized AB, D- RBCs, which resulted in a positive direct antiglobulin test and, in some samples, spontaneous agglutination in saline. One intent of the surveys was to monitor the accuracy of the reported Rh(D) type. On an initial survey, 19 of 115 (16.5%) participants reported the RBCs as D(+). Of these laboratories, 63.2 percent (12/19) had used a monoclonal/ polyclonal blend anti-D reagent. On a subsequent survey, after educational material had been distributed, only five of 113 (4.4%) participants reported the Rh type as D(+). Two of these five laboratories had used a monoclonal/polyclonal blend anti-D reagent. As RBCs coated with immunoglobulin may give unreliable results with Rh typing reagents, laboratories should follow the guidelines of the AABB Technical Manual. An appropriate control should be performed whenever RBCs from patients type as AB, D(+).

The most likely cause of fatality in blood transfusion is transfusion of the wrong unit of blood to a patient. This type of error is usually attributed to improper patient identification at the time of sample collection or transfusion. A retrospective analysis of the results of an external proficiency testing program identified a common source of error occurring during laboratory testing that has not been previously reported. Results were analyzed when major errors were assigned to laboratories for obviously switching donor units in compatibility testing and/or subsequent investigation. In 24 surveys sent to extended testing (Level A) laboratories and 18 sent to basic testing (Level B) laboratories, the antigenic composition of the two donor cells made it possible to determine whether the cells had been switched. Seven errors were assigned to Level A participants for switching donor units during testing, constituting 38.9 percent of the 18 major errors assessed. Level B participants were assigned eight errors for switching donor units, 26.7 percent of the 30 major errors assessed. Approximately one-third (31.3 percent) of major errors committed on 42 proficiency testing surveys were caused by switching of donor cells during compatibility testing. This type of error may result in transfusion of an incompatible donor unit.

Sera from 29 patients who had reacted to a platelet (27) or packed red cell (2) transfusion and from 5 patients who had received platelets without reacting were collected over a 13-month period. The sera were assayed for total IgE, and IgE specific for ethylene oxide, phthalic anhydride, hexamethylene diisocyanate, methylene diphenyl diisocyanate, toluene diisocyanate, and mast cell tryptase. Three patients with reactions had elevated total IgE levels, and specific IgE was positive for hexamethylene diisocyanate in 2 of 28 (7.1%), methylene diphenyl diisocyanate in 1 of 29 (3.4%), and toluene diisocyanate in 14 of 27 (51.9%). No positives were found in patients without reactions and no patients had an elevated tryptase level. It is unlikely that anti-plasticizer hypersensitivity was responsible for the transfusion reactions, but the prevalence and significance of such antibodies in both the hospital population and the general population would merit further investigation.