In vitro and in vivo persistence of reticulocytes from donor red cells

BACKGROUND: Reticulocytes are important in the phenotyping of transfused patients. Reticulocytes can persist in blood units for the shelf life of the unit. STUDY DESIGN AND METHODS: Temperature dependence of reticulocyte persistence was examined in vitro at 4, 24, and 37 degrees C by using thiazole orange staining and flow cytometric analysis. Two-color flow cytometric analysis was used to evaluate the persistence of donor reticulocytes in transfused patients. RESULTS: Flow cytometric analysis using thiazole orange demonstrated that persistence of reticulocytes in units of stored CPDA-1 blood was temperature-dependent. Reticulocytes disappeared over 13 and 6 days at 24 degrees C and 37 degrees C, respectively, but at 4 degrees C the reticulocyte count changed little over 35 days. Two-color flow cytometric analysis of reticulocyte antigens was used to follow donor reticulocytes in 14 transfusion events in nine different patients. Donor reticulocytes persisted through 24 hours in 75 percent of the patients and were detectable at 48 hours in three patients. CONCLUSION: This study demonstrates that reticulocytes persist during refrigerated storage; they are detectable in the circulation of most recipients for the first 24 hours after transfusion and in the circulation of a few recipients after 48 hours. These findings may have relevance for separation techniques based on reticulocyte density in samples drawn shortly after transfusion and for evaluation of reticulocyte counts in patients with hematologic abnormalities.     

Early introduction to interprofessional learning: a simulated ward environment

OBJECTIVES: To develop an interprofessional simulated ward environment for junior medical and nursing students and to identify themes for future evaluations and modify criteria for formative assessment of the exercise. SUBJECTS: Second year medical and nursing students. SETTING: The multiprofessional Clinical Skills Centre at the Faculty of Medicine, and Nursing, University of Dundee, Scotland. METHOD: A simulated ward environment was created in the Clinical Skills Centre around patients with common medical conditions. Students were allocated to interprofessional teams and, after a briefing given in the form of a ward report, were asked to take responsibility for the ward for 'a shift'. Observers from the Schools of Medicine and Nursing charted their progress in relation to evidence of collaborative team working, effective leadership, the ability to prioritise workload and competence in clinical performance. Evaluations of the exercise were taken from all participants. The criteria for formative assessment were reviewed by the observers after the exercise and a focus group was used to generate additional criteria and modify those piloted. RESULTS: The exercise was perceived positively by all participating groups. Themes for evaluation of future exercises and modified criteria for future assessment were identified. CONCLUSIONS: The exercise gave students their first experience of participating independently in a realistic and safe operational ward setting. It proved to be a powerful learning experience for the students.     

Influence of HLA-A2 on the effectiveness of platelet transfusions in alloimmunized thrombocytopenic patients

Platelet transfusions from donors selectively mismatched for cross- reactive and certain non-cross-reactive HLA antigens were found to be more effective in HLA-A2 negative than in HLA-A2 positive, alloimmunized thrombocytopenic patients. The two groups of patients responded equally well to platelets matched for antigens of the HLA-A and B loci. Certain alloimmunized patients negative for HLA-A2 continued to respond satisfactorily to platelets selectively mismatched for non-cross-reactive HLA antigens as long as platelets containing HLA- A2 were avoided. The data indicate that platelet transfusion support can be provided within a broader range of donor-recipient HLA antigenic disparity to HLA-A2 negative alloimmunized patients than to those who are positive for this antigen.