Studies of the ABO and FORS Histo-Blood Group Systems: Focus on Flow Cytometric and Genetic Analysis

ABO is the clinically most important blood group system and its antigens are carbohydrate moieties present on the surface of the red blood cell (RBC) but also on other tissues throughout the body. The ABO gene encodes an enzyme, a glycosyltransferase (GT),that adds a terminal monosaccharide to the precursor structure, H antigen, to define the A or B antigens. Blood group O is due to a non-functional GT that leaves the precursor unchanged. Weak expression of ABO antigens can be acquired or be due to polymorphisms in the ABO gene. The aim of this study was to characterise normal/weak/aberrant expression of ABO and related structures on RBCs in light of genetic variations of the ABO gene or acquired changes in the setting of transfusion, pregnancy or stem cell transplantation. The O2 allele has been proposed sometimes to give rise to weak A expression. In 40 group O blood donors heterozygous for the O2 allele no A antigen expression could be detected nor could any GTA activity be noted in enzyme activity testing. (Paper I) Flow cytometry was used to examine genetically-defined ABO subgroups and flow cytometric patterns were shown to correlate with many genetic changes seen at the ABO locus. In addition, this method was found invaluable for semi-quantification of ABO antigens in clinical samples from individuals with weak antigen expression, both acquired or inherited but genetically unexplained. (Paper II) Thirteen new ABO alleles were defined based on an A2-allelic backbone. A combination of genetics, flow cytometry and 3D-modelling gave an insight to possible mechanisms underlying the diminished GT activity in these samples. For instance, the first reported change in the important DVD motif was noted in this cohort. (Paper III) Synthetic A- and B-glycolipids called Functional-Spacer-Linker (FSL) derivatives were used to modify group O RBCs. Different amounts of FSL were used for upload, and flow cytometry was applied to semi-quantify the acquired A or B expression. The purpose of the modification was to create RBCs that mimic the ABO antigen expression of naturally-occurring subgroups and to use these for control purposes. Certain concentrations of FSL gave similar flow cytometric patterns to genetically defined Ax and Bw RBCs included as controls in the study. (Paper IV) The phenomenon of donor-derived group O RBCs acquiring weak A/B expression following transfusion or ABO-incompatible stem cell transplants were examined. By flow cytometry, antigen levels ranging from very low in A1 non-secretor individuals to levels almost equivalent to the Ax control sample in secretor individuals were noted. The major role of adsorption of A/B antigen from plasma as the probable mechanism was supported but our findings also indicate a secretor-independent mechanism.(Paper VI) The enigmatic ABO subgroup Apae was examined and shown to be ABO-independent. The A-like antigen was proven by structural analysis to be the Forssman (Fs) antigen and shown to be expressed in normal haematopoietic tissue. The Fs gene (GBGT1) is thought to be inactive in humans but in Apae individuals a missense mutation in the GBGT1 gene was identified. Transfection studies showed a significant difference in antigen expression between the wildtype and the mutant GBGT1. Naturally-occurring anti-Fs exists in plasma and was shown to cause haemolysis of Fs-positive cells in vitro, hinting at potential risk for intravascular lysis of transfused RBCs. Furthermore, some E. coli strains are known to bind specifically to the Fs antigen, which suggests biological implications. (Paper V) In summary, the combination of a sensitive flow cytometry method for semi-quantification of ABO antigens, genetic analysis and 3D-modelling provide good tools to examine ABO subgroups. The elucidation of the Apae subgroup provided insight into the complex world of glycobiology and established a novel blood group system designated FORS

Kund eller patient? – Till kritik mot en marknadsanpassning av patientbemötandet

Syftet med denna uppsats är att, utifrån en analys om läkarprofessionens eventuellt förändrade syn på patientbemötandet - gällande både sin egen och patientens roll - kritisera och kontrastera New Public Management och Service Management angående marknadsanpassning av läkar- och patientrollen. Vi utgår från ett tolkande paradigm och använder oss av en kvalitativ metod. Vi kritiserar New Public Management och Service Management inom svensk sjukvård huvudsakligen utifrån Etienne Wengers teori om sociala grupper i samhället, men även utifrån Michel Foucaults och Jean Baudrillards teorier. Empirisk data presenteras tillsammans med teorin och tolkas utifrån teorin. Empirin härstammar från åtta intervjuer och en observation, men består även av sekundärdata i form av artiklar från läkarfackpress. Vi har gjort ett försök till att dekonstruera den idealbild som New Public Management och Service Management målar upp angående hur relationen mellan läkare och patient bör vara. Vi menar att en idealbild inte har möjlighet att få fotfäste utan att ha såväl historisk som samtida förankring

Many genetically defined ABO subgroups exhibit characteristic flow cytometric patterns.

BACKGROUND: A flow cytometric method for detection of low levels of A/B antigen had been developed previously in our laboratory. The aim of this study was to investigate if this approach could be utilized to characterize different ABO subgroups and constitute a useful tool in a reference laboratory. STUDY DESIGN AND METHODS: Blood samples causing ABO discrepancies (n = 94) by routine serology were further analyzed by ABO genotyping and flow cytometry. To verify the specificity of the monoclonal anti-A and -B reagents and to establish normal flow cytometric patterns, samples from 80 blood donors with common phenotypes were also assessed. RESULTS: Distinguishable flow cytometric patterns were detected for several subgroups but were more apparent for A(weak) (n = 80) samples than B(weak) (n = 14). Two subgroups, A(finn) (n = 11) and A(3) (n = 10) displayed diagnostic features and were used to establish reproduciblity over time and between donors. In general, the consistency within subgroups was remarkable. The allelic enhancement phenomenon was clearly visualized among A(x) samples (n = 10) where different alleles in trans resulted in high, low, or no A antigen expression. Nonsubgroup samples including O/A and O/B chimeras or A(h) and B(h) para-Bombay phenotypes displayed clearly distinguishable histograms. Samples from pregnant women (n = 10) displayed acquired A antigen loss, apparently accentuated during the third trimester. CONCLUSIONS: Genetically defined ABO subgroups and other anomalous phenotypes displayed flow cytometric profiles that may contribute valuable information to the investigation of ABO discrepancies. We conclude that the presented assay may complement traditional serology and genetic analysis in the reference laboratory setting

May the FORS be with you : a system sequel

This article is an update of the review of the FORS system published in Immunohematology in 2017 (Hult AK, Olsson ML. The FORS awakens: review of a blood group system reborn. Immunohematology 2017;33:64-72). This update incorporates the most recently presented knowledge on this still enigmatic system and its genetic, enzymatic, and immunological aspects. Further insight into the genetic variation and allele frequencies of the GBGT1 locus has been reported, and screening studies regarding the prevalence of naturally occurring anti-FORS1 in human plasma have been performed and presented. More basic knowledge on the specificity of the gene product, the Forssman synthase, has been obtained in several detailed studies, and its relation to the homologous ABO gene has been investigated. Taken together, we summarize recently added information about the carbohydrate-based FORS blood group system (International Society of Blood Transfusion number 031)

The struggle to understand : Exploring medical students’ experiences of learning and understanding during a university course

The aim of the research reported in this paper was to explore students' ‘journey’ towards conceptual understanding during an undergraduate course. The task that medical students face – to learn a substantial quantity of detailed knowledge and integrate into a coherent whole in a limited time frame – is demanding. Seven students were interviewed in a group, and 17 students gave their reflections in writing. Data was gathered from both groups on five separate occasions. The findings suggest that students seek different kinds of understandings as they get to grips with their studies. The forms of understanding were: understanding as ‘knowing the language’, ‘knowing the map’, ‘knowing the catalogue’ and ‘experiencing an integrated whole’. Students first appeared to focus on the first two forms, and later in the course, as they learned more, they focused on the ‘catalogue’ or the ‘integrated whole’. The findings point to potential pathways students might take towards gaining deeper understanding.QC 20160220</p

Emotionally challenging learning situations : medical students’ experiences of autopsies

Objectives: To explore medical students' experiences of an emotionally challenging learning situation: the autopsy. Methods: Qualitative data were collected by means of written accounts from seventeen students after their first and third autopsies and a group interview with seven students after their first autopsy. Data was interpreted using inductive thematic analysis. Results: Students experienced the autopsy in three ways: as an unnatural situation, as a practical exercise, and as a way to learn how pathologists work. Most students found the situation unpleasant, but some were overwhelmed. Their experiences were characterised by strong unpleasant emotions and closeness to the situation. The body was perceived as a human being, recently alive. Students who experienced the autopsy as a practical exercise saw it mainly as a part of the course and their goal was to learn anatomy and pathology. They seemed to objectify the body and distanced themselves from the situation. Students who approached the autopsy as a way to learn how pathologists work concentrated on professional aspects of the autopsy. The body was perceived as a patient rather than as a biological specimen. Conclusions: Autopsies are emotionally challenging learning situations. If students attend autopsies, they need to participate in several autopsies in order to learn about procedures and manifestations of pathological changes. Students need opportunities to discuss their experiences afterwards, and teachers need to be aware of how different students perceive the autopsies, and guide students through the procedure. Our findings emphasize the importance of investigating emotional aspects of medical education.QC 20160226</p