Background: Ethnicities differ in prevalence of blood groups and antigens. Substantial donor-recipient mismatch within mixed-ethnic societies may render certain recipients at higher risk for alloimmunization. Data regarding antigen distribution within Switzerland by ethnicity is limited. We examined immigration patterns against the distribution of ABO blood groups using large cross-sectional Swiss samples spanning 70 years. Methods: Historical ABO blood group distribution data (1940-1945) from Swiss army personnel (n = 275,664) were sourced from the literature. Recent blood group phenotypes of 122,925 individuals who presented themselves at army recruitment centers (2004-2015) were obtained, alongside a validation sample of 175,202 patients from a university hospital. Two-sample tests with z-statistics assessing blood groups between samples were used. Results: The respective proportions of A (47.2% and 45.2%), B (8.4% and 9.8%), and AB (3.0 and 4.1) in the historical and recent army samples were significantly different (p < 0.001), while group O was not. Conclusion: ABO blood groups in Switzerland have remained stable despite substantial immigration with a changing foreign-national profile. Further research is needed to improve the understanding of antigen differences in newly introduced ethnic groups. Blood product requirements and public health initiatives aimed at recruiting blood donors would benefit from this information.

To conduct a study project on the inactivation of pathogens in whole blood using acridine derivatives in Africa, in order to prevent the transmission of pathogens, it is important to look for possible immunization to acridine in the blood donor population. It is therefore important to undertake an estimate of the prevalence in the sub-Saharan population in order to guide the design of the clinical study that will use the INTERCEPT Red Blood System procedure on whole blood for transfusion. to define the starting point in the evaluation of the immunological safety and transfusion safety of the product treated by this process. The objective of this study is to determine the prevalence of AAA among blood donors in sub-Saharan Africa. We conducted a multicenter prospective descriptive study of 902 blood donors collected in Côte d'Ivoire, Benin and Cameroon over the period from June 2015 to January 2017. Blood samples were collected from voluntary blood donors, of any sex, aged between 18 and 65, having given their consent for the study and having participated in the medical consultation for the donation of blood. The samples were analyzed according to the technique of the RAI gel card of the company BIORAD after centrifugation and incubation using test red cells treated with S-303 and glutathione. In the case of positive RAI results, to confirm the presence of anti-acridine, the donor plasma should be incubated with S-300. S-300 is a degradation product of S-303. The donor serum and S-300 are then incubated with the same red test cells. S-300 binds to the antibody and produces a negative result in the gel map in the presence of anti-acridin antibodies. Of the 903 samples tested both at the Abidjan laboratory in Côte D'Ivoire and at the Frankfurt laboratory, we found 1 positive sample and 8 reactive samples (positive for anti-erythrocyte antibodies). Positive donor plasma was incubated with S-300 which is the degradation product of S-303. The result is always positive, whereas according to the instructions of the reference laboratory of Frankfurt, it should be negative in case of presence of Locustacan. The results on AAA testing among 903 donors in three sub-Saharan countries show the absence of AAA in the sample of subjects included in the study according to the hypothesis emitted from this study. This opens the door to the prospect of conducting a clinical study on the inactivation of pathogens by acridine derivatives.

A part from any incompatible blood transfusion, anti-erythrocyte alloimmunization is observed to pregnant women. It is the result of the passage of red blood cells carrying antigens different from those of the mother during pregnancy and delivery. The Rhesus D system is the most involved; but there are also other systems involved in this alloimmunization. Non-transfusion alloimmunization is an extremely rare event in the order of 1 of 4000 to women in Europe and in most cases concerns the Rhesus D. In sub-Saharan Africa, there are no statistics collected on foeto-maternal alloimmunization. As part of our postgraduate thesis on the sensitization status of red blood cells to acridine, we used the technique of looking for irregular agglutinins. The goal was to find anti-erythrocyte alloimmunization to blood donors in sub-Saharan Africa. We conducted a two-year multicenter prospective and descriptive study of 903 blood donors in Côte d'Ivoire, Benin and Cameroon. The samples were analyzed in the laboratories of the National Blood Transfusion Center of Côte D'Ivoire and Frankfurt according to the technique of the RAI gel card of the BIORAD company after centrifugation and incubation using test red cells treated with S-303. In the case of a positive reaction, identification is made by a panel of red blood cells in the different blood group systems. In our study population, there is a male predominance with a male/female ratio of 7.42. We found a very low prevalence of alloimmunization to non-transfused blood donors (0.9% or 8 cases out of 902). 4 anti-erythrocyte antibodies have been identified (1 Ac anti D and 3 AC anti S); 2 pan-agglutination, 2 unidentified Ac (insufficient serum) and suspicion of anti-glutathione. Anti-erythrocyte alloimmunization to sub-Saharan Africa blood donor is about 0.9% in our series. It remains high compared to European data. This alloimmunization is mainly observed to women with low frequency antigens to black peoples.