Polymorphisme ABO dans une population de donneurs de sang tunisiens

Infantile pyknocytosis, a neonatal hemolytic anemia with Heinz bodies: A cohort study

Infantile pyknocytosis (IP) is a rare, probably misestimated, cause of non-immune neonatal hemolytic anemia evolving in two phases: an initial phase with severe jaundice, followed by a second phase with hemolytic anemia, which may require neonatal intensive care. The diagnosis of IP is based on the transient presence on blood smear of hyperdense, contracted, and/or spiculated red blood cells (pyknocytes), associated with the spontaneous resolution of clinico-biological features and the exclusion of other causes. If the etiology remains undetermined, some contributing factors, such as oxidative stress, have been proposed. We report the description of 16 patients with IP aiming at clarifying the circumstances associated with the development of this acquired disorder. In the acute phase, the mean hemoglobin nadir and pyknocyte count were 7.8 g/dL and 11%, respectively, and strikingly, Heinz bodies were evident in 50% of the newborns, but in 100% after prolonged incubation (4 hours). A high proportion of Mediterranean or African ancestry was noted in newborns, as well as a significant number of peripartum events, such as respiratory distress. If the etiology of IP is certainly multifactorial, our series reinforces the role of oxidative stress, which may, at least in part, find origin in desaturation episodes in newborns.

Blood Group Distribution in Switzerland - a Historical Comparison

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.

Frequencies and ethnic distribution of ABO and Rh(D) blood groups in Mauritania: results of first nationwide study

There is no data available on the ABO/Rh(D) frequencies in the Mauritanian population. We retrospectively analysed records of a 5-year database that contained ABO/Rh phenotype and ethnic origin of 10 116 volunteers giving blood at the national blood transfusion centre to derive the frequencies of ABO/Rh(D) groups in the Mauritanian population. The two race categories in the country and their sub-ethnic groups: the Moors (whites and black) and the black Africans (Pulhars, Soninkes and Wolof) were included in this study. Globally, group O had the highest frequency (49.10%) followed by A (28.28%), B (18.56%) and AB (4.05%). This order more common in North African populations was found in four of the five ethnic groups composing our population. Allele frequencies were, respectively, 70.20%, 17.74% and 12.04% giving the same order of O > A > B. We observed no significant variation in these frequencies between the different ethnic groups. Rhesus study showed that with a percentage of 94.23% Rh(D) positive is by far the most prevalent, while Rh(D) negative is present only in 5.77% of the total population. This frequency distribution supports the mixed-race composition of the Mauritanian population.

The blood donor in sub-Saharan Africa: a review

The high prevalence of numerous endemic and epidemic diseases such as malaria, HIV infection and viral hepatitis in some areas of sub-Saharan Africa (SSA) affects the health status of blood donors. Considering the difficulties in ensuring sufficient and safe blood supply, analysing epidemiological factors that impact blood donors in this community may further bring light on issues of supply and safety, and help in planning for its rational use. This review does not aim to propose new strategies but describes the main characteristics of blood donors in SSA as collected from different reports. Data were mainly obtained from the reports of the World Health Organization and national blood transfusion programmes and also from relevant literature and conference reports. Several characteristics are common in blood donors, such as the predominance of young adult males, the high frequency of Transmission-transmitted Infections (TTIs) and some erythrocytic phenotypes. The data indicate variations in the level of improvement of blood collection and blood safety from one area to another, particularly in the field of donor motivation or screening strategies for TTIs. These data could be useful to supplement previous reports and to provide updates for governments and international organizations' programs involved in the improvement of blood safety in Africa.