Distribution of ABO alleles in the Northeast Algerian population.

OBJECTIVES: The study of ABO polymorphism has contributed to the understanding of human genetic diversity. The objective of our work is to determine the phenotypic and allelic frequencies of the ABO system in the population of the Algerian Northeast, and to make a comparative study with other national and world populations. METHODS: The study included 10,208 blood donors, originating from the Northeast of Algeria, the ABO grouping was carried out by serological techniques on plate and gel card, the comparison of the ABO allelic frequencies, and the genetic distances between the populations, were carried out respectively by using the R software, and the SPSS version 20 software. RESULTS: The order of frequency of ABO phenotypes is O>A>B>AB, with respectively 46.32%, 33.47%, 15.93% and 4.28%, while the order of frequency of ABO alleles is O>A>B with respectively 0.6820, 0.2112, 0.1068. The estimation of the genetic distances between our study population and other national, North African and world populations, allowed us to observe that our study population is very close genetically to North African populations, and the genetic differences were less pronounced with sub-Saharan populations, than with European and Asian populations. CONCLUSION: Our region has known multiple movements and population mixtures that have contributed to the genetic identity of our population, linked in part to its geographical location at the gateway to Africa, and on the southern shore of the Mediterranean, but also to several historical events such as invasions, trade, and Islamic conquests.

HPA antibodies in Algerian multitransfused patients: Prevalence and involvement in platelet refractoriness.

BACKGROUND: Patients receiving cellular blood components may form HLA or HPA antibodies. The frequency and the specificity of HPA antibodies after a series of blood transfusions have never been reported in the Algerian population which is ethnically diverse and runs a higher risk of platelet alloimmunization due to high b allelic frequencies observed for the HPA systems. METHODS: 117 polytransfused patients were included in this study; the detection of HPA antibodies was performed by the Monoclonal Antibody-specific Immobilization of Platelet Antigens method (MAIPA). Post-transfusion platelet effectiveness was evaluated by the calculation of corrected count increment (CCI). RESULTS: The antibodies against platelets were detected in 10.26% of the patients. In this study, the platelet systems concerned by the alloimmunizations were specifically HPA-1, -3 and -5 with particular predominance of HPA-1. Twenty two patients were refractory to platelet transfusion, as assessed by a CCI; in which 64% have factors associated with increased platelet consumption. Platelet Immunization was found in 14% of platelet refractoriness (PTR) cases. 03 Anti-platelet antibodies were directed against GPIb-IX (n = 1), anti-HPA-1b (n = 1) and anti HPA-5b (n = 1) associated with anti-HLA antibodies in two cases. CONCLUSION: HLA and HPA alloimmunization is common among chronically transfused patients. PTR detection, identification of the underlying causes, and selection of the appropriate product for transfusion are fundamental to reduce the risk of major bleedings.