Allelic polymorphisms of human platelets-specific alloantigens in South Tunisian population.

Objectives: Human platelet-specific alloantigens (HPA) are polymorphic epitopes which vary among ethnic groups.
Background: In Tunisia, HPA frequencies were determined in North and centre; however, the pattern of HPA in South Tunisian population is not been studied yet. The aim of this work was to determine allelic frequencies of HPA-1, -3, and -5 systems in south Tunisian population, in order to estimate the risk of anti-platelet allo-immunization and to create a register of HPA-typed blood donors.
Methods: Our study concerned 212 unrelated healthy, regular blood donors from southern Tunisia. Allelic polymorphisms of each system were determined using a polymerase chain reaction with sequence-specific primers.
Results: Genotype frequencies a/a, a/b, and b/b were, respectively, 0.670, 0.288, and 0.042 for HPA-1 system, 0.430, 0.462, and 0.108 for HPA-3 system, and 0.750, 0.241, and 0.009 for HPA-5 system. The allele frequencies were 0.814 and 0.186 for HPA-1a and -1b alleles; 0.660 and 0.340 for HPA-3a and -3b alleles and 0.870, and 0.130 for HPA-5a and -5b alleles.
Discussion: The reported frequencies are more similar to those of Caucasians than those of north Tunisian population.