GENOTYPING OF HUMAN PLATELET ANTIGENS IN AN ADMIXED POPULATION

MIGONI, ARIANA; LUJAN BRAJOVICH, MELINA; RACCA, LILIANA; MATTALONI, STELLA MARIS; TRUCCO BOGGIONE, CAROLINA; GARCIA BORRAS, SILVIA; COTORRUELO, CARLOS; ENSINCK, MARÍA ALEJANDRA; MUFARREGE, NICOLÁS; BIONDI, CLAUDIA

Copenhague

Congreso; 27th Regional Congress of the International Society of Blood Transfusion; 2017

International Society of Blood Transfusion

Background: Human Platelet Antigens (HPAs) are polymorphic structures located on the platelet glycoprotein complexes and havebeen implicated in alloimmune disorders, including foetal and neonatal alloimmune thrombocytopenia, post-transfusion purpura andplatelet transfusion refractoriness. The frequencies of HPAs vary between different populations. In Caucasians, HPA-1 is the mostimportant antigenic system involved in platelet alloimmunity. The population of Argentina is composed predominantly by CaucasianEuropeans admixed with Amerindians and Africans and the admixture degree varies among different social groups within a city. Inthis sense, the HPA polymorphism distribution occurring in our population is scarcely known.Aims: The aim of this work was to investigate the genotype and allele frequencies of the HPA-1, HPA-2 and HPA-3 systems inindividuals from two groups representing different social strata of the population.Methods: Two sample cohorts of unrelated adults of both sexes from the city of Rosario, the third largest city located in the centralarea of Argentina, were studied. The first cohort (Group 1 [G1]) included 131 blood samples collected at a public health care center,where the assistance is supported by the provincial government and is intended for the low-income population. The second cohort(Group 2 [G2]) included 105 blood samples collected at a private clinical laboratory, where clinical tests are financed throughinsurance companies. HPA typing was performed by molecular strategies based on PCR-SSP and PCR-RFLP.Results: HPA-1 genotype frequencies for G1 were: 1a/1a=0.83, 1a/1b=0.17, 1b/1b=0.00 while for G2 were 1a/1a=0.71, 1a/1b=0.28,1b/1b=0.02. The allele frequencies found for G1 were: HPA-1a=0.92, HPA-1b=0.08 while for G2 were HPA-1a=0.84, HPA-1b=0.18.HPA-2 genotype frequencies for G1 were: 2a/2a=0.73, 2a/2b=0.26, 2b/2b=0.02 while for G2 were: 2a/2a=0.85, 2a/2b=0.13,2a/2b=0.02. The allele frequencies found for G1 were: HPA-2a=0.86, HPA-2b=0.15 while for G2 were HPA-2a=0.91, HPA-2b=0.09.HPA-3 genotype frequencies for G1 were: 3a/3a=0.38, 3a/3b=0.47, 3b/3b=0.15 while for G2 were: 3a/3a=0.44, 3a/3b=0.53,3b/3b=0.03. The allele frequencies found for G1 were: HPA-3a=0.62, HPA-3b=0.38 while for G2 was HPA-3a=0.71, HPA-3b=0.30.According to chi-square test, statistically significant differences were found for the HPA genotype distribution between both groups(HPA-1: p