Revista Brasileira de Hematologia e Hemoterapia Revista Brasileira de Hematologia e Hemoterapia
Rev Bras Hematol Hemoter 2017;39:122-6 DOI: 10.1016/j.bjhh.2017.01.003
Original article
Molecular typing of human platelet antigens in immune thrombocytopenia patients in northern Brazil
Julia Cavalcante do Carmoa, Prissyla de Souza Klippela, Sabrine da Costa Cordeirob, Ângela Maria dos Santos Fernandesb, Raquel Medeiros Pintoa, Simone Schneider Weberc,d,, , Cleiton Fantina
a Universidade do Estado do Amazonas (UEA), Manaus, AM, Brazil
b Fundação de Hematologia e Hemoterapia do Amazonas (Hemoam), Manaus, AM, Brazil
c Universidade Federal do Amazonas (UFAM), Itacoatiara, AM, Brazil
d Universidade Federal do Mato Grosso do Sul (UFMS), Campo Grande, MS, Brazil
Recebido 26 Outubro 2016, Aceitaram 05 Janeiro 2017

Immune thrombocytopenia is an immune disease characterized by thrombocytopenia and bleeding due to platelet antibodies against platelet membrane glycoproteins. Human platelet antigens are derived from polymorphisms of these glycoproteins. The aim of this study was to investigate human platelet antigen frequencies in immune thrombocytopenia patients from the state of Amazonas, Brazil and investigate the potential association between specific antigens and risk for immune thrombocytopenia.


Human platelet antigen typing was performed by BeadChip technology to determine allelic variants of 11 systems (HPA-1 to HPA-9, HPA-11 and HPA-15). Thirty-six patients (8 male and 28 female) with a median age of 34 years (range: 9–69 years) were evaluated and compared with data from Amazonas blood donors.


Platelet counts varied from 3 to 98×109/L. The allele frequencies were 0.944 for HPA-1a, 0.056 for HPA-1b, 0.847 for HPA-2a, 0.153 for HPA-2b, 0.555 for HPA-3a, 0.444 for HPA-3b, 0.805 for HPA-5a, 0.222 for HPA-5b, 0.9975 for HPA-9a, 0.025 for HPA-9b, 0.486 for HPA-15a and 0.513 for HPA-15b. Among immune thrombocytopenia individuals, no b allele of the HPA-4, -6, -7, -8 and -11 were found.


The results suggest HPA-1a, HPA-3b and HPA-5b are immune thrombocytopenia-specific autoepitopes.

Immune thrombocytopenia, Platelets, BeadCheap technology, Genotyping, HPA
Rev Bras Hematol Hemoter 2017;39:122-6 DOI: 10.1016/j.bjhh.2017.01.003