title: Frequencies of human neutrophil antigen-4 and human neutrophil antigen-5 among Thai blood donors.
abstract: BACKGROUND
  Antibodies against human neutrophil antigens (HNAs) are implicated in immune-mediated neutropenia, transfusion-related acute lung injury and febrile transfusion reactions.
  
  
  OBJECTIVE
  This study aimed to determine HNA gene frequencies of the HNA-4 and HNA-5 systems among Thai populations and compare these frequencies with those previously reported for other populations.
  
  
  METHODS
  800 DNA samples obtained from 500 unrelated healthy blood donors from Bangkok and 300 samples from Chiang Mai, Thailand were included. Samples were typed for each HNA allele including HNA-4a, HNA-4b, HNA-5a, and HNA-5b using an in-house polymerase chain reaction with sequence-specific primer technique.
  
  
  RESULTS
  The frequencies of HNA-4a and HNA-4b alleles in central Thais were 0.975 and 0.025, respectively and for Northern Thais, their frequencies were 0.965 and 0.035, respectively. For HNA-5a and HNA-5b alleles, their frequencies were 0.771 and 0.229; 0.748, and 0.252 in central and Northern Thais, respectively. The frequencies of HNA-4 and HNA-5 systems in central Thais are closely related to those in Northern Thais (P > 0.05). However, their frequencies were different from other populations (P < 0.001), except HNA-5a and HNA-5b gene frequencies in Thais were similar to Caucasians (P > 0.05).
  
  
  CONCLUSIONS
  This study could contribute to predict the risk of alloimmunization to HNA-4 and HNA-5 systems, especially in feto-maternal incompatibility in Thais.
authors.affiliation: Department of Medical Technology, Faculty of Allied Health Sciences, Thammasat University, Pathum Thani, Thailand.
authors.forename: Onruedee
authors.initials: O
authors.lastname: Khantisitthiporn
authors.affiliation: Department of Medical Technology, Faculty of Allied Health Sciences, Thammasat University, Pathum Thani, Thailand.
authors.forename: Chollanot
authors.initials: C
authors.lastname: Kaset
authors.affiliation: Department of Graduate Program, Faculty of Allied Health Sciences, Thammasat University, Pathum Thani, Thailand.
authors.forename: Kamphon
authors.initials: K
authors.lastname: Intharanut
authors.affiliation: Department of Blood Bank Section, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Nipapan
authors.initials: N
authors.lastname: Leetrakool
authors.affiliation: Department of Graduate Program, Faculty of Allied Health Sciences, Thammasat University, Pathum Thani, Thailand.
authors.forename: Oytip
authors.initials: O
authors.lastname: Nathalang
keywords: Gene frequencies; Thais; human neutrophil antigen-4; human neutrophil antigen-5