title: Lack of association between alopecia areata and HLA class I and II in a southeastern Brazilian population.
abstract: BACKGROUND
  Alopecia areata (AA) is a common disorder of unknown etiology that affects approximately 0.7% to 3.8% of patients among the general population. Currently, genetic and autoimmune factors are emphasized as etiopathogenic. Studies linking Human Leukocyte Antigens (HLA) to AA have suggested that immunogenetic factors may play a role in the disease's onset/development.
  
  
  OBJECTIVE
  To investigate an association between AA and HLA class I/II in white Brazilians.
  
  
  METHODS
  Patients and control groups comprised 33 and 112 individuals, respectively. DNA extraction was performed by column method with BioPur kit. Allele's classification was undertaken using the PCR-SSO technique. HLA frequencies were obtained through direct counting and subjected to comparison by means of the chi-square test.
  
  
  RESULTS
  Most patients were aged over 16, with no familial history, and developed partial AA, with no recurrent episodes. Patients showed a higher frequency of HLA-B*40, HLA-B*45, HLA-B*53 and HLA-C*04 compared with controls, although P was not significant after Bonferroni correction. Regarding HLA class II, only HLA-DRB1*07 revealed statistical significance; nevertheless, it featured more prominently in controls than patients (P=0.04; Pc=0.52; OR=0.29; 95%; CI=0.07 to 1.25). P was not significant after Bonferroni correction.
  
  
  CONCLUSIONS
  The development of AA does not seem to be associated with HLA in white Brazilians, nor with susceptibility or resistance. The studies were carried out in populations with little or no miscegenation, unlike the Brazilian population in general, which could explain the inconsistency found.
authors.affiliation: Universidade do Oeste Paulista (UNOESTE) - Presidente Prudente (SP), Brazil.
authors.forename: Ângela Marques
authors.initials: ÂM
authors.lastname: Barbosa
authors.affiliation: Universidade do Oeste Paulista (UNOESTE) - Presidente Prudente (SP), Brazil.
authors.forename: Luiz Euribel
authors.initials: LE
authors.lastname: Prestes-Carneiro
authors.affiliation: Universidade Estadual de Maringá (UEM) - Maringá (PR), Brazil.
authors.forename: Aldri Roberta Sodoschi
authors.initials: AR
authors.lastname: Sobral
authors.affiliation: Universidade Estadual de Maringá (UEM) - Maringá (PR), Brazil.
authors.forename: Marcelo Jun
authors.initials: MJ
authors.lastname: Sakiyama
authors.affiliation: Universidade do Oeste Paulista (UNOESTE) - Presidente Prudente (SP), Brazil.
authors.forename: Bruna Cerávolo
authors.initials: BC
authors.lastname: Lemos
authors.affiliation: Universidade do Oeste Paulista (UNOESTE) - Presidente Prudente (SP), Brazil.
authors.forename: Marilda Aparecida Milanez Morgado de
authors.initials: MA
authors.lastname: Abreu
authors.affiliation: Universidade do Oeste Paulista (UNOESTE) - Presidente Prudente (SP), Brazil.
authors.forename: Luciana Leite Crivelin
authors.initials: LL
authors.lastname: Martos
authors.affiliation: Universidade Estadual de Maringá (UEM) - Maringá (PR), Brazil.
authors.forename: Ricardo Alberto
authors.initials: RA
authors.lastname: Moliterno
mesh_terms: D000293:Adolescent; D000328:Adult; D000506:Alopecia Areata / Q000235:genetics / Q000276:immunology; D001938:Brazil; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D015235:HLA-B Antigens / Q000097:blood / Q000235:genetics; D015236:HLA-C Antigens / Q000097:blood / Q000235:genetics; D059811:HLA-DRB1 Chains / Q000097:blood / Q000235:genetics; D015395:Histocompatibility Antigens Class I / Q000097:blood / Q000235:genetics*; D000949:Histocompatibility Antigens Class II / Q000097:blood / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D044465:White People; D055815:Young Adult
chemical_list: D015235:HLA-B Antigens; D015236:HLA-C Antigens; D059811:HLA-DRB1 Chains; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II