title: Influence of human leukocyte antigen class II alleles on susceptibility to Entamoeba histolytica infection in Bangladeshi children.
abstract: BACKGROUND
  The association of antibody responses with both innate and acquired immunity to amebiasis indicate that CD4+ T cells play a role in protection against Entamoeba histolytica infection. To test this hypothesis, we compared the genotype frequencies of human leukocyte antigen (HLA) class II alleles in a cohort of Bangladeshi children intensively monitored for E. histolytica infection for a 3-year period.
  
  
  METHODS
  Using logistic regression, we calculated the odds of disease by genotype and by haplotype.
  
  
  RESULTS
  The DQB1*0601 heterozygous and homozygous genotypes were found in 55% of E. histolytica-negative children but in only 34% of E. histolytica-positive children (overall odds ratio, 2.39; 95% confidence interval [CI], 1.26-4.54). Children who were heterozygous for the DQB1*0601/DRB1*1501 haplotype were 10.1 times (95% CI, 2.02-50.6) more likely to be both E. histolytica negative and serum anti-lectin immunoglobulin G negative at baseline. Other DQB1 and DRB1 alleles (DQB1*0202, DQB1*0301, and DRB1*0701) were not associated with any of the clinical outcomes related to amebiasis.
  
  
  CONCLUSIONS
  A potential protective association was observed with the HLA class II allele DQB1*0601 and the heterozygous haplotype DQB1*0601/DRB1*1501. This association may explain why amebiasis does not occur in some children who are exposed to the parasite and implicates HLA class II-restricted immune responses in protection against E. histolytica infection.
authors.affiliation: Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Priya
authors.initials: P
authors.lastname: Duggal
authors.forename: Rashidul
authors.initials: R
authors.lastname: Haque
authors.forename: Shantanu
authors.initials: S
authors.lastname: Roy
authors.forename: Dinesh
authors.initials: D
authors.lastname: Mondal
authors.forename: R Bradley
authors.initials: RB
authors.lastname: Sack
authors.forename: Barry M
authors.initials: BM
authors.lastname: Farr
authors.forename: Terri H
authors.initials: TH
authors.lastname: Beaty
authors.forename: William A
authors.initials: WA
authors.lastname: Petri
mesh_terms: D000483:Alleles; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D001459:Bangladesh; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004748:Entamoeba histolytica / Q000276:immunology; D004749:Entamoebiasis / Q000097:blood / Q000235:genetics* / Q000276:immunology; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006683:HLA-DQ Antigens / Q000235:genetics*; D059866:HLA-DQ beta-Chains; D006239:Haplotypes; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D016015:Logistic Models; D008297:Male; D011446:Prospective Studies; D014505:Urban Population
chemical_list: D000913:Antibodies, Protozoan; D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D007074:Immunoglobulin G