title: Genetic response to an environmental pathogenic agent: HLA-DQ and onchocerciasis in northwestern Ecuador.
abstract: The aim of this study is to explore human leukocyte antigen (HLA)-DQ variability in two populations (Cayapas Amerindians and Afro-Ecuadorians) who live near one another along the Cayapa River and who are exposed to the same environmental stresses, such as infection by Onchocerca volvulus. HLA-DQA1 and HLA-DQB1 of 149 unrelated individuals (74 Cayapas and 75 Afro-Ecuadorians) have been analyzed. HLA high-resolution molecular typing was performed by sequence-based typing, sequence-specific oligonucleotides hybridization and sequence-specific primer (SSP) amplification. The comparison between affected (cases) and unaffected people (controls) in both populations shows the key role of several HLA-DQA1 alleles in susceptibility and protection against onchocerciasis. In both populations, there is strong evidence related to the protective role of DQA1*0401 against onchocerciasis. Alleles HLA-DQA1*0102 and *0103 seem to represent risk factors in Afro-Ecuadorians, while HLA-DQA1*0301 is only a suggestive susceptibility allele in Cayapas. These findings represent new positive/negative associations with onchocerciasis in South America, whereas previous findings pertained only to African populations.
authors: Department of Biology, University of Rome Tor Vergata, Rome, Italy. flavio.de.angelis@uniroma2.it
authors: F
authors: F
authors: De Angelis
authors: A
authors: A
authors: Garzoli
authors: A
authors: A
authors: Battistini
authors: A
authors: A
authors: Iorio
authors: G F
authors: GF
authors: De Stefano
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D044467:American Indian or Alaska Native; D000818:Animals; D044383:Black People; D016022:Case-Control Studies; D002648:Child; D017931:DNA Primers; D004198:Disease Susceptibility; D004484:Ecuador / Q000453:epidemiology; D005260:Female; D005787:Gene Frequency; D059647:Gene-Environment Interaction; D059848:HLA-DQ alpha-Chains / Q000235:genetics* / Q000276:immunology; D059866:HLA-DQ beta-Chains / Q000235:genetics* / Q000276:immunology; D006239:Haplotypes; D006650:Histocompatibility Testing; D006801:Humans; D008297:Male; D008875:Middle Aged; D021141:Nucleic Acid Amplification Techniques; D009854:Onchocerca / Q000276:immunology*; D009855:Onchocerciasis / Q000208:ethnology / Q000235:genetics* / Q000276:immunology; D011110:Polymorphism, Genetic
chemical_list: D017931:DNA Primers; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; C069050:HLA-DQA1 antigen; C069051:HLA-DQB1 antigen