title: Association analysis of human leukocyte antigen class II (DRB1) alleles with leprosy in individuals from São Luís, state of Maranhão, Brazil.
abstract: Epidemiological studies have demonstrated that the variability of the clinical response to infection caused by Mycobacterium leprae is associated with host genetic factors. The present study investigated the frequency of human leukocyte antigen (HLA) class II (DRB1) alleles in patients with leprosy from São Luís, Maranhão, Brazil. A case-control study was performed in 85 individuals with leprosy and 85 healthy subjects. All samples were analysed via polymerase chain reaction-sequence specific oligonucleotide probes. The HLA-DRB1*16 allele showed a higher frequency in the group with leprosy [(9.41% vs. 4.12%) odds ratio (OR) = 2.41 95% confidence interval (CI) (0.96-6.08) p = 0.05], whereas the HLA-DRB1*11 allele was less frequent in the group with leprosy [(6.47% vs. 11.76%) OR = 0.51 95% CI (0.23-1.12) p = 0.09]. The frequency of HLA-DRB1* alleles between the control group and leprosy patient subgroups presenting different forms of the disease showed that the HLA-DRB1*16 (16.13% vs. 8.24%, OR = 4.10, CI = 1.27-13.27, p = 0.010) and HLA-DRB1*14 (5% vs. 3.53%, OR = 4.63, CI = 1.00-21.08, p = 0.032) alleles were significantly more frequent in patients with different clinical subtypes of leprosy. The sample size was a limitation in this study. Nevertheless, the results demonstrated the existence of a genetic susceptibility associated with the clinical forms of leprosy. The low frequency of the HLA-DRB1*11 allele should be further studied to investigate the possible protective effect of this allele.
authors.affiliation: Grupo de Pesquisa em Epidemiologia de Doenças Transmissíveis , Universidade Federal do Maranhão, São Luís, MA, Brasil. profaritacarvalhal@gmail.com
authors.forename: Rita da Graça Carvalhal Frazão
authors.initials: Rda G
authors.lastname: Corrêa
authors.forename: Dorlene Maria Cardoso
authors.initials: DM
authors.lastname: de Aquino
authors.forename: Arlene de Jesus Mendes
authors.initials: Ade J
authors.lastname: Caldas
authors.forename: Humberto de Oliveira
authors.initials: Hde O
authors.lastname: Serra
authors.forename: Fábio França
authors.initials: FF
authors.lastname: Silva
authors.forename: Maxwellem de Jesus Costa
authors.initials: Mde J
authors.lastname: Ferreira
authors.forename: Elton Jonh Freitas
authors.initials: EJ
authors.lastname: Santos
authors.forename: Emygdia Rosa Rêgo Barros Pires Leal
authors.initials: ER
authors.lastname: Mesquita
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D001938:Brazil; D016022:Case-Control Studies; D002648:Child; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D059811:HLA-DRB1 Chains / Q000235:genetics*; D006801:Humans; D007918:Leprosy / Q000235:genetics* / Q000276:immunology*; D007962:Leukocytes / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D059811:HLA-DRB1 Chains