title: Genetic and immunological evidence implicates interleukin 6 as a susceptibility gene for leprosy type 2 reaction.
abstract: In leprosy, type 1 reaction (T1R) and type 2 reaction (T2R) are major causes of nerve injury and permanent disabilities. A previous study on plasma levels of 27 cytokines in patients with T1R or T2R and controls with nonreactional leprosy identified the gene for interleukin 6 (IL-6) as a candidate for genetic analysis. Two nested case-control studies were built from a cohort of 409 patients with leprosy from central Brazil, monitored for T1R and T2R. There was evidence for association between T2R and IL-6 tag single-nucleotide polymorphisms rs2069832 (P = .002), rs2069840 (P = .03), and rs2069845 (P = .04), with information on the entire IL-6 locus, as well as functional IL-6 variant rs1800795 (P = .005). Moreover, IL-6 plasma levels in patients with T2R correlated with IL-6 genotypes (P = .04). No association was found between IL-6 variants and T1R. Identifying genetic predictive factors for leprosy reactions may have a major impact on preventive strategies.
authors.affiliation: Tropical Pathology and Public Health Institute, Federal University of Goiás, Goiania, Brazil.
authors.forename: Ana Lucia M
authors.initials: AL
authors.lastname: Sousa
authors.forename: Vinicius M
authors.initials: VM
authors.lastname: Fava
authors.forename: Lucas H
authors.initials: LH
authors.lastname: Sampaio
authors.forename: Celina Maria T
authors.initials: CM
authors.lastname: Martelli
authors.forename: Mauricio B
authors.initials: MB
authors.lastname: Costa
authors.forename: Marcelo T
authors.initials: MT
authors.lastname: Mira
authors.forename: Mariane M A
authors.initials: MM
authors.lastname: Stefani
mesh_terms: D000328:Adult; D000368:Aged; D001938:Brazil; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D056426:Genetic Loci; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D007918:Leprosy / Q000175:diagnosis / Q000235:genetics* / Q000276:immunology / Q000503:physiopathology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020641:Polymorphism, Single Nucleotide; D011446:Prospective Studies; D012641:Selection, Genetic; D055815:Young Adult
chemical_list: D005819:Genetic Markers; C508600:IL6 protein, human; D015850:Interleukin-6