title: Evaluation of polymorphic variants in apoptotic genes and their role in susceptibility and clinical progression to systemic lupus erythematosus.
abstract: Background Systemic lupus erythematosus (SLE) is an autoimmune disease marked by the disruption of the immune homeostasis. Patients exhibit a wide range of clinical manifestations, and environmental and genetic factors are involved in SLE pathogenesis. Evidence suggests that abnormalities in the cellular and molecular events that coordinate apoptosis may favour the generation of autoantigens involved in autoimmunity. In this way, the apoptotic deregulation may be affected by polymorphic variants in apoptotic-related genes. Methods We analyzed FAS, FASL, BCL-2 and BAX polymorphisms in order to correlate to SLE susceptibility and clinical features. A total of 427 SLE patients from the Hospital de Clínicas de Porto Alegre and 543 controls from southern Brazil were evaluated. Results We observed higher frequencies of the FASL -844CC genotype and -844C allele, as well as of the FASL-844C/IVS2nt-124A haplotype in African-derived SLE patients when compared to controls ( P < 0.001). FASL -844C, which is related to high FasL expression, could contribute to increased apoptosis and to the breakdown of immunological tolerance, favouring autoantibody production and inflammation. On the other hand, the BAX -248GA genotype and the -248A allele , related to low protein expression, were observed as a protective factor against SLE in this same population. The rate of apoptosis and cell death was evaluated in peripheral lymphocytes, and SLE patients presented a higher percentage of dead lymphocytes (CD3+Annexin V+7-AAD+) compared to the control group. Conclusion Our data support a role for apoptosis in SLE susceptibility.
authors.affiliation: 1 Laboratory of Immunogenetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: N
authors.initials: N
authors.lastname: Glesse
authors.affiliation: 1 Laboratory of Immunogenetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: P
authors.initials: P
authors.lastname: Vianna
authors.affiliation: 1 Laboratory of Immunogenetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: L M G
authors.initials: LMG
authors.lastname: Paim
authors.affiliation: 1 Laboratory of Immunogenetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: M C C
authors.initials: MCC
authors.lastname: Matte
authors.affiliation: 1 Laboratory of Immunogenetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: A K K
authors.initials: AKK
authors.lastname: Aguiar
authors.affiliation: 1 Laboratory of Immunogenetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: P L
authors.initials: PL
authors.lastname: Palhano
authors.affiliation: 2 Division of Rheumatology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: O A
authors.initials: OA
authors.lastname: Monticielo
authors.affiliation: 2 Division of Rheumatology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: C V
authors.initials: CV
authors.lastname: Brenol
authors.affiliation: 2 Division of Rheumatology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: R M
authors.initials: RM
authors.lastname: Xavier
authors.affiliation: 1 Laboratory of Immunogenetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: J A B
authors.initials: JAB
authors.lastname: Chies
mesh_terms: D000328:Adult; D000483:Alleles; D017209:Apoptosis / Q000235:genetics*; D001938:Brazil; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000235:genetics* / Q000503:physiopathology; D008214:Lymphocytes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic
keywords: Bcl-2; Fas/FasL pathway; Systemic lupus erythematosus; apoptosis; genetic polymorphisms