Lack of replication of interactions between polymorphisms in rheumatoid arthritis susceptibility: case-control study.

INTRODUCTION: Approximately 100 loci have been definitively associated with rheumatoid arthritis (RA) susceptibility. However, they explain only a fraction of RA heritability. Interactions between polymorphisms could explain part of the remaining heritability. Multiple interactions have been reported, but only the shared epitope (SE) × protein tyrosine phosphatase nonreceptor type 22 (PTPN22) interaction has been replicated convincingly. Two recent studies deserve attention because of their quality, including their replication in a second sample collection. In one of them, researchers identified interactions between PTPN22 and seven single-nucleotide polymorphisms (SNPs). The other showed interactions between the SE and the null genotype of glutathione S-transferase Mu 1 (GSTM1) in the anti-cyclic citrullinated peptide-positive (anti-CCP+) patients. In the present study, we aimed to replicate association with RA susceptibility of interactions described in these two high-quality studies. METHODS: A total of 1,744 patients with RA and 1,650 healthy controls of Spanish ancestry were studied. Polymorphisms were genotyped by single-base extension. SE genotypes of 736 patients were available from previous studies. Interaction analysis was done using multiple methods, including those originally reported and the most powerful methods described. RESULTS: Genotypes of one of the SNPs (rs4695888) failed quality control tests. The call rate for the other eight polymorphisms was 99.9%. The frequencies of the polymorphisms were similar in RA patients and controls, except for PTPN22 SNP. None of the interactions between PTPN22 SNPs and the six SNPs that met quality control tests was replicated as a significant interaction term--the originally reported finding--or with any of the other methods. Nor was the interaction between GSTM1 and the SE replicated as a departure from additivity in anti-CCP+ patients or with any of the other methods. CONCLUSIONS: None of the interactions tested were replicated in spite of sufficient power and assessment with different assays. These negative results indicate that whether interactions are significant contributors to RA susceptibility remains unknown and that strict standards need to be applied to claim that an interaction exists.

Experiencia con rituximab en el tratamiento de pacientes con lupus. La base de datos LESIMAB / Use of rituximab in the treatment of lupus patients. The LESIMAB database

El lupus eritematoso sistémico es una enfermedad autoinmune sistémica que a menudo compromete la función de los órganos y reduce la supervivencia. Los avances en el diagnóstico y la terapéutica han mejorado su pronóstico a corto y medio plazo. No obstante, la mayoría de las mejoras terapéuticas proceden de avances alcanzados en otras áreas de la medicina y solo en los últimos años está cambiando esta tendencia. Lamentablemente el desarrollo de nuevos fármacos para el lupus se está enfrentando a unas dificultades especiales que han hecho que el desarrollo de rituximab en esta enfermedad haya sido detenido a pesar de los buenos resultados obtenidos en los estudios observacionales. La presente revisión analiza algunos de los aspectos que influyen en estas dificultades desde la perspectiva de LESIMAB una base de datos del grupo de trabajo EASSER (AU)

Systemic lupus erythematosus is an autoimmune disease that may involve the function of organs and reduce the survival of patients. Advances in the diagnosis and treatment have improved the short-term prognosis.However, most therapeutic improvements come from progress in other areas of medicine and only in recent years is this trend changing. Unfortunately, the development of new drugs for lupus is facing specific difficulties and the development of rituximab in lupus has been stopped despite good results in the observational studies. This review examines some of the aspects that influence these difficulties from the perspective of the LESIMAB database (AU)

[Use of rituximab in the treatment of lupus patients. The LESIMAB database]. / Experiencia con rituximab en el tratamiento de pacientes con lupus. La base de datos LESIMAB.

Systemic lupus erythematosus is an autoimmune disease that may involve the function of organs and reduce the survival of patients. Advances in the diagnosis and treatment have improved the short-term prognosis.However, most therapeutic improvements come from progress in other areas of medicine and only in recent years is this trend changing. Unfortunately, the development of new drugs for lupus is facing specific difficulties and the development of rituximab in lupus has been stopped despite good results in the observational studies. This review examines some of the aspects that influence these difficulties from the perspective of the LESIMAB database.

Analysis of TNFAIP3, a feedback inhibitor of nuclear factor-kappaB and the neighbor intergenic 6q23 region in rheumatoid arthritis susceptibility.

INTRODUCTION: Genome-wide association studies of rheumatoid arthritis (RA) have identified an association of the disease with a 6q23 region devoid of genes. TNFAIP3, an RA candidate gene, flanks this region, and polymorphisms in both the TNFAIP3 gene and the intergenic region are associated with systemic lupus erythematosus. We hypothesized that there is a similar association with RA, including polymorphisms in TNFAIP3 and the intergenic region. METHODS: To test this hypothesis, we selected tag-single nucleotide polymorphisms (SNPs) in both loci. They were analyzed in 1,651 patients with RA and 1,619 control individuals of Spanish ancestry. RESULTS: Weak evidence of association was found both in the 6q23 intergenic region and in the TNFAIP3 locus. The rs582757 SNP and a common haplotype in the TNFAIP3 locus exhibited association with RA. In the intergenic region, two SNPs were associated, namely rs609438 and rs13207033. The latter was only associated in patients with anti-citrullinated peptide antibodies. Overall, statistical association was best explained by the interdependent contribution of SNPs from the two loci TNFAIP3 and the 6q23 intergenic region. CONCLUSIONS: Our data are consistent with the hypothesis that several RA genetic factors exist in the 6q23 region, including polymorphisms in the TNFAIP3 gene, like that previously described for systemic lupus erythematosus.