Analysis of IRF5 gene functional polymorphisms in rheumatoid arthritis.
OBJECTIVE
Recent findings suggest that interferon regulatory factor 5 (IRF-5) may play a crucial role in several cellular processes, including the transcription of genes for inflammatory cytokines. Two genetic variants of the IRF5 gene (rs2004640 in exon 1 and rs2280714 in the 3'-untranslated region) have been shown to exert functional modifications affecting IRF5 messenger RNA splicing and expression, and have been associated with genetic predisposition to systemic lupus erythematosus (SLE). The aim of this study was to analyze the possible contribution of the IRF5 gene to the predisposition to rheumatoid arthritis (RA).


METHODS
Three case-control cohorts from Spain (724 RA patients and 542 healthy controls), Sweden (281 RA patients 474 healthy controls), and Argentina (284 RA patients and 286 healthy controls) were independently analyzed. Genotyping for IRF5 rs2004640 and rs2280714 was performed using a TaqMan 5' allele-discrimination assay.


RESULTS
In the 3 cohorts studied, no statistically significant differences in allele or genotype frequencies of the rs2004640 and rs2280714 IRF5 polymorphisms were observed between RA patients and controls. Accordingly, haplotype analysis revealed that none of the IRF5 haplotypes was associated with genetic predisposition to RA.


CONCLUSIONS
Our results suggest that the IRF5 functional polymorphisms analyzed do not seem to be implicated in genetic susceptibility to RA.
Rueda
Blanca
B
Instituto de Biomedicina López-Neyra, Granada, Spain.
Reddy
M V Prasad Linga
MV
González-Gay
Miguel A
MA
Balsa
Alejandro
A
Pascual-Salcedo
Dora
D
Petersson
Ingemar F
IF
Eimon
Alicia
A
Paira
Sergio
S
Scherbarth
Hugo R
HR
Pons-Estel
Bernardo A
BA
González-Escribano
Maria F
MF
Alarcón-Riquelme
Marta E
ME
Martín
Javier
J
D001118:Argentina; D001172:Arthritis, Rheumatoid / Q000235:genetics*; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D050835:Interferon Regulatory Factors / Q000235:genetics* / Q000378:metabolism; D008297:Male; D020641:Polymorphism, Single Nucleotide; D012042:Registries; D013030:Spain; D013548:Sweden
C431713:IRF5 protein, human; D050835:Interferon Regulatory Factors