Tumor necrosis factor alpha promoter polymorphisms in patients with juvenile idiopathic arthritis

CER2731
2006 Vol.24, N°1
PI 0103, PF 0108
Paediatric Rheumatology

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PMID: 16539828 [PubMed]

Abstract

OBJECTIVES:
To investigate the potential association of tumor necrosis factor-α (TNF) promoter alleles within subtypes of juvenile idiopathic arthritis (JIA) compared to healthy controls in a Caucasian population.
METHODS:
TNF-α promoter polymorphisms at positions –163, –238, -244, -308, -376 were determined in 228 patients with JIA and 196 healthy individuals. Genomic DNA was isolated and a PCR fragment of about 500 base pairs of the TNF gene promoter were amplified by PCR. Detection of polymorphisms was achieved by a single sequencing procedure.
RESULTS:
The TNF –238A allele was more frequent in the psoriatic arthritis JIA subgroup compared to healthy controls as well as to non-psoriatic JIA patients (p < 0.001, chi-square-test) and was associated with the more frequent occurrence of joint erosion (p < 0.05, chi-square-test). The frequency of the TNF –308A allele was significantly lower in patients with rheumatoid factor negative polyarthritis JIA patients compared to healthy controls, respectively (p < 0.05, chi-square-test). Joint erosions were detectable more often in rheumatoid factor negative polyarthritis JIA patients with the G/A genotype (80%) than in those with the G/G genotype (45%) (p = 0.20). The rare alleles at position –376 or at positions –163 and –244 were found very infrequently.
CONCLUSIONS:
TNF promoter polymorphisms may play a role in the pathogenesis of JIA. The TNF–238A allele seems to be associated with juvenile psoriatic arthritis. The TNF–308A allele is less frequently found in rheumatoid factor negative but not in rheumatoid factor positive polyarthritis and may therefore be associated with a more severe disease, while the more common TNF-308G allele may be protective.