Genome-wide and species-wide dissection of the genetics of arthritis severity in heterogeneous stock mice.

Objective: Susceptibility to inflammatory arthritis is determined by a complex set of environmental and genetic factors, but only a portion of the genetic effect can be explained. Conventional genome-wide screens of arthritis models using crosses between inbred mice have been hampered by the low resolution of results and by the restricted range of natural genetic variation sampled. The aim of this study was to address these limitations by performing a genome-wide screen for determinants of arthritis severity using a genetically heterogeneous cohort of mice.

A broad analysis of IL1 polymorphism and rheumatoid arthritis.

Objective: It has been suggested that polymorphisms in IL1 are correlated with severe and/or erosive rheumatoid arthritis (RA), but the implicated alleles have differed among studies. The aim of this study was to perform a broad and well-powered search for association between allelic polymorphism in IL1A and IL1B and the susceptibility to or severity of RA.

Methods: Key coding and regulatory regions in IL1A and IL1B were sequenced in 24 patients with RA, revealing 4 novel single-nucleotide polymorphisms (SNPs) in IL1B.

Comparison of 2 doses of etanercept (50 vs 100 mg) in active rheumatoid arthritis: a randomized double blind study.

Objective: To assess the safety and efficacy of etanercept 50 mg administered twice weekly versus 25 mg administered twice weekly as monotherapy in patients with tumor necrosis factor-alpha (TNF-alpha) blocker-naäve active rheumatoid arthritis (RA).

Methods: Seventy-seven patients with RA were randomized in an unequal allocation (2:1) in a blinded fashion to receive either 50 mg (51 patients) or 25 mg (26 patients) of etanercept twice a week for 24 weeks.

Results: The primary outcome measure, the ACR-N AUC at 24 weeks, showed no difference between the 2 dose groups.