Joint involvement in patients with early polymyalgia rheumatica using high-resolution ultrasound and its contribution to the EULAR/ACR 2012 classification criteria for polymyalgia rheumatica.

OBJECTIVE: To assess joint involvement and the contribution of musculoskeletal ultrasound (MSUS) to the novel European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) 2012 classification criteria in patients with polymyalgia rheumatic (PMR). METHODS: MSUS was performed in 54 consecutive patients with recent-onset PMR. RESULTS: Biceps tenosynovitis of at least 1 shoulder has been observed in 70.4% of patients, and 64.8% had a bilateral biceps tenosynovitis. Subdeltoid bursitis (27.8% unilateral, 5.6% bilateral), glenohumeral synovitis (22.2% unilateral, 9.3% bilateral), and hip involvement (22.2% unilateral, 16.7% bilateral) were observed less frequently. The sensitivities of the classification criteria were 85.2% for EULAR/ACR without MSUS and 81.5% for EULAR/ACR with MSUS. CONCLUSION: The most common MSUS pathology was a biceps tenosynovitis. However, US findings had no effect on the sensitivity of the novel EULAR/ACR criteria for PMR.

High molecular weight complex analysis of Epstein-Barr virus Latent Membrane Protein 1 (LMP-1): structural insights into LMP-1's homo-oligomerization and lipid raft association.

LMP-1 is a constitutively active Tumor Necrosis Factor Receptor analog encoded by Epstein-Barr virus. LMP-1 activation correlates with oligomerization and raft localization, but direct evidence of LMP-1 oligomers is limited. We report that LMP-1 forms multiple high molecular weight native LMP-1 complexes when analyzed by BN-PAGE, the largest of which are enriched in detergent resistant membranes. The largest of these high molecular weight complexes are not formed by purified LMP-1 or by loss of function LMP-1 mutants. Consistent with these results we find a dimeric form of LMP-1 that can be stabilized by disulfide crosslinking. We identify cysteine 238 in the C-terminus of LMP-1 as the crosslinked cysteine. Disulfide crosslinking occurs post-lysis but the dimer can be crosslinked in intact cells with membrane permeable crosslinkers. LMP-1/C238A retains wild type LMP-1 NF-κB activity. LMP-1's TRAF binding, raft association and oligomerization are associated with the dimeric form of LMP-1. Our results suggest the possibility that the observed dimeric species results from inter-oligomeric crosslinking of LMP-1 molecules in adjacent core LMP-1 oligomers.