Serum levels of matrix metalloproteinases-2 and-9 and their tissue inhibitors in inflammatory neuromuscular disorders

We monitored serum levels of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) before and during intravenously applied immunoglobulin (IVIG) therapy in 33 patients with chronic immune-mediated neuropathies and myopathies and 15 controls. Baseline MMP-2 and TIMP-2 serum levels were lower and MMP-9 and TIMP-1 serum levels higher in all patients compared to age-matched controls. Eight days after IVIG treatment, MMP-2, TIMP-2, and TIMP-1 serum levels increased, while MMP-9 serum levels decreased, indicating tissue repair. After 60 days, MMP-9 levels increased, MMP-2 approached normal levels, while TIMP-1 and TIMP-2 serum levels were below day 8 levels, indicating relapsing tissue damage. Comparing the MMP/TIMP results with the clinical courses, IVIG treatment tended to change MMP/TIMP levels in a way that paralleled clinical improvement and relapse. In sum, during a distinct time period, IVIG therapy seems to be able to modulate VIMP-mediated tissue repair. Copyright (c) 2006 S. Karger AG, Basel

Mutations in CAV3 cause mechanical hyperirritability of skeletal muscle in rippling muscle disease

Hereditary rippling muscle disease (RMD) is an autosomal dominant human disorder characterized by mechanically triggered contractions of skeletal muscle. Genome-wide linkage analysis has identified an RMD locus on chromosome 3p25. We found missense mutations in positional candidate CAV3 (encoding caveolin 3; ref. 5) in all five families analyzed. Mutations in CAV3 have also been described in limb-girdle muscular dystrophy type 1C (LGMD1C; refs. 6,7), demonstrating the allelism of dystrophic and non-dystrophic muscle diseases