An Interferon Signature in the Peripheral Blood of Dermatomyositis Patients is Associated with Disease Activity
Recent studies have shown increased expression of interferon (IFN)-regulated genes in the peripheral blood cells of patients with systemic lupus erythematosus. A similar interferon signature has been observed in affected muscle tissue from patients with dermatomyositis (DM), but it has not yet been determined if this signature extends to the peripheral blood in DM. We performed global gene expression profiling of peripheral blood cells from adult and juvenile DM patients and healthy controls. Several interesting groups of genes were differentially expressed in DM, including genes with immune function, and others that function in muscle or are involved in mitochondrial/oxidative phosphorylation. Investigation of type I IFN-regulated transcripts revealed a striking interferon signature present in most DM patients studied. Levels of type I IFN-regulated proteins were also elevated in DM serum samples. Furthermore, both the transcript and serum protein IFN signatures were associated with disease activity. These data suggest that the IFN signature may be a useful marker for DM disease activity, and that sampling peripheral blood may be a more practical alternative to muscle biopsy for measuring this signature.
Funding was provided by the Minnesota Partnership for Biotechnology and Medical Genomics, and, in part, by grants and contracts from the National Institutes of Health. ECB was supported by NIH AR50938-01.
- 5.Greenberg SA et al. (2005) Interferon-alpha/betamediated innate immune mechanisms in dermatomyositis. Ann. Neurol. 57:664–78.Google Scholar
- 32.Schulze zur Wiesch A et al. (2004) Myeloid related proteins MRP8/MRP14 may predict disease flares in juvenile idiopathic arthritis. Clin. Exp. Rheumatol. 22:368–73.Google Scholar