Intrinsic Gene Expression Subsets of Diffuse Cutaneous Systemic Sclerosis Are Stable in Serial Skin Biopsies

Department of Genetics, Dartmouth Medical School, Hanover, New Hampshire 03755, USA.
Journal of Investigative Dermatology (Impact Factor: 7.22). 02/2012; 132(5):1363-73. DOI: 10.1038/jid.2011.472
Source: PubMed


Skin biopsy gene expression was analyzed by DNA microarray from 13 diffuse cutaneous systemic sclerosis (dSSc) patients enrolled in an open-label study of rituximab, 9 dSSc patients not treated with rituximab, and 9 healthy controls. These data recapitulate the patient "intrinsic" gene expression subsets described previously, including fibroproliferative, inflammatory, and normal-like groups. Serial skin biopsies showed consistent and non-progressing gene expression over time, and importantly, the patients in the inflammatory subset do not move to the fibroproliferative subset, and vice versa. We were unable to detect significant differences in gene expression before and after rituximab treatment, consistent with an apparent lack of clinical response. Serial biopsies from each patient stayed within the same gene expression subset, regardless of treatment regimen or the time point at which they were taken. Collectively, these data emphasize the heterogeneous nature of SSc and demonstrate that the intrinsic subsets are an inherent, reproducible, and stable feature of the disease that is independent of disease duration. Moreover, these data have fundamental importance for the future development of personalized therapy for SSc; drugs targeting inflammation are likely to benefit those patients with an inflammatory signature, whereas drugs targeting fibrosis are likely to benefit those with a fibroproliferative signature.

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    • "Indeed, earlier works by the Whitfield group and collaborators have shown reproducible, disease-specific gene expression signatures in scleroderma skin when compared with healthy controls and have also shown that, surprisingly, the disease-specific gene expression profiles are shared by lesional and nonlesional skin (Whitfield et al., 2003). More recently, Whitfield and collaborators analyzed the gene expression profile of skin biopsy samples from 17 patients with dSSc, 10 patients with lSSc and morphea, and 6 healthy controls (Milano et al., 2008). Cluster analysis of the gene profiles derived from these biopsies revealed three groups: (1) a normallike group, which included the healthy controls and some dSSc and lSSc patients; (2) an inflammatory group, which included a small subset of dSSc patients as well as patients with lSSc and morphea; and (3) a diffuse-proliferation (fibrotic) group, which was composed solely of dSSc patients. "
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