Specific Tests Identify Biomarkers for Dermatomyositis

Most patients with dermatomyositis have auto-antibodies circulating in their bodies that cause distinct clinical disease features and are associated with increased risk of malignancy.

Scientists at Stanford University (Redwood City, CA, USA) performed blood analysis on 111 patients from their Dermatology Clinic and 102 patients from the Johns Hopkins University Myositis Center (Baltimore, MD, USA). Both groups were similar in gender and age at diagnosis.

The team used both immunoblotting and immunoprecipitation techniques to detect antibodies against antitranscriptional intermediary factor-1 (TIF-1γ) and nuclear matrix protein (NXP-2) proteins. The results of the tests showed that 17% of subjects in the two cohorts had antibodies against NXP-2 and 38% had antibodies to TIF-1γ. The specific assays, found 83% of dermatomyositis patients with cancer had a reaction to NXP-2 or TIF-1γ. Further analysis indicates that cancer, older age, and male gender were linked to NXP-2 or TIF-1γ antibodies, with anti-NXP-2 specifically associated with cancer in men.

David F. Fiorentino, MD, PhD, the lead author said, “For the physician treating patients with dermatomyositis, identifying those at higher risk for cancer is a top priority. Our team focused on creating specific tests to detect antibodies against two specific proteins and then testing if those antibodies can identify dermatomyositis patients at higher risk of cancer." Prof. Fiorentino added, “Our findings confirm the link between cancer and age in dermatomyositis, with a sharp increase in frequency at roughly 60 years of age. By determining the presence or absence of NXP-2 and TIF-1γ antibodies, we believe that this will aid clinicians in identifying those with the highest cancer risk." The study was published on September 3, 2103, in the journal Arthritis & Rheumatism.

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Stanford University
Johns Hopkins University