Anti-interferon inducible protein 16 (Anti-IFI16) antibodies are associated with digital gangrene in scleroderma. This according to a study of sera from 94 patients with scleroderma and 47 healthy controls and a separate case-control study of 39 patients with scleroderma and digital gangrene and 39 patients with scleroderma and Raynaud’s alone. Researchers found:

• Anti-IFI16 antibodies were present in 18% of patients with scleroderma vs 2% of healthy controls.

• Patients with anti-IFI16 antibodies were more likely to have limited scleroderma (77% vs 46%), longer disease duration (15.2 vs 6.0 years), digital gangrene (24% vs 4%), and a low DLCO, vs patients without anti-IFI16 antibodies.

• In the case-control study, 45% of participants were anti-IFI16 positive.

• Anti-IFI16 antibodies levels were significantly higher in patients with digital gangrene.

• Adjusted for age, cutaneous subtype, smoking, and DLCO, high anti-IFI16 antibody levels associated with digital gangrene (aOR=2.3).

• Odds of digital gangrene increased with higher antibody titers in a dose dependent manner.

Citation: McMahan ZH, Shah AA, Vaidya D, Wigley FM, Rosen A, Casciola-Rosen L. Anti-IFI16 antibodies in scleroderma are associated with digital gangrene. [Published online ahead of print December 29, 2015]. Arthritis Rheumatol. doi: 10.1002/art.39558.