Anti-TIF1-beta autoantibody-positive dermatomyositis: a case-based review.

To describe the clinical features and cancer risk in patients with dermatomyositis (DM) and anti-TIF1β autoantibodies without other DM-specific autoantibodies (anti-TIF1β-monospecific DM) through a case-based review. Case report of anti-TIF1β-monospecific cancer-associated DM and literature review of cases of anti-TIF1β-monospecific DM. We describe a case of a person with cancer-associated DM in whom we identified anti-TIF1β autoantibodies through immunoprecipitation-mass spectrometry. He had typical cutaneous involvement, mild myositis and a good response to medical therapy after curative treatment of an underlying renal cell cancer. A literature search of Pubmed and Scopus identified 9 more persons with anti-TIF1β-monospecific DM revealing a homogeneous phenotype with typical cutaneous involvement, mild to absent muscular involvement and absence of interstitial lung disease. Two out of ten (20%) had cancer-associated DM. Anti-TIF1β-monospecific DM represents a homogeneous subset of DM characterized by typical cutaneous involvement, mild to absent myositis and potentially an elevated cancer risk (20%). More cohort studies with adequate detection methods are needed to formally assess the cancer risk as compared to anti-TIF1γ and other DM-specific autoantibodies.