Clinical characteristics of Hispanic patients with anti-SAE dermatomyositis.

INTRODUCTION/OBJECTIVES: Five autoantibodies are considered specific for dermatomyositis (DM). Among them, anti-small ubiquitin-like modifier (SUMO) activating enzyme (SAE) antibodies are the most infrequent. Information on anti-SAE DM remains limited. We aimed to describe the clinical and serological features of Hispanic patients with anti-SAE DM.

METHODS

We performed a cross-sectional study at the University Hospital "Dr. José Eleuterio González" in Monterrey, Mexico. The rheumatology laboratory database was searched for all autoimmune inflammatory myopathy immunoblot panels performed from February 2016 to December 2023. Patients with moderate positive or strong positive for anti-SAE, a DM diagnosis by a rheumatologist, and follow-up at our institution were included. Clinical and demographic information was then retrieved from medical records.

RESULTS

A total of 1018 panels were evaluated. Anti-SAE was moderately positive in 4 (0.39%) cases and strongly positive in 10 (0.98%), of which 7 patients met the inclusion criteria. All patients presented skin involvement, including atypical manifestations such as hiker's feet, erythroderma, and panniculitis. Four patients had muscle involvement, of which 2 had elevated creatine kinase levels. Dysphagia was reported in 3 cases. Two patients had interstitial lung disease. No cases of malignancy were identified at follow-up.

CONCLUSIONS

Our study highlights the clinical presentation of anti-SAE DM in Hispanic patients, emphasizing the prevalent cutaneous involvement and variable systemic manifestations. Recognizing these features can aid in earlier diagnosis and management. Key Points • Anti-SAE antibody-associated dermatomyositis is uncommon, with 1.4% of evaluated panels showing moderate to strong positivity. • All seven patients with anti-SAE DM in our case series presented with cutaneous involvement. • Atypical skin manifestations were present and included erythroderma, panniculitis, and hiker's feet.