Conclusions
GI involvement is a unique complication in patients with adult NXP2+DM. Timely recognition and targeted therapy may turn out to be lifesaving.
Methods
We retrospectively collected the data of the cohort of NXP2+ DM from 2012 to 2022 in our hospital. RNA sequencing was performed in intestinal samples of perforated patients compared with healthy controls data set.
Objective
Gastrointestinal (GI) involvements were scarcely reported in adult anti-nuclear matrix protein 2 (NXP2) dermatomyositis (NXP2+DM). In this study, we investigated the clinical, pathological and molecular features as well as treatment options of this rare yet life-threatening disease.
Results
A total of 56 patients with adult NXP2+DM were collected including 10 cases with GI involvements. Abdominal pain and melena were the initial manifestations for GI involvements with a median 10-month time lag after the diagnosis of NXP2+DM when myositis largely subsided. Within weeks, GI perforation occurred in 8 of 10 patients, while five patients underwent eight surgical interventions subsequently. The short-term mortality was observed in four patients. NXP2+DM with GI involvements presented with more extramuscular systemic manifestations such as interstitial lung disease and subcutaneous calcinosis. The GI pathological features encompassed vasculitis/vasculopathy with high MxA expression, intestinal smooth muscle necrosis and serosal calcinosis. Gene expression profile validated the type-I interferon activation and revealed that epithelial mesenchymal transition and focal adhesion pathway may also contribute. Finally, vedolizumab, an anti-α4β7-integrin monoclonal antibody, exhibited promising therapeutic signals which should be further investigated. Conclusions: GI involvement is a unique complication in patients with adult NXP2+DM. Timely recognition and targeted therapy may turn out to be lifesaving.