Abstract: Objective To summarize the clinical features of severe gastrointestinal tract involvement and perforation in juvenile dermatomyositis (JDM).Methods Four cases of JDM with severe gastrointestinal tract involvement in our hospital were summarized. Relevant studies were reviewed.Results Four patients (P1-P4) were involved in the study with one boy and three girls, aged between 1.6 and 5 years. The onset of gastrointestinal involvement occurred between the 4^th and 10^th month after the diagnosis of JDM, and the primary symptom was abdominal pain. P1 had duodenal and transverse colon perforation; P2 had duodenal perforation combined with hepatic artery rupture; intestinal perforation site on P3 was unknown and P4 had thickened intestinal wall without perforation. Four cases had strong positive results for anti-NXP2 antibody (3+) and had been treated with steroids and/or immunosuppressants. P1 and P2 underwent surgical intervention and P4 received autologous hematopoietic stem cell transplantation(AHSCT)owing to their resistance to the traditional treatment. P1 experienced complete remission during follow-up for 2 years, but she died after repairing digestive tract fistula; P2 died of infection and duodenal fistula; P3 died of diffuse abdominal wall hemorrhage; P4 experienced complete remission after autologous stem cell transplantation. Twelve patients with JDM with gastrointestinal perforation from the literature were summarized. The primary symptom in the digestive tract was severe abdominal pain with or without fever and vomiting, which appeared between 2 months and 9 years after the diagnosis of JDM. Perforations were reported in the duodenum (8 patients), colon (3 patients), jejunum (1 patient), pylori area (1 patient), cervical area of the esophagus (1 patient) and an unclear location (1 patient), with perforations at multiple sites or recurrent perforations reported in five patients. None of them were tested for myositis-specific antibodies. Surgery was performed in 11 patients. Nine patients experienced relief of their symptoms; 3 patients died; 1 patient died of repeated intestinal perforation; 1 patient died of postoperative acute respiratory distress syndrome, and 1 patient of death was unknown.Conclusion Refractory JDM patients may suffer from intestinal perforation and the primary symptom of JDM with gastrointestinal complications was abdominal pain. Common intestine perforation was duodenal peritoneal perforation, and its clinical symptoms were atypical and prone to delay diagnosis. Our patients were positive for the anti-NXP2 antibody. Intestinal perforation has a high mortality rate. In particular, there is no effective procedure for duodenal perforation. Autologous stem cell transplantation might be an option to control the high mortality rate.

Key words: Anti-NXP2 antibody, Intestinal perforation, Juvenile dermatomyositis