Clinical features, triggers, and risk factors of severe gastrointestinal involvement in anti-NXP2-positive juvenile dermatomyositis: a retrospective cohort study

BACKGROUND: This study aimed to examine the clinical characteristics, triggers and risk factors for gastrointestinal (GI) complications in anti-NXP2-positive JDM (anti-NXP2-JDM) patients. METHODS: A retrospective analysis was performed on 57 anti-NXP2-JDM patients, including 19 with severe GI complications (GI group) and 38 without GI involvement (Non-GI group). RESULTS: The GI group had a male-to-female ratio of 6:13 and a mean onset age of 5.83 years, with abdominal pain as the most common initial symptom. All severe GI involvement occurred during active JDM, and 16 patients (84%) had prodromal infections (potential triggers). Compared with the Non-GI group, the GI group showed significantly lower proximal muscle strength grade, CMAS score, BMI, hemoglobin, albumin, creatinine and lymphocyte count, and higher rates of severe JDM at onset, malnutrition, infection, skin ulcer, edema, livedo reticularis. The GI groups also had higher CAT-A score, CAT-D score, WBC, CRP, ESR, ferritin and LDH. Multivariate analysis identified severe JDM at onset, infection, malnutrition, CAT-A score, skin ulcer, edema and ESR as independent risk factors for GI complications, and lymphocyte count, proximal muscle strength, CMAS score, hemoglobin and albumin as protective factors. Kaplan-Meier analysis showed significantly different survival rates between groups. The proportion of deaths was 26.3% (5/19) in the GI group compared to 0% (0/38) in the non-GI group (p = 0.002). CONCLUSIONS: Anti-NXP2-JDM patients require vigilant monitoring and early intervention to mitigate GI complications and improve outcomes. Infection may be an important trigger. Risk factors for GI complications include severe JDM at onset, malnutrition, skin ulceration, edema, low CMAS score, high CAT-A score, lymphocytopenia, anemia, hypoalbuminemia and elevated ESR.