Lower CH50 as a predictor for intractable or recurrent lupus enteritis: A retrospective observational study.

OBJECTIVES: Lupus enteritis (LE) is a rare but well-known gastrointestinal manifestation of systemic lupus erythematosus (SLE). This study was conducted to identify prognostic factors associated with poor responses in patients with LE. METHODS: We consecutively registered patients diagnosed with LE between January 2009 and October 2019, and retrospectively compared their clinical characteristics based on whether they had good or poor responses to treatment. RESULTS: A total of 13 patients (17 episodes) were included. The median age was 41 years, and 12 patients were female. A comparison of clinical characteristics between groups revealed similar computed tomography (CT) findings. However, serum CH50 levels were significantly lower in the poor response group (median [interquartile ranges (IQR)]; 29.2 [25.3-46.9] U/mL vs 19.3 [7.8-24.0] U/mL, p = .0095). More patients in the poor response group had higher titers of anti-cardiolipin ß2-glycoprotein I antibody (anti-CL ß2GPI Ab) and were started on glucocorticoids (GCs) at moderate doses. In multivariable analysis, serum CH50 level was independently associated with poor response to induction therapy. CONCLUSION: Lower levels of CH50 at the time of initial treatment predicted inadequate treatment response in patients with LE.