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

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. 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. 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 β2-glycoprotein I antibody (anti-CL β2GPI 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. Lower levels of CH50 at the time of initial treatment predicted inadequate treatment response in patients with LE.