Treatment of immunoglobulin G4-related sialadenitis: outcomes of glucocorticoid therapy combined with steroid-sparing agents

Background Immunoglobulin G4-related sialadenitis (IgG4-RS) is a newly recognized immune-mediated systemic disease. Despite its good response to steroid therapy, its treatment protocol is not standardized and the long-term outcome is controversial. The study was conducted to determine the short-term and long-term outcomes of IgG4-RS patients treated with glucocorticoids and steroid-sparing immunosuppressive agents, to analyze secretory function, serological and radiological changes in salivary glands and to assess the usefulness of serum IgG4 level as an indicator of disease activity. Methods IgG4-RS patients who were treated for more than 3 months were enrolled. Serological tests, salivary gland function assessment and computed tomography (CT) were performed before treatment and during follow up. The treatment outcomes in the short and the long term were evaluated, and the relationship between serum IgG4 level and salivary gland volume was analyzed. Results Glucocorticoids were used in all 43 patients and steroid-sparing immunosuppressive agents in 38 patients (88.4%). The follow-up period was 24.6 ± 14.9 months. Clinical remission was achieved in all patients after induction therapy. During short-term observation, salivary gland secretion significantly increased, and the serum IgG4 levels, the volumes and CT values of submandibular and parotid gland decreased significantly (P