To analyze and investigate the clinical characteristics, diagnosis, treatment and prognosis of IgG4-related sialadenitis cases and improve the understanding of the disease.

The clinical manifestations, serological and pathological results, and therapeutic effects of three cases of IgG4 related sialadenitis were retrospectively analyzed and the related literature were reviewed.

(1) Case report: the main clinical manifestation of the three patients was submandibular gland swelling, bilaterally in two patients and unilaterally in the other. Serological test showed some increase in IgG4, IgG, κ and λ chain, SAA, complements C3 and C4. Ultrasonographical results revealed diffuse swelling of the glands. Pathological examination demonstrated cellular infiltration mainly composed of lymphocytes and plasma cells, with IgG4 (+) plasma cells ≥ 30/HPF, and IgG4/IgG ≥ 40%. IgG4-related sialadenitis was mainly treated with glucocorticoid, showing good clinical result and no recurrence. (2) Literature review: 80 cases of IgG4-related sialadenitis were reported in China. The common clinical manifestation of all these cases was painless swelling of unilateral or bilateral salivary glands. The expression of IgG4 in serum was found to increase in some cases. Pathological cellular infiltration was mainly lymphocytic and plasma cell infiltration, with IgG4 (+) cells ≥ 50/HPF, and IgG4/IgG ≥ 40%. Good clinical effect was obtained with the combined use of glucocorticoid and immunosuppressants.

IgG4-related sialadenitis is an autoimmune disease that is characterized with painless swelling of the salivary gland and abnormal increase of serum IgG4. Its pathological feature is that a large number of IgG4 (+) plasma cells infiltrate in the tissue. Clinically, biopsy or serological examination should be carried out as early as possible for the diagnosis of this disease. Once diagnosed, a combined treatment of glucocorticoid and immunosuppressants is the first choice, to avoid unnecessary surgery or chemoradiotherapy.