IgG4-Related Disease: A Retrospective Chinese Study of Features and Treatment Response of 98 Patients Including 4 Rare Cases.

The features and treatment of 98 Chinese patients with immunoglobulin G4 (IgG4)-related disease (IgG4-RD) referred to a single tertiary referring centre were reviewed. Patients diagnosed with IgG4-RD according to the comprehensive diagnostic criteria (CDC) were included in the retrospective study from May 2012 to March 2019. We collected data on clinical, laboratory, imaging, histological features and treatment. Totally, 98 patients with IgG4-RD were enrolled. The common clinical manifestations included abdominal pain, salivary gland swelling and lymphadenopathy. 51% of the patients had multiple organs involvement. Lymph nodes, pancreas and salivary glands were most commonly involved. Four rare sites including ulna, cerebellum, scalp, and mammary gland were found. The serum IgG4 level was increased by 85.7%. The serum IgG4 level was positively correlated with the number of involved organs, IgG and IgG4/IgG. Low C3 and C4 levels were observed in 37.5% and 12.2% patients respectively, and all patients with kidney involvement had hypocomplementemia. A total of 54 patients underwent tissue biopsies, and 55.6%, 31.5% and 11.1% cases were diagnosed as definite, probable and possible IgG4-RD, respectively. Eighty-eight patients received glucocorticoids (GCs) therapy. Five patients underwent radical surgery to remove the lesion. 73% of them presented a complete or partial remission. IgG4-RD is a systemic fibroinflammatory disease with involvement of multiple organs throughout the body including some rare sites. Most IgG4-RD patients had increased serum IgG4 levels and patients with kidney involvement showed hypocomplementemia. GCs therapy is effective. More research is needed to provide a more reliable basis for the diagnosis and treatment of patients.