Sonographic Evaluation of the Treatment Response in Patients With Immunoglobulin G4–Related Disease of the Submandibular Glands

Objectives To evaluate the usefulness of sonography for monitoring the response to glucocorticoid treatment in patients with immunoglobulin G4 (IgG4)–related disease. Methods We conducted a retrospective study using sonography in 12 patients with bilateral swollen submandibular glands who had a diagnosis of IgG4‐related disease based on an elevated serum IgG4 level (>135 mg/dL) and histopathologic findings between January 2010 and December 2012. Among these patients, 6 were treated with prednisolone, and the other 6 were placed under observation. B‐mode sonographic examinations of the submandibular glands were performed with or without color Doppler imaging at the initial examination and 6 months later. Findings were compared between the groups (treated and untreated), and their relationship with the treatment response of the primarily involved organs was investigated. Results In the treated group, the submandibular glands of all 6 patients decreased in both size and volume after treatment (average volume ± SD, 27,449.7 ± 24,227.6 to 4609.7 ± 1911.4 mm3; P = .004). The internal echo texture, characterized by multiple hypoechoic foci scattered against a heterogeneous hyperechoic background of submandibular tissue with demarcated hyperechoic lines, with or without hypoechoic tumor formation, disappeared or was obscured in all cases. In addition, the blood flow signals were reduced in all 3 patients who underwent color Doppler sonography, and the response observed on sonography was found to correlate with the IgG4 level and recovery of specific organ involvement. In contrast, in the untreated group, the submandibular glands showed a tendency to increase in both size and volume (average volume, 9326.3 ± 3054.8 to 12,217.4 ± 4605.5 mm3; P= .2) without a decrease in the blood flow signals. Conclusions Sonography is considered useful for evaluating the response to glucocorticoid therapy in patients with IgG4‐related disease of the submandibular glands.