Table 4.

Comprehensive clinical diagnostic criteria for IgG4-RD (from [5], with permission)

1. Clinical examination showing characteristic diffuse/localized swelling or masses in single or multiple organs

2. Hematological examination shows elevated serum IgG4 concentrations(135 mg/dl)

3. Histopathologic examination shows:

(1) Marked lymphocyte and plasmacyte infiltration and fibrosis.

(2) Infiltration of IgG4+ plasma cells: ratio of IgG4+/IgG+ cells >40 % and >10 IgG4+ plasma cells/HPF

Definite: 1) + 2) + 3)

Probable: 1) + 3)

Possible: 1) + 2)

However, it is important to differentiate IgG4-RD from malignant tumors of each organ (e.g., cancer, lymphoma) and similar diseases (e.g. Sjögren’s syndrome, primary sclerosing cholangitis, Castleman’s disease, secondary retroperitoneal fibrosis, Wegener’s granulomatosis, sarcoidosis, Churg–Strauss syndrome) by additional histopathological examination

Even when patients cannot be diagnosed using the CCD criteria, they may be diagnosed using organ-specific diagnostic criteria for IgG4RD.