**9. Evaluation of disease activity and efficacy of the therapy**

For evaluation of disease activity and efficacy of the therapy, IgG4 Responder index is used. This index includes 25 domains, regarding organ location of lesions and general symptoms. For every domain, 0 to 3 scores may be assigned. The disease is active if the index score is 3 or higher [93].

The prognosis regarding IgG4-RD is not known. There are no long-term, welldesigned observational studies. It seems that spontaneous remissions rarely occur. However, the disease recurrences are frequently observed when glucocorticoids are reduced. The disease, if not diagnosed, may lead to irreversible fibrosis and damage of the involved organs. It should be remembered that due to the diversity of clinical pictures in IgG4-RD, all physicians may encounter this entity in their practice, regardless of their specialty.
