**4. Clinical manifestations of IgG4-RD**

In the course of IgG4-RD, infiltrations composed mainly of IgG4 are formed, and characteristic fibrosis of affected organs is seen. These lesions usually form pseudotumors, which may occur in every organ. Most commonly observed locations of IgG4-RD are shown in **Table 2**. Single clinical cases of disease occurrence in the brain and cerebrospinal meninges, as well as intestines, causing ileus, have also been reported [40, 41]. IgG4-RD may affect one organ or occur in a generalized form. It seems that some locations may be more common for a particular sex. For example, lesions in the pancreas are more common in men, while sialadenitis

	- infiltration composed of lymphocytes and plasmatic cells and fibrosis
	- infiltration of IgG4+ cells: >10 cells IgG4+ hpf in a high-resolution microscope and quantitative ratio of IgG4+/IgG > 40%

Certain diagnosis of IgG4-RD: meeting the requirements of 1, 2, 3 Probable diagnosis of IgG4-R: meeting the requirements of 1 and 3 Possible diagnosis of IgG4-RD: meeting the requirement of 1 and 2

#### **Table 2.**

*Criteria of IgG4-RD diagnosis.*

and dacryoadenitis in women [42]. Patients with IgG4-usually do not present general symptoms such as fever, night sweats, or weight loss [43].
