Table 1 Clinical features of the enrolled patients at baseline (n = 459) and during the follow-up period (n = 312)

 Gender (male to female)

1.7:1

1.8:1

0.771

 Age at onset (mean ± SD) (years)

53.4 ± 12.8

52.8 ± 12.4

0.519

 Disease duration (months, median, IQR)

12 (4–36)

12 (4–36)

0.824

 Allergy disease (n, %)

201 (43.8%)

150 (48.1%)

0.241

 IgG4-RD RI scores (mean ± SD)

11.1 ± 5.3

11.7 ± 5.5

0.198

 Follow-up period (months, median, IQR)

–

36 (24–54)

–

 Lacrimal gland

233 (50.8%)

166 (53.2%)

0.505

 Parotid gland

73 (15.9%)

53 (17.0%)

0.690

 Submandibular gland

239 (52.1%)

161 (51.6%)

0.899

 Pancreas

166 (36.2%)

112 (35.9%)

0.939

 Bile duct

86 (18.7%)

64 (20.5%)

0.541

 Retroperitoneal tissue

79 (16.5%)

55 (17.6%)

0.881

 Lung

117 (25.5%)

80 (25.6%)

0.962

 Kidney

51 (11.1%)

34 (10.9%)

0.926

 Lymph nodes

210 (45.8%)

153 (49.0%)

0.369

 Liver

11 (2.4%)

7 (2.2%)

0.890

 Paranasal sinus

130 (28.3%)

102 (32.7%)

0.194

 Thyroid

13 (2.8%)

8 (2.7%)

0.822

 Pituitary

7 (1.5%)

5 (1.6%)

0.932

 IgE (KU/L)

332 (125–756)

332 (146–699)

0.323

 IgG4 (mg/L)

9202 (3580–18,325)

8960 (3730–16,600)

0.837

 IgG (g/L)

18.83 (14.8–25.53)

18.65 (14.69–23.70)

0.678

 Eosinophils (10⁹/L)

0.21 (0.11–0.43)

0.23 (0.12–0.48)

0.750

 ESR (mm/h)

21 (8–50)

18 (7–44)

0.782

 CRP (mg/L)

2.1 (0.76–6.9)

1.57 (0.63–5.3)

0.837

 C3 (g/L)

0.93 (0.74–1.11)

0.94 (0.77–1.12)

0.981

 C4 (g/L)

0.16 (0.11–0.23)

0.17 (0.11–0.22)

0.723