Characteristics
|
Women, n (%)
|
156/196 (80)
|
54/101 (53)
|
< 0.001
|
Age, mean (range)
|
63.9 (25–87)
|
48.6 (20–74)
|
< 0.001
|
Disease duration years, mean (range)
|
12.2 (0–57)
|
–
| |
Erosions, n (%)
|
109/193 (56)
|
–
| |
Biologics, n (%)
|
72/196 (37)
|
–
| |
Glucocorticoids, n (%)
|
52/196 (27)
|
–
| |
Methotrexate, n (%)
|
148/196 (76)
|
–
| |
Other csDMARD, n (%)
|
40/196 (20)
|
–
| |
Risk factors
|
Ever smoker, n (%)
|
99/192 (52)
|
34/99 (34)
|
0.006
|
Current smoker, n (%)
|
15/192 (8)
|
10/99 (10)
|
0.514
|
Never smoker, n (%)
|
93/192 (48)
|
65/99 (66)
|
0.006
|
Cigarette pack-years, mean (SD)
|
13.9 (13.8)
|
8.3 (11.3)
|
0.009
|
Shared epitope carriage, n (%)
|
163/196 (83)
|
47/101 (47)
|
< 0.001
|
No allele, n (%)
|
34/196 (17)
|
54/101 (54)
|
< 0.001
|
One allele, n (%)
|
97/196 (50)
|
33/101 (33)
|
0.007
|
Two alleles, n (%)
|
65/196 (33)
|
14/101 (14)
|
< 0.001
|
Antibodies
|
RF-positive, n (%)
|
145/195 (74)
|
–
| |
IgG ACPA
|
Positive, n (%)
|
157/196 (80)
|
0/101 (0)
|
< 0.001
|
Level, median U/mL (SD)
|
444.1 (923.8)
|
0.1 (0.0)
|
< 0.001
|
IgA ACPA
|
Positive, n (%)
|
88/196 (45)
|
0/101 (0)
|
< 0.001
|
Level, median AU/mL (SD)
|
1.3 (151.9)
|
1.3 (0.0)
|
< 0.001
|
Level total IgA in serum, median g/L (SD)
|
2.5 (1.4)
|
2.0 (0.7)
|
< 0.001
|
Level total IgA in saliva, median μg/mL (SD)
|
61.5 (85.8)
|
35.7 (24.7)
|
< 0.001
|