| |
ACPA-negative
|
ACPA-positive
| |
|---|
|
Parameter
|
Cases (N = 36)
|
Controls (N = 268)
|
OR (95% CI)
|
Cases (N = 27)
|
Controls (N = 15)
|
OR (95% CI)
|
OR (95% CI) for ACPA within strata of HLA-SE
|
|---|
|
HLA-SE absent
|
17
|
153
|
1.0 (ref)
|
6
|
8
|
7.7 (2.2 to 27.5)
|
7.7 (2.2 to 27.5)
|
| | | | | | |
P = 0.002
|
P = 0.002
|
|
HLA-SE present
|
19
|
115
|
1.4 (0.7 to 2.9)
|
21
|
7
|
33.3 (11.1 to 99.6)
|
23.8 (7.9 to 71.8)
|
| | | |
P = 0.38
| | |
P < 0.0001
|
P < 0.0001
|
|
OR (95% CI) for HLA-SE present
| | |
1.4 (0.7 to 2.9)
| | |
4.3 (1.0 to 18.6)
| |
|
within strata of ACPA
| | |
P = 0.38
| | |
P = 0.05
| |
- aACPA: anticitrullinated antibody, CI: confidence interval, HLA-SE: human leukocyte antigen shared epitope, OR, odds ratio, ref: reference value. Measure of effect modification on the additive scale: Synergy Index = 4.5 (95% CI = 0.9 to 21.6; P = 0.06). Measure of effect modification on the multiplicative scale: ratio of odds ratios = 3.1 (95% CI = 0.6 to 15.8; P = 0.18). ORs estimated by logistic regression models adjusted for matching factors and age at blood draw, alcohol intake, body mass index, regularity of menses and pack-years of smoking. Restricted to cases with blood draw less than 5 years before diagnosis (cases = 63, controls = 283) in the Nurses’ Health Study and Nurses’ Health Study II.
