Table 2.
Comparison of Frequency of Autoimmune Diseases in Siblings in Family Groups, Stratified by Diagnosis of Proband[Note]
|
No. (%) of Siblings Affected with |
||||||||
| Family Groupa(No. of Probands) | No. of Affected Siblings | AITD | RA | MS | SLE | T1D | IBD | Psoriasis |
| All probands (265) | 232 | 69 (30) | 36 (16) | 16 (7) | 19 (8) | 23 (10) | 15 (6) | 25 (11) |
| Probands with: | ||||||||
| AITD (43) | 40 | 19 (48)b | 9 (23) | 2 (5) | 3 (8) | 6 (15) | 3 (8) | 0 (0) |
| RA (46) | 51 | 15 (29) | 20 (39)c | 2 (4) | 2 (4) | 3 (6) | 5 (10) | 6 (12) |
| MS (82) | 64 | 17 (27) | 5 (8) | 3 (5) | 6 (9) | 9 (14) | 7 (11) | 12 (19)d |
| SLE (65) | 53 | 23 (43)b | 9 (17) | 4 (8) | 6 (11) | 4 (8) | 1 (2) | 4 (8) |
| T1D (10) | 9 | 2 (22) | 0 (0) | 0 (0) | 1 (11) | 3 (33)e | 0 (0) | 1 (11) |
| IBD (7) | 8 | 2 (25) | 1 (13) | 3 (38)f | 0 (0) | 2 (25) | 0 (0) | 0 (0) |
| Psoriasis (8) | 8 | 1 (13) | 2 (25) | 1 (13) | 0 (0) | 0 (0) | 0 (0) | 3 (38) |
Note.— Bold italics indicate P<.1 (two-sided Fisher’s exact test).
a
Stratified by proband diagnosis.
b
AITD in siblings of probands with AITD: OR 2.13, 95% CI 1.08–4.2, P=.043; AITD in siblings of probands with SLE: OR 1.81, 95% CI 0.98–3.34, P=.073.
c
RA in siblings of probands with RA: OR 3.5, 95% CI 1.8–6.8, P=.0003.
d
Psoriasis in siblings of probands with MS: OR 1.9, 95% CI 0.90–4.0, P=.09; psoriasis in siblings of probands with psoriasis: OR 4.96, 95% CI 11.1–22.0, P=.053.
e
T1D in siblings of probands with T1D: OR 4.54, 95% CI 1.06–19.40, P=.06.
f
MS in siblings of probands with IBD: OR 8.1, 95% CI 1.77–37.0, P=.018.