Frequencies of IL1α, IL1β, and IL1Ra genotypes and associations with SLE*
| Genotypes | African Americans | Whites | ||||
|---|---|---|---|---|---|---|
| Cases (n = 144) n (%) | Controls (n = 73) n (%) | OR (95% CI)† | Cases (n = 86) n (%) | Controls (n = 202) n (%) | OR (95% CI) | |
| *Frequencies based on total number shown except as follows. In African Americans: IL1α +4845 based on 143 patients and IL1β +3953 based on 72 controls. In whites: IL1β +3953 based on 201 controls; †OR (odds ratios) and 95% CI (confidence intervals) were derived from logistic regression models comparing the homozygous wild-type genotype with other genotypes. Values are derived from single locus models except where shown for the five locus models. Odds ratios and confidence intervals are not presented for genotypes with fewer than three cases or controls; ‡χ2 statistic shown. Fisher’s exact statistic also calculated for IL1Ra (p = 0.01 in African Americans and p = 0.61 in whites), and for IL1α +4845 (p = 0.33) and IL1β +3953 (p = 0.28) in African Americans. | ||||||
| IL1α −889 | ||||||
| C/C | 62 (43) | 18 (25) | 1.0 (referent) | 43 (50) | 68 (34) | 1.0 (referent) |
| C/T | 57 (40) | 43 (59) | 0.4 (0.2 to 0.7) | 32 (37) | 109 (54) | 0.5 (0.3 to 0.8) |
| T/T | 25 (17) | 12 (16) | 0.6 (0.3 to 1.4) | 11 (13) | 25 (12) | 0.7 (0.3 to 1.6) |
| χ2 (2df)‡ | 8.4, p = 0.015 | 7.6, p = 0.022 | ||||
| C/T or T/T v C/C (single locus model) | 0.4 (0.2 to 0.8) | 0.5 (0.3 to 0.8) | ||||
| C/T or T/T v C/C (five locus model) | 0.3 (0.2 to 0.7) | 0.3 (0.2 to 0.7) | ||||
| IL1α +4845 | ||||||
| G/G | 96 (67) | 54 (74) | 1.0 (referent) | 45 (52) | 95 (47) | 1.0 (referent) |
| G/T | 39 (27) | 18 (25) | 1.2 (0.6 to 2.4) | 27 (31) | 83 (41) | 0.7 (0.4 to 1.2) |
| T/T | 8 (6) | 1 (1) | – | 14 (16) | 24 (12) | 1.2 (0.6 to 2.6) |
| χ2 (2df) | 2.5, p = 0.28 | 2.1, p = 0.26 | ||||
| G/T or T/T v G/G (single locus model) | 1.4 (0.7 to 2.6) | 0.8 (0.5 to 1.3) | ||||
| G/T or T/T v G/G (five locus model) | 1.8 (0.9 to 3.5) | 1.3 (0.6 to 2.7) | ||||
| IL1β −511 | ||||||
| C/C | 23 (16) | 21 (29) | 1.0 (referent) | 41 (48) | 89 (44) | 1.0 (referent) |
| C/T | 73 (51) | 27 (37) | 2.5 (1.2 to 3.8) | 36 (42) | 87 (43) | 0.9 (0.5 to 1.5) |
| T/T | 48 (33) | 25 (34) | 1.8 (0.8 to 3.8) | 9 (10) | 26 (13) | 0.8 (0.3 to 1.7) |
| χ2 (2df) | 5.9, p = 0.052 | 0.48, p = 0.79 | ||||
| C/T or T/T v C/C (single locus model) | 2.1 (1.1 to 4.2) | 0.9 (0.5 to 1.4) | ||||
| C/T or T/T v C/C (five locus model) | 2.4 (1.2 to 4.9) | 0.8 (0.4 to 1.3) | ||||
| IL1β +3953 | ||||||
| C/C | 111 (77) | 61 (85) | 1.0 (referent) | 49 (57) | 121 (60) | 1.0 (referent) |
| C/T | 32 (22) | 10 (14) | 1.8 (0.8 to 3.8) | 31 (36) | 67 (33) | 1.1 (0.7 to 2.0) |
| T/T | 1 (1) | 1 (1) | – | 6 (7) | 13 (6) | 1.1 (0.4 to 3.2) |
| χ2 (2df) | 2.3, p = 0.31 | 0.26, p = 0.88 | ||||
| C/T or T/T v C/C (single locus model) | 1.6 (0.8 to 3.5) | 1.1 (0.7 to 1.9) | ||||
| C/T or T/T v C/C (five locus model) | 1.6 (0.7 to 3.5) | 1.6 (0.8 to 3.0) | ||||
| IL1Ra VNTR | ||||||
| 1/1 | 130 (90) | 63 (87) | 1.0 (referent) | 63 (73) | 160 (79) | 1.0 (referent) |
| 1/2 | 6 (4) | 3 (4) | 1.0 (0.2 to 4.0) | 12 (14) | 18 (9) | 1.7 (0.8 to 3.7) |
| 2/2 | 1 (1) | 0 (0) | – | 8 (9) | 15 (7) | 1.4 (0.6 to 3.4) |
| 1/3 | 1 (1) | 6 (8) | – | 3 (3) | 7 (3) | 1.1 (0.3 to 4.3) |
| 3/3 | 0 (0) | 0 (0) | – | 0 (0) | 2 (1) | – |
| 1/4 | 6 (4) | 0 (0) | – | 0 (0) | 0 (0) | – |
| χ2 (4df) | 12.2, p = 0.016 | 2.9, p = 0.58 | ||||
| 1/2 or 2/2 v other genotypes (single locus model) | 1.2 (0.3 to 4.7) | 1.6 (0.8 to 3.0) | ||||
| 1/2 or 2/2 v other genotypes (five locus model) | 0.8 (0.2 to 3.2) | 1.7 (0.9 to 3.4) | ||||