| ANCA positive (n = 26) | ANCA negative (n = 22) | ANCA not recorded | p Value (univariate analysis) | OR (logistic regression analysis, 95% CI) | p Value (multivariate logistic regression) | OR (multivariate logistic regression, 95% CI) | |
| LTA type | |||||||
| Pranlukast | 12 (80%) | 3 (20%) | 1 | 0.04† | 6.7 (1.5 to 30)* | 0.33 | 4.6 (0.4 to 48)* |
| Zafirlukast | 5 (56%) | 4 (44%) | 8 | 2.1 (0.4 to 9.8)* | 0.20 | 4.5 (0.1 to 194)* | |
| Montelukast | 9 (38%) | 15 (62%) | 5 | 1.0 | 0.43 | 1.0 | |
| Organ | |||||||
| Lung | 17 (46%) | 20 (54%) | 11 | 0.05 | 0.2 (0.04 to 0.99) | 0.04 | 0.12 (0.01 to 0.98) |
| Heart | 3 (38%) | 5 (62%) | 8 | 0.3 | 0.4 (0.09 to 2.1) | 0.29 | 0.12 (0.003 to 5.8) |
| Nerves | 19 (68%) | 9 (32%) | 9 | 0.02 | 3.9 (1.1 to 13.2) | 0.19 | 8.6 (0.3 to 225) |
| Skin | 13 (72%) | 5 (28%) | 6 | 0.05 | 3.4 (1.05 to 12.0) | 0.01 | 14.3 (1.8 to 110) |
| Interval between LTA use and CSS (mean (SEM)) | 6.7 (2.3) | 5.9 (1.0) | 0.8 | ||||
| No of organs affected (mean (SEM)) | 2.2 (0.2) | 2.2 (0.1) | 0.95 | 0.11 |
Univariate analysis was performed using the χ2 test with logistic regression (with a single predictor variable) used to generate ORs.
Using multivariate logistic regression analysis, lung involvement was independently associated with a negative ANCA test and skin involvement with a positive ANCA, but the association with LTA type and neurological involvement was lost.
*Relative to montelukast. †For all three drugs.
ANCA, antineutrophil cytoplasmic antibodies status; LTA, leukotriene antagonist; CSS, Churg–Strauss Syndrome.