Table 1.
Clinical characteristics of azathioprine‐induced leukopenia (≥ grade 2; WBC ≤ 3,000 cells/μL) patients, general population, and azathioprine tolerant control during 2012–2017
| AZA‐induced leukopenia (n = 40) | AZA tolerant control (n = 86) | General population controls (n = 507) | P value | |
|---|---|---|---|---|
| N (%) | N (%) | N (%) | ||
| Age, years, mean ± SD | 47.4 ± 18.0 | 41.2 ± 19.2 | 56.0 ± 19.2 | 0.113a |
| Male, n (%) | 17 (42.5) | 41 (47.7) | 253 (49.9) | 0.530c |
| Initial AZA dose ≥2 mg/kg/day, n (%) | 11 (27.5) | 21 (24.4) | – | 0.712c |
| Periods, day | 68.2 ± 55.2 | 314.9 ± 239.7 | – | < 0.001c |
| Indication, n (%) | ||||
| Eczema/AD | 33 (82.5) | 73 (84.9) | – | 0.993c |
| Urticaria | 3 (7.5) | 9 (10.5) | – | 0.993c |
| Bullous pemphigoid | 3 (7.5) | 2 (5.0) | – | 0.993c |
| Others | 1 (2.5) | 2 (5.0) | – | 0.993c |
| Comorbidity, n (%) | ||||
| CKD | 7 (17.5) | 8 (9.3) | – | 0.310c |
| CVD | 11 (27.5) | 18 (20.9) | – | 0.648c |
| DM | 4 (10.0) | 7 (8.1) | – | 0.810c |
| Liver disorderb | 6 (15.0) | 9 (10.4) | – | 0.876c |
We excluded AZA users of SLE, sepsis, and patients with leukemia to avoid confounding factors of leukopenia.
AD, atopic dermatitis; AZA, azathioprine; CKD, chronic kidney disease; CVD, cardiovascular disease; DM, diabetes mellitus; SLE, systemic lupus erythematosus; WBC, white blood cell.
This P value was calculated by using two‐tailed Student’s t tests.
Liver disorders include all kinds of hepatitis, necrosis of liver, hepatic failure, liver replaced by transplant (see Methods section), or patient’s GPT/GOT value was twofold higher than the normal value range (36 U/L) before AZA intake.
P values were calculated with AZA‐induced leukopenia comparing to AZA tolerant control by using logistic regression model.