2017 Volume 39 Issue 1 Pages 22-27
Background. Mizoribine (MZR) is a purine analog, and is administered as a disease modifying anti-rheumatic drug (DMARD). MZR-induced acute lung injury is rare as an adverse effect. Case. A 68-year-old woman complaining of high fever and dyspnea was admitted to our hospital. She was a patient with rheumatoid arthritis, and had been given prednisolone, methotrexate (MTX) and tacrolimus orally by her primary care doctor who specializes in rheumatology. Six days before admission, she changed her prescription from MTX to MZR. SpO2 was 71%, and chest radiograph and computed tomography on admission showed diffuse ground-glass opacities in both lung fields. Laboratory data showed high serum LDH and KL-6 levels. The bronchoalveolar lavage fluid (BALF) showed an increase in the proportion of lymphocytes (50%). A drug lymphocyte stimulation test (DLST) using peripheral blood was positive for MZR. Based on these findings, the present case was diagnosed as acute lung injury caused by MZR. The patient's symptoms immediately improved by withdrawing MZR and administration of corticosteroid. Conclusion. MZR-induced acute lung injury is rare and its mechanism and frequency are unknown. This case is important to provide awareness of using MZR.
