UNUSUAL CASE OF DASATINIB-INDUCED ORGANIZING PNEUMONIA PATTERN, DIAGNOSED BY LUNG BIOPSY

초록

INTRODUCTION: Dasatinib, a tyrosine kinase inhibitor (TKI), is usually used for chronic myeloid leukemia (CML) and Philadelphia chromosome?positive acute lymphoblastic leukemia. In dasatinib-associated pulmonary toxicities, pleural effusion and pulmonary arterial hypertension are relatively well known. For interstitial pneumonitis (IP), a few cases were reported as nonspecific IP (NSIP). However, organizing pneumonia (OP) cases were not observed in the English literature. Herein, we present a case of dasatinib-induced OP, diagnosed by lung biopsy. CASE PRESENTATION: On August 2, 2022, a 51-year-old man consulted our outpatient clinic owing to an abnormal chest Xray, despite being asymptomatic. He was a salesman. He had been diagnosed with CML and had been taking dasatinib 100 mg daily from January 23, 2019. His smoking history amounted to 30 pack-years until 2008. A chest CT scan showed the peribronchial consolidations, ground glass opacities (GGO), and nodules in both lower lung areas, which worsened by September 15, 2022. Adverse effect of dasatinib was suspected, but there were no reports of an OP pattern, and the CML attending doctor hoped to maintain the treatment. We started oral corticosteroids (OCS) 40 mg daily from September 16, 2022, with dasatinib, with the intention to discontinue if unresponsive. The lesions improved gradually. On March 7, 2023, new consolidative lesion suddenly developed in the right middle lobe, despite receiving 10 mg of OCS daily. The antibiotic was unresponsive, and we increased the OCS dose to 40 mg daily from March 30. However, the lung lesion extended to the peribronchial and subpleural areas in both lower lungs. After rapid tapering of OCS, we performed the transbronchial lung biopsy of the right lower lobe, which showed the typical OP pattern. We discontinued dasatinib permanently on June 16.