LAUSR

Dear Editor, Nocardiosis is a rare gram-positive bacillus infection that mainly occurs in immunocompromised hosts.1 The most common site of infection is the lungs (62.5%), followed by the skin and soft tissue, bloodstream, andbrain.2 AlthoughNocardia is an environmental organism, it shouldbe treated if isolated in a clinical setting.1 The incidenceof nocardiosis in patients undergoing hematopoietic stem cell transplantation (HSCT) is rare (0.3%–0.75%),3,4 but nocardia-related mortality in HSCT patients is high (14%–60%)3–7. Although there have been a few reported cases of nocardiosis developing after HSCT,5–7 to our knowledge there have been no reports of patients with active nocardiosis who underwent HSCT. Whether transplantation can be safely performed during the treatment of nocardiosis remains unclear. We report our experience with a patient who had acute myeloid leukemia (AML) and preexisting nocardiosis and underwent successful HSCT. A 71-year-old man with no significant medical history was diagnosed with myelodysplastic syndrome (MDS) 13 months prior to receiving a cord blood transplantation (CBT). The patient was transfusion-dependent, but neutrophil counts were maintained above 500/μl. The patient was treated with azacitidine and venetoclax until transformation to AML occurred 3 months prior to HSCT. He had not experienced any infection since the diagnosis of MDS. The AML was refractory to cytotoxic therapy, therefore, a reduced-intensity conditioning regimen followedbyCBTwas planned.However, a solitary infiltrative consolidation appeared in the left lung on CT. Transbronchial lungbiopsy revealedorganizing andeosinophilic pneumoniawithnegative cultures. Prednisolone therapy (1mg/kg/day)was initiated to treat