Successful allogeneic hematopoietic stem cell transplantation in a patient with acute myeloid leukemia and preexisting pulmonary nocardiosis

Abstract

Nocardia, allogenic hematopoietic stem cell transplant, acute myeloid leukemia 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, and brain. 2 Although Nocardia is an environmental organism, it should be treated if isolated in a clinical setting. 1 The incidence of 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][4][5][6][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 followed by CBT was planned. However, a solitary infiltrative consolidation appeared in the left lung on CT. Transbronchial lung biopsy revealed organizing and eosinophilic pneumonia with negative cultures. Prednisolone therapy (1 mg/kg/day

Outcomes of transplant recipients with pretransplant Nocardia colonization or infection

“…We also only had one HSCT recipient, which should be considered with the only other reported case of pre-HSCT nocardiosis. 18 We are not able to draw conclusions on optimal timing of transplantation in the setting of active nocardiosis or Nocardia colonization due to variability in time to transplant in our cases. All cases were either attributed to colonization, had completed therapy, or had demonstrated a clinical response to treatment prior to transplantation, and these patients may carry a different risk than those with a recent diagnosis in the early stages of therapy.…”

“…There were also relatively few patients, also specifically few with disseminated infection, so it remains possible that this subgroup could have a different risk of posttransplant outcomes. We also only had one HSCT recipient, which should be considered with the only other reported case of pre‐HSCT nocardiosis 18 . We are not able to draw conclusions on optimal timing of transplantation in the setting of active nocardiosis or Nocardia colonization due to variability in time to transplant in our cases.…”

“…A recent case report described a patient who underwent allogeneic HSCT while receiving treatment for pulmonary nocardiosis, with a favorable posttransplant outcome. 18 Published data are otherwise absent and current guidelines do not comment on management in this clinical context. 19 There is precedent for other pretransplant infections, such as nontuberculous mycobacteria and Mycobacterium abscessus specifically, being associated with recurrent infection and poor posttransplant outcomes.…”

“…A recent case report described a patient who underwent allogeneic HSCT while receiving treatment for pulmonary nocardiosis, with a favorable posttransplant outcome 18 . Published data are otherwise absent and current guidelines do not comment on management in this clinical context 19 .…”