Repeated spontaneous remission of acute myeloid leukemia in response to various infections: a case report
Osamu Imataki, Tomoya Ishida, Jun‐ichiro Kida, Makiko Uemura, Haruyuki Fujita, Norimitsu Kadowaki
Abstract
BACKGROUND: Acute myeloid leukemia (AML) is a progressive hematological malignancy that can be fatal when left untreated. However, spontaneous remission is rarely observed in the presence of infectious diseases. CASE PRESENTATION: We treated an 80-year-old woman with AML who spontaneously underwent remission after infections. Spontaneous remission was observed after each of three independent clinical infections caused by different pathogens-nontuberculous Mycobacterium infection, pulmonary aspergillosis, and Escherichia coli bacteremia. All infections were treated promptly with antimicrobials. Mycobacterium avium infection was treated with azithromycin, rifampin, and ethambutol. Pulmonary aspergillosis was treated with itraconazole followed by voriconazole. E. coli infection was treated with meropenem. During each infectious episode, leukemic cells disappeared from the patient's peripheral blood and pancytopenia improved without routine blood transfusion. These clinical effects lasted for several months. The patient has survived for > 2 years beyond the median survival time of end-stage AML. Thus, this case represents an immunological antileukemic effect of systemic infections. CONCLUSIONS: We have discussed a common mechanism of spontaneous remission of AML without chemotherapy, clinically exhibited by infection immunology. We believe that infections exert a limited immunological effect against AML, which may prolong survival among elderly individuals with AML.