INTRODUCTION
The current treatment regimens for acute lymphoblastic leukemia have successfully attained cure rates of approximately 90-95%1,2. A remaining significant challenge, however, is to improve the survival of patients with relapsed ALL. Patients with relapsed ALL have a suboptimal prognosis 1,3. Down syndrome patients with relapsed ALL have even worse outcomes. DS itself was proved to be an independent prognostic factor of outcome after ALL relapse.4 There are several case reports of patients with leukemia who attained spontaneous remission after severe infection5-7. There are no reports of a patient with relapsed leukemia with sustained remission following cessation of therapy secondary to severe infections, except an older patient with relapsed FLT3 internal tandem duplication mutant acute myeloid leukemia whose disease underwent spontaneous remission for 35 days without precipitating cause 8.
We describe a case of a 37 year-old man with Down syndrome and ALL who had a late bone marrow relapse and sustained remission for 2 years after only receiving three cycles of ALL R3 chemotherapy due to severe systemic infections.