Remission of acute myeloblastic leukemia after severe pneumonia treated with high-dose methylprednisolone

We report a case of acute myeloblastic leukemia (AML)-M2 (by French-American-British classification) with t(8;21) (q22:q22) that was complicated with severe pneumonia. The patient tested positive by fluorescence in situ hybridization (FISH) for AML1 splitting and positive by reverse transcriptase polymerase chain reaction (RT-PCR) for chimeric AML1/MTG8 messenger RNA (mRNA), which indicated splitting of the MTG8 gene on chromosome 8 (q22) and the AMLI gene on chromosome 22 (q22). High-dose methylprednisolone was administered, and the leukemic cells disappeared without chemotherapy, although dysplastic hematopoietic cells were observed transiently after the first therapy. After the disappearance of leukemic cells, FISH for AML1 splitting was negative, and real-time PCR results for quantitative chimeric AML1/ MTG8 mRNA were less than the detectable level, however, RT-PCR results for AML1/MTG8 mRNA remained positive. These findings suggest that the patient acquired morphological, cytogenetic. and possibly molecular genetic remission by the synergistic effects of severe infection and high-dose methylprednisolone.